Spot On Encryption Suite: Democratization Of Multiple & Exponential Encryption. Manual
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Communicating like dolphins with
Spot-On
Encryption Suite:
Democratization of Multiple & Exponential Encryption.
Handbook and User Manual
as practical software guide
with introductions into Cryptography,
Cryptographic Calling and Cryptographic Discovery,
P2P Networking, Graph-Theory, NTRU, McEliece,
the Echo Protocol and the Spot-On Software.
Scott Edwards & Spot-On.sf.net Project (Eds.)
More about the project:
https://spot-on.sf.net
.
Communicating like dolphins with
Spot-On
Encryption Suite:
Democratization of Multiple & Exponential Encryption.
Handbook and User Manual
as practical software guide
with introductions into Cryptography,
Cryptographic Calling and Cryptographic Discovery,
P2P Networking, Graph-Theory, NTRU, McEliece,
the Echo Protocol and the Spot-On Software.
Scott Edwards & Spot-On.sf.net Project (Eds.)
Bibliographic Information:
Detailed bibliographic data can be found in the Internet under:
https://portal.dnb.de
Edwards, Scott / Spot-On.sf.net Project (Eds.): Communicating like
dolphins with Spot-On Encryption Suite:
Democratization of Multiple & Exponential Encryption;
Handbook and User Manual as practical software guide
with introductions into Cryptography, Cryptographic
Calling and Cryptographic Discovery, P2P Networking,
Graph-Theory, NTRU, McEliece, the Echo Protocol and
the Spot-On Software,
ISBN 9783749435067, BOD, Norderstedt 2019.
1. Printed Release.
Editors:
Scott Edwards, Mele Gasakis, Michael Weber, et al.
Publisher: BOD, Norderstedt, 2019
ISBN: 9783749435067
Book-Layout-Template with references to Johann-Christian Hanke.
Recommendations also to Wikipedia, in which a lot of cryptographic
terms can be looked up in greater depth.
5
Freidank, Bescheidenheit, 1229
diu bant mac nieman vinden,
diu mîne gedanke binden.
man vâhet wîp unde man,
gedanke niemen gevâhen kann.
Georg Friedrich Benecke; Wilhelm Müller; Friedrich Zarncke: Mittelhochdeutsches
Wörterbuch. Leipzig 1854–1866, hier Bd. 1, Sp. 354b-357a, Artikel: gedanc, II, 5.
Spot-On.sf.net Encryption Suite - Handbook and User Manual
6
Content
Content .................................................................................................... 6
1 What is Spot-On? ................................................................................ 13
1.1 Main Functions in Spot-On Encryption Suite ...................................... 13
1.2 Why is it important for Internet users to encrypt their
communication? ................................................................................. 17
2 Alternatives to RSA encryption: Spot-On as the first NTRU &
McEliece Encryption Suite .................................................................. 21
2.1 A-symmetric encryption with PKI: RSA, Elgamal and especially
NTRU and McEliece in comparison ..................................................... 23
2.2 Another method, another layer: Symmetric Encryption with AES ..... 30
2.3 Superencipherment: Hybrid & Multi Encryption ................................ 33
2.4 Further Examples of state-of-the-art encryption & process
implementations ................................................................................. 35
3 What is the Echo Protocol? ................................................................. 37
3.1 Full Echo .............................................................................................. 43
3.2 Half Echo ............................................................................................. 48
3.3 Echo Accounts ..................................................................................... 48
3.4 The Echo Grid ...................................................................................... 51
3.4.1 Examples of key exchanges by Alice, Bob, Ed & Maria ....................... 53
3.5 Adaptive Echo (AE) and its AE tokens ................................................. 55
3.5.1 Hansel and Gretel - An example of the Adaptive Echo mode ............. 57
4 Cryptographic Discovery ..................................................................... 59
5 First Set-up of the software Spot-On ................................................... 67
5.1 Set up a first installation – e.g. with the wizard .................................. 67
5.2 Passphrase creation within the Wizard: Two login methods & a
virtual keyboard .................................................................................. 70
5.3 Generation of 12 Keys for Encryption ................................................. 75
5.3.1 A posteriori Key (re-)generation: Switching from RSA
provided by the Wizard to McEliece and other .................................. 76
5.4 Activation of the kernel....................................................................... 78
5.5 Connect a neighbor with the IP address ............................................. 81
5.6 Key Exchange ...................................................................................... 83
Content
7
5.7 GoldBug: Alternative Graphical User Interface (GUI) ......................... 83
6 The chat function with Cryptographic Calling ..................................... 87
6.1 Adding a friend by swapping and inserting the keys ......................... 88
6.1.1 Special feature: REPLEO – Encrypting the public key ......................... 91
6.2 Starting a first secure chat ..................................................................92
6.3 Cryptographic Calling - additional security feature invented by
Spot-On .............................................................................................. 95
6.3.1 Asymmetric Calling ............................................................................. 97
6.3.2 Instant Perfect Forward Secrecy (IPFS) ............................................... 97
6.3.3 Symmetric Calling ............................................................................... 98
6.3.4 Two-way Calling ................................................................................. 98
6.4 Additional security feature: Socialist Millionaire Protocol (SMP) .... 102
6.4.1 SMP-Calling ...................................................................................... 107
6.5 Cryptographic Calling with Secret Streams .......................................107
6.6 Additional security feature: Forward Secrecy (a-symmetric) ........... 109
6.6.1 Forward Secrecy Calling ................................................................... 110
6.6.2 Fiasco Forwarding & Fiasco Calling .................................................. 111
6.7 Overview of the different Calling types............................................ 111
6.8 Emoticons aka Smileys ..................................................................... 114
6.9 File transfer in the chat pop-up window.......................................... 114
7 Group chat in IRC style ..................................................................... 117
8 Smoke Mobile Chat Client ................................................................ 121
8.1 Smoke Android Client....................................................................... 121
8.2 Fire chat to Buzz chat ....................................................................... 121
9 The e-mail function .......................................................................... 123
9.1 POP3 ................................................................................................. 125
9.2 IMAP ................................................................................................. 125
9.3 P2P E-Mail: without data retention ................................................. 128
9.4 Setting up C/O: e-mail postboxes at a friend ................................... 130
9.4.1 Care-Of method (C/O) ...................................................................... 131
9.4.2 Virtual E-Mail Institution (“VEMI”) method ..................................... 133
9.4.3 Ozone Postbox ................................................................................. 135
9.5 Additional Encryption: Put a “Goldbug” on an e-mail ..................... 136
9.6 Forward Secrecy for e-mail ............................................................... 137
9.7 Secret Streams for e-mail ................................................................. 142
9.8 Further research perspectives ......................................................... 143
Spot-On.sf.net Encryption Suite - Handbook and User Manual
8
10 POPTASTIC Protocol - Encrypted chat (and e-mail) utilizing POP3 &
IMAP Servers .................................................................................... 145
10.1 Chat over POPTASTIC ........................................................................ 146
10.2 E-mail over POPTASTIC ...................................................................... 147
10.3 Setting up POPTASTIC ....................................................................... 148
10.4 Further development of the POPTASTIC protocol ............................ 149
11 File-Sharing: with StarBeam ............................................................. 152
11.1 Creating StarBeam Magnets with cryptographic values ................... 154
11.1.1 Option “NOVA”: Encrypt the file before transferring the file! .......... 156
11.1.2 Using a one-time Magnet ................................................................. 158
11.1.3 Overview of Magnet-URI standards for cryptographic values .......... 160
11.1.4 Rewind function ............................................................................... 161
11.1.5 Comparison with Turtle-Hopping ..................................................... 161
11.2 StarBeam upload: transferring a file ................................................. 162
11.3 StarBeam downloads ........................................................................ 164
11.3.1 Tool: StarBeam Analyzer ................................................................... 165
11.3.2 Outlook for Cryptographic Torrents .................................................. 167
12 Open Source web search engine with encrypted URL database ......... 168
12.1 URL Database Setup .......................................................................... 171
12.1.1 SQLite ............................................................................................... 172
12.1.2 PostgreSQL ....................................................................................... 173
12.2 URL-Filter .......................................................................................... 173
12.3 URL-Community: Open Source URL-Database .................................. 175
12.4 Pandamonium Webcrawler .............................................................. 176
12.5 RSS reader and URL import ............................................................... 178
13 Setting-up an own server – for chat and p2p e-mail .......................... 181
13.1 Set up the chat / e-mail server via a listener .................................... 181
13.1.1 Server broadcast ............................................................................... 182
13.1.2 Security options ................................................................................ 184
13.1.3 Proxy and firewall annotations ......................................................... 185
13.1.4 Spot-On as LAN Messenger .............................................................. 187
13.2 Server / Listener Creation at home behind a router / Nat ................ 187
13.3 Use of Spot-On in the Tor network ................................................... 188
13.4 Spot-On Kernel Server ....................................................................... 189
13.5 Spot-On Lite Server as Deamon ........................................................ 190
13.6 SmokeStack Server on Android ......................................................... 190
13.7 Spot-On Bluetooth Server ................................................................. 191
Content
9
13.8 Spot-On UDP Server ......................................................................... 191
13.9 Spot-On DTLS Server ........................................................................ 192
13.10 Spot-On SCTP Server ........................................................................ 192
13.11 Spot-On Ncat connection ................................................................. 193
14 Integrated Encryption Tools .............................................................. 195
14.1 Tool: Encryption of files with Spot-On FileEncryptor ....................... 195
14.2 Tool: The Rosetta CryptoPad for text conversion in Spot-On ........... 196
14.3 Tool: Echo Public Key Share (EPKS) & AutoCrypt ............................. 198
14.4 Pass-Through functionality (“Patch-Points”) .................................... 199
14.5 Statistics & Analyzing Tools .............................................................. 200
15 BIG SEVEN STUDY: Crypto-Messenger-Audit ..................................... 204
16 Outlook with Graph-Theory: Initial Welcome in the New Era of
Exponential Encryption .................................................................... 209
16.1 Multiplication towards Exponential ................................................. 209
16.2 Four Arms within the Era of Exponential Encryption ....................... 212
16.3 Implications ...................................................................................... 213
16.4 Outlook ............................................................................................ 214
17 Digital Encryption of Private Communication in the Context of … ..... 216
17.1 Principles of the protection of private speech, communication
and life: Universal Declaration of Human Rights, 1948 (Art. 12) ..... 216
17.2 International Covenant on Civil & Political Rights, 1966 (Art. 17) ... 216
17.3 European Convention on Human Rights, 1950 (Art. 8) .................... 217
17.4 Charter of Fundamental Rights of the European Union, 2000
(Art. 7, 8) .......................................................................................... 217
17.5 Basic Law e.g. for the Federal Republic of Germany, 1949 (Art. 2
Abs. 1 i. V. m. Art. 1 Abs. 1) .............................................................. 218
17.6 Privacy of correspondence, posts and telecommunications (Art.
10) .................................................................................................... 218
17.7 Verletzung des Post- oder Fernmeldegeheimnisses (§ 206) ............ 219
17.8 United States Constitution: Search and Seizure (Expectation of
Privacy, US Supreme Court) ............................................................. 220
18 History of Program Publications ....................................................... 221
19 Website ............................................................................................ 221
20 Open source code & Compilation ..................................................... 222
20.1 Compile Information ........................................................................ 222
Spot-On.sf.net Encryption Suite - Handbook and User Manual
10
21 Bibliography ..................................................................................... 226
22 Index of Figures ................................................................................ 241
23 Glossary ........................................................................................... 245
24 Keywords ......................................................................................... 295
11
For all those, who have (or are)
a real virtual friend, have family
far away and regard privacy
and alternative and expressed opinions
as a basic and constitutional element
for human rights and democracy
and try to foster these beliefs
within their communities:
Freedom is the respect
to the other’s cipher text!
12
What is Spot-On?
13
1 What is Spot-On?
Spot-On Encryption Suite is a
secure instant chat messenger and
encrypting e-mail client
that also includes additional features such as
group chat,
file transfer, and a
URL search based on an implemented URL data-
base, which can be peer-to-peer connected to oth-
er nodes.
Thus, the three basic functions frequently used by a regular
Internet user in the Internet - communication (chat / e-
mail), web search and file transfer - are represented in an
encrypted environment safely and comprehensively.
It can be spoken from Spot-On as of an encryption suite. It
might be regarded as the most elaborated, up-to-date and
diversificated encryption software currently.
The three S: Speaking (by text), Searching and Sending - are
now secure over the Internet within one software suite.
Open source for everyone.
1.1 Main Functions in Spot-On Encryption Suite
In addition, Spot-On has also implemented a number of
useful tools, such as encrypted chat server functionality,
proxy-enabled pass-through, text and cipher text conver-
sion pads (and vice versa), a feed-reader and a web-crawler,
or dash-boards for the friends of statistics and analysis, and
much more.
Furthermore, the application also offers next to
Communication
(chat / e-mail),
web search and
f
ile transfer
are represented
in an en
crypted
environment.
A dolphin
is the
symbol of the Spot-
On Encryption
Suite
using the Echo Pro-
tocol to communi-
cate like dolphins
within the sea.
Spot-On.sf.net Encryption Suite - Handbook and User Manual
14
chat messaging as well
decentralized public group chat in IRC style,
decentralized and encrypted e-mail: The e-mail
can be IMAP, POP3 and thirdly, p2p e-mail. Spot-
On is thus a fully functional e-mail client. As soon
as encrypted e-mails are sent, it is necessary that
the friend also uses this (or any other Echo) cli-
ent. This has the advantage that the encryption
key is only to be exchanged once, but then no
longer has to be applied to every single e-mail.
This function of transferring the key encrypted
back in a direct way is called in Spot-On “RE-
PLEO” based on the Echo-Public-Key-Sharing Pro-
tocol (EPKS) and later on this was also taken over
in other projects under the name Autocrypt or
KeySync (within an automatic process).
As in any messaging program, files can be shared
and sent. The transfer is always encrypted per
sé.
As said, there is also the function to implement a
URL web search in a decentralized database re-
pository: Users can store URLs and the content
of a website - as we do it so far with bookmark
URLs in the browser and its cache - in a comfort-
able searchable database in Spot-On. A thematic
RSS feeds can import these URLs into the en-
crypted database, which is based either on SQL
or PostGres and is also p2p network able.
With the tools “Rosetta CryptoPad” and the
“File-Encryptor” the user can encrypt text
and/or files additionally or convert them back.
This adds one more encryption layer to the ci-
pher text or file and turns encryption into multi-
encryption. These encryption tools can therefore
also be used for other transmission paths (such
as an unencrypted path outside of Spot-On like
uploading a file into a cloud box, sending a mes-
sage over another messenger or email service or
posting ciphertext to any board).
T
he
thr
e
e S
:
Speaking (by text)
,
Searching and
also
Sending
are now
secure over
the In-
ternet.
What is Spot-On?
15
With the use of Spot-On the user can therefore be relatively
sure - because of the modern and elaborated encryption
techniques and processes - that no unwanted third party
can eavesdrop on the conversations or read e-mails or look
into file transfers. The URL search also happens on the local
machine, so that search queries are protected and secured.
The user-to-user communication via the Internet should
remain in private, protected space with this application.
Spot-On uses for this purpose strong and hybrid encryption,
also called multi-encryption, with different levels of modern
encryption technology based on established encryption
libraries - such as libgcrypt (known from OpenPGP or
GnuPG and OpenSSL) and other.
For example, it creates separate and different public /
private keys for encryption and signatures for each function
- based on the encryption algorithms RSA, or alternatively
Elgamal and NTRU. In addition to NTRU, the encryption al-
gorithm McEliece is open source implemented. These latter
two algorithms are considered to be particularly secure
against attacks that are known from Quantum Computing
and are becoming increasingly relevant in the future be-
cause of fast quantum computers.
Spot-On is thus one of the first communication suites
worldwide to implement these two algorithms, thus initiat-
ing the renunciation of - or alternatives to - the RSA algo-
rithm that has been officially considered as broken since
2016 (see NIST cited in Adams/Maier 2016).
Figure 1: The tabs in Spot-On Encryption Suite application
The RSA
algorithm
has been officially
considered as
broken since 2016.
Spot-On.sf.net Encryption Suite - Handbook and User Manual
16
The tabs in the Spot-On software are sorted by default on
top (in the north) and provide these functions:
Buzz Tab: Here the group chat in IRC style is found.
Chat Tab: Here the private 1:1 chat messaging takes
place.
E-mail Tab: Within the e-mail tab the user can send
and receive e-mails. This refers to (1) IMAP/POP3 e-
mails which are encrypted (over the POPTASTIC key),
(2) POPTASTIC-messages which provide chat over e-
mail servers (also with the POPTASTIC key) and third
p2p e-mails over the Echo Network connections based
on either the C/O function or the VEMI institutions
function which provide a postbox in the peer-to-peer
network. (3) Also regular @-e-mail is possible, if the re-
ceiver uses another e-mail-client (not based on any key
as identifier; instead the @-e-mail-address is used).
Listeners Tab: With the term “listener” a chat server
software function is described. Within Spot-On it is also
possible to operate an own chat and communication
server. Several protocols are supported.
Neighbors Tab: The neighbors tab creates the connec-
tion to other nodes, friends and chat servers.
Search Tab: This tab provides the search in the local
URL-Database.
Settings Tab: The interface of Spot-On requires an ac-
tive and running kernel. The settings tab is regularly
used to start and stop the kernel of Spot-On. Also, the
key generation is steered within this tab.
StarBeam Tab: If a user wants to send a file this is pos-
sible within the chat pop-up window – Additionally,
very detailed information about the sent or received
file is provided in this StarBeam tab.
URLs Filter Tab: Here the filters and distillers for the
URL exchange with other nodes are defined. This func-
tion allows to filter URLs, e.g. from one domain, in case
a user wants URLs just from e.g. www.wikipedia.org.
Login Tab: The last tab is the login page to unlock the
application with a password.
What is Spot-On?
17
Main Menu: Above the tabs the main menu is found,
where options (e.g. chosen icon set), key import and
export and also the further encryption tools are pro-
vided like Rosetta Crypto Pad (for conversion of text:
from plain text to cipher text and vice versa) or the
FileEncryptor (to convert files from a plain file to an
encrypted file).
With all its equipment, Spot-On is therefore a so-called
“Communication Suite” - a program with numerous func-
tions for secure communication, which realizes the trans-
mission of the encrypted packets mainly with the so-called
Echo Protocol (or in addition the later explained POPTASTIC
Protocol or EPKS Protocol). The Echo Protocol is particularly
secure, as it will be explained in the upcoming chapters.
1.2 Why is it important for Internet users to en-
crypt their communication?
Today almost all wireless Internet accesses are password
protected. (So-called “Freifunk.net”-activities are currently
trying to reverse this over-regulation through password-
free and account-free wireless Internet access). In a few
decades plain text messages or e-mails to friends* via the
Internet should be encrypted as well. In order to consoli-
date this change, sometimes c-mail (for crypto-mail) rather
than e-mail is or should be used as a new term.
Encryption is not a question of having something to hide
or not, it is the paradigm of whether we, ourselves control
our communication - or whether it is controlled by others,
third parties and their communication servers. Users need
to have the right to choose an alternative communication
server or even create their own with less effort.
Controlling communication is ultimately also a question
of attacking free thinking and a question of deleting the
* In this book all terms always apply to all sex and genders: female,
divers and male.
T
h
e change
from plain text t
o
cipher text
converts
e-mail to c-mail.
Spot
-
On
Communication
Suite
provides
multiple, and ev
en
exponential
Encryption within a
network based on
the Echo Protocol.
Spot-On.sf.net Encryption Suite - Handbook and User Manual
18
presumption of innocence (“In doubt for the accused” - if
every citizen in the Internet ever belongs to a dock!).
Democracy requires thinking and discussing alternatives
in private as well as in public.
The communication and data transmission over the In-
ternet should be protected as parents would also protect
their loved ones or a mother bird would protect their young
against the unknown: Everyone should protect her or his
privacy and human rights with modern cryptographic func-
tions.
Strong multi-encryption (also so-called “hybrid encryp-
tion”) thus ultimately secures the declarations of human
rights in their broadly constituted consensus and is a digital
self-defense that everyone should learn and use - to ulti-
mately contribute to democracy and support this process-
es.
Why it is necessary to encrypt and learn about encryption:
Economy is based on encryption. Securing the data at the
heart of our modern economy: Encryption helps business-
es to stay compliant as well as to protect the valuable data
of their customers.
Law and regulations require encryption: Healthcare pro-
viders are required e.g. by the Health Insurance Portability
and Accountability Act (HIPAA) to implement security fea-
tures that protect patients’ sensitive health information.
Institutions of higher learning must take similar steps un-
der e.g. the Family Education Rights and Privacy Act
(FERPA), while retailers must contend with the Fair Credit
Practices Act (FCPA) and similar laws. In Europe
GPDR/DSGVO requires the protection of sensitive data.
Guaranteeing data security: Providers of data services —
storing, managing or transmitting personal or business da-
ta — must guarantee to use the best available technology
to thwart attacks against that data or the entities and indi-
viduals who depend on those services.
Spot
-
On is the
initial welcome for
multiple and
exponential
encryption.
Privacy by default
requires e-mail and
chat messaging
software for users
encrypting by de-
faul
t. Communica-
tion software with-
out encryption is
outdated and obso-
lete today.
What is Spot-On?
19
Old Internet protocols provide only plain text: It is simply
clear that every sent e-mail has to be regarded as a post
card everyone can read.
Consistent privacy by default: Individuals have a right to
be secure in their public, private and commercial lives and
interactions. Encryption by default protects privacy by
turning personal information into “always encrypted”
messages. Everyone should make sure that e-mails are on-
ly being sent over an end-to-end encrypted connection.
That means that users are encrypting each message with a
shared password or with a public key of the receiver of the
message. For the Spot-On software the messages are al-
ways encrypted once a key exchange has been done. Pri-
vacy by default requires e-mail and chat messaging soft-
ware for users encrypting by default. Communication
software without encryption must be regarded as outdat-
ed and obsolete today.
Protecting government information: National, state and
local agencies should ensure that the data they hold is se-
cure against threats of domestic and foreign intrusion. All
the rest belongs to open data government.
Encouraging innovation: Developers and providers of in-
novation need digital security. Copy-cats are only kept out
with encryption.
Defending critical infrastructure: Providers of essential
services, such as banking, health, electricity, water, Inter-
net and other critical infrastructure providers, are to be
empowered to provide the best available encryption and
security technologies.
Hacking and collecting user data is big business: Hackers
aren’t just bored kids in a basement anymore. They’re big
business.
The Snowden papers (2013) demonstrate that all internet
traffic is saved as big data for possible analyses. Do not
send any plaintext since mid-thirteen anymore!
The Spot-On Encryption Suite tries to be an elaborated and
strong tool for this responsibility. Similar to the develop-
ment of safety in automobiles, the e-mail & chat and file
En
cryption is a
precondition for
human rights and
democracy.
L
a
w
a
n
d
regulations
require
encryption.
Spot-On.sf.net Encryption Suite - Handbook and User Manual
20
encryption will also develop: if we initially drove without a
seatbelt in the car, today we drive with obligatory safety
belts (e.g. since 1968 in the U.S.) and additional airbags or
thirdly additional electronic security information systems.
Spot-On is an easy-to-use application, but to some extent
also a program, which needs to be learned; it requires - as
with the car driver’s license - the knowledge of the various
controls and options. Similar to a cockpit of an aircraft,
there are some control buttons available in this original
user interface. As we describe later, there is another inter-
face available, in which these options are reduced a bit.
Also, another minimal view is offered for beginners in this
software for cryptographic processes. In this respect: We
have to learn what is still unknown and - to note that - it is
already a reduced scope to applied encryption in software.
This handbook and user manual can help readers to under-
stand the individual functions. And users who first read and
then try out have - as always - clearly an advantage. :-) Oth-
erwise it might be the inspiration of teachers to provide this
reference and knowledge to young learners, if they don’t
find out by themselves what the needful things and actions
are.
The unencrypted plain text e-mail or chat message should
therefore have actually become obsolete after the Snow-
den Papers revealed in 2013 that private plain text e-mails
are widely intercepted and systematically collected and
evaluated by many interested parties worldwide. 2013 was
also the year in which Spot-On and the complementary
GoldBug User Interface have been released after several
years of research. Today, we have to send out cipher text
messages only. As one algorithm for encryption might be
broken, just use two or several: Spot-On is the initial wel-
come of multiple and even exponential encryption, as it will
be referenced in more detail as well in the further sections
of this handbook.
Lea
rning
abo
ut en-
cryption within the
Internet is required
latest since mid-
thirteen.
Spot-On is a practi-
cal software suite
to learn encryption
in a school class
with friends.
Alternatives to RSA encryption: Spot-On as the first NTRU & McEliece Encryption Suite
21
2 Alternatives to RSA encryption:
Spot-On as the first NTRU &
McEliece Encryption Suite
There are basically two methods of encryption:
First, the symmetric encryption: Both users use the
same password, e.g. a so-called AES (Advanced Encryption
Standard) with 32 characters, which will be explained in
more detail below. And on the other hand, there is the a-
symmetric encryption.
Second, in a-symmetric encryption: each user has two
keys: a private and a public key. Each user exchanges the
public key with the friend and can then encrypt data using
the private key in combination with the public key.
Figure 2: How asymmetric encryption with Public Key Infra-
structure (PKI) works
After transmission, the other party is also able to decipher
the message with the own keys in combination with the
Spot-On.sf.net Encryption Suite - Handbook and User Manual
22
cipher text and the known public key of the friend. This is,
mathematically speaking, based on the prime factorization,
which requires today years of computational effort. Encryp-
tion is only as good as the mathematical calculations cannot
be calculated by the automation of computers at lightning
speed. The a-symmetric method is also called PKI: Pubic Key
Infrastructure, which can be built on different algorithms
for key generation, e.g. like RSA.
However, encryption - be it via AES or PKI - is not un-
breakable, and the procedures and libraries must also be
well-used to be secure. RSA is considered “today as an es-
sential, widely studied and not yet breakable encryption
standard - although the further development of fast com-
puters might bring a different future”, - it was still 2014 in
this (first only online hosted) manual noted. In 2016, the
official NIST Institute announced that the algorithm RSA is
considered broken in the age of Quantum Computing (see
NIST).
The media has barely picked up this announcement, as
everyone will probably agree that you cannot buy a quan-
tum computer in the nearest supermarket, so the problem
might be not relevant.
It has the charm of children who hold their hand in front
of their eyes and thus do not let the problem or risk endan-
ger their perception of reality. Nevertheless, it is officially
confirmed that RSA can be broken - with special means. The
security is gone. This also has an impact on our Internet
economy and online banking, because so far, the so called
“secure” economic connections are relying on RSA. And a
SSL/TLS protocol to secure the connection to online bank-
ing or shopping portals based on more secure algorithms
like McEliece or NTRU is not yet developed.
Further research is
needed on e.g. a
SSL/TLS connection
based on alterna-
tive algorithms like
e.g. McEliece.
Alternatives to RSA encryption: Spot-On as the first NTRU & McEliece Encryption Suite
23
2.1 A-symmetric encryption with PKI: RSA, El-
gamal and especially NTRU and McEliece in
comparison
Therefore, Spot-On encryption suite has already intro-
duced additional alternatives to RSA at an early stage - if
this RSA encryption algorithm standard would ever be inse-
cure: RSA with a correspondingly large size of the key (at
least 3072 bytes) might still (or just) be regarded as a time
hurdle for non-specialized technical administrative staff.
In addition to RSA Spot-On has implemented the encryption
algorithms Elgamal and also NTRU and McEliece. The latter
two are both considered to be particularly more resistant to
the attacks known from Quantum Computing.
Figure 3: McEliece’s algorithm for advanced protection
against attacks from Quantum Computing in the Settings Tab
Spot-On uses the libgcrypt, libntru, and McEliece libraries
to create persistent private and public key pairs. Currently,
the application generates key pairs for each of the six func-
tions during initialization. Key generation is optional. As a
result, Spot-On does not require public key infrastructure.
A mix of symmetri
c
encryption (based
on passwords) and
a-symmetric en-
cryption (based on
public/
private keys
– also called PKI)
provides hybrid and
even multi-
encryption.
Spot-On.sf.net Encryption Suite - Handbook and User Manual
24
Of course, the desired algorithms can be selected, and keys
can be generated.
Figure 4: RSA and its alternatives in Spot-On
McEliece cryptosystem
The McEliece cryptosystem is an a-symmetric encryption
algorithm. It was presented in 1978 by cryptographer and
founder Robert J. McEliece. Even with the use of quantum
computers, there is no known efficient method by which
the McEliece cryptosystem can be broken. This makes it a
promising algorithm for post-quantum cryptography.
NTRU Algorithm
NTRU is an a-symmetric encryption technique developed in
1996 by mathematicians Jeffrey Hoffstein, Jill Pipher and Jo-
seph Silverman. It is loosely based on lattice problems that
are considered unbreakable even with quantum computers.
However, NTRUEncrypt has not been extensively studied so
far as more common methods (e.g. RSA). Ntruencrypt is by
IEEE P1363.1 standardized (see Ntruencrypt).
Elgamal Algorithm
The Elgamal encryption method or Elgamal cryptosystem is
a public-key encryption method developed in 1985 by the
cryptographer Taher Elgamal, based on the idea of a Diffie-
Hellman key exchange. The Elgamal encryption method, like
the Diffie-Hellman Protocol, relies on operations in a finite-
order cyclic group. The Diffie–Hellman key exchange meth-
od allows two parties that have no prior knowledge of each
other to jointly establish a shared secret key over an inse-
cure channel. This key can then be used to encrypt subse-
Spot
-
On is regarded
as one – if not the –
fir
st open source
encryption suite
worldwide which
has implemented
the McEliece en-
cryption algorithm.
Alternatives to RSA encryption: Spot-On as the first NTRU & McEliece Encryption Suite
25
quent communications using a symmetric key cipher. The
Elgamal encryption method is provably IND-CPA-safe, as-
suming that the Decisional-Diffie-Hellman problem is not
trivial in the underlying group. Related to the encryption
method described here (but not identical with it) is the El-
gamal signature method (the Elgamal signature method is
not yet implemented in Spot-On). Elgamal is not subject to a
patent.
RSA Algorithm
RSA (after the people Rivest, Shamir and Adleman) is an a-
symmetric cryptographic procedure that can be used for
both encryption and digital signature since 1978. It uses a
key pair consisting of a private key used to decrypt or sign
data and a public key to encrypt or verify signatures. The
private key is kept secret and can only be calculated from
the public key with extremely high expenditure. Clifford
Cocks, an English mathematician working for the British in-
telligence agency Government Communications Headquar-
ters (GCHQ), had developed an equivalent system already in
1973, but this was not declassified until 1997.
Spot-On’s encryption is designed so that any user can com-
municate with any user, no matter what encryption algo-
rithm a user has chosen. Communication between users
with different key types is thus well defined when the
nodes share common versions of the libgcrypt and libntru
libraries: anyone who has chosen a RSA key can also chat
and e-mail encrypted with an user who has chosen an El-
gamal key. Try it also for a McEliece Key. This is because
everyone supports each algorithm and the library supports
it. If you want to test the program with a friend, it is best
for both to use the latest version of Spot-On.
Well defined and
established librar
ies
are
the basis for the
cryptographic rou-
tines in the applica-
tion Spot-On.
C
h
a
tting from a
RSA-Key user to a
McEliece Key user
should be tested in
p
ractice over the
integrated open
source McEliece
algorithm library.
Spot-On.sf.net Encryption Suite - Handbook and User Manual
26
Figure 5: Individual Crypto-DNA: Customizable cryptography,
e.g. based on key size and further values
Of course, every user in Spot-On can set an own
“cipher”,
the individual „key size“– e.g. 3072 bit or higher for
RSA,
the “hashtype”,
furthermore “iteration count”,
and the “cryptographic salt length”
.. which are often typical parameters for key creation and
encryption.
The advantage is that every user can define this individually
and manually according to the own gusto. Other applica-
tions - even open source applications - hardly provide for
the user this choice, to determine these key values for the
encryption process itself. With Spot-On now every user is
able to set up an own definition of the, so to say, “Crypto-
graphic DNA” – for the encryption algorithms as well as for
the authenticating signatures.
Using a signature means: that the generated encryption key
is re-signed with a key to prove that a message is coming
from a particular subscriber and nobody else. Signatures
Spot
-
On democra-
tizes the choice of
individual Crypto-
graphic DNA for
encryption and sig-
natures by its open
source code.
Alternatives to RSA encryption: Spot-On as the first NTRU & McEliece Encryption Suite
27
provide some authentication. There is also a comprehen-
sive choice of encryption methods available for such signa-
tures: DSA, ECDSA, EdDSA, Elgamal, and RSA.
RSA signature: To verify the origin of a message, RSA
can also be used to sign a message: Suppose Alice uses
Bob's public key to send him an encrypted message. In
the message, she can claim to be Alice but Bob has no
way of verifying that the message was actually from
Alice since anyone can use Bob's public key to send
him encrypted messages. Suppose Alice wishes to
send a signed message to Bob. She can use her own
private key to do so. She produces a hash value of the
message, raises it to the power of d (modulo n) (as she
does when decrypting a message), and attaches it as a
"signature" to the message. When Bob receives the
signed message, he uses the same hash algorithm in
conjunction with Alice's public key. He raises the signa-
ture to the power of e (modulo n) (as he does when
encrypting a message) and compares the resulting
hash value with the message's actual hash value. If the
two agree, he knows that the author of the message
was in possession of Alice's private key, and that the
message has not been tampered with since. In Spot-
On the OAEP and PSS schemes are used with the RSA
encryption and RSA signature respectively.
DSA signature: The Digital Signature Algorithm (DSA)
is another Standard for digital signatures, based on the
mathematical concept of modular exponentiations
and the discrete logarithm problem. Since 1994 the
National Institute of Standards and Technology (NIST)
adopted DSA for use in their Digital Signature Standard
(DSS). DSA is covered by U.S. Patent 5,231,668, filed
July 26, 1991 and attributed to David W. Kravitz, a
former NSA employee. And NIST has made this patent
available worldwide royalty-free. DSA is a variant of
the ElGamal signature scheme and works in the
framework of public-key cryptosystems. Messages are
Spot-On.sf.net Encryption Suite - Handbook and User Manual
28
signed by the signer's private key and the signatures
are verified by the signer's corresponding public key.
The digital signature provides message authentication,
integrity and non-repudiation.
ECDSA signature: The Elliptic Curve Digital Signature
Algorithm (ECDSA) offers a variant of the Digital Signa-
ture Algorithm (DSA) which uses elliptic curve cryptog-
raphy. As with elliptic-curve cryptography in general,
the bit size of the public key believed to be needed for
ECDSA is about twice the size of the security level, in
bits. For example, at a security level of 80 bits (mean-
ing an attacker requires a maximum of about 2^80 op-
erations to find the private key) the size of an ECDSA
public key would be 160 bits, whereas the size of a
DSA public key is at least 1024 bits. On the other hand,
the signature size is the same for both DSA and ECDSA:
approximately 4t bits, where t is the security level
measured in bits, that is, about 320 bits for a security
level of 80 bits.
EdDSA signature: The Edwards-curve Digital Signature
Algorithm (EdDSA) is a digital signature scheme using a
variant of Schnorr signature based on Twisted Edwards
curves. It is designed to be faster than existing digital
signature schemes without sacrificing security. It was
developed by a team including Daniel J. Bernstein,
Niels Duif, Tanja Lange, Peter Schwabe, and Bo-Yin
Yang. The reference implementation is public domain
software.
Elgamal signature: The Elgamal signature scheme is a
digital signature scheme which is based on the difficul-
ty of computing discrete logarithms. It was described
by Taher Elgamal in 1984. A variant developed at the
NSA and known as the Digital Signature Algorithm is
much more widely used. The Elgamal signature
scheme must not be confused with Elgamal encryption
which was also invented by Taher Elgamal. The Elgamal
Alternatives to RSA encryption: Spot-On as the first NTRU & McEliece Encryption Suite
29
signature scheme allows a third-party to confirm the
authenticity of a message.
Spot-On is regarded as one – if not the – first open source
encryption suite which has implemented the McEliece En-
cryption for a communication application. It is regarded as
more secure against the attacks knowing from Quantum
Computing.
Quantum Computers
breaking the security of public key cryptographic systems
Most of the popular public key ciphers are based on the dif-
ficulty of factoring integers - if they are the product of few
prime numbers - or the discrete logarithm problem, both of
which can be solved by Shor's algorithm. Informally, it solves
the following problem: Given an integer N, find its prime
factors.
By comparison, a Quantum Computer could efficiently solve
this problem using Shor's algorithm to find its factors and
break the security of public key cryptographic systems: In
particular, the RSA, Diffie–Hellman, and elliptic curve Diffie–
Hellman algorithms could be broken. These are used to pro-
tect secure Web pages, encrypted email, and many other
types of data.
However, other cryptographic algorithms do not appear to
be broken by those algorithms: Some public-key algorithms
are based on problems other than the integer factorization
and discrete logarithm problems to which Shor's algorithm
applies, like the McEliece cryptosystem based on a problem
in coding theory. Lattice-based cryptosystems are also not
known to be broken by Quantum Computers. Large-scale
Quantum Computers would theoretically be able to solve
certain problems much more quickly than any classical
computers.
Quantum Comput-
ers could break the
PKI of certain algo-
rithms.
McE
liece and NTRU
are today more
secure algorithms
in this regard.
Spot-On.sf.net Encryption Suite - Handbook and User Manual
30
Let’s go into more detail about symmetric encryption with
an AES password string, which can complement PKI encryp-
tion as follows.
2.2 Another method, another layer: Symmetric
Encryption with AES
Symmetric encryption uses often AES - a 32-character
password string generated by processes including random.
Since all characters are used in the generation, the set of
options is also sufficiently large that even fast machines can
not try out all variants within a short time. While a-
symmetric encryption uses a public and private key pair, in
symmetric encryption it is a secret passphrase that both
subscribers need to know (hence called symmetric) (- or for
Spot-On: in the later discussed Gemini function it is also
called “Gemini” (from the Greek term for “twin” derived):
Both sides have to exchange and know the secret pass-
phrase).
Figure 6: Example of an AES Password string
5847 088B 15B6 1CBA 59D4 E2E8 CD39 DFCE
Spot-On thus uses both standards as described above: a-
symmetric keys and/or symmetrically encrypted messages
are sent through SSL/TLS (i.e. a-symmetric) encrypted con-
nections, and the a-symmetrically encrypted message can
possibly also be secured with symmetric encryption (e.g.
AES). That means Spot-On could use three levels of encryp-
tion like this example of encapsulation shows (simplified, as
shown without HASH/MAC or signature):
Figure 7: Example of Encapsulation with three levels of encryp-
tion
RSA-SSL/TLS (AES (Elgamal (Message)))
W
hat an AES can
do: Encrypting the
cipher text once
more to cipher text
- or defining the
next used secure
channel
(e.g. initiated by
Cryptographic
Calling).
Alternatives to RSA encryption: Spot-On as the first NTRU & McEliece Encryption Suite
31
Translation of this formula: First, the text message is en-
crypted with the public (a-symmetric) key of the friend via
the Elgamal algorithm, then the encrypted text is encrypted
again with an AES algorithm (symmetric password) (a sec-
ond time) (and secured) and this capsule is then sent to the
friend through the existing SSL/TLS encrypted (a-
symmetric) connection (using RSA). This is though a simpli-
fied structure as it does not show the hashes and signa-
tures.
This specific structure to apply different methods of encryp-
tion is defining the protocol used in the encryption suite
Spot-On: It is called the Echo Protocol, which is just a pure
HTTP/S-Transfer and can be seen in a regular browser.
Figure 8: Discovering Spot-On’s sent cipher text to a localhost
HTTP-Listener in a browser
If a HTTP (not HTTPS) listener is set up and the encrypted
message capsule is not sent via HTTPS - over the third en-
cryption layer, via a SSL/TLS connection - the cipher text
(layer 2) of the message capsule can also be viewed in the
browser. It turns out that even with two encryption layers
Spot
-
On uses
pure
HTTP/S for the
transfer of cipher
text in the so called
Echo Protocol.
Spot-On.sf.net Encryption Suite - Handbook and User Manual
32
only cipher test is sent (see figure from the practice demo
of Adams / Maier 2016).
It is also possible to exchange the symmetric passphrase
(the AES) with the remote friend using an established a-
symmetric (SSL/TLS) encryption. The passphrase can be
automatically generated or manually defined.
This symmetric encryption now can be applied to either to
convert plain text or even already converted text, that is
cipher text, another time to cipher text (as shown in the
message format above) - or the symmetric password can be
used to define a new end-to-end encrypted channel (a fast
change of the layer 2 credentials in the message example
above).
A (symmetric) end-to-end encryption is thus to differentiate
from the point-to-point encryption. Therefore, the word
“continuous” end-to-end encryption is also added (better
still: continuous symmetric end-to-end encryption) - be-
cause it’s about that only the participant Alice and the par-
ticipant Bob know the secret passphrase. Point-to-point
encryption would be when Alice connects to the server and
then the server connects to Bob. This may mean that the
server can read the message, so it unpacks and repackages
the message, especially if there is an a-symmetric key be-
tween the participants and the server located in the mid-
dle.
Instead, Spot-On offers continuous symmetric end-to-end
encryption that can not only be manually defined, but can
also be instantaneously renewed with automation. This
defines the function of “Cryptographic Calling” - a way to
instantly renew the end to end encrypting (e.g. symmetric)
credentials e.g. within the session (see the Chat Section for
a deeper explanation how Cryptographic Calling is defined).
There are hardly any other - also open source - applications
that include an end-to-end (e2e) encryption from one par-
ticipant to the other participant, in which the user can
manually and individually define the passphrase (e.g. an
AES string).
C
r
y
p
to
graphic
Calling:
Superencip
herment
refe
rs to hybrid and
multi encryption.
Alternatives to RSA encryption: Spot-On as the first NTRU & McEliece Encryption Suite
33
What now if we mix and serialize symmetric and a-
symmetric encryption? We end at hybrid and multi encryp-
tion, also so called: superencipherment.
2.3 Superencipherment: Hybrid & Multi Encryp-
tion
Spot-On implements a hybrid encryption system, including
authenticity and confidentiality. Hybrid means first of all:
“both variants are available” and can be combined with
each other. Thus, a message can first be a-symmetrically
encrypted with PKI shown above and then symmetrically
with an AES again. Or the other way around, there is also
another variant conceivable: The PKI transmission path
transmits with permanent keys again only temporarily used
keys, with which then the further communication takes
place over this temporary channel. The temporary channel
can then again transmit a symmetric encryption with an
AES.
Thus, not only in the method change from PKI to AES re-
spective from a-symmetric encryption to symmetric en-
cryption exists one option to build a hybrid system, but also
in the switch from permanent PKI keys to temporary PKI
keys.
Encrypting often and switching between these methods
or using time-limited keys is a strong competence of Spot-
On in this hybrid and multiple encryption.
Multi-Encryption
Multiple encryption is the process of encrypting an already
encrypted message one or more times, either using the
same or a different algorithm. It is also known as cascade
encryption, cascade ciphering, multiple encryption, and su-
perencipherment. Superencryption refers to the outer-level
encryption of a multiple encryption. Cipher text is converted
to cipher text to cipher text and to cipher text…
E
p
h
e
m
e
r
a
l
K
e
y
s
are
temporary Keys.
Spot-On.sf.net Encryption Suite - Handbook and User Manual
34
Spot-On holds even more extensive security especially with
multiple encryptions: Here cipher text is either converted
another time to cipher text or sent through an SSL/TLS
channel.
With these possibilities one can now play and apply it in
various ways. Is the permanent or the temporary key ap-
plied first, or once again the symmetric and then the a-
symmetrical as the second level of encryption? or vice ver-
sa? Hybrid and multi encryption have many potentials and
offer various research perspectives.
One part of the system in Spot-On generates the key for
authentication and encryption per message. These two keys
are used to authenticate and encapsulate data (that is, the
message). The two keys (for authentication and encryption)
are then encapsulated across the public-key part of the sys-
tem. The application also provides a mechanism for distrib-
uting session keys for this data encapsulation (or encryption
of the message) as described above, the temporary key.
Again, the keys are encapsulated and transmitted via the
public key system: an additional mechanism allows the dis-
tribution of the session keys over the predetermined keys.
Encryption algorithms for the cipher text, signature algo-
rithms and hash values create an encapsulation of the in-
formation. As a first example, this format may serve the
mentioned message encryption:
Figure 9: Message Encryption Format of the Echo Protocol
EPUBLIK Key
(Encryption Key || Hash Key)
|| EEncryption Key (Data)
|| HHash Key (EEncryption Key (Data)).
For those who are dealing with encryption for the first time,
the above example of encapsulation is a first example to
further study and understand the methods; - In any case,
one can see how the encryption key is supplemented by the
Alternatives to RSA encryption: Spot-On as the first NTRU & McEliece Encryption Suite
35
hash key (see MAC) and also the data is embedded in dif-
ferent encryption levels.
Next to the modern algorithms also the process innovations
are to be mentioned with further examples as follows:
2.4 Further Examples of state-of-the-art encryp-
tion & process implementations
Spot-On has not only standardized, forward-looking algo-
rithms or numerous details (such as the switch from AES-
128 to AES-256 or the use of very high, because necessary
key sizes), but also implemented the professional integra-
tion of established and new encryption processes.
Spot-On uses CBC with CTS to provide confidentiality. The
file encryption mechanism supports the Galois/Counter
Mode (GCM) algorithm without the authenticity property
provided by the algorithm. To provide authenticity, the ap-
plication uses the methodical approach of “Encrypt-then-
MAC” (ETM). MAC stands for Message Authentication Code
- and means that the order is determined: first encrypt, and
then authenticate the message with a code.
Non-NTRU private keys are evaluated for correctness by
the gcry_pk_testkey () function. The public key must also
meet some basic criteria, such as the inclusion of the public
key identifier.
The authentication of the private key and the encryption
mechanism is identical to the method as further discussed
in the documentation of the source code in the section on
the encrypted and authenticated container. (The documen-
tation for the source code for the section of encrypted and
authenticated containers contains further technical details.)
Another example for innovation is the implementation of
the ThreeFish hash, which was available as an alternative to
SHA-3 when it was realized that SHA-1 was no longer able
to cope with future requirements. Threefish is a block en-
cryption developed as part of the design of the crypto-
graphic hash function Skein, which participated in the NIST
selection process for SHA-3. Threefish does not use S-boxes
M
e
s
s
a
g
e
A
uthentication
Code: Encrypt-then-
MAC.
Spot-On.sf.net Encryption Suite - Handbook and User Manual
36
or other lookup tables to complicate time-side attacks
(computing time attacks).
Figure 10: Threefish implementation
Many more examples can be found, which show that the
encryption processes in Spot-On are very state-of-the-art.
Questions and further Research & Development Fields
Discuss the most important function of Spot-On from
your point of view and give some reasons.
What is PKI? And how is an AES differentiating from it.
Find literature about multi-encryption and summarize
it.
Why is McEliece more resistant against attacks?
Describe why it is important to encrypt in the Internet
and how to foster the use of encryption.
What is the Echo Protocol?
37
3 What is the Echo Protocol?
This special way of mixing a-symmetric PKI and symmetric
AES, multiplying permanent and ephemeral temp-keys, ty-
ing keys from last session to the current one as it is a char-
acteristic for multiple encryption on the way to exponential
encryption within a node network, as well as having for the
cipher text a transfer via a SSL/TLS tunnel connection in
place are referring characteristics of the Echo Protocol,
which is to be deepened in this section.
Next to multiple encryption the Echo Protocol contains two
further characteristics: one is given by sending messages to
the network, the other by unpacking the encrypted capsule
and matching its content. So, what exactly are the full spe-
cific properties of the Echo Protocol?
With the Echo Protocol is meant - simply spoken – that
first, every message transmission is encrypted…
Figure 11: Example of message encryption within the Echo
SSL (AES (RSA* (message)))
*) instead of RSA one can also use Elgamal or NTRU or McEliece.
… and second, in the Echo Network, each node
sends each message to each connected neighbor.
Full Stop. That’s how easy the world is. Underly-
ing is the so-called “small-world phenomenon”:
Anyone can reach anyone somehow over seven
corners in a peer-to-peer or friend-to-friend
network - or simply distribute the message over
a shared Echo-chat server in the circle of friends.
Spot-On.sf.net Encryption Suite - Handbook and User Manual
38
A third criterion for the Echo Protocol can be
added, that is a special feature when unpacking
the encrypted capsule: The capsules have nei-
ther a receiver nor sender information included -
and here they are different from TCP packets.
The message is identified by the hash of the un-
encrypted message (compared to the conversion
text of all known keys in the node) as to whether
the message should be displayed and readable
to the recipient in the user interface or not. For
this so-called “Echo Match” see even more de-
tailed below.
Figure 12: Graphical depiction of a message within the Echo
Protocol
T
h
e
E
c
h
o
M
a
t
c
h
compares two
Hashes: One of
the original plain
text message and
one of the con-
verted text mes-
sage by one key.
What is the Echo Protocol?
39
The graphical figure shows from inside to outside the pro-
cess of how the encrypted capsule is formed in the context
of the Echo Protocol:
First level of encryption: The message is encrypted and the
cipher text of the message is hashed and then the a-
symmetric key (e.g. with the RSA algorithm) can also be
used to encrypt the symmetric keys. In an intermediate
step, the encrypted text and the hash digest of the message
are bundled into a capsule and packed together. It follows
the paradigm: Encrypt-then-MAC. To prove to the recipient
that the cipher text has not been corrupted, the hash digest
is first formed before the cipher text is decrypted.
Third level of encryption: Then this capsule can be trans-
mitted via a secure SSL/TLS connection to the communica-
tion partner.
Second level of encryption: Optionally, there is also the
option of symmetrically encrypting the first-level capsule
with an AES-256, which is comparable to a shared, 32-
character password. Hybrid encryption is then added to
multiple encryptions (see Adams / Maier 2016:46).
The “Half Echo” mode sends a message only one hop, i.e.
from Bob to Alice. Alice then stops sending the message (as
is the default with the Full Echo).
Thirdly, in addition to Full Echo and Half Echo, there is the
Adaptive Echo (AE). Here, the message is only sent to
neighbors or friends, if they know an encryption token,
they have previously stored. So if the user does not know
the token, the message will not be forwarded to this user.
After all, the Echo still knows Echo Accounts. A kind of
firewall. This ensures that only friends who know the ac-
count access can connect. So a web-of-trust can be created,
which is a network exclusively among friends. It is not
based on the encryption key but is independent of it. This
means that the user does not have to associate his public
key with his IP address or even announce it in the network.
Spot-On.sf.net Encryption Suite - Handbook and User Manual
40
Basically, in the Echo, each node sends a message to each
connected node: If a user should then receive a message a
second time, it is compared in a temporary cache (based on
the hash value for that message) and, if applicable, when
the hash is upcoming again, the message is discarded and
thus not forwarded. This approach is called “congestion
control” and balances the number of messages in the net-
work from multiple nodes or servers.
Assembling Surprise Eggs - An analogy: The cryptography
of the Echo Protocol can be compared with the giving and
taking of so called “surprise eggs”, a capsule with a to as-
semble mini-toy in the famous chocolate egg. Bob gives
Alice a surprise egg, Alice opens it and consumes the choco-
late and bumps inside into the plastic capsule of the sur-
prise egg, trying to open it and assemble the pieces into a
toy, a smurf. However, she fails in the assembly, the Smurf
cannot be formed and therefore she packs the items back
into the plastic capsule, pours new chocolate around and
passes the egg to her neighbor, who also tries to assemble
some of the pieces. Alice does not know who can assemble
the surprise egg or build the smurf successfully, so she con-
tinues to copy it (- what a miracle, Alice has a surprise-egg
copying machine -) and gives each of her friends a copy.
(Unpacking, crafting, evaluating, packing, giving away and
unpacking, crafting, evaluating, wrapping, giving away, and
so on ...).
From the point of view of the entities represented in the
network (kernels), the network would have become a sur-
prise-egg circulation network in this analogy, if the crafting
processes were not reduced again with Congestion Control.
Once known, assembling parts are not built a second time
together. Alice tinkers many packets until she recognizes a
smurf with a red cap, she has received the figure of the Pa-
pa smurf intended for her (or as her message).
What is the Echo Protocol?
41
To exclude time and frequency analyzes in the Internet or
Echo Network, there are other functions in Spot-On which
increase encryption or make cryptographic analysis more
difficult:
For example: with the Spot-On application the user can also
send a kind of a “fake” message (from the simulacra func-
tion) and also “simulated” communication messages (“im-
personated messages”). On the one hand, encryption is
here not encryption in the sense of cipher text, but it is a
block of pure random characters that are emitted from time
to time, and the other is a simulated human conversation,
which is also based only on scrambled random characters:
Figure 13: Simulacra, Impersonator, Super-Echo
Simulacra
The Simulacra feature sends a “simulated” chat message to
the Echo Network when the checkbox is activated. This
“fake” message consists of pure random numbers, making it
harder for analysts to distinguish encrypted messages with
real and random content appearance like cipher text. Simu-
lacrum is a term that is not unknown from both the movie
“Matrix” (https://en.wikipedia.org/wiki/Matrix_(Film)) and
Baudrillard’s philosophy (Neo uses this name for the reposi-
tory for software in his home. And the book ‘‘Simulacres et
Simulation’’ by the French media philosopher Jean
Baudrillard explores the relationship between reality, sym-
bols and society). Several years after the publication of the
Echo Protocol, donors to the Tor network have developed a
similar software called Matrix Dot Org, which sends en-
crypted capsules to the network comparable to the Echo
Protocol and also addresses a messaging function; an analy-
sis is pending where the Echo over the plagiarism-like archi-
tecture offers differences and benefits or offered further
open source suggestions.
Spot-On.sf.net Encryption Suite - Handbook and User Manual
42
Impersonator
In addition to random fake messages, the Spot-On program
can also simulate a chat with the Impersonator function as if
a real person chats from time to time and sends out replies.
Also, these messages are filled with pure random data, but
they vary – a simulation of a real chat conversation. Thus,
analysis of messages can be made more difficult if third-
party recorders should temporarily store and record all user
communication, which may be assumed. But even more:
even the absence of meta-data (see data retention) gives no
reason to suspect that a message was for the user. Anyone
who has been able to successfully unpack a message nor-
mally does not send it back to the Echo Network. A record
of metadata could have increased interest in the un-re-
submitted messages, assuming that this message could then
have been successfully decoded by the user. For this case
there is also the option of the SuperEcho:
Super-Echo
The feature of Super-Echo also redirects successfully decod-
ed and readable messages back to all friends. A lack of re-
transmitting a message may then no longer indicate - be-
cause of the Super-Echo - that the message may have been
successfully decoded.
Super-Echo, Simulacra and Impersonation are three options
of the Spot-On program, which should make it harder for
attackers to understand the messages that are of interest to
the user (and apparently others) in the multitude of mes-
sages.
Now let’s take a closer look at the individual Echo modes of
operation:
What is the Echo Protocol?
43
3.1 Full Echo
The “Full Echo” modus underlies an assumption, as it is also
in the so-called “small world phenomenon” given: with
hopping over a few friends everyone can send a message to
each of them. Somehow, everyone knows everyone about a
maximum of seven corners. This is also applicable in a peer-
to-peer or friend-to-friend network. Therefore, a user can
reach anyone if each node sends each message to all other
known nodes.
Small World Phenomenon
The small-world experiment comprised several experiments
conducted by Stanley Milgram and other researchers exam-
ining the average path length for social networks of people.
The research was groundbreaking in that it suggested that
human society is a small-world-type network characterized
by short path-lengths. The experiments are often associated
with the phrase "six degrees of connectedness", although
Milgram did not use this term himself.
Guglielmo Marconi's conjectures based on his radio work in
the early 20th century, which were articulated in his 1909
Nobel Prize address, may have inspired Hungarian author
Frigyes Karinthy to write a challenge to find another person
to whom he could not be connected through at most five
people. This is perhaps the earliest reference to the concept
of six degrees of separation, and the search for an answer to
the small world problem.
Mathematician Manfred Kochen and political scientist Ithiel
de Sola Pool wrote a mathematical manuscript, "Contacts
and Influences", while working at the University of Paris in
the early 1950s, during a time when Milgram visited and
collaborated in their research. Their unpublished manu-
script circulated among academics for over 20 years before
publication in 1978. It formally articulated the mechanics of
social networks and explored the mathematical conse-
quences of these (including the degree of connectedness).
Spot-On.sf.net Encryption Suite - Handbook and User Manual
44
The manuscript left many significant questions about net-
works unresolved, and one of these was the number of de-
grees of connectedness in actual social networks.
Milgram took up the challenge on his return from Paris, and
his Psychology Today article generated enormous publicity
for the experiments, which are well known today, long after
much of the formative work has been forgotten. The small-
world question is still a popular research topic (also for net-
work and graph theory) today, with many experiments still
being conducted.
In computer science, the small-world phenomenon (alt-
hough it is not typically called that) is used in the develop-
ment of secure peer-to-peer protocols, new routing algo-
rithms for the Internet and ad hoc wireless networks, and
search algorithms for communication networks of all kinds.
Alternatively, a user can support this decentralized ap-
proach or abbreviate the message paths by installing an
own chat server based on the Echo Kernel for friends, so
that all encrypted messages can be sent to the participants
and the server can serve as an e-mail-postbox or interme-
diate chat server.
What is the Echo Protocol?
45
The mapping describes sending the message from a starting
point to all network nodes across all connected network
nodes.
Figure 14: Echo Simulation: Each node sends to each connected
node
So basically, in the Echo, each node sends each message to
each node. This sounds simple: The Echo Protocol is a very
simple Protocol, but also has wider implications, that is:
There are no routing information within the Echo given and
even metadata can hardly be recorded from the individual
node or even network. The nodes also do not forward the
message. The term “forwarding” is incorrect, because each
node actively resends the message to the (its) connected
friends, respective neighbors.
This may result in receiving a message (from multiple
connected nodes) multiple times - however, in order to
avoid this happening and being efficient, the message hash
is cached, and the message may be rejected for retransmis-
sion if it is identified as a doublet. This is called as already
indicated above: “Congestion Control”.
The message is in a capsule, so to speak, similar to a ZIP
file. This capsule is created by a-symmetric encryption with
the public key. Added is the hash of the plain text message.
Spot-On.sf.net Encryption Suite - Handbook and User Manual
46
When another node (receiver) tries to decode the cipher
text, a new text comes out depending on the used and
available key - which can either be decoded correctly or
incorrectly, that is to say, it is human-readable - or, if the
decoding key was incorrect, out of random characters (the
cipher text) became only random characters (wrong decod-
ed text, not readable plain text). This resulting text after the
decoding attempt is thus again hashed.
Now, if the hash of the decoded message is identical to
the hash of the original message that the sender already
attached (readable) to the capsule, it is clear that the deci-
phering node has used the correct key and this message in
plain text is for him: hence, the message is readable and
displayed in the user interface. This can be called an “Echo
Match”. Unsuccessful decoding attempts, in which the hash
value between the original message and the message text
of the decoding attempt do not match, are not displayed in
the user interface, but remain in the kernel of the program
for further transmission to the connected neighbors.
The node must therefore try with all the keys of his
friends to unpack the message and compare the hash val-
ues. If the hash value is not identical, the node packs the
ingredients back together in one capsule and sends it to
each of the connected friends, who then try the same.
The hash value of a message is not invertible, therefore
the encryption cannot be broken with the (enclosed) hash
of the original message, it still requires the correct key.
A message that has been successfully unpacked will no
longer be sent, unless the user uses the “Super Echo” op-
tion, which also retransmits the successfully unpacked mes-
sages. Thus, no one who records the Internet packets along
the line can identify messages that are not sent again.
Finally, as described above, it is also possible from time
to time to send out false messages (“simulacra fake mes-
sages”) and also “simulated impersonated messages”, so
that it is difficult for network traffic collectors to find out
the message capsule, which has been of interest for the
user’s own readability. Because it is to be noted that it may
be assumed today that all communication data of an Inter-
T
he Echo
-
Match
can be regarded as
one sustainable
innovation and
invention in net-
work theory and
routing with a di-
rect perspective to
Cryptographic Dis-
covery.
What is the Echo Protocol?
47
net user is somewhere stored and recorded on the Internet
and in the case of interest also automated and manually
evaluated.
Then: This encrypted capsule is again sent over an en-
crypted SSL/TLS channel that is established between the
nodes. This is a decentralized, self-signed p2p connection, a
“two-pass mutual authentication Protocol”, so the term.
The implementation is precisely defined according to
SSL/TLS, but it can also be switched off: The network nodes
thus communicate via HTTPS or even only HTTP.
Figure 15: Example and Process Description of the Echo-Match
Practical Example and Process Description
of the Echo-Match
Sender A hashed his original text to a hash 123456789, en-
crypts the text and packs the crypto-text and hash of the
original message into the capsule (before he adds an AES-
Password and sends it out via a TLS/SSL connection). Recipi-
ent 1 converts the received encoded text of the capsule to a
(supposed) plain text, but this has the hash 987654321 and
is therefore not identical to the supplied original text hash
of 123456789. This is repeated with all available keys of all
friends of the recipient 1. Since all hash comparisons, how-
ever, were unsuccessful, he re-packs the message again and
sends it on. The message is obviously not for him or one of
his friends. Recipient 2 now also converts the received, en-
crypted text to a (supposed) plain text, this has the hash
123456789 and is thus identical to the supplied original text
hash of 123456789, the decoding was apparently successful
with one of the existing keys of his friends and therefore the
message is displayed on the screen of this receiver (and if
Super-Echo is selected, also re-packed again and sent-out
again).
However, of course, the transfer becomes more susceptible
if one does not use the multiple encryption. Therefore, one
should always establish a HTTPS connection to his or her
Spot-On.sf.net Encryption Suite - Handbook and User Manual
48
friends and send over this encrypted channel his encrypted
capsules in which the message waits, to be kissed awake
from the right key (using the “Echo Match” method based
on the hash comparison) and to be converted in readable
plain text.
No one on the net can see which message a user success-
fully unpacked, because everything happens on the user’s
local machine.
3.2 Half Echo
The Half Echo mode sends the user’s message only one hop
to the next node, e.g. from Bob to Alice. Alice then does not
send the message down the path of her connected friends
(as it is customary for the Full Echo). This Echo mode is
technically defined by the connection to another listener:
Bob’s Node, when connecting to the node of Alice, notifies
that Alice should stop sending the message to her friends.
Thus, two friends or nodes can exclude via a direct connec-
tion that the message is carried into the wider network via
the other, further connection(s) that each node has.
3.3 Echo Accounts
And in addition: The Echo also knows Echo Accounts. An
account is a kind of firewall. It can be used to ensure that
only friends connect who know the credentials to the ac-
count. Thus, a so-called Web-of-Trust, a network based on
trust, is formed. It is not based on the encryption key like in
other applications, it is independent of it. This has the ad-
vantage that the encryption public key does not need to be
associated with the IP address (as it is the case with Retro-
Share, for example); or that the user must announce the
own IP address in the network of friends, for example in a
DHT where users can search for it. The Echo Accounts pro-
vide a peer-to-peer-(P2P)-connection to a friend-to-friend-
(F2F)-network or allow both types of connection. This
makes Spot-On suitable for both paradigms.
What is the Echo Protocol?
49
Figure 16: Account Firewall of Spot-On
The Echo Accounts work as follows:
Binding endpoints are responsible for defining the ac-
count information. During the creation process for an ac-
count, this can be defined for one-time use (one-time ac-
count or one-time use). Account name and also the pass-
phrase for the account require at least 32 bytes of charac-
ters. So, a long password is required.
After a network connection has been established, the
binding endpoint informs the requesting node with a re-
quest for authentication. The binding endpoint will drop
the connection if the peer has not identified within a fifteen
second time window.
After the request for authentication has been received,
the peer responds to the binding endpoint. The peer then
transmits the following information: HHash Key (Salt /
Time) // Salt, where the hash key is a concise summary of
the account name and also the account password.
Currently, the SHA-512 hash algorithm is used to gener-
ate this hash result. The time variable has a resolution of a
few minutes. The peer retains the value for the crypto-
graphic salt.
Spot-On.sf.net Encryption Suite - Handbook and User Manual
50
The binding endpoint receives the information of the
peer. Consequently, this then processes HHash Key (Salt //
Time) for all accounts he has set up. If the endpoint cannot
identify an account, it will wait one minute and perform
another search. If an account matching this hash key was
found, the binding endpoint creates a message similar to
the one the peer created in the previous step and sends the
information to the peer. The authenticated information is
stored. After a period of about 120 seconds, the infor-
mation is deleted again.
The peer receives the information of the binding end-
point and performs a similar validation process, this time
including the analysis of the cryptographic salt value of the
binding endpoint. The two salt values must then be clearly
consistent. The peer will drop the connection if the end-
point has not identified itself within a fifteen-second time
window.
It should be noted, by the way, that the account system
can be further developed by including a key for encryption.
The additional key then allows even more precise time
windows to be defined.
If SSL/TLS is not available during this negotiation, the Pro-
tocol may become vulnerable as follows: An intermediate
station may record the values from the third step and con-
sequently send to the binding endpoint. Then, the binding
endpoint could also grant access to the account to an un-
known connection. The recording device could then grab
the response of the binding endpoint, that is, the values of
the fourth step, and forward the information to the peer. If
the account information or password is then accurately
maintained, the peer would then accept the response from
this new binding endpoint. That’s why, as always, it’s about
protecting passwords and to use HTTPS connections.
In Spot-On, therefore, a server account - if it is specified
to be dedicated - therefore requires a password equal to
the length of an AES-256: this is a passphrase of 32 charac-
ters.
What is the Echo Protocol?
51
3.4 The Echo Grid
When students talk, or be taught (or teach themselves)
about the Echo Protocol, they can simply draw an Echo Grid
with the letters E_C_H_O. The nodes from E1 to O4 are
numbered and connect the letters with a connecting line on
the ground (see figure).
Figure 17: The Echo Grid Template
For example, then the connection E1-E2 denotes an IP con-
nection to a neighbor.
If the individual nodes now exchange keys, connections
are created that arise as a new level at the level of the IP
connections of the P2P / F2F network.
With the architecture underlying in Spot-On not only the
cryptographic routing/discovery in a kernel program was
invented and elaborated, also - as stated above - the term
“cryptographic routing” was paradoxically removed from
the routing with the Echo Protocol. It is therefore necessary
to speak in more detail of the “Cryptographic Echo” instead
of “Cryptographic Routing”. One further item to differenti-
ate the Protocols is the Protocol of the “Cryptographic Dis-
covery” which will be discussed below in an extra section.
Echo is thus “beyond routing” (Gasakis/Schmidt 2018):
Firstly, the message packets do not contain routing infor-
mation (addressees) and the nodes also do not use “for-
T
he Echo
-
G
r
i
d
to discuss
Graph Theory.
Spot-On.sf.net Encryption Suite - Handbook and User Manual
52
warding” in the original sense, because they simply send
everything to all connections. And secondly: Even the cryp-
tographic key that tries to decode the message is not an
address (which would even be attached to the message
package), but only a polarizing glass: it lets us see texts dif-
ferently and possibly understand. The Echo Protocol there-
fore also uses the term “traveling” rather than the term
“routing”. Or just in short: “Cryptographic Echo Discovery”.
From a legal point of view, a different evaluation is then
also to be made here, since a node does not forward in the
name of an addressee as a middleman, but informs the
neighbors independently (see, for example, the forwarding
in other routing models such as AntsP2P with its ant algo-
rithm, Mute, AllianceP2P, RetroShare, Onion-Routing or
I2P).
As well as spreading an established reputation or news in
the neighborhood, the message also spreads in the Echo -
otherwise the echoing protocol allows any cryptographic
“stuff” to “float” away (by being not decoded or being un-
readable).
It seems to be a reminiscence to the Star Trek Borg col-
lective paradigm: everyone has access to all the neighbors’
messages (unless half or Adaptive Echo is used and if the
message text can be understood (decoded) at all).
In the Echo, the node is more of a “sovereign” for “giving
and receiving (non-directional) information”; in other net-
works, a node could be more referred to as a “postman”,
“dealer”, “forwarder” or “intermediary”. Yes, in the Echo
the node is a sovereign!
The Echo Grid as a simple network representation is not
only used for the analysis of “routing” (or “travel”-ways) to
represent Echo modes and encryption stati, but can also be
found in graph theory considerations: which path takes a
message? depending on the structure of the network? And
it also can be used to evaluate the use of Echo Accounts,
Half or Full Echo and the Adaptive Echo, as the following
examples of the graphs between Alice, Bob, Ed and Maria
illustrate.
T
h
e
Ech
o n
ode
as a sovereign.
What is the Echo Protocol?
53
3.4.1 Examples of key exchanges by Alice, Bob, Ed &
Maria
Figure 18: Alice, Bob, Ed and Mary in the Echo Grid - An exam-
ple of Echo paths and for Graph Theory
The following examples of the figure can be further dis-
cussed (a few vocabulary and processes of functions of the
Spot-On client are used, so that in the program inexperi-
enced readers can also skip this section and refer back once
the basic functions (installation, chat, e-mail, File transfer
or URL search) have been explained – so that these tech-
nical examples are understood better at a later stage):
Alice (IP = E1) and Bob (IP = C3) have exchanged their
public key and are connected via the following IP
neighbors: E1-E3-E5-E6-C3.
Bob (C3) and Maria (O4) are also friends, they’ve al-
so swapped their public keys for encryption: and use
their neighbors’ IP connections: C3-C4-H5-H3-H4-H6-
O3-O4.
Finally: Maria (O4) is a friend of Ed (H1). They either
communicate via the path: O4-O3-H6-H4-H3-H1 or
Spot-On.sf.net Encryption Suite - Handbook and User Manual
54
they use the path of: O4-O2-O1-O3-H6-H4-H3-H1.
Since, in the Echo Protocol, every IP neighbor sends
every message to every connected IP neighbor, the
path that delivers the message fastest will succeed.
(The second incoming message is then filtered out by
Congestion Control).
Direct IP connections from neighbors such as E1-E3
can be further secured by the creation of a so-called
“Echo Account”: No other IP address than E1 can
then connect to the so-called “listener” of the
neighbor E3. This method can be used to create a
web-of-trust - without relying on keys for encryption
- nor does it require a friend as a neighbor to ex-
change their chat or e-mail key.
So-called “Turtle-Hopping“ becomes much more effi-
cient in the Echo Network: when Ed and Alice start a
file transfer (via the StarBeam function and using a
Magnetic URI link), the Echo Protocol transports the
packets via the path H1-H3- H5-C4-C3-E6-E5-E3-E1.
Maria is not in the route, but she will also receive the
packets over the Full Echo if she knows the StarBeam
Magnet. The advantage is that the hopping is not
done over the keys, but over the IP connections (e.g.
the Web-of-Trust). Basically, everything is always en-
crypted, so why not take the shortest route on the
net?
A so-called “Buzz” or “Echo’ed IRC Channel” (there-
fore also short: e’IRC) room can be created or “host-
ed” by the node O2, for example. Since only the user
Ed knows the buzz room name (which is tied into the
Magnet), all other neighbors and friends are left out.
Advantage: The user can talk to unknown friends in a
room without having exchanged a public e.g. RSA key
with them. Instead, a one-time Magnet is simply
used for this “buzz” / “e’IRC” room.
Maria is a mutual friend of Ed and Bob and she acti-
vates the C/O (care of) feature for e-mails: this al-
lows Ed to send e-mails to Bob, even though he’s of-
What is the Echo Protocol?
55
fline, because: Maria saves the e-mails in her in-
stance, until Bob comes online.
Furthermore: Alice created a so-called virtual “e-mail
institution”. This is not comparable to a POP3 or
IMAP server because the emails are only cached: Ed
sends his public e-mail key to Alice - and Ed adds the
Magnet of Alice’s “E-Mail Institution” to the pro-
gram. Now, e-mails from Bob and Ed are also cached
within Alice (at the so-called e-mail institution), even
if Maria should be offline.
It is helpful to follow the examples on the above graphic or
to come back to this at the end of the manual after further
explanations of the functions.
3.5 Adaptive Echo (AE) and its AE tokens
In addition to the Full and Half Echo, there is the third:
Adaptive Echo (AE). Here, as it will be described below, the
message is sent to connected neighbors or friends only if
the node knows a particular cryptographic token - similar to
a secret passphrase.
Of course, this passphrase must first be defined, shared
and stored in the respective nodes. Thus, defined ways of a
message in a network configuration can be used. For exam-
ple, if all nodes in a country use a common Adaptive Echo
passphrase, the message will never appear in other nations’
nodes if they do not know the passphrase. Thus, a routing
can be defined that is not located within the message, but
in the nodes. If you do not know the passphrase, one does
not get the message forwarded respective further sent out!
Adaptive Echo turns messages that cannot be opened into
messages that are not known or even exist.
For the explanation of the “Adaptive Echo” another Echo-
Grid with the connected letters A and E can be drawn (see
following figure).
Natural Evolve-
ment:
The Echo is a natu-
r
al evolvement. An
Ec
ho Server is just a
reflector of mes-
sages.
First in - First out.
Probably Amazon`s
Echo (2015) has
been derived
from
the Echo Protocol
released sinc
e 2013
and earli
er. Coinci-
dence?
Spot-On.sf.net Encryption Suite - Handbook and User Manual
56
Figure 19: Adaptive Echo (AE): The “Hansel and Gretel” Exam-
ple of the Adaptive Echo
If a user, his or her chat friend, and a configured third node
as a chat server insert the same AE token (“Adaptive Echo
Token”) into the program, then the chat server will only
send the user’s message to his friend, and not to all other
connected neighbors (or users), as it would normally be the
case in the Full Echo (server) mode.
The AE token consists, like a passphrase, of at least 96
characters. In the case of Adaptive Echo, the information
from the sending node of the encrypted capsule is attached
- and all other nodes learn that one is only forwarding
What is the Echo Protocol?
57
(sending) the message to nodes or connection partners,
who also know this AE token.
With an AE token, no other node that does not know the
passphrase will be able to receive or view the user’s mes-
sage. Thus, potential “recorders” can be excluded: these are
possible neighbors, which presumptive record all the mes-
sage traffic and then try to break the multiple encryption to
get to the message core of the capsule.
In order to be able to determine the graph, the travel
route for the Adaptive Echo, several nodes must agree with
each other and note the passphrase on the way path with-
out any gaps. In the case of the Adaptive Echo it can be
spoken of a routing.
3.5.1 Hansel and Gretel - An example of the Adap-
tive Echo mode
To illustrate the Adaptive Echo, a classic example is the tale
of Hansel and Gretel.
In the AE grid explained above, the characters Hansel,
Gretel and the evil witch are drawn as nodes. Now Hansel
and Gretel think about how they can communicate with
each other without the evil witch noticing this. According to
the fairy tale, they are in the woods with the witch and
want to find out again of this forest and mark the way with
bread crumbs and white pebbles.
These fairy tale contents can now also illustrate the
Adaptive Echo in the above grid pattern and show at which
points of the grid or the communication graph a crypto-
graphic token called “white pebbles” can be used:
If nodes A2, E5 and E2 use the same AE token, then node
E6 will not receive a message that node A2 (Hansel) and
node E2 (Gretel) will exchange. Because the node E5 learns
about the known token “white pebbles”, it does not send
the messages to the node E6, the “Wicked Witch”. It is a
learning, adaptive network.
An “Adaptive Echo” network reveals no target infor-
mation (compare again above: “Ants Routing” et. al.). Be-
cause - as a reminder: The mode of “Half Echo” sends only
Spot-On.sf.net Encryption Suite - Handbook and User Manual
58
one hop to the connected neighbor and the “Full Echo”
sends the encrypted message to all connected nodes over
an unspecified hop number. While “Echo Accounts” en-
courage or hinder other users as a kind of firewall or au-
thorization concept when connecting, “AE tokens” provide
graph or path exclusivity - for messages that are sent via
connected nodes that know the AE token.
Chat Server Administrators can exchange their tokens
with other server administrators if they trust each other
(so-called “Ultra-Peering for Trust”) and define a Web-of-
Trust. In network labs or at home with three or four com-
puters, the Adaptive Echo is easy to test and to document
the results:
For an Adaptive Echo test, simply use a network with
three or more computers (or “SPOTON_HOME” as the (suf-
fix-less) file in the binary directory to launch and connect
multiple program instances on a single machine) and then
implement this example flow:
How to test Adaptive Echo
1. Create a node as a chat server.
2. Create two nodes as a client.
3. Connect the two clients to the chat server.
4. Exchange keys between the clients.
5. Test the normal communication skills of both cli-
ents.
6. Put an AE token on the server.
7. Test the normal communication skills of both cli-
ents.
8. Now set the same AE token in a client as well.
Note the result: The server node no longer sends the mes-
sage to other nodes that do not have or know the AE token.
This example should be easy to replicate.
Cryptographic Discovery
59
4 Cryptographic Discovery
Cryptographic Discovery describes the method of an Echo-
ing Protocol to find nodes in an Echo Network. The Echoing
Protocol is supplemented with another useful method, if
not even more important, than the Echo itself: Crypto-
graphic Discovery is available in existing clients such as the
Spot-On compatible chat server for the Android operating
system, SmokeStack, and implemented within the code
base. The source code and its documentation define the
method accordingly. For example, Cryptographic Discovery
can replace a Distributed Hash Table (DHT) to find a friend
on the network.
On the mobile device, on the other hand, it makes more
sense for reasons of efficiency and battery protection to
receive and decode only the messages, which are intended
for the own use as a participant.
This initial question: how the number of encrypted mes-
sage packets can be reduced, especially for mobile devices -
was the goal of further development of the Echo Protocol.
A response offers the in the meantime developed, and
the Echo Protocol supplementing protocol "Cryptographic
Echo Discovery" (CRED).
Cryptographic Echo Discovery can be described as follows
and can, as we shall see, replace the concept of a Distribut-
ed Hash Table (DHT) with its disadvantages.
If a user sends a message to a regular Echo server, it does
not know where to send it to and so it sends it to everyone.
One of those everyones is the correct one. The correct one
will then send the message to the other user. The alterna-
tive is to have the peer knowing my peer in a virtual cryp-
tographic software structure. These peers are separate pro-
cesses. Then the peer of the user could send the message
to peer A and peer Z instead of peers: A through Z. Peers
would be aware of other peers based on a cryptographic
discovery with cryptographic identities. Complex stuff - but
Spot-On.sf.net Encryption Suite - Handbook and User Manual
60
already coded in into the mobile client of Spot-On: Smoke
Messenger and its Server Smoke Stack.
In its brief form, Cryptographic Echo Discovery is a simple
protocol where clients share presence information with
nearby and connected servers. Nearby servers, if acting as
clients, share their information with nearby servers, and so
on. Presence information is shared whenever necessary.
In the following, we look closer at several examples in a
detailed explanation. Lets assume, we have a graph as fol-
lowing:
C1 => S1 => S2 <= S3 <= C2.
Client C1 connects to Server S1 and shares some semi-
private key material. When S1 connects as a Client to S2, it
shares its pool of semi-private material. C2 connects to S3
and performs a similar task as C1. S3, similarly.
In the end, S2 knows both, C1 and C2 through the near-
est-neighbor Sprinkling Effect (SE) (see also further below
for a further description of the so called Sprinkling Effect):
S1 knows about C1. S3 knows about C2. Also S2 and S3
know each other. And so, C1 can address the message to C2
and these messages can be limited and defined to certain
paths.
If knowledge is not known, the Echo controls the data
flow.
Let's explain the “Cryptographic Echo Discovery” (CRED)
with the “Sprinkling Effect” (SE) over the Echo Protocol with
another simple example from the development source:
Cryptographic Discovery
61
Figure 20: SECRED – Sprinkling Effect (SE) & Cryptographic
Echo Discovery (CRED) via the Echo Protocol
SECRED
Sprinkling Effect (SE) &
Cryptographic Echo Discovery (CRED)
via the Echo Protocol
Source: Description of the sprinkling effect based on the Spot-On Pro-
ject Documentation 07/2016
In the above diagram, the Cs represent clients whereas the
Ss represent servers. Servers may behave as clients (see
directions of arrows in the diagram). Let C4 and S0 establish
a network connection. The connection need not support
SSL / TLS. Assuming that a correct connection has been es-
tablished, C4 will optionally share some non-private discov-
ery details with S0.
The client tells the server any hint: any kind of infor-
mation. This information may include, e.g., digests of Buzz
magnets for a group chat room, digests of StarBeam mag-
nets, digests of personal (not private) public keys, etc..
Some of this information may also be shared later.
That means, the server of the user knows of a means of
delivering something to the user.
Spot-On.sf.net Encryption Suite - Handbook and User Manual
62
If the server of the user has other servers, it tells them
the hint of the user. If the server does not know another
server, the hints end there.
So, such hints are needed to get the message from A to Z.
Also, let’s suppose that C1 performs a similar task. As the
network contracts and expands, entities such as S0 get in-
formed of some of the virtual materials of C0, C1, C4, and
S2.
• Notice that S0 is aware of neither C6 nor S3 within a
direct connection, because the paths to S3 are in-
ward within the network.
• Also notice that S0 may become aware of Node C3
and Node C5 courtesy of S2.
So, what's the purpose of Cryptographic Echo Discovery?
CRED's primary purpose is to place the performance of data
inspection on certain servers. Servers will be able to direct
traffic by inspecting packets and delivering them to their
correct clients.
Let's assume that the above network is static for the re-
maining portion of the exercise.
Also it is assumed that the discovery process has estab-
lished sufficient knowledge with each of the servers in the
given chain, a steady state.
Now, suppose C4 wishes to communicate with C3. C4 will
deliver a message to S0. S0, having a delicate knowledge
database, will deliver the message to S2. Likewise, S2 will
deliver the message to C3.
It is therefore clear: Without Cryptographic Echo Discov-
ery, C4's message would spread through the entire network
over the Echo Protocol.
The decisive factor is not only the protocol inherent data
inspection, but also the pre-existing process of the division
of clients representing presence information (for example,
one of the above-mentioned hash digest options).
Cryptographic Discovery
63
Figure 21: Definition of SECRED
Process of the Sprinkling Effect
via Cryptographic Echo Discovery
The sprinkling effect (SE) can be understood as a watering
that can feed and nourish a flower. The collected infor-
mation is passed on by a node to the neighbors. Each
neighbor participating in the Cryptographic Echo Discovery
distributes this complementary CRED information to the
other neighbors. So, every neighbor is sprinkled.
SECRED
is an acronym for the term = Sprinkling Effect via
CRyptographic Echo Discovery.
The Echo Protocol then regulates the rest to the respective
graph. Clients, e.g. mobile devices, then receive over the
SECRED exchange only those messages which are intended
for them.
One doesn’t always own the server. One also cannot pos-
sibly configure it. So, one has to teach it, how to give some-
one the messages. And the server teaches. Or not.
That is quite simpler than a search for a friend in a Dis-
tributed Hash Table (DHT) or the distribution of sender and
receiver information.
A Distributed Hash Table (DHT) is a data structure that
can be used, for example, to store the location of a file or
the precision information in a p2p system: is my friend
online and if so, which current IP and which port does the
referring friend use?
Thanks to the SECRED and Echo Protocol, a user need not
to care what happens up-stream, after the message has
been sent on its journey.
That is a big advantage of SECRED even compared to the
Adaptive Echo (A.E.): A.E. requires configurations - a token
S
E
C
R
E
D
i
s
t
h
e
beginning of
teaching machine
s
by Cryptographic
Discovery and
the
Sprinkling Effect.
Spot-On.sf.net Encryption Suite - Handbook and User Manual
64
that is based on the user’s definition. SECRED does not
need a token manually inserted in an intermediate server.
Hence, SECRED is an elegant way to organize, that peo-
ple, who know the user, can derive messages for the user.
And, when the user address others, they can be given the
data properly: here is this data for user X.
The criterion for this hint is, that the data is identifying
something about the to-be-addressed person in a graph
chain. The server sees and knows things from neighbors.
Data is free. Sometimes there are lots of data, sometimes
not. So, there will be localized networks. And servers learn-
ing and teaching, because one can be a client, a server, or
both - and based on own roles, one can learn and/or teach.
If a node doesn't know where to send to, it sends it
wherever it can.
Perfection is not required. Nor is completeness required,
because the Echo is redundant.
The method of SECRED removes now some of the mes-
sages from the network flow, so that mobile devices can be
easily addressed and save battery and CPU-capacity.
The default implementation of the “hint” in the “Sprin-
kling Effect” of the “Cryptographic Echo Discovery” is based
on keys. E.g. a cryptographic digest hash is the secret a user
tells the server.
And messages to the user will be signed by that digest.
Because friends know the keys of the friend, they can ad-
dress this specific user over the SECRED Protocol.
The message is not signed in the sense of a digital signa-
ture. The hint for the user is just added to the message in
this format: D (Public Key) = XYZ. Hash (Message, D).
The Hash () is the product (signature) and the server can
compute it.
And then the server knows, that this specific us-
er/neighbor should get it: Message || H(Message, D).
The server computes H(Message, D) and knows this user
is D. So, it hands it to this user.
If it doesn't know D, it hands it to everyone.
Cryptographic Discovery
65
As an example in other words: Mary assigns the word “Po-
pocatépetl” to your presence. And Mary can write you us-
ing “Popocatépetl”. And if there are two “Popocatépetl”s,
both get the message. So, a semi-private construct, while
the Hash Digest offers great variety to be unique within
your environment.
H(Message, D) is visible to all. D is the hash of the key. D
is also a digest of something that the friends know about
you.
Need the hash to be shared? Well, users have their public
keys. So, a user can compute an ID based on those. A user
has the friend’s public keys, so this user can process it too. I
tell the server that I am so-and-so. I address my message to
so-and-so.
The server doesn't know so-and-so, so it echoes it. The
server knows only that something from me is being sent to
a recipient. The server doesn't know I wrote. In general: the
server knows that something from somewhere is sent to
another node.
This describes also the programmable functions of the
sprinkling effect via the Cryptographic Echo Discovery
(SECRED).
The more stable the network is, the more qualitative the
mapping will work. Decisive for the stability is not only the
online and offline status of friends, or the continuous avail-
ability of a chat server, but also the basic (stable) structure
of the friends, one wants to address with a mobile chat
messenger.
Here it is an advantage that the friend structures are usu-
ally relatively stable.
That is, also with the context of a "steady state" the rela-
tionship in the SECRED protocol can be compared:
Some communication applications try to find the friend
in a Distributed Hash Table (DHT) to obtain updated port
and IP information as well as status information about the
presence.
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66
However, the mixture of peers and servers in the network
means that the SECRED protocol has the advantage that
presence information (as in a DHT) is no longer required, as
intermediate entities keep the messages ready for the re-
trieval.
Likewise, binding nodes with stable addresses for the
mobile end devices are relieving and fostering security as
they do not have to connect to numerous foreign nodes in
the DHT for presence and IP or port queries.
SECRED is also a more secure alternative to DHTs (Dis-
tributed Hash Tables).
The implementation of a SECRED or DHT is thus not only
dependent on the requirement of the battery and the
hardware capacity of a possibly mobile device, but also on
consideration of efficiency and also demands on the privacy
of the data in the network at other nodes.
Questions and further Research & Development Fields
Describe the encryption layers of the Echo Protocol.
Explain Half and Full Echo within an Echo Grid.
Explain Adaptive Echo within a graph.
What is the Echo-Match? Give a Process Description.
What’s the idea of SECRED & Cryptographic Discovery?
Describe the Sprinkling Effect in comparison of a DHT.
Set up in your class a network with several computers
and test the Adaptive Echo.
First Set-up of the software Spot-On
67
5 First Set-up of the software
Spot-On
In this chapter the first setup of the software Spot-On is
described before the main functions of the software will be
explain each in an own chapter.
5.1 Set up a first installation – e.g. with the wiz-
ard
The first initial setup of the software is very simple done in
a few steps:
1 - Downloading & Installing the Software
The user unpacks the program from the Zip (for Windows)
and starts (under Windows) the Spot-On.exe from the path
to which the program was unpacked,
e.g. C: /Spot-On/Spot-On.exe
or C: /Programs/Spot-On/Spot-On.exe.
For Linux users a .deb installer file is provided and for Ma-
cOS users a .dmg file.
Download the software under:
https://sourceforge.net/projects/spot-on/files/
or from Github under:
https://textbrowser.github.io/spot-on/
2 - Key Generation with the Wizard
After starting the binary the user interface and a wizard
appear, with which the settings can be implemented step
by step. Alternatively, the user can close the wizard and
create the settings manually in the tab for the settings re-
Spot-On.sf.net Encryption Suite - Handbook and User Manual
68
spective the tab-section for kernel activation. It is recom-
mended to use the wizard.
Figure 22: Initial Wizard of Spot-On
In the wizard, the necessary cryptographic keys are then
generated with the user name and a passphrase to be en-
tered twice.
The wizard has the following sub-pages:
1 Initial Welcome,
First Set-up of the software Spot-On
69
2 Setting the passphrase for the login: Choosing be-
tween passphrase and question-and-answer method,
3 Confirmation of creating (default) RSA keys,
4 Launch Kernel upon completion of the wizard,
5 Enable URL-Distribution and set-up a SQLite Database
for it: Here the user must confirm the check boxes,
6 Button Initialize: The setup will be prepared.
3 - Activating the Spot-On Kernel
After completing the wizard, the kernel must still be acti-
vated. That means, the Spot-On Encryption suite has a user
interface (also called Graphical User Interface (GUI)) and a
kernel. Both are given as a binary file (in Windows called
Spot-On.exe and Spot-On-Kernel.exe).
Hence, the user must activate the kernel via the “Acti-
vate” button in the tab for settings (section for kernel acti-
vation) after each start of Spot-On.exe, which then coordi-
nates the connections to friends or to a chat server. So the
kernel file Spot-on-Kernel.exe will be turned on or off from
Spot-On’s program user interface.
4 - Connecting a Neighbor/Server IP
If the kernel is running, the user connects to a neighbor or
server with the appropriate IP and Port in the neighbors
tab.
5 - Key Exchange with a Friend
Then the user exchanges the key with a friend and the en-
crypted communication via chat or e-mail can begin… if
both have entered the key(s) of the friend.
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70
6 – Starting a Chat from the Chat Tab
If the key has been added, the friend appears in the chat
tab, and if a neighbor is connected, kernel running, and the
network set up, both friends should be able to chat and
communicate.
Let´s close the application after the wizard has been com-
pleted and let’s start again with this process – not with the
wizard, but with the login into the application after the wiz-
ard has been completed successfully: and look more into
the details and options within this above described process
to start a first chat. So let’s start again to go through this
above briefly proposed process in more detail:
5.2 Passphrase creation within the Wizard: Two
login methods & a virtual keyboard
If the user starts Spot-On for the first time, the user enters
a nickname in the corresponding box and defines a pass-
phrase for the login into the application (see figure widget
box “passphrase” – as explained for the wizard).
The password must be at least 16 characters long. If this
is too long, the user can repeat a shorter password three
times, such as “password_password_password”, but then
the password is not as secure as one with a random string.
First Set-up of the software Spot-On
71
Figure 23: Set Passphrase - if not the Wizard is used, it is found
in the settings Tab for kernel activation - here shown within the
GoldBug GUI
There are two methods to define this: the passphrase
method or the question-and-answer method. They can be
differentiated as follows:
Passphrase method: When the password is created, it is
not stored locally, just the hash of the input. The hash is
supplemented by a supplementary string, the so-called
cryptographic salt. This complements the hash and makes it
Spot-On.sf.net Encryption Suite - Handbook and User Manual
72
safer. The “Salted Hash” is thus defined as follows: hash
(passphrase + salt). To achieve that the password is also
trained for the user and typing errors are excluded, it must
be entered a second time.
Question / Answer Method: This method does not enter a
password twice but defines a string as a question and a
string as the answer. Both strings will not be checked a sec-
ond time. Technically, this login method is implemented via
a HMAC: Hash (Question, Answer), indicates that an
“HMAC” (Keyed-Hash Message Authentication Code) is
used. And: neither the question nor the answer is stored on
the user’s machine and no cryptographic salt is randomly
generated by the machine. Instead of the question, the user
can of course also enter two passwords without a question
mark. It should be noted that here the question and the
answer must be entered in subsequent logins exactly as
they were defined and here at the first definition no second
input check (“confirmation”) regarding typing errors is given
as in the password method.
Please note, that in Spot-On no password or question and
answer is stored on the encrypted hard disc container. Also
not via the ciphertext of it.
Figure 24: Authentication: Login to the application Spot-On
with a passphrase
Since the hash generated from the login passphrase unlocks
the encrypted containers that also store the private key for
encryption, it is especially important to protect the login
process and login password. Therefore, the above two
First Set-up of the software Spot-On
73
methods have been taken into account to make it more
difficult for attackers: they do not know a) which method a
user has chosen and b) the question-answer method is saf-
er, as described above, because neither the question, nor
the answer can be stored somewhere and a HMAC may be
more complex than a password as a “just” salted hash. Only
the user knows question and additionally the answer and
only the match of both can open the container.
Virtual keyboard: In order not to reveal information to
keypad loggers, there is the possibility to use a virtual key-
board when logging in (see image). The user starts this by
double-clicking on the input line for the password. At best,
only mouse clicks can be recorded here, but no keystrokes.
In principle, it is important that the private key is kept en-
crypted in a sufficiently secured container. It is reasonable
to suppose that, in particular, access by providers to mobile
operating systems would otherwise make it easy to fetch
the private key.
This is especially critical for web mail offers to provide
the encryption in the browser or with keys that are depos-
ited at and with the mail provider online. Encryption should
always take place on the user’s machine and for this login
procedure purpose. An open source client and no online
web application in the browser should be used for encrypt-
ing chat and e-mail.
Spot-On.sf.net Encryption Suite - Handbook and User Manual
74
Figure 25: Virtual Keyboard of the Spot-On application
The risk of seizing the possibly insufficiently encrypted pri-
vate key is far too great. Program audits should also pay
attention to capturing passwords for the encrypted con-
tainer in which the private key is located, as well as to re-
mote accessing the private key over the operating system
supplier or Trojan applications.
Even the few open source messengers with encryption
that can be counted on one hand for the desktop as well as
for mobile devices that have undergone a security audit are
hardly sufficient with regard to the security of the encrypt-
ed storage of private keys and their processes to access
these.
First Set-up of the software Spot-On
75
5.3 Generation of 12 Keys for Encryption
When the user launches the Spot-On application for the
first time, the wizard asks if the user wants to generate the
encryption keys. For key creation the user should choose a
key of at least 3072 bits (default for RSA) or larger. The user
can also choose other options such as algorithm, hashtype,
cipher, salt-length or iteration count, for example, if he re-
generates the key. The first setup has a presetting based on
RSA ready: So if the user wants to test out NTRU or
McEliece as an algorithm, then after the first setup the user
has to generate again new keys with one of the then se-
lectable algorithms.
The generated keys are stored in the sub-path “/.spot-
on”. If the user wants to set up a new login with new keys
and all user data should be deleted, then this path can
simply be deleted and the Spot-On.exe has to be restarted.
For Linux and the other operating systems the adequate
path specifications apply accordingly. The same can be
done in the main menu with “!!! Total_Database Erase !!! “.
Asymmetric keys are generated for the following func-
tions (a key for the encryption as well as a key for the (op-
tional) signature):
Chat Key: This is about the 1: 1 chat,
E-mail Key: This is about e-mail to other users of
Spot-On or any other Echo client like GoldBug or
other,
POPTASTIC Key: This is about the chat via e-mail
server,
URL Key: This involves searching for URLs in the
URL database (web search),
Public Library Key: This is a pair of keys reserved for
further implementation of sharing public files
out of a library,
Rosetta Key: With the Rosetta encryption pad, text
with a-symmetric keys can be converted back
and forth from plain text to cipher text and vice
versa before the texts are sent. This is recom-
mended when other insecure messengers or e-
Spot-On.sf.net Encryption Suite - Handbook and User Manual
76
mail applications are used or the cipher text
should be posted anywhere on the web - or the
plain text, before it is sent in Spot-On, should
again receive an additional encryption level!
That each function uses its own key pair is again a security
feature. If the (permanent or temporary) chat key were
compromised, the e-mail encryption will not be affected.
Furthermore, the user can only pass friends his chat key
and not the e-mail key. Thus, the user can decide whom he
allows to chat with or just to e-mail or possibly also to ex-
change URLs for the function of p2p web search in the inte-
grated URL database.
Also a minimal view on the user interface is possible: Via
the main menu one can choose between “full view” or
“minimal view”. If the user is not familiar with computers,
one should choose the minimal view because it fades out
the possibly unnecessary variety of options. Keep it simple:
The GoldBug Echo client is fully compatible with Spot-On
and provides an even simpler interface than the minimal
view of the Spot-On client.
Qt developers, and those who are looking for an exercise
project for their own Qt development or a university pro-
ject, may even minimize the user interface within their own
Echo Client (and are invited to “fork” the Spot-On client).
5.3.1 A posteriori Key (re-)generation: Switching
from RSA provided by the Wizard to McEliece
and other
During the first setup over the wizard, the option of the
maximum view is not available; it will only be shown and
set-able at the further logins. The possibility of looking at
even more details in the user interface should therefore be
addressed briefly here, since many details also refer to the
last-mentioned point of the cryptographic values for key
generation, which is also contained in the settings tabulator
for the kernel activation and generation of encryption keys:
First Set-up of the software Spot-On
77
Key-Generation e.g. with the McEliece algorithm is here to
be found.
The algorithm and values can be set individually for a
new key generation (after and without the wizard). Howev-
er, if the user is using the client for the first time, the typical
setting values are in the wizard automatically available, i.e.
the key has a (predefined) size of 3072 bits of the RSA algo-
rithm.
In case of a non-minimal view, for example, the tab “Acti-
vate Kernel” shows the following elements in the user inter-
face:
Path to kernel: Here the user can enter the path to the
kernel. If the kernel with the “spot-on-kernel.exe” in
the path specified correctly, then the path is highlight-
ed in green. Otherwise, the user has to look at the ex-
ecutable file of the kernel or copy it to the executable
file of the GUI (Spot-On.exe) or adjust the path accord-
ingly.
PID: The PID number identifies the process ID that
identifies the executable file in Windows. The user al-
so finds the process IDs in the Windows Task Manager.
“Key regeneration” function: With the “re-
generation” function, the user can also generate indi-
vidual keys - with new values and options. For this the
check box has to be activated, the values have to be
set and the respective keys have to be re-generated.
This is the way to get e.g. keys of the McEliece or
NTRU algorithm. Then the user has to put his new key
back to his friends, because the key is a kind of com-
munication ID for the cryptographic Echo-Matching.
Another variety of options can also be found under the
main menu / options in a pop-up window, which will be
explained later (for example to choose another icon set
(e.g. Nuvola instead of Nueve icon set).
Spot-On.sf.net Encryption Suite - Handbook and User Manual
78
Figure 26: Options for Display: e.g. change icon set
For now, it is more important to start the kernel after the
first key generation via the wizard has taken place.
5.4 Activation of the kernel
When the user launches the Spot-On application for the
first time, a pop-up window at the end of the wizard asks if
the kernel should be activated. Otherwise, the “Activate
Kernel” button in the settings tab should be pressed on all
subsequent starts after the login. Without a running kernel
no communication process is possible.
When the user closes the program interface, a pop-up
window also asks if the kernel should continue running. So
it’s a good idea to first deactivate the kernel and then close
the GUI of Spot-On if the user wants to completely close
the program.
First Set-up of the software Spot-On
79
Otherwise, the user runs the kernel without a GUI, which is
sometimes desired on a web server, so that nobody can
manipulate within the open user interface. (In addition to
the Spot-on kernel, there is also the Spot-on-Lite kernel for
this daemon web server purpose, which can be found in
the repository of the source code as a standalone reposito-
ry.)
Figure 27: Lock of the user interface in the status bar
If the user wants to leave the GUI in place, but no one
should be able to enter or change anything during the ab-
sence, it is also possible to click the “Lock” button on the
left in the lower status line: the user interface will close and
return to the login tab for the input of the password back,
so that the running processes and inputs of other tabs are
not visible. To unlock the interface, the user presses the
lock button again in the status bar and enters then the
passphrase(s) in a pop-up window.
Spot-On.sf.net Encryption Suite - Handbook and User Manual
80
Figure 28: Activation of the kernel in the Settings Tab
The user can also enable/disable the kernel by pressing the
first LED in the status line at the bottom left. If it is green,
the kernel is active; if it is red, the kernel is off. The middle
LED indicates whether the user has set up a listener / chat
server and the third LED indicates whether the user has an
active and successful connection to a neighbor / server.
Figure 29: Encryption between kernel and GUI and three LEDs.
The connection of the user interface (Spot-On.exe) to the
kernel (Spot-On-Kernel.exe) is also encrypted, although
both run on the same machine of the user. A tool-tip with
the mouse-over action over the first LED indicates the en-
cryption.
First Set-up of the software Spot-On
81
5.5 Connect a neighbor with the IP address
Upon initial activation, the IP address of the project chat
server (or a localhost) is automatically added as a neighbor.
This serves as a temporary chat server through which the
user can chat with his friend’s test-wise until a separate
connection node has been created on a web server or at
home (or two users connect directly to each other). The
test server will not last forever, so far, users will need to first
set up a server themselves before they can connect two
clients (see chapter server setup).
Up to now, the user has been connected to a chat server
directly after activation of the kernel by the provided test
server. If the user would like to add another, the tab “Con-
nect neighbor” must be used. Here is an input field for the
IP address of the neighbor respective the web server, on
which a Spot-On Kernel is running, or a friend also uses a
Spot-On instance with an accessible listener/server.
Figure 30: Creating a connection to a neighbor/server
In the field, enter the IP address of the neighbor node. The
points are each separated by three digits of the IP address
(according to IP-V4). If a block only contains two digits, e.g.
37.100.100.100, then the 37 can be placed arbitrarily in the
first block or entered as 37 in the first two positions. Then
the user presses the “Connect” / “Add” button. The IP ad-
Spot-On.sf.net Encryption Suite - Handbook and User Manual
82
dress is then stored on the default port 4710 and appears
as a link in the neighbors table.
Figure 31: Connected neighbors/ servers
If an error message appears, then this IP address has al-
ready been entered. In order to delete all neighbors, the
button “Delete all neighbors” can be pressed (via the con-
text menu button or via the right mouse button in the table
in which the neighbor appears) and the IP address can be
entered again. Optionally, the user can also delete the file
“neighbors.db” in the installation path “./spot-on” on the
hard disk. It rebuilds immediately and is then empty.
When the kernel is activated (left, first LED in the status
bar is green) and the neighbor or server is connected (mid-
dle LED is green) everything is successfully installed and
online. Entering an IP address and pressing the connect
button should be quite easy.
If the user wants to connect directly to another user
without a server, one of them must create a so-called lis-
tener in the tab chat server (and release the firewall for the
port and, if necessary, forward the port in the router to the
First Set-up of the software Spot-On
83
own machine, see below in the create server section in
more detail).
Or: if both users are on the same Windows network, the
existing neighbor “239.255.43.21” can be activated, then
the Spot-On Messenger is converted into a LAN messenger
and finds all other Spot-On participants in the local LAN
automatically and connects these as a neighbor. If the users
then exchange the keys, the communication can start.
By default, Spot-On uses the port 4710. Furthermore, the
program can also be operated via IPv6, as well as to a lis-
tener/server which is linked via the dynamic DNS-URL. Then
DNS is no number sequence for the IP, but a domain name
to be added in a textfield. Please choose then the DNS radio
button. Further security options can also be defined, e.g.
the connection to the server can be addressed via a proxy
(e.g. if the user wants to use Spot-On via the Tor network or
behind a firewall).
5.6 Key Exchange
How to copy the own key, how to exchange the key with a
friend and to paste the friend’s key into the application is
described with an example for the chat key within the next
chapter for starting a chat, which follows immediately. Let’s
just pint out the option to use an even more simpler inter-
face for the Spot-On-Kernel, which is called: GoldBug.
5.7 GoldBug: Alternative Graphical User Inter-
face (GUI)
Spot-On is a very detailed, customizable and for some
probably also a complex software. It requites some learning
about all the buttons and functions, like a pilot in an aircraft
also has many options and things to learn.
After the first setup has been done and before all the
functions of Spot-On are described at this point the hint,
that there is a second Graphical User Interface for the Spot-
On kernel, which has a reduced overview. This allows be-
ginners in practical encryption to start with a simplified in-
Spot-On.sf.net Encryption Suite - Handbook and User Manual
84
terface: called GoldBug. GoldBug is an own software compi-
lation based on the Spot-On GUI und code, with the differ-
ence, that it provides a simplified interface and the tabs are
in right east and not default on the top north like in Spot-
On. Thus, users who want to test a simpler graphical user
interface (GUI), can also try out the GoldBug client as a fur-
ther Echo application. GoldBug is quite popular in the web
and at download portals and can be found in the source of
the Spot-On source tree at Github.com and at the dedicated
website of Sourceforge.net:
http://goldbug.sf.net/
The name GoldBug derives from a historical situation: The
Gold Bug is a short story by Edgar Allan Poe: The plot is
about William LeGrand, who recently encountered a gold-
colored ladybug.
His buddy, Jupiter, now expects LeGrand to evolve in his
quest for insight, wealth, and wisdom after being in contact
with the Golden Bug - and thus goes on to another friend of
LeGrand, a narrator not further mentioned by name, who
thinks it would be a good idea to visit his old friend again.
After LeGrand then encountered a secret message and was
able to decrypt it successfully, the three start an adventure
as a team.
The Gold Bug - as one of the few pieces in the literature -
integrates cipher text as an element of the short story. Poe
was thus far ahead of the popularity of cipher texts of his
time when he wrote “The Gold Bug” in 1843, in which the
success of history turned to such a cryptogram and meta-
phorically to the search for the knowledge of the philoso-
pher’s stone.
The Gold Bug was a much-read story, extremely popular
and by the literati the most studied work by Poe during his
lifetime. His ideas also helped to promote the writing of
encrypted texts and so-called cryptograms.
Over 170 years later, encryption in the Internet age has
more weight than ever. Encryption should be a standard
when we send communications over the insecure internet -
W
ebsite of
the
GoldBug software,
which has a more
si
mplified Graphical
User Interf
ace for
the Spot-
On kernel
than the Spot-
On
application itself.
First Set-up of the software Spot-On
85
reason enough to use this name for this application and
therefore to remember the origins of the encrypted writing.
The GoldBug GUI is thus a historical tribute, which possi-
bly requires an adaptation to the term, because “bug” is
often understood in the IT context as an error correction.
Depending on the person, the idea of valuing a golden la-
dybug as much as another cuddly toy may require a strong
cognitive reorganization of a so far dominated worldview or
the routinized expansion of the appreciation of bug-finds as
interesting research finds.
Those who like exploring new things, openly approaching
what is found, will be able to learn and deepen many things
in cryptographic processes with this software application, if
so far no access to this “new territory” has been made pos-
sible. For teachers, the software is therefore an interesting
teaching tool that can introduce and test encryption in
practical implementation and exercises with playful testing,
reminiscent of the beginnings of popular cryptography at
the time.
Incidentally: The logo of the GoldBug logo is written in the
font “Neuland” (which means translated: new territory) - a
font that was developed in 1923 by the typographer Rudolf
Koch.
Interestingly enough, the logo has been an allusion to the
German ‘‘sentence of the year’’ 2013, when German Chan-
cellor Angela Merkel - in connection with the surveillance
and espionage affair in 2013 and the Listening to her per-
sonal mobile phone - in a conversation with American Pres-
ident Barack Obama coined the phrase: “The Internet is a
new territory for us all.” ..
.. - How long encryption for the subsequent student gen-
erations will remain a new territory (or ‘’Neuland‘’) or liter-
ally ‘secret science’ - or a kind of “seat belt”, which will also
convert e-mails to c-mails, decide the learners, teachers
and the media and technicians - but in any case everyone
(e.g. the reader of this manual) with the own friends with
whom this (or other) encryption software is used.
Spot-On.sf.net Encryption Suite - Handbook and User Manual
86
Figure 32: Logo of the GoldBug Crypto Chat Application
Questions and further Research & Development Fields
Set up the application without the Wizard and write a
description about the process.
Use Spot-On as a LAN Messenger and try to find other
nodes automatically.
Regenerate Keys with the McEliece algorithm.
The chat function with Cryptographic Calling
87
6 The chat function with Crypto-
graphic Calling
Now that the infrastructure is set up, that means: if login-
password is defined, key generated, kernel enabled and a
neighbor-server connected - so in the status bar two LED-
lights are green - then the user can exchange the own key
with a friend and the communication for a defined partici-
pant can start. Personal 1:1-chat takes place in the chat tab
or in the pop-up window (see figure, opened by a double-
click on the friend in the chat tab).
Figure 33: 1:1 chat in the pop-up window
1
:
1
p
e
r
s
o
n
a
l
c
h
a
t
has a share button
to send files
encrypted to a
dedicated friend.
Spot-On.sf.net Encryption Suite - Handbook and User Manual
88
But step after step: if the software is running and server-
connected, the key exchange is still the pre-condition to
start a secure chat. The key exchange is done over:
the “Copy public keys” button in the neighbors tab,
and pasting the key(s) into the pop-up-window for
“adding participants” - found under: Main-
Menu/Tools/Add-Participant.
6.1 Adding a friend by swapping and inserting
the keys
Spot-On uses a public/private key infrastructure, as it is
well-known in the case of encryption: The public key(s) can
be exchanged with friends and the private key(s) remain(s)
on the user’s hard disk in an encrypted container that is
opened (mounted) by the login password – and used for the
application runtime.
The user and the partner, both friends, must first ex-
change their public key, i.e. copy it out, transfer it and then
insert the friend’s key: Add participant and confirm (see
figure). The friend can send the key via e-mail or another
messenger. The user then copies the key into this window
and presses the “Add” button at the bottom.
The user finds the own public key in the neighbors tab.
The large button (“Copy Public Keys”) allows the user to
copy all own (or selected) keys to the clipboard. The user
copies the full text here and sends it to the friend. Likewise,
the friend does the same and the user inserts the friend’s
key in the “Add Participant”-textbox.
The main menu also provides a menu item to export and
import keys.
The chat function with Cryptographic Calling
89
Figure 34: Add Friend/Key
Optionally only as a note – IP transfer of the keys: it is also
possible to share a key over the direct IP connection (to a
friend or to a server). Then it may be necessary to confirm a
new friend as friend with the right mouse button in the
context menu of the friends list in the chat tab (make-friend
function). If a friend uses the Spot-On client and builds a
direct IP connection to another user with a Spot-On client,
then it is possible to transfer the key via a direct IP connec-
tion instead of copy/paste. The friend appears with his nick
T
h
e
o
w
n
c
h
a
t
k
e
y
consists of
ciphertext like data
and begins with the
letter K or R.
Spot-On.sf.net Encryption Suite - Handbook and User Manual
90
name in the chat tab (or e-mail tab) (with a different icon)
and can be confirmed as a friend with the right mouse but-
ton from the context menu: Make Friend.
This is a further development of the REPLEO function,
which is the function of encrypting the own key with the
friend’s public key (upon receipt) before the return trans-
mission starts. The key exchange over IP is thus automated:
a synchronization process follows. The user must agree that
the key will be displayed after synchronization via the
neighbor connection in their own client respective their
own friend list.
Further option - only as a note - Sharing via Echo Public
Key Sharing (EPKS) function: In addition to send the key
online via e-mail, another messenger, as a REPLEO or over
the direct IP-connection to a friend, the Echo Public Key
Sharing (EPKS) protocol, function and tool can also be used
(as also further described below). This is used if the friend is
not connected to a direct IP-connection (e.g. both partners
use a shared chat server or a node is in the middle). Both
partners then enter a common password secret in EPKS and
send their public keys to the Echo Network via this pass-
word protected EPKS channel. See the more detailed infor-
mation in the section of this tool, which may be a good al-
ternative to the often uncomfortable and insecure usual
key servers known from a PGP key exchange.
This innovation by a REPLEO, and the synchronization of
the keys via the so-called Echo Public Key Share function
(EPKS), or via an existing IP-connection, has later also been
taken up (copied) by other projects under the name Au-
toCrypt or KeySync. These functions are therefore based on
the REPLEO, EPKS and the key exchange via IP-connection
of Echo nodes. Autocrypt has been invented within the
Spot-On Project and been overtaken several years later by
other projects under the name AutoCrypt, e.g. using the
IMAP protocol for the key exchange.
However, the key sharing problems over PGP-key servers
have been avoided and differentiated with some alterna-
tives: The key(s) can be shared by copy/paste, can be ex-
E
P
K
S
=
Echo Public
Key Sharing,
later also known as
A
utoCrypt.
The chat function with Cryptographic Calling
91
ported, copied by menu and buttons, resent by a REPLEO,
and shared via EPKS and also shared via a direct IP-
connection or an IP-broadcast.
Furthermore, there is an even simpler way to share keys –
over the Group Chat function: two people create a Group
Chat Room within Spot-On, which is just based on the same
group room name. The Group Chat Room is provided in the
first tab, called Buzz, and will be explained in the next chap-
ter. The room name is quasi semi-anonymous, if only the
two users agree upon a secret room name. In this secret
room two users can share their public keys in privacy. As
EPKS channels and BUZZ rooms (which work on the same
principle of symmetric encryption) will be explained later
on, let’s have a short explanation of the REPLEO function in
more detail first.
6.1.1 Special feature: REPLEO – Encrypting the
public key
If the user has already received a key from the friend (e.g.
the chat key) and inserted it into the own client, but now
does not want to disclose the own public (chat) key to the
public, does not want to transfer and store it in an e-mail
program (although the public key may actually be public),
then the user can also encrypt the own public key with the
received key of the friend. This is called REPLEO. Hence, the
key is transmitted encrypted as soon as a user has already
received a public key of the other party.
This process then has to be carried out for each function
or key, i.e. the user can in each case send back the chat RE-
PLEO, the e-mail REPLEO and the URL REPLEO etc.. The
friend can also insert a REPLEO in the window for “Add Par-
ticipant/Key”. In older versions, above the insert-box, the
user just defines the radio-select-button: whether it’s a Key
(K), a REPLEO (R), or an e-mail address (E) the user would
like to add. Meanwhile, the K and R radio buttons in Spot-
On have disappeared because the client automatically de-
Spot-On.sf.net Encryption Suite - Handbook and User Manual
92
tects if it’s a (K)ey or a (R)EPLEO. The current versions have
an automated recognition of keys and REPLEOs:
The text of a key always starts with a letter “K” or “k” and a
REPLEO starts with a “R” or “r”. The user still can recognize
it if the key or REPLEO is copied out. So the user has in the
Add Participant window today the option to add a key or an
e-mail address (which is used within the e-mail functionali-
ty, explained further below).
6.2 Starting a first secure chat
A user finds the chat friend in the “Chat” tab after a suc-
cessful key exchange. For getting the chat to work, both
parties should ideally use the same and most up-to-date
version of the program, generate and exchange their keys,
and connect to a network node or chat server (neighbor)
on the web. When the first two LEDs in the status line at
the bottom are highlighted green and the friend’s name
appears in the chat tab, it looks excellent.
If the friend’s online status turns blue (absent), red
(busy), or green (ready to talk), the chat can start. Either
the user marks the friend in the table and chats out of the
tab, or the user double-clicks on the friend and a pop-up
chat window opens for that friend.
The advantage of chatting in the chat tab is that the user
can mark multiple friends so that the message reaches all
friends. If the user uses the pop-up chat (see figure), then
the user no longer needs to look at the marker to select a
friend from the friends-list in the chat tab.
And: In pop-up chat modus, the user has the button
“Share StarBeam”, with which the user can select a file
from the hard drive, so that it is then encrypted and secure-
ly transferred to the friend (see also the section below
about StarBeam-File-Sharing). This feature, which sends a
chat friend a file simply by a mouse-click, provides a fully
encrypted end-to-end transport. That is not included in
many closed or even open source applications. Encrypted
transmission e.g. of a ZIP with vacation pictures to own sib-
The chat function with Cryptographic Calling
93
lings becomes thus quite simple and is possible without the
use of a hosting or cloud platform in the Web.
Figure 35: Chat Tab
In the status line at the top of the pop-up window, the user
can see the nickname and online status and, for example,
launch the Socialist Millionaire Protocol (SMP) to authenti-
cate a friend and test whether the friend knows a common
secret and enters it correctly, as it will be described below.
Both users will be authentic if they enter the same pass-
word within this SMP process.
But before we explain the Socialist Millionaire Protocol
(SMP) for authentication - that means if the real friend is in
Spot-On.sf.net Encryption Suite - Handbook and User Manual
94
front of his or her machine and not a theft, who has stolen
the machine - let’s first have a look how to secure the end-
to-end encryption with Cryptographic Calling.
Cryptographic Calling sends out - over an already existing
secured connection - another temporary key, so that this
encryption layer is (solely) used (or additionally used). The
temporary key can be a-symmetric (PKI) or symmetric (a
password string also known as a passphrase).
Figure 36: Chat in the pop-up window with the SMP authenti-
cation option
The figure shows a
lock-symbol for a
successful SMP-
process for authen-
tication.
The chat function with Cryptographic Calling
95
6.3 Cryptographic Calling - additional security
feature invented by Spot-On
In the early development, Cryptographic Calling started
with one button. It was called MELODICA and described the
Calling over a long distance with multi-encrypted layers of
encryption. The MELODICA button performs the Crypto-
graphic Calling function.
Figure 37: The MELODICA Button since 2013
MELODICA Button
MELODICA stands for “Multi-Encrypted LOng DIstance CAll-
ing” – that means: “Multiple-Encrypted Calls over a Long
Distance”. The MELODICA symbol is therefore a piano key-
board as musical instrument and was first implemented in
GoldBug’s User Interface of Spot-On.
The Cryptographic Calling has been developed by the Spot-
On kernel project and secures the connection via an imme-
diately renewed end-to-end encryption by transmitting the
password via the a-symmetric connection of the Echo Pro-
tocol. Cryptographic Calling with the MELODICA button
means calling a friend like with a phone - only that it cre-
ates a secure end-to-end encryption.
The end-to-end passphrase - also known as Gemini
(Greek word for twin) - is mapped through an AES string
and should be kept secret between both parties. Therefore,
it is important to secure the electronic transmission always
very secure with further encryption levels (as here in the
Echo Protocol with the a-symmetric chat key and the
TLS/SSL connection), as the transmission can potentially be
eavesdropped.
Spot
-
On in
vented
the Cryptographic
Calling.
Spot-On.sf.net Encryption Suite - Handbook and User Manual
96
In the meantime, Cryptographic Calling has been elaborat-
ed in a great way and further methods have been added, so
that the term Cryptographic Calling (besides the historical
MELODICA button) has established and is used in Spot-On.
Other projects even overtook some years later the term,
which had been brought up by the Spot-On development
many years before, as it is proved by the code commits.
Cryptographic Calling
Cryptographic Calling is the immediate transfer of end-to-
end encrypting credentials to secure a communication
channel. Cryptographic Calling has been invented and intro-
duced by the Software Project Spot-On. It refers to sending
new end-to-end encryption credentials to the other partici-
pant through an existing secured online channel.
That means, a “Call” transfers over a public/private key en-
crypted environment e.g. a symmetric key (e.g. AES). It is a
password for the session talk, only the two participants
know. With one click a user can instantly renew the end-to-
end encrypting password for the messaging. It is also possi-
ble to manually define the end-to-end encrypted password
(manually or self-defined Calling in the sense of Customer
Supplied Encryption Keys: #CSEK). There are some further
different ways to call: Asymmetric Calling, Forward Secrecy
Calling, Symmetric Calling, SMP-Calling and 2-Way-Calling,
which will be explained later below.
The Calling with a-symmetric credentials refers to ephemer-
al a-symmetric keys, which are used for the time of the call.
This could be one session or even a shorter part of time of
the session. It depends on whenever a communication
partner starts to initiate a call. The asymmetric ephemeral
credentials for the call should be transferred over a secure
connection, which is either a symmetric key, over a a-
symmetric key (PKI) or over an already existent call-
connection, in this case an ephemeral asymmetric key.
“Cryptographic Calling” can even replace an a-symmetric
channel with a symmetric channel.
Cryptographic Call-
ing transfers over a
secure connection
new credentials for
a switch to a new
secure connection
with new creden-
tials. These can be
symmetric as well
as a-symmetric cre-
dentials.
The chat function with Cryptographic Calling
97
The following modes of Calling can be differentiated:
6.3.1 Asymmetric Calling
Spot-On has solved the end-to-end password transfer ques-
tion by encrypting the Gemini (the to be formed string for
symmetric encryption, e.g. the AES) a-symmetrically (using
the key for chat) and then encrypting again (a-symmetric)
the SSL/TLS channel, over which it is transmitted.
As said: Gemini is the Greek term for twin, meaning it re-
fers to both participants who should then know the pass-
phrase.
This function thus generates a “Cryptographic Call”, a call
in which the password is transmitted, which then later
forms the end-to-end encryption. Strictly speaking, the
Gemini consists of two keys or components, because the
Gemini is authenticated by another process: This further
component is also called MAC-Hash, as explained above.
The “Cryptographic Calling” as an executable Protocol
with the MELODICA button respective Call menu thus ex-
tends the old paradigm of Forward Secrecy as follows:
6.3.2 Instant Perfect Forward Secrecy (IPFS)
The user can now renew the (symmetric) encryption or the
Gemini at any time. This means that the paradigm of “per-
fect forward secrecy” has been extended by two compo-
nents: on the one hand, one can manually or automatically
define the end-to-end passphrase (the Gemini) and, on the
other hand, renew it immediately, i.e. “instant” at any time.
Therefore, we speak of “Instant Perfect Forward Secrecy”
(IPFS).
By comparison, many other applications offer only one
key per online session and the user cannot manually and
individually edit the symmetric end-to-end encryption
phrase.
The Instant Perfect Forward Secrecy (IPFS) here in Spot-
On uses a-symmetric encryption (of the chat key), whereby
I
P
F
S
:
Instant
Perfect Forward
Secrecy
Spot-On.sf.net Encryption Suite - Handbook and User Manual
98
the temporary key could be a symmetric key (the Gemini,
an AES string).
6.3.3 Symmetric Calling
Another option is Spot-On’s innovative ability to send a new
Gemini through the channel of an existing Gemini: Here,
the end-to-end key (that is, the symmetrically-encrypting
Gemini) is sent through another existing end-to-end Gemini
connection (i.e. channel of a symmetric key). The symmet-
ric encryption phrase (the Gemini or the AES password) is
therefore not encrypted with a-symmetric encryption (the
chat key) (e.g. with RSA, Elgamal, McEliece or NTRU) and
then sent over a secure channel (SSL/TLS) from point-to-
point, but it is itself encrypted with the existing (symmetric)
Gemini and then sent by the described Echo method (again
via SSL/TLS).
Compare the double-rachet method of the Signal-
Protocol, in which the key of the following message is in the
encrypted content of the previous packet: it may have been
ajar or derived from Symmetric Calling.
Thus, an A-symmetrical Call and a Symmetric Call can be
fundamentally differentiated. Symmetric Calls use an exist-
ing Gemini. Asymmetric Calls send the Gemini over the a-
symmetrically encrypted connection (namely the perma-
nent chat key) to the friend. Even when Calling over an ex-
isting Gemini, the sent Gemini can be instantaneously re-
newed at any time.
In sum: Secure end-to-end multi-encryption arises in the
Echo when an encrypting messenger encodes a manually-
defined symmetric key with an existing symmetric key and
then encrypts it with an a-symmetric key. And then this
package is sent through a secure connection. What’s a pre-
ferred hybrid concept?
6.3.4 Two-way Calling
Finally, in the context menu (right mouse-click on a friend
in the friend list), a third method for a so-called “Crypto-
The chat function with Cryptographic Calling
99
graphic Call” is added: Two-way Calling. Here, the user
sends an AES-256 as a passphrase for the future end-to-end
encryption to the friend, and the friend also sends an own
generated AES-256 to the first user in response. Now the
first half of the AES of the first user and the second half of
the AES of the second user are taken, respectively, and as-
sembled into a common AES-256. It refers to the method of
2-way safety.
Figure 38: Definition of Two-way Cryptographic Calling
Fifty-Fifty: Two-way Cryptographic Calling
Spot-On implements a plain two-pass key-distribution sys-
tem. The protocol is defined as follows:
1. A peer generates 128-bit AES and 256-bit SHA-512
keys via the system's cryptographic random number
generator.
2. Using the destination's public key, the peer encapsu-
lates the two keys via the hybrid cryptographic system.
3. The destination peer receives the data, records it, and
generates separate keys as in step 1.
4. The destination peer transmits the encapsulated keys
to the originating peer as in step 2.
Once the protocol is executed, the two peers shall possess
identical authentication and encryption keys. Please note
that duplicate half-keys are allowed.
This ensures that no third party - if someone succeeds in
compromising the friend’s machine - sends a Gemini (or an
old Gemini) in the friends name from a third, foreign ma-
chine (which is not really possible, since it would mean the
unnoticed acquisition of a machine or breaking the existing
TLS and RSA (or NTRU or Elgamal) encryption). The ping-
pong game of two participants in Two-way Calling ensures
that both participants are currently doing their part to
agree on a secure end-to-end password: Both define it Fif-
ty-Fifty.
Make it Fifty
-
Fifty!
Spot-On.sf.net Encryption Suite - Handbook and User Manual
100
Figure 39: Two-Way Calling in the context menu from the
friends-list
The possibility for the Gemini password
first, to be edited manually,
second, to be able to be renewed every second -
or within each call,
third, to send the password through an existing
end-to-end encryption,
and finally, being able to generate the end-to-
end encrypting passphrase in a two-way process
makes it very difficult for attackers to break the end-
to-end encryption of the Spot-On Cryptographic Call-
ing feature.
The chat function with Cryptographic Calling
101
Additionally (see below) the SMP-Calling authenticates the
sender for the Call.
“Perfect Forward Secrecy” (PFS) has become not only “In-
stant Perfect Forward Secrey” (IPFS), but (in this feature)
even a “2-Way Instant Perfect Forward Secrecy”: 2WIPFS.
This feature has significantly advanced PFS and the im-
portant element of instant end-to-end encryption with this
process implementation. The encryption itself is not new,
instead the process is sophisticatedly implemented to pro-
vide more security by Cryptographic Calling.
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102
6.4 Additional security feature: Socialist Million-
aire Protocol (SMP)
While Spot-On encrypts the messages three times -
on the one hand the message is indeed sent in a
secure TLS/SSL channel,
second, every message is encrypted a-symmetric
(e.g. with RSA-, NTRU-, McEliece- or Elgamal-PKI,
i.e. with the chat key),
and third, yes, it is possible to use the “Crypto-
graphic Calling” function to send a Gemini to set a
symmetric end-to-end encryption passphrase (as
seen with different methods to perform the “Call”),
Fourth, there is an additional security enhance-
ment mechanism: it is the “SMP” Protocol: Socialist
Millionaire Protocol (a method also described here
for off-the-record messaging (OTR):
https://otr.cypherpunks.ca/Protocol-v3-4.0.0.html).
The idea behind this is to ask a friend a question like: “What
is the name of the city we visited together last year?”; Or,
to ask a question like: “What is the name of the restaurant,
in which we met for the first time?” etc. (see figure).
Both participants usually sign the messages with a RSA
(or other) algorithm to verify that the key used is from the
original sender. But for the (possibly unlikely) case that a
machine would be hacked or stolen, or if the encryption
algorithm were broken, the Socialist Millionaire Protocol
(SMP) process can simply identify a friend by entering the
same password on both sides. It is important to ensure that
the password is not to be sent through the chat, instead
both friends should describe a situation that leads to the
same password. If the SMP process is tested for the first
time, the users can just enter the password “test” on both
sides (in lower case and without the quotes).
The chat function with Cryptographic Calling
103
Figure 40: SMP Protocol in the pop-up chat window
It is practically applied as follows: The user opens a person-
al pop-up chat window to use SMP and clicks the question
mark icon next to the user name on top of the chat win-
dow. Then a password is defined with the menu. Then the
chat friend is asked to enter the same password. Third, the
first user then finally clicks on the Verify button.
If both participants have set the same password - respec-
tive the same hash value has been generated from the
same password - then the question mark icon changes to a
“lock” symbol. The chat friend has now been authenticated
and the chat remains safe – in the sense of authenticated.
Please note, that the hash or password is not transmitted
over the secure connection! The process is based on a so-
called Zero-Knowledge-Proof.
SMP is thus another ideal way to authenticate the chat
friend with a shared secret in the live process, so it is not
additional encryption!
An example illustrates the calculation process of this Proto-
col as follows: Spot-On describes this so-called “Zero-
Knowledge-Proof” during SMP’s various data exchange pro-
Spot-On.sf.net Encryption Suite - Handbook and User Manual
104
cesses. Spot-On also uses the SHA-512 of the entered secret
passphrase as the x and y components. Let’s assume in an
example that Alice begins the exchange:
Alice:
1. Picks random exponents a2 and a3
2. Sends Bob g2a = g1a2 and g3a = g1a3
Bob:
1. Picks random exponents b2 and b3
2. Computes g2b = g1b2 and g3b = g1b3
3. Computes g2 = g2ab2 and g3 = g3ab3
4. Picks random exponent r
5. Computes Pb = g3r and Qb = g1r g2y
6. Sends Alice g2b, g3b, Pb and Qb
Alice:
1. Computes g2 = g2ba2 and g3 = g3ba3
2. Picks random exponent s
3. Computes Pa = g3s and Qa = g1s g2x
4. Computes Ra = (Qa / Qb) a3
5. Sends Bob Pa, Qa and Ra
Bob:
1. Computes Rb = (Qa / Qb) b3
2. Computes Rab = Rab3
3. Checks whether Rab == (Pa / Pb)
4. Sends Alice Rb
Alice:
1. Computes Rab = Rba3
2. Checks whether Rab == (Pa / Pb)
If everything is done correctly, then Rab should hold the
value of (Pa / Pb) times (g2a3b3)(x - y), which means that
the test at the end of the protocol will only succeed if x
== y. Further, since g2a3b3 is a random number not
known to any party, if x is not equal to y, no other in-
formation is revealed.
(See also the formulas in the documentation of the source
code).
The chat function with Cryptographic Calling
105
Zero-Knowledge-Proof
A zero-knowledge proof or zero-knowledge protocol is a
method by which one party (the prover) can prove to an-
other party (the verifier) that they know a value x, without
conveying any information apart from the fact that they
know the value x. The essence of zero-knowledge proofs is
that it is trivial to prove that one possesses knowledge of
certain information by simply revealing it; the challenge is to
prove such possession without revealing the information it-
self or any additional information.
If proving a statement requires that the prover possess
some secret information, then the verifier will not be able
to prove the statement to anyone else without possessing
the secret information. The statement being proved must
include the assertion that the prover has such knowledge,
but not the knowledge itself. Otherwise, the statement
would not be proved in zero-knowledge because it provides
the verifier with additional information about the statement
by the end of the protocol. A zero-knowledge proof of
knowledge is a special case when the statement consists on-
ly of the fact that the prover possesses the secret infor-
mation.
Interactive zero-knowledge proofs require interaction be-
tween the individual (or computer system) proving their
knowledge and the individual validating the proof.
Research in zero-knowledge proofs has been motivated by
authentication systems where one party wants to prove its
identity to a second party via some secret information (such
as a password) but doesn't want the second party to learn
anything about this secret. This is called a "zero-knowledge
proof of knowledge". However, a password shouldn’t typi-
cally be too small or insufficiently random is used in many
schemes for zero-knowledge proofs of knowledge. A zero-
knowledge password proof is a special kind of zero-
knowledge proof of knowledge that addresses the limited
size of passwords.
Spot-On.sf.net Encryption Suite - Handbook and User Manual
106
Figure 41: Socialist Millionaire Protocol (SMP) in the chat win-
dow to authenticate the chat partner
SMP therefore requires sharing a common secret with the
communication partner. This is described by SMP-
Cryptographic-Calling.
The chat function with Cryptographic Calling
107
6.4.1 SMP-Calling
Above, we explained the Call function of how to generate
and transfer a Gemini. A user can not only define the Gem-
ini manually or through the AES function, but it can also be
derived from the password used in the SMP process as out-
lined above. Thus, the password input from the SMP pro-
cess is used (not the SMP process itself). It is another way
of “Cryptographic Calling” and thus securely transmits to its
counterpart an end-to-end password that does not! origi-
nate from an AES generator this time - if someone doubts
the randomness of a machine number generator. Once the
basic functions of encryption in Spot-On are explained in
detail, the user can see, for example, the interconnected-
ness of the individual processes in this architecture and
encryption suite, here: how the SMP process is used to cre-
ate a secure end-to-end encryption. A zero-knowledge
proof to derive end-to-end encrypting credentials does not
transfer any key over the internet. That is the queen meth-
od of Cryptographic Calling. It can be multiplied within so
called Secret Streams.
6.5 Cryptographic Calling with Secret Streams
Figure 42: Definition of Secret Streams
Secret Streams
Secret Streams are a dedicated function within the Spot-On
Encryption Suite to provide a bunch of passphrases for end-
to-end encryption, which are not deriving from an AES
based on a random number generator but are built on a ze-
ro-knowledge proof provided by the same password en-
tered of two participants within the Socialist Millionaire Pro-
tocol (SMP) process. This not only authenticates both users,
but also provides derived passphrases on both ends, which
are not transferred over the web. The Secret Streams gen-
erate a stream of bytes via the secret within the SMP pro-
cess and the selected friend. The key sharing problem has
A
zero
-
knowledge
proof to derive
end-
to-end encrypting
credentials does no
t
transfer any key
over the internet.
That is the queen
method of Crypto-
graphic Calling. It
can be multiplied
within so called
Secret Streams.
Spot-On.sf.net Encryption Suite - Handbook and User Manual
108
been solved with Spot-On’s invention of Secret Streams
based on a zero-knowledge proof method. This way, a ran-
dom number generator of the machine (which could be
manipulated) is avoided, and also a possibly taped connec-
tion or keyboard cannot record any end-to-end encrypting
password.
Hence, if the SMP password is present, it can also be used
as a basis for other and more elaborated functions: The
Secret Streams function - relevant for Forward Secrecy not
only in chat, but also in e-mail - can be also derived from
this SMP process. Secret Streams - a bunch of verified zero
knowledge proofs generated by the SMP process - can also
be built on the successfully verified SMP password.
Figure 43: Secret Streams based on SMP Protocol
The chat function with Cryptographic Calling
109
6.6 Additional security feature: Forward Secrecy
(a-symmetric)
Spot-On is also supporting Perfect Forward Secrecy within
the function as an e-mail client, making it the first e-mail
client to offer Forward Secrecy for e-mail, with both, sym-
metric and a-symmetric Forward Secrecy.
While Cryptographic Calling with a Gemini for the chat
function has the “Instant Perfect Forward Secrecy” (IPFS)
and refers to a symmetric key (just the Gemini or the AES
string), the Perfect Forward Secrecy is for e-mail with tem-
porary, a-symmetric keys defined.
This variant of the use of temporary a-symmetric keys
can of course also be transferred to the chat function. And
this has been done since the release in 2015.
Figure 44: Definition of Forward Secrecy
Perfect Forward Secrecy
Perfect Forward Secrecy (PFS) is a feature of specific key
agreement protocols that gives assurances your session keys
will not be compromised even if the private key is compro-
mised. Forward Secrecy protects past sessions against fu-
ture compromises of secret keys or passwords. By generat-
ing a unique session key for every session, a user initiates,
even the compromise of a single session key will not affect
any data other than that exchanged in the specific session
protected by that particular key.
While chat with the permanent chat key is always (a-
symmetric) encrypted, a temporary a-symmetric key is now
used with this new layer of end-to-end encryption. This
temporary a-symmetric key is called an ephemeral key. This
key is created by the forward secrecy function in the chat,
which is displayed via the context menu (right mouse click)
or via the menu button.
A tooltip on the screen (in the systray) indicates when the
chat partner in chat has created a forward secrecy with
temporary (ephemeral) a-symmetric keys, so that the user
Forward Secrecy
means a compro-
mised key cannot
reve
al the user, as it
is a temp-key.
Spot-On.sf.net Encryption Suite - Handbook and User Manual
110
can confirm this in his client in a pop-up window. The user
looks at the bottom of the status line for the newly appear-
ing icon, clicks on it and can then confirm the forward-
secrecy process in the appearing pop-up window. Then, the
(temporary) chat key is no longer used, but the new, tem-
porary a-symmetric keys. The permanent chat key is thus
complemented by the temporary chat key.
Only few software applications understand end-to-end en-
cryption as a-symmetric and build forward secrecy via a-
symmetric encryption.
6.6.1 Forward Secrecy Calling
Thus, the Cryptographic Calling can be extended again: The
symmetric Gemini is sent in the Forward Secrecy Calling
(FSC) not as described above by the permanent (a-
symmetric) chat key or by an existing (symmetric) Gemini,
but by the new ephemeral, temporary and a-symmetric
chat key.
While sending a Gemini over an existing Gemini defines a
‘‘symmetric’’ “instant perfect forward secrecy”, sending a
Gemini over the ephemeral keys of the initiated “forward
secrecy” in the chat function may be considered an “a-
symmetric” one of “Instant Perfect Forward Secrecy”.
(While sending a Gemini via the permanent chat keys is
also called an a-symmetric “Instant Perfect Forward Secre-
cy”).
While “Forward Secrecy Calling” and “Call by a Gemini”
already have a “Forward Secrecy” and then define the re-
newability of the end-to-end key at any time (Instant Per-
fect Forward Secrecy), the other Calling Types are not with
Forward Secrecy given in advance. Instant Perfect Forward
Secrecy is generated here only by a call as a result of the
call.
The continuation of Forward Secrecy is called – to ab-
stract a bit more from MELODICA and Instant Perfect For-
ward Secrecy (IPFS) - Forward Secrecy Calling.
The chat function with Cryptographic Calling
111
6.6.2 Fiasco Forwarding & Fiasco Calling
Fiasco Forwarding should be mentioned here only brief:
Forward Secrecy has been developed to Instant Perfect
Forward Secrecy (IPFS, or even 2WIPFS) and this paradigm
has already been extended by Fiasco Forwarding (FF) within
the mobile Echo Client: Smoke. Here Fiasco Calling – as a
another further development of Cryptographic Calling - has
been introduced, which sends a bunch of keys to the friend
with one Call.
Then the recipient must try out over a dozen keys which
are sorted and tried out from newest to oldest.
This Fiasco Forwarding has not been yet implemented in
Spot-On Echo Client, as it was developed for the Smoke
Echo Client. It should be mentioned here in this context,
that even another Calling Feature could be established
structurally and is already coded into the Smoke Client,
which is also compatible with the Listeners/Servers from
Spot-On.
This is especially of interest to be compared with the Sig-
nal Protocol, which is more schematic and determines the
(one) key for the message in the last message sent out be-
fore and is not able to be steered by a manual action of the
user to send out a new ephemeral key or even a bunch of
these. A Fiasco for old-fashioned protocols? Multiplied po-
tential Keys for a Message.
6.7 Overview of the different Calling types
End-to-end encryption in Spot-On is as simple as making a
phone call - simply by pressing a button: just pick up or
hang up the phone. At any time, the communication re-
mains a-symmetric encrypted and the symmetric end-to-
end encryption can be easily added - and also renewed by
a-symmetric or symmetric encryption (within a TLS/SSL
channel). This is a new architectural implementation stand-
ard established by these methods of Cryptographic Calling,
invented through the development of the software applica-
tion Spot-On.
Cryptographic Call-
ing with Fiasco
Forwarding has
been implemented
in the Mobile Echo
Client of Smoke and
the referring Crypto
Chat Server Smoke-
Stack.
Spot-On.sf.net Encryption Suite - Handbook and User Manual
112
From the methods described to transfer an end-to-end
key to the friend, the following overview can be created,
which highlights the different methods with their respective
specific characteristics (see figure).
The call information - that is the end-to-end encrypting
passphrase (if not ephemeral PKI is used) - can of course
also be transmitted manually, e.g. verbally or by telephone.
If one adds the above-mentioned existing call types, it con-
cludes then in total in seven different ways to be able to
implement a call. For the first time, the Spot-On architec-
ture has spoken in the cryptographic discipline of “Crypto-
graphic Calling” in regard of the transmission of end-to-end
passwords. Later concepts have borrowed this term.
Figure 45: Overview of the different types of Cryptographic
Calling with respective criteria
Criteria
Asymmet-
ric Calling
Forward
Secrecy
Calling
Symmetric
Calling SMP Calling Secret
Streams
Fiasco
Forwarding
2-Way
Calling
TLS/SSL-Connection
YES YES YES YES YES YES YES
Permanent asymmet-
ric Chat/E-Mail Key
YES YES YES YES YES YES YES
Symmetric AES as
Gemini
NO NO YES NO NO NO NO
Half AES + Half AES
NO NO NO NO NO NO YES
Secret SMP Password
NO
NO
NO
YES
YES
NO
NO
Ephemeral/temp.
Chat/E-Mail PKI-Key
NO YES NO NO NO NO NO
Forward Secrecy as
Pre-Condition
NO YES YES NO NO YES NO
Instant Perfect
Forward Secrecy as
result
YES YES YES YES YES YES YES
Several keys as a
result
NO NO NO NO YES YES NO
Please note the following explanations:
Each of the presented methods results in Instant
Perfect Forward Secrecy (IPFS).
Only Symmetric and A-symmetric Calling requires
no action on the part of the other party.
Forward Secrecy Calling and Symmetric Calling re-
quire an existing status of Forward Secrecy.
‘Symmetric Calling’ and ‘Forward Secrecy Calling’
have triple encryption layers (TLS/SSL, Permanent
The chat function with Cryptographic Calling
113
Chat Key, as well as a temporary symmetric or a-
symmetric key through which the new Gemini will
then be sent).
‘SMP Calling’ and ‘2-Way-Calling’ break AES gener-
ation by replacing parts of the AES phrase and cre-
ating a new password string.
Secret Streams and Fiasco Forwarding provide a
bunch of potential temporary future keys.
The message formats with the encryption levels then look
simplified - since signatures, HMACs and hashes are not
included - as follows:
Asymmetric Calling: (TLS/SSL (Permanent Chat Key
e.g. RSA (message is an AES string)))
Forward Secrecy Calling : (TLS/SSL (Permanent Chat
Key e.g. RSA (ephemeral keys RSA (message is an
AES string))))
Symmetric Calling: (TLS/SSL (AES (Permanent Chat
Key e.g. RSA (message is an AES string)))
SMP Calling : (TLS/SSL (permanent chat key e.g.
RSA (message is a string formed from the SMP)))
Two-way-calling: (TLS/SSL (Permanent chat key e.g.
RSA (message is an AES string that is 50% modified
with friend’s AES)))
From this variety of options in securing end-to-end encryp-
tion or even defining and manually entering the end-to-end
encryption passphrase, the slogan, claim or headline has
emerged: “Your Instant Definition in Decentralized Crypto”
(as provided in the GoldBug GUI). The encryption is thus
not only a user-specific, which can be renewed (instant) at
any time, but also a decentralized at the user’s place and
machine - defined and designed by him- or herself.
A simple litmus test compared to other software applica-
tions is the simple question of whether the user can enter
the end-to-end encrypting password himself; or, if the user
can send a bunch of keys; or, if the user can use a zero-
knowledge-proof to create security besides the random of
Spot-On.sf.net Encryption Suite - Handbook and User Manual
114
the number generator of the machine. With Spot-On the
user can do all this (as well as with the mobile version of
Spot-On: Smoke Chat currently for Android).
6.8 Emoticons aka Smileys
Spot-On offers a variety of different emoticons - also called
smileys - for chatting (see figure).
Figure 46: Emoticon list in Spot-On Encryption Suite
To use the emoticons, the user clicks twice on a friend, so a
pop-up chat window opens for private chat. If the user now
moves the mouse over the Send button, the smileys are
displayed in a tooltip that appears. By entering the ASCI
code, the emoticons are then displayed in the chat.
In settings, the options also allow the user to turn off the
graphical display of smileys in general.
6.9 File transfer in the chat pop-up window
The Qt menu allows to remove individual menu parts from
the regular user interface and to create a pop-up window
for certain settings.
The chat function with Cryptographic Calling
115
Figure 47: Tear-off / hook-up of controls
Likewise, the file-sharing function in particular is integrated
in a pop-up menu: In the 1:1 chat window. So if a user
wants to send a file to a specific friend, the user can simply
click the button “share” within the pop-up chat window for
that friend.
The shared file as well as the text is transmitted securely
and encrypted to the friend. The file transfer feature is
called StarBeam and also has its own tab but is already built
into the 1:1-chat-window for easy and direct usability. Just
another little hook-up menu.
Spot-On.sf.net Encryption Suite - Handbook and User Manual
116
Figure 48: File transfer in the pop-up chat window
In general, the chat is easy to use with several ways for
Cryptographic Calling and end-to-end security of the con-
nection. The user can be authenticated with SMP and a file
can easily be shared over the secure connection within the
chat. In which other application can a file be sent over in-
stantly renewable end-to-end-secured connections over an
own encryption handling chat server?
Questions and further Research & Development Fields
Describe one method for Cryptographic Calling.
What`s the difference between Secret Streams and Fi-
asco Forwarding?
Describe the zero-knowledge proof in the SMP process.
What’s the advantage of IPFS?
File Sharing in an
encrypting messen-
ger is based on
frie
nd-to-friend
(web of trust) con-
nections. No one
can investigate the
fi
le, which
is sent to
a friend. That’s en-
cryption.
Group chat in IRC style
117
7 Group chat in IRC style
In addition to chat and e-mail and transferring files to the
communication partners, Spot-On Encryption Suite also has
also a group chat feature. This works like an IRC chat. The
transmission of the messages to all group participants is
again fully encrypted via the Echo Protocol. The encryption
is symmetric, similar to a password string. Finally, in the
p2p network or via the chat server, all subscribers can read
a group chat who know the particular symmetric end-to-
end key that defines the chat room. The group chat is also
based on the Echo Protocol.
Figure 49: The e’IRC group chat
Spot-On.sf.net Encryption Suite - Handbook and User Manual
118
It is therefore spoken of Echo’ed IRC (or in short e’IRC). That
opens new options for the IRC chat, since the transport
routes of the e’IRC chat are also encrypted.
As normal POP3 or IMAP e-mails today also have at least
one transport encryption, e.g. with TLS 1.3, IRC can also be
understood as an encrypted group chat. Also, the tradition-
al IRC chat can therefore learn from such security models
and improve: The e’IRC chat can represent a model of a
new group chat generation. Echo introduced and provides a
kind of transport encryption for IRC group chat.
The encryption details of the group chat are again de-
fined via a Magnet URI link (see below) (defined in the link
with extension &URN=buzz). Buzz is the technical name in
the source code for the e’IRC group chat.
To start the Spot-On group chat, open the as preset given
community chat room, which can serve as an example.
Here, the user can ask the other present users questions
about the program or just use this channel with a friend
(e.g. to exchange their public keys).
To join an own channel, the user simply enters a room or
channel name or uses the Magnet link method above. The
Magnet link has embedded additional values for encryption
in addition to the room name, such as key, hash or cipher
for the encryption type.
If the user enters only the room name and does not use a
Magnet URI, the additional encryption details are set to the
value 0000 and the encryption of the room is based on the
room name only. If the user has entered all the values or
the room name (or pasted the Magnet link), then the “Join”
button is just to be pressed.
If the user has inserted a Magnet as link, then in the pull-
down menu the command “de-Magnetize” should be used
first. The Magnet is then broken down into its individual
components and the room is created and entered based on
the encryption values embedded in the Magnet link.
If the room is open, the user can also save the room as a
bookmark or copy the corresponding Magnet-URI at any
time from this chat room as a bookmark and send it to
friends to invite them to the room.
Buzz Group Chat is
based on sym
metric
encryption: The
room name is the
passphrase.
Group chat in IRC style
119
Figure 50: IRC-style group chat within the e’IRC buzz channel
In order to send a message, the user then enters a text in
the chat room and presses the send button.
The Buzz or e’IRC chat room can be public or private, de-
pending on how much the user announces the Magnet or
the individual encryption values. As a public e’IRC chat
room, the user can post or link the Magnet-URI on the own
website and everyone knows how to get into that chat
room: with “de-Magnetize”.
Ultimately, it works for these news channels like an IRC
chat, only with the difference that the Internet provider
and other rooting servers cannot look into the communica-
Spot-On.sf.net Encryption Suite - Handbook and User Manual
120
tion, since it is encrypted - as a connection in online bank-
ing too.
So it does not make any difference whether a user is talk-
ing to friends or to the online bank advisor.
If the user wants to use the chat room as a private room,
the user can secretly share the Magnet-URI only with the
own friends and they stay on their own privacy. This is a
convenient feature of the Spot-On program: the user can
simply chat encrypted without first exchanging a-symmetric
(PKI) keys. The user simply tells his friend verbally that he
should come in Spot-On on a certain server in the room
“Amber Room” and both participants can very easily and
securely chat encrypted using a common chat server.
Tip: The user can create a one-time Magnet for a room.
This is used to protect his public chat key when exchanging
the key with the communication partner through the (self-
defined) IRC channel. It requires that the Magnet-URI is
only known to the friend.
With the REPLEO, with EPKS and the key exchange via an
one-time Magnet (OTM) for a private e’IRC group chat
room, Spot-On offers several methods for a secure key
transfer. Thus, public keys no longer have to be public!
(compare: Kerckhoffs's principle, Shannon's maxim). Let’s
foster and re-define or re-define and foster!
Questions and further Research & Development Fields
Define a Magnet for the Group Chat and let a friend de-
magnetize it.
Program a bridge in Qt, so that in Spot-On also regular
plaintext IRC channels can be read.
Try to bring a group chat window into the browser with
a Spot-On-Kernel connected to Python, Apache and fur-
ther tools like PHP or JavaScript.
A One
-
Time
Magnet is a link to
a
chat room (or to a
fil
e), which is ran-
domly composed
and used only once.
Smoke Mobile Chat Client
121
8 Smoke Mobile Chat Client
While Spot-On is a desktop client that is compiled and de-
ployed on numerous operating systems as well as platforms
such as Raspberry Pi, the mobile client of the Echo Protocol
is called “Smoke Chat” and developed in Java.
8.1 Smoke Android Client
Smoke offers a direct 1:1 chat to a friend as well as a group
chat. The group chat in Smoke is called FireChat and it is
similar and compatible to the Buzz/e’IRC group chat in
Spot-On.
The 1:1 chat of Smoke on the mobile device does not use
the phone number of the participants as an identifier, but a
short string, a so-called SIP hash, is used as an identifier.
Smoke users connect to a common server - this can be a
Spot-On, GoldBug, Spot-On-Lite, and SmokeStack server
listener - and then swap their public key over the SIP hash
connection, which is used for symmetric encryption of this
channel. SmokeStack is a chat server for Android and can
serve around 500 users on an Android device - ideal for a
workshop group, family or within school.
8.2 Fire chat to Buzz chat
Since Java and C++ programming do not know common key
formats from the crypto libraries, it is usually not possible
to use an open source Java client to chat encrypted to a C
++ client.
Smoke, however, has innovated and implemented a way
to do so: the so-called FireChat in Smoke can also be used
to reach a user in Spot-On and vice versa. This is based on a
symmetric encrypted chat (like a symmetric Crypto Call).
Spot On is c
oded
in
C++ wit Qt and
used on Desktops.
Th
e Android mobile
version is called
Smoke and uses
Java.
Group chat from
both clients is pos-
sible over FireChat
(of Smoke) and
Buzz-Chat
(of Spot-On).
Spot-On.sf.net Encryption Suite - Handbook and User Manual
122
Other applications mostly use the Java Script Crypto li-
braries for the browser or connect to a central server, but
these methods are generally considered to be less secure.
So if a user wants to use a mobile version of Spot-On for
the chat, this can be found in Smoke Chat and under the
concept description MOMEDO (both at Github:
https://github.com/textbrowser/smoke).
Offline Messaging in Smoke uses so-called Ozone-
Postboxes on the SmokeStack Server for Android. These
offline messaging postboxes will be also described in the
next chapter about e-mail and p2p e-mail postboxes.
Figure 51: Mobile Smoke Messenger with left-right chat layout
Questions and further Research & Development Fields
Define a Group Chat from FireChat of Smoke to a Group
Chat of Spot-On.
Essen
tial for mobile
encrypted Messag-
ing is not the GUI
of
the client, but the
option to set up an
own server.
Smoke uses the Ap
p
SmokeStack as
Server on Android
or a Spot-On-
Listener.
The e-mail function
123
9 The e-mail function
Spot-On is a fully functional e-mail client.
Not fully - like e-mail applications that have existed for
decades - here it still needs further programming from the
community, but fully functional in the sense of a fully usa-
ble e-mail client. The advantage: the reading and writing of
e-mails is shown very efficiently in the user interface on
one page respective in one tab (see figure). And: the emails
to other Spot-On users are always encrypted.
Spot-On uses technically the library CURL and supports
POP3, SMTP and IMAP. Finally, Spot-On’s special feature is
that it also supports p2p e-mail and p2p hosted mailboxes:
Here the e-mail is stored in the distributed network of the
participants and not at a central provider. With Spot-On,
users can very easily provide an e-mail server and com-
municate with it. The infrastructure is not only easy to in-
stall but can also be created by the user.
From a future perspective, this is also the (necessary)
progress, that users of the Internet organize the Internet
again more on their own and use cryptography within their
own encrypted mailboxes that are not deposited at central
hosters, but on their own network of participants.
Spot-On.sf.net Encryption Suite - Handbook and User Manual
124
Figure 52: E-Mail - read view (shown here in the GoldBug GUI)
After all, centralization is always followed by decentraliza-
tion, even though only the users, who recognize and value
this freedom, will pay attention to decentralization necessi-
ties and such remaining opportunities in the future.
Here’s how to set up the three ways to load own emails:
The e-mail function
125
9.1 POP3
The Post Office Protocol POP3 is a transmission Protocol
that enables a client to pick up e-mails from an e-mail serv-
er. POP3 allows you to list, retrieve and delete emails on
the e-mail server. For sending e-mails, additionally the Sim-
ple Mail Transfer Protocol (SMTP) is usually implemented in
clients and servers as a complement to POP3.
The POP3 Protocol is thus integrated in all popular e-mail
programs, including Spot-On. How it is set up next to IMAP
is explained below and also further below in the description
of the window of POPTASTIC (see the following pages).
9.2 IMAP
The Internet Message Access Protocol (IMAP) on the other
hand was designed in the 1980s with the emergence of
personal computers to resolve the e-mail storage on indi-
vidual client computers in the mail communication.
That is, the (PC) clients instead access the information
online on the servers and, if necessary, receive copies of it.
While a user of POP3 has lost all e-mails after losing his
or her PC (if e-mails on the server are not kept), a mail cli-
ent at IMAP only copies the requests to the server for the
information currently required.
For example, if a user wants to see the content of the in-
box folder, the client will get an up-to-date copy of the
message list from the server. If the content of an e-mail is
to be displayed, it is loaded as a copy from the server. As all
data remains on the central server, a ‘‘local storage of the
data’’ is unnecessary and extended possibilities such as the
search of mails are also performed only on the server side.
This also makes a local taking-over of the data - by taking
it away from the server - mostly impossible, as the configu-
ration of IMAP by default is not geared to it. At the same
time, the issue of confidentiality and security of data that is
outsourced to IMAP servers comes to the fore in the case of
unencrypted e-mail. The question arises as to whether the
Spot-On.sf.net Encryption Suite - Handbook and User Manual
126
recipient of an e-mail has jurisdiction over the confidentiali-
ty and storage of the e-mail itself, e.g. has the right not to
show it to anyone or to delete it in secret, or if the recipient
only has one copy, gets a “right of view” of the own mail.
However, and however the central delete of POP3 or
IMAP e-mails on a central server is defined, with regard to
the findings from 2013 – to better encrypt emails funda-
mentally - IMAP is to be judged particularly critically in this
light: The storage of emails is not made at IMAP as in POP3
in the mail client on the machine of the user, but the per-
sonal data remains mostly still unencrypted on the server
of the provider. With IMAP the cloud, which is widely used
today, was invented in the field of e-mail in the 1980s.
POP3 is more likely to enable on-premises handling of e-
mail storage on the local machine.
Spot-On supports both standards and makes it possible
to receive and send plain text messages via IMAP and
POP3. If data is encrypted in IMAP or POP3 postboxes, it
does not matter, which of both is used. Here’s how to enter
the settings for an e-mail account in Spot-On.
Detailed description of POP3 / IMAP setup options:
Via the main menu “View” of the Spot-On Encryption Suite
the own e-mail address and the POP-3 or IMAP server de-
tails are stored. These are the same details that are also
entered, for example, in the Thunderbird e-mail client or
Outlook, for example:
’’Incomming Server Server:‘’ pop.gmail.com Port: 995
TLS Username: mygmailname@gmail.com Password:
** **
’’Outgoing Server Server:‘’ smtp.gmail.com Port: 587
TLS Username: mygmailname@gmail.com Password:
** **
The user can press the test button to check the functionali-
ty of the server input. With the “OK” button then the in-
puts are stored.
(If the value “Disabled” is used in the selection menu in-
stead of POP3 or IMAP, the program no longer sends e-
mails: the mail function is completely switched off.)
Still it i
s better to
store even encrypt-
ed e-mails in the
local repository on
the own machine,
in case the algo-
rithm can be com-
promi
sed. Don’t
leave e-mail copies
on central servers,
even if they are
encrypted, if you
want to have exclu-
sive ownership or
priv
acy of it.
The e-mail function
127
Users who want to use the chat function described below
via the POP3/IMAP e-mail server (that is the POPTASTIC
protocol, see below) should therefore not deactivate the e-
mail information.
Figure 53: POPTASTIC: chat via e-mail server
According to the above security considerations, a user
should always load own e-mails right from the server onto
the own machine and delete the e-mails on the server, if
they are not encrypted. So, there seems to be much to talk
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128
about using POP3 instead of IMAP, as IMAP is more focused
on keeping emails on the server. A central repositorium.
In general, e-mails in this light do not belong to a remote
server, not into the cloud, not into a browser-based web
service - they are stored on the user’s own machine - or
they are in any case to be encrypted for such a temporary
postbox cache.
But the trend today is exactly the opposite: Central serv-
ers that store the messages, without encryption, without
own infrastructure in the hands of users define the main-
stream. This will last, until the trend reverses again, and
users will rediscover their own sovereignty. Spot-On offers
for this transition encryption for the old-fashioned e-mail-
post box caches (of IMAP and POP3) and also several meth-
ods to store e-mails in modern encrypted postbox caches
based on the peer-to-peer network.
9.3 P2P E-Mail: without data retention
Third, in addition to IMAP and POP3, there is the option of
using p2p e-mail in Spot-On. This means that the e-mails
are not stored or cached in a central server, but in the client
of a friend.
Regarding encryption, it has already been shown that the
e-mail function uses a different encryption key than the
chat function. So the user can add a friend to the chat, but
refuse the e-mail or vice versa. It makes sense, however, to
copy all the keys as a whole, then the user has his friend
present in all functions (so e.g. in addition the URL key, the
POPTASTIC key and the Rosetta key - several functions that
will be described in the upcoming chapters).
Of course, with the key transfer for the e-mail function,
the security of a REPLEO can be used again, if a user does
not want to reveal the own public e-mail key to the public.
No matter which e-mail method a user chooses, whether
POP3, IMAP or P2P, outgoing e-mails to cryptographic keys
in Spot-On are always encrypted, there is only one excep-
tion, that is if the user in the Add Participant Window does
not adds a Key (or a REPLEO), but chooses the selection:
To e
-
mail a friend,
use the e-mail key,
the POPTASTIC key
or the @-e-mail
address.
The e-mail function
129
Add E-Mail-Address. Then the e-mail program of Spot-On
sends unencrypted text from @ -mail to @ -mail.
Note: Anyone entering a POPTASTIC key will also see the
@E-Mail address in the contact list for e-mail, but it is color-
coded and also has a padlock icon, which means it will be a
POPTASTIC e-mail address (a key) – just used for encrypted
emailed - and also chat. After all, a key is inserted for POP-
TASTIC (and not an @-e-mail address). Only e-mails sent to
@-e-mail addresses that do not have a lock symbol remain
unencrypted.
To clarify again:
The user can use the following ways by e-mail
The e-mail key: This can send e-mails via POP3, IMAP
and P2P.
The POPTASTIC KEY: This can send chat via POP3 and
IMAP.
The @mail address: This can send unencrypted emails
from regular @mail addresses via POP3 and IMAP to
@mail addresses (not to keys).
Therefore, two Spot-On users can exchange encrypted e-
mails with normal @Mail, e.g. via the major e-mail provid-
ers such as Ymail, Gmail, GMX, Outlook etc. without any
further technical knowledge: either unencrypted via @-mail
addresses or encrypted as chat over the POPTASTIC key,
which will be explained later. And thirdly, the user can al-
ways use the e-mail key to send encrypted e-mails, includ-
ing p2p.
This is very comfortable in that it is enough to exchange
the keys once. So, it is not every single e-mail that the user
writes, to encrypt each time again individually (as previous-
ly practiced in other software procedures). Each @-mail
provider can now be exempted from viewing the user’s e-
mails by simply pushing encrypted cipher text over the cen-
tral server to the communication partner. What is needed is
the agreement with the friend that the friend also uses
Spot-On or one of the other Echo clients as an e-mail client
to exchange the keys only once.
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130
E-Mail attachments can also be attached to an e-mail as a
file and are automatically encrypted regardless of which
encryption e-mail method is chosen. This is also possible
with several attachments.
In addition to the discussion for the encryption of e-
mails, the meta-data is still stored in many countries, i.e.
when and how often a user retrieves the messages from
the own mailbox. Here is the alternative method of p2p e-
mails interesting: Spot-On also makes it possible to store e-
mails on the subscriber network (or on its own server) and
decentralize the corresponding e-mail inboxes, which also
exclusively and automatically handle the standard of en-
crypted e-mails.
The e-mail client thus also contains a peer-to-peer-based
component, i.e. the e-mails are sent over the network of
the encrypted connections and buffered in the nodes of
friends. This network is provided by the integrated architec-
ture of the Spot-on kernel. The advantage of p2p e-mail is
that the e-mail inbox does not reside with a central host
and public e-mail provider but can be set up in the decen-
tralized network of the user’s own friends.
With Spot-On everyone can easily set up an e-mail inbox
for own friends. Nobody can then log when and how often
a user retrieves own e-mails. The Echo Protocol also helps
to minimize metadata that reveals who has read which e-
mail and who is storing an e-mail for whom (since the
opening of the encrypted messages occurs exclusively on
the user’s machine and each node - according to the Echo
Protocol - sends each message to everyone).
How to set up a mailbox for friends is shown in the fol-
lowing section:
9.4 Setting up C/O: e-mail postboxes at a friend
The interesting thing about the Spot-On e-mail feature -
and here it may differ from other p2p e-mail implementa-
tions - is that it’s also possible to send e-mail to friends who
are offline.
There are three different methods for doing this:
3 ways to store
e
-
mails in the p2p net-
work:
C/O-function,
VEMI Institutions,
OZONE Postboxes.
The e-mail function
131
9.4.1 Care-Of method (C/O)
One method is to use a third, common friend to temporari-
ly store the e-mails there with this dedicated friend. So, if
Alice and Bob set up a common chat server on the web on
their web infrastructure, and all three of them have
swapped their keys, the web server (as common friend)
acts like an e-mail inbox, as we know it from POP3 or IMAP.
Figure 54: P2P e-mail from the postbox to a friend: C/O func-
tion (shown in the GoldBug Interface)
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132
Basically, the e-mails do not need central servers; it can also
be a third friend or a small Raspberry Pi computer at home,
which remains online. It therefore makes sense to have
more than one friend in the own list and to network friends
with other friends who can act for a caching. Since all e-
mails are encrypted, the friends who provide a cache func-
tion cannot read the user’s e-mail either.
Also, the e-mails are stored in encrypted databases. The
figure shows that even cipher text is displayed even when
viewing the structure of the database file.
Figure 55: Database encryption – file email.db
In order to activate this Care-Of (C/O) caching function, the
check-box “Care-Of” must be activated in the sub-tab “E-
Mail Settings”. If two friends are then connected to each
other and to the third friend and want to enable the cach-
ing of e-mails in their own clients, then all have just to in-
sert the other two friends in the own e-mail contact list.
The e-mail function
133
The Spot-On user can also choose to have the e-mails
sent authenticated or unauthenticated in the p2p e-mail
network, so they can simply be sent encrypted without evi-
dence that the key belongs to a particular user.
The Care-Of P2P e-mail feature is one of the simplest in
the software landscape for P2P e-mail at all. If three users
share a common Echo server and have added each other as
a friend, only the C/O feature needs to be activated, and
the e-mails are stored in the friends of friend’s cache, in
case they are offline. Nothing is simpler than this architec-
ture: The user only needs a few friends who want to partic-
ipate in this process for internal communication within a
group.
The second method is the establishment of a virtual e-
mail institution. This is great for people who like to equip
an entire community of friends with an e-mail inbox. It re-
quires a bit administration but the VEMI method for post-
boxes could replace IMAP postboxes in the future, as it
handles only encrypted e-mails.
9.4.2 Virtual E-Mail Institution (“VEMI”) method
For this it is also necessary to activate the C/O function with
the check box as described above.
Then the user can create a so-called “Virtual E-Mail Insti-
tution” (VEMI).
For the text and definition fields “Name” and “Address”
of the institution, the user can freely get creative and
choose any name. Then the public e-mail keys of the
friends who want to save e-mails in this institution are still
to be copied into this node.
Finally, the user can then copy out the created Magnet-
URI-link and make it available to friends who then tempo-
rarily store in that mailbox. (For the Magnet-URI standard
and what that is, see also below in the file transfer section
with “StarBeam”). In addition, please remember: the node
that sets up the e-mail institution must always also add the
public e-mail key of the user for which it is to save the e-
mails.
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134
The advantage over the first method is that the public e-
mail key of the node setting up the institution need not be
disclosed to anyone. With the C/O method, however, the
public e-mail key must be exchanged. Therefore, one can
easily say that in the small friends network a common node
with the C/O function is ideal and the VEMI method of set-
ting up Virtual E-Mail Institutions tends to focus on vendors
who want to set up mailboxes for a larger number of sub-
scribers.
Settings example:
Here is an example of how the C/O function and the VEMI
function, i.e. the creation of a virtual e-mail institution, are
implemented step by step:
The user activates the C/O function in the e-mail set-
tings tab.
The user creates an institution and chooses a name
and address for the institution.
Example: Institution-Name = “p2p mailbox” and ad-
dress = “Dotcom”
The user inserts the e-mail key of a friend into the
own client. The user then copies the available e-mail
Magnet from the own e-mail institution and has the
friends to paste it into their program.
The user recognizes an e-mail Magnet at his ending: URN =
institution. Then you know that the Magnet is not a buzz-
group chat Magnet nor a StarBeam Magnet for file sharing -
they would have the suffix “URN = buzz” or “URN = star-
beam”. The Magnet for an institution will look like this one:
Figure 56: URN = Institution (VEMI Method)
URN = Institution
Magnet: in = p2p mailbox & ct = aes256 & pa = Dotcom &
ht = sha512 & xt = urn: institution
The e-mail function
135
So, after adding the Magnet-Link for an Institution the re-
ferring node will cache the e-mails of the friends in the es-
tablished institution - if necessary especially for partici-
pants, which appear to be offline.
The user (as creator of an e-mail institution) does not
need to exchange his own e-mail key with the friends or
“subscribers” of this institution. The creator of an e-mail
institution can also exchange the e-mail keys of the friends
in a group chat room via e’IRC/Buzz. The exchange process
of key & e-mail Magnet does not have to impart any further
identities.
9.4.3 Ozone Postbox
Ozone Postbox is a method, which should be just men-
tioned here, as it is implemented in the application Smoke
and Smokestack Server, the first Echo applications for An-
droid. SmokeStack provides a Postbox for all users of this
mobile Echo Messenger, which is also compatible with the
Servers/Listeners of Spot-On. Currently Smoke is workable
with a Spot-On Listener/Server, but Spot-On has currently
no Ozone Postboxes, as they are only provided for the
Smoke Messenger Client in relation to the mobile Smoke-
Stack Server.
It will be up to further research based on customer and case
needs to compare the three messaging methods to offline
users: C/O, Institutions (VEMI) and Ozone Postboxes in their
optimal functionality and probably also add the IMAP/POP3
postbox method for the POPTASTIC Protocol (which might
have probably a bit of a delay in comparison to presence
messaging servers and their postboxes for offline appearing
users).
Next to IMAP and POP3 Postboxes now also further meth-
ods exist like C/O, Institutions and Ozone-Postboxes, which
are more related to encryption than the old storage op-
tions.
Ind
ividual, custom-
er-oriented a
nd
further research is
needed for the best
method to reach
other off
line users
over own commu-
nication server
s in a
p2p
federate-
able
network.
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136
9.5 Additional Encryption: Put a “Goldbug” on an
e-mail
Regardless of which transmission and cache method a user
chooses, whether POP3, IMAP or p2p, the e-mails are al-
ways encrypted using the public (a-symmetric) e-mail (or
POPTASTIC) key and the Echo Protocol for transmission.
This is also the case if e-mails are cached in an intermedi-
ate station such as a provider mailbox or a virtual institu-
tion or an intermediate node of a friend. Transport encryp-
tion and end-to-end encryption is consistent throughout.
As additional security for the e-mail function there is -
similar to the so-called “Gemini” for Cryptographic Calling
in chat-, now for e-mails the option to set a password on
the e-mail: Not only the alternative GUI for the Spot-On
Kernel is called GoldBug, but also the function in the e-mail
client to set an additional password on the e-mail is called
“Goldbug” (please note the different writing).
E-mails that have a “Goldbug” password set (see below
the description of the file transfer function “StarBeam”,
here the additional password is “NOVA”) can only be read
by the recipient if they have the appropriate “Goldbug“ - so
the user needs to know the golden key as a password. The
user should therefore inform the friends about the pass-
word to be entered if the user sends them e-mails that still
require an additional password in order to be opened.
This can be, for example, in the e-mails to the own wife,
that the user always encrypts the e-mails with the name of
the city in which the wedding or the wedding holiday took
place.
Again, as with the chat with the Gemini, and as we will
still see with file-sharing with the NOVA, the Goldbug Pass-
word is an important feature of symmetric and end-to-end
encryption for e-mail that the user can individually and
manually create for an end-to-end encrypting password.
In addition to the reminiscence of the short story by Ed-
gar Allen Poe about a cryptogram and his work for cryptog-
raphy in the early years of the beginning of industrialization
- the Goldbug on an e-mail is a new idea, next to automati-
If
you
like
it, put a
Goldbug on It.
Symmet
ri
c
Encryption:
Gemini for chat,
Goldbug for e-
mail,
Nova for file
transfer.
The e-mail function
137
cally encrypted e-mail created by the key exchange. It is a-
symmetric encrypted e-mail, but also with a symmetric en-
cryption: the Goldbug on an e-mail. It is another, hybrid
and multi-encrypting layer per single e-mail, as this process,
to touch each individual e-mail, is so far the standard
(elsewhere by PGP, but here additionally symmetric).
This process is done without additional encryption soft-
ware, which elsewhere must be additionally installed e.g. as
a plugin. Here, integrated within the e-mail client.
9.6 Forward Secrecy for e-mail
Using the included architecture of the Spot-on kernel, Spot-
On is one of the first e-mail programs in the world to offer
Forward Secrecy encryption, which can be both, a-
symmetric and symmetric for e-mail – so both methods
within one e-mail Program are supported.
Forward Secrecy means – just to remember - that tempo-
rary keys are used to transmit the end-to-end encrypting
password, so that if later an analysis should be made in re-
gard of the communication and the encryption, not the
regular (permanent) key for the communication is affected.
The user now sends the e-mail partner a session-based,
symmetric (forward secrecy) key via the usual a-
symmetrical encryption of the e-mail key (see figure).
S
p
o
t
-
O
n
i
s
o
n
e
o
f
the first e-mail pro-
grams to offer FS
Encryption with
both encryption
methods.
Spot-On.sf.net Encryption Suite - Handbook and User Manual
138
Figure 57: E-mail with forward secrecy
If the partner confirms the request and returns his tempo-
rary key, then both parties can use session-based a-
symmetric keys to further secure the e-mail communica-
tion. Incidentally, this method of a-symmetrical end-to-end
backup was not only integrated for e-mail, but also for the
chat function (see above: Forward Secrecy (FS) Calling).
The permanent public key is then used only to transport
the session-based keys - not to transport the message (or:
the previous message becomes the new key to the follow-
ing message). That is, the ephemeral (temporary) key is
shared with the partner via the permanent public e-mail
key. Then, if the ephemeral public key was correctly accept-
ed by a recipient, said recipient also generates an ephem-
eral session key (symmetric), which is then sent back to the
user via the user’s public key as well.
The initiator then deletes its a-symmetric ephemeral keys
as soon as the temporary session has ended.
The e-mail function
139
So, when a user writes an e-mail, Spot-On has four forward-
secrecy modes available to encrypt the e-mail:
Normal encrypted: The e-mail is sent as usual within
the encrypted system (Echo or POPTASTIC), that is,
the regular permanent symmetric e-mail key is used
to encrypt the message.
Forward Secrecy Encrypted: Regular encryption uses
session-based forward secrecy keys - that is, the user
sends session-based keys over the permanent e-mail
key channel and then encrypts his message with the
temporary keys. So, this adds to the message anoth-
er a-symmetrically encrypted level to the already ex-
isting e-mail encryption.
Pure Forward Secrecy Encrypted (“Pure FS”): The
message is encrypted and sent only through the us-
er’s session-based (ephemeral) e-mail key. The per-
manent e-mail key is thus not used in the “Pure FS”:
This can therefore also be called the “instant” option
within the e-mail process, that means it is immediate
(in the sense of volatile) and a kind of one-time e-
mail. This generates quasi mail-addresses and mail-
boxes in the sense of encrypted data packets - which
can be deleted after the session. This creates one-
time e-mail accounts thanks to Pure Forward Secre-
cy.
Goldbug encrypted: A Spot-On node sets as de-
scribed above a Goldbug password on the e-mail
(e.g. with an AES, symmetric encryption) and the us-
er must inform the e-mail partner about the pass-
word, ideally verbally. Just another layer: The thus
symmetrically encrypted message is then also sent
via the a-symmetric e-mail encryption (permanent e-
mail key).
If the user selects the checkbox option “plain” next to the
e-mail text, the e-mail is not written in HTML rich text
mode, but in plain text mode. Word plain text has nothing
to do here in terms of an antonym to cipher text.
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140
Again, with the following attention to understanding:
through the permanent (a-symmetric) key (for e-mail (or so
in chat) ephemeral keys (as a-symmetrical keys) are ex-
changed, which are then the basis for the use of end-to-end
encryption. That means, the ephemeral keys can be deleted
at any time after use and the communication is not tied to
the identities in the sense of permanent keys.
One should not be confused here, because even the end-
to-end encrypting symmetric passphrases are ephemeral
keys. But it becomes more apparent if only the a-symmetric
temporary keys which are pushed through the permanent
a-symmetric e-mail keys are initially referred to as ephem-
eral keys (so that this is not confusing to those who are
dealing with the forward-secrecy process or the word
“ephemeral key” for the first time).
The encryption levels in Forward Secrecy in the Spot-On
e-mail program can be described simplified as follows:
External encryption level: SSL/TSL connection,
Possible, additional encryption level: permanent
a-symmetric e-mail key (not with “Pure FS” - oth-
erwise: first-ephemeral-then-permanent),
Further level, which may later be deleted:
Ephemeral, temporary a-symmetric key (used on-
ly to transfer symmetric keys),
First encryption level via Forward Secrecy: Sym-
metric key,
Alternative first encryption level via a Goldbug
Password on an e-mail: Symmetric key via a man-
ually defined Goldbug on the e-mail. The mes-
sage format is thus: (TLS/SSL (AES-Goldbug (e-
mail message)).) According to Encrypt-then-Mac,
this can be called “Goldbug-then-Permanent.”
The Goldbug on an e-mail encrypts the text in the
envelope.
Temporary keys are not derived from permanent keys and
have no relation to them in the generation. Session periods
are defined manually by the user. This means that unlike
other programs, the session is automatically defined by the
online coming and going back offline, but the user himself
The e-mail function
141
determines when he wants to use new session-based keys.
Again, this can be anytime and “instant” (see above: IPFS).
The process or Protocol for forward secrecy within e-mail
can be described as follows with this example:
1. I send you my postal address. This is public.
2. You also send me your postal address. This is public.
3. Our addresses are permanent. These addresses
change only when we move.
Days later -
4. I make a unique envelope, an ephemeral envelope.
5. I send you, and only you, my unique envelope. Of
course, I use your postal address to send you this. We
assume, only you can read the written sentences. I
could also sign the draft with my signature.
On the same day -
6. You will receive my unique envelope and you will also
verify it by my signature, if you like.
7. You create a special letter.
8. You bundle the special letter into the unique envelope
I sent you.
9. Once you have sealed it, only I can open it.
10. You send the unique envelope back to my postal ad-
dress. Optionally you can of course also sign the creat-
ed bundle again.
Still the same day -
11. I receive your bundle. In this bundle is my unique en-
velope.
12. In my unique envelope that only I can open is your
special letter.
13. We use the special letter as often as we want … Once,
twice. Etc.
A set of session-based keys is sent back via the ephemeral
key. The first bundle is transported via the permanent keys.
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Permanent bowls do not have to be, but they do exist (be-
cause the SSL/TLS connection is still there). That is, the user
sends the ephemeral key (one way) over the permanent
key, and the partner returns the set of session-based (sym-
metric keys) via the ephemeral key.
At the end - after the log is completed - the ephemeral
keys are deleted and only the set of session-based keys re-
mains.
9.7 Secret Streams for e-mail
It has already been described as innovative in an e-mail
client, offering both a-symmetric and symmetric forward
secrecy. The new and so far uniquely implemented function
of the Secret Streams can be further appreciated as even
more innovative: Secret Streams are, so to speak, a list of
temporary keys generated by the password in the SMP au-
thentication of the Socialist Millionaire Protocol. The SMP
process has been extensively described above in the chat
section and can also be used for Cryptographic Calling.
And now, this breathtaking new feature of the Secret
Streams has not seen the world like this yet, is satisfying
users and getting used to companions within the market - if
that phrase is allowed - because it solves the key transfer
problem fundamentally: both users receive a password
known only to them in the SMP process through reciprocal
contextual clues or just on commonly known secrets. Once
this authentication has taken place, this password can also
be used to derive numerous temporary, ephemeral keys
that are the same in both clients, without them having to
be transmitted - because SMP authentication is the respon-
sibility of a so-called zero-knowledge process, we already
know.
The purpose of the SMP filter is to generate key streams
from a secret. The secret is mathematically negotiated
through the SMP process without it being transmitted as
such. Thus, the keys of the Secret Stream function are de-
rived from a zero-knowledge proof!
Mathematically
breathtaking:
Spot-On’s Secr
et
Streams as
a bunch
of keys bas
ed on a
zero-knowledge
process a
nd
there-
fore not transferred
over the internet
-
but derived
within
the elaborated
SMP
protocol.
The e-mail function
143
The function of the Secret Streams is available for chat, e-
mail and also POPTASTIC: Temporary keys, which do not
have to be transmitted anymore! Secret Streams should
represent a small revolution in cryptography, because the
password transmission problem would be partially solved.
Only the SMP secret - that was previously used for authen-
tication, not yet for encryption - is required.
Figure 58: Implementation of Secret Streams here for e-mail
9.8 Further research perspectives
It should be remembered that the permanent (or addition-
al) keys are transformed into transport keys, if temp-keys
should be used. If these are compromised, the encryption
Spot-On.sf.net Encryption Suite - Handbook and User Manual
144
becomes recognizable with still the other encryption layers.
This concept creates a creative research area within the
Echo Protocol environment. Here are some concept sugges-
tions that could be further incorporated:
Participants could consistently generate ephemeral (a-
symmetric) key pairs and exchange session-based (symmet-
ric) keys over the ephemeral keys. Participants would be
notified if there were not enough keys left. Replacement
(from ephemeral keys to permanent key or session-based
(symmetric)keys to (session-based) ephemeral (a-
symmetric) keys would then be automatically regulated …
similar to exchanging status messages via online status in
chat exchanged only over session-based keys in the Echo or
POPTASTIC Protocol. This is what Echo Client Spot-On estab-
lished with Secret Streams and the Echo Client Smoke es-
tablished with Fiasco Forwarding:
Instead of exchanging one set of private session keys,
multiple sets of private session bowls could be exchanged
for supplies. Retaining data differently for a variety of anon-
ymous e-mail addresses with session-based keys.
The OTR concept (so far for chat) could be applied within
the permanent keys and also for e-mail. POPTASTIC in a
different way, if chat goes via e-mail, then the chat key with
OTR can also be sent via e-mail. Now keys or a bunch of
keys mix functions.
By using unique keys, information transfers in a session
can be ideally protected - even if there are attempts to
compromise it. That means, forward secrecy offers a sub-
stantial improvement in the protection of encrypted trans-
missions for little effort and no cost.
After describing e-mail and its numerous options for im-
proved and innovated encryption, we come to the already
announced term POPTASTIC - the function of chat over e-
mail servers. As e-mail and chat is possible with this POP-
TASTIC key, temp-keys can here also be shared for chat and
for e-mail.
POPTASTIC Protocol - Encrypted chat (and e-mail) utilizing POP3 & IMAP Servers
145
10 POPTASTIC Protocol - Encrypt-
ed chat (and e-mail) utilizing
POP3 & IMAP Servers
POPTASTIC is an innovation in messaging: encrypted chat
over e-mail servers.
With the POPTASTIC function all e-mail accounts, e.g.
from Gmail, Outlook or Yahoo!-Mail can be encrypted a-
symmetric end-to-end with Spot-On - and additionally hy-
brid symmetric. The clou: every POP3 or IMAP server can
now also be used for encrypted chat. And that also through
firewalls when e-mail is given and going out.
Figure 59: POPTASTIC Protocol Graphic
Spot-On.sf.net Encryption Suite - Handbook and User Manual
146
Let’s take a closer look at the POPTASTIC protocol here at
the desktop client of Spot-On.
10.1 Chat over POPTASTIC
So why should a user still use a dedicated chat server or a
secure chat protocol with plug-ins for encryption, if the us-
er can just use the own e-mail address for e-mail and also
for chat at the same time? The multi-decade old POP3 or
IMAP Protocol and numerous e-mail servers can now be
used for encrypted chat with Spot-On. The e-mail server is
simply converted to a chat server. That’s an invention by
the Spot-On development.
For this, the chat message is converted into an encrypted
e-mail, sent via POP3 or IMAP, and the recipient is convert-
ing it back into a chat message. Since the Spot-On Messen-
ger is also an e-mail client at the same time, the encrypted
message exchange also works via e-mail. The program will
automatically detect if it is an e-mail via POP3 or a chat
message via POP3 (or IMAP).
Chat and e-mail through POPTASTIC are proxy enabled
and can therefore be operated from work, the university or
behind a firewall, even through the Tor network. If the us-
ers logs in to the own e-mail account with a web browser,
one can see what the encrypted chat message looks like
among all other e-mails.
The additional symmetric end-to-end encryption via
POP3 can - as with the Echo Protocol - not only be used as
forward secrecy, but can also be renewed “instantaneous-
ly” every second. Therefore, here too (as above) of Instant
Perfect Forward Secrecy (IPFS) is spoken, which is now pos-
sible via POP3 and IMAP for the POPTASTIC chat! Finally,
there is also the option in POPTASTIC of making a call for
the transmission of a Gemini using the methods differenti-
ated above.
This option variety of the chat encryption with POP-
TASTIC is not given so far also with the architectural deriva-
tives for mobile devices.
POPTASTIC Protocol - Encrypted chat (and e-mail) utilizing POP3 & IMAP Servers
147
However, for users surely an interesting and easy way to
chat encrypted via this special e-mail POPTASTIC Protocol.
10.2 E-mail over POPTASTIC
Just as there is e-mail utilizing the e-mail key and as to chat
over the POPTASTIC key, it is also possible to e-mail via
POPTASTIC. Since POPTASTIC is a key which the friend is
adding to the own client (via the Add-Participant-window),
the POPTASTIC contact or the e-mail address is provided
with a lock symbol and additionally marked with a back-
ground color to indicate that the message exchange here
always happens only encrypted.
If the user adds an e-mail address in the Add-Participant
window, that contact will also be added to the contact list
in the e-mail tab - but without the locked icon and back-
ground color. This indicates that the e-mail messages are
unencrypted with this contact (as it is @-e-mail). This is the
case if someone does not use the Spot-On client. Then the
mail program will send the e-mail unencrypted to the
@mail address (from the own @-mail-address – as long as
AutoCrypt is not applied).
The program knows: if the users mails from the POP-
TASTIC key to a POPTASITC key, then this is always encrypt-
ed and can also be chat. And if the user mails from the own
@-mail-address without the POPTASTIC key to an @mail
address, then the message is unencrypted. This is the only
and rare case that the client leaves the message unencrypt-
ed, since it does not use the Echo Protocol, but the regular
e-mail Protocol SMTP!
In any case: if the contact also uses Spot-On, both can
permanently e-mail encrypted when the POPTASTIC key is
entered in the Add-Participant window.
E-Mail via POPTASTIC is then a simple permanent en-
crypted e-mailing, by simply swapping once the POPTASTIC
key at the beginning.
P
O
P
T
A
S
T
I
C
encrypts data
over the
unencrypted SMTP
Protocol.
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10.3 Setting up POPTASTIC
A detailed description of the configuration options of the e-
mail server can be found above in the section on POP3 and
IMAP (see also figure).
Figure 60: POPTASTIC Settings: Encrypted Chat and Encrypted
E-Mail over POP3 and IMAP
Short Note for setting e.g. Gmail up for POPTASTIC
Note: In Gmail the user should set the option on the Web
that retrieved POP3 messages are deleted from the INBOX.
To connect, it’s also a good idea to set the security setting in
Gmail so that the user can connect to all local e-mail clients
(Gmail should allow unknown clients):
Settings / Forward and POP & IMAP / POP Download: Ena-
ble POP for all Mail
Settings / Accounts & Import / Change Account Settings:
Other Settings / [New window] / Security / Access for less
secure / unknown Apps: Enabled.
It may be advisable to set up an extra e-mail account for a
first test and further use: It may be important to note that
new e-mail accounts, e.g. for Gmail, may be limited to the
POPTASTIC Protocol - Encrypted chat (and e-mail) utilizing POP3 & IMAP Servers
149
first 30 days for the sending of e-mails (e.g. Gmail for max.
500 chat messages or e-mails per day). This should be suffi-
cient for a test or normal need if necessary.
Otherwise the user can set up an own e-mail server with
Spot-On and the user is no longer dependent on the @Mail
accounts of the major providers, if it is a small internal user
groups that use the Echo mail - represented here with its
own server need.
10.4 Further development of the POPTASTIC pro-
tocol
This idea of the POPTASTIC architecture has been devel-
oped by the Spot-On development team, published and
described also in the study “Big 7” by the auditors of the
program (op. cit 2016). Then this idea has been taken over
by the mobile application Lettera-Chat, though the encryp-
tion there also should runs soon via PGP and exclusively
only via IMAP server. Also, the Delta-Chat project has taken
it over. Commits show, that these projects have started
years later than the POPTSASTIC idea was published in the
Spot-on and GoldBug Software. The original commits and
publication data show the historical origins to these refer-
ences, and credits could be made in order not to seek the
proximity of any meaning of plagiarizing the POPTASTIC
architecture of this encrypted communication by following
projects†.
However, a fork and a progression of the POPTASTIC pro-
tocol idea (encrypted chat over e-mail servers) that is to be
welcomed (and referenced) if it’s in a mobile chat client
with an appealing user interface.
†
(See the release of POPTASTIC in 2014 and further publication in mid-2016
and its derivatives with first commits a few years later:
https://sf.net/projects/Spot-On/files/bigseven-crypto-audit.pdf (p134,
2016), https://sourceforge.net/p/Spot-On/wiki/release-history/ (2014), Let-
tera under http://gitbub.com/textbrowser/lettera and
https://delta.chat/en/blog (2016)).
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Figure 61: MOMEDO Analysis Report
The MOMEDO Analysis report:
Comparing Lettera E-mail & Chat Client
The MOMEDO Analysis Report (2018) has analyzed the ben-
efits of Lettera, Spot-On and Delta Chat in regard of their ar-
chitecture. While Lettera is pure Java development on An-
droid and uses the Java e-mail-lib by Oracle, Delta-Chat is
not only relying on many different libraries, which have to
be compiled, it also exists of one core and a GUI, which dif-
ferentiate with Java and C/C++. So, for developing it is more
difficult to choose such a complex application, in case it
should be forked. Lettera offers here a cleaner coding and
library use and will provide chat as well. The MOMEDO re-
port analyses the need to find a successor of WhatsApp in
consideration of the European Law of GPDR / DSGVO and
recommends several criteria to compare the first new mo-
bile applications based on the POPTASTIC protocol for chat
over e-mail servers.
Found at: http://momedo.github.io/momedo
Further development of the POPTASTIC protocol could be in
adding file sharing over it: As the e-mail friends in the client
found a friend-to-friend network (a kind of web-of-trust)
there is no malicious peer which can interfere. As the con-
nections are always encrypted, the idea is near the concept
of a mobile Retroshare.sf.net.
If Lettera would implement a kind of Turtle hopping
known from RetroShare over the POPTASTIC Protocol and
would send files over encrypted postboxes on e-mail serv-
ers from friends to friends of friends, then this results in a
secure way to revive a f2f Gnutella over e-mail servers. As
this is addressing the mobile world in the future, let’s focus
first on file-sharing within messaging on desktop clients,
using the Echo Protocol with Echo server and listener be-
side e-mail servers.
POPTASTIC Protocol - Encrypted chat (and e-mail) utilizing POP3 & IMAP Servers
151
Figure 62: GUI Screenshot of the Lettera Application (Android)
with also intended chat over e-mail servers
Source: https://github.com/textbrowser/lettera
Questions and further Research & Development Fields
Set up Spot-On as e-mail client and send an e-mail to
either the e-mail key, and the POPTASTIC key of a friend.
Look up an encrypted POPTASTIC chat message in the
regular e-mail client or web interface.
Test and develop the chat of two Lettera clients.
Investigate how file sharing in Lettera can be designed
and realized. Make a concept for a file sharing protocol
based on Turtle Hopping over POPTASTIC.
Discuss pro and cons of C/O, VEMI, Ozone Postboxes in
comparison and compare it also to IMAP/POP3.
Describe the concept of Secret Streams.
Encrypt an e-mail attachment with File-Encryptor.
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11 File-Sharing: with StarBeam
As in any messenger, a file transfer in Spot-On is also possi-
ble and in general this file-sharing function is always en-
crypted between two defined friends or even multiple peo-
ple. This happens in the tab “StarBeam”. The term Star-
Beam (SB) implies that File-Sharing should be as simple as
the light of the stars projected or “beamed” through the
galaxies.
While traditional file-sharing programs such as EMule or
BitTorrent have initially relied on specific links such as the
ed2k link or the torrent link, file transfers today have to do
with the linking of files using the Magnet-URI standard,
which is known from both, torrents and nearly all of the
more advanced Gnutella clients, even for the Edonkey net-
work it is established in the Shareaza client.
The elaboration of Spot-On and the Spot-On-kernel has
developed the architecture of this Magnet-URI standard
further and added cryptographic values to the Magnet-URI.
If the user now wants to download a file via Spot-On
from others, the user has to copy a Magnet URI link into the
program. And accordingly: If the user wants to prepare an
upload of a file, a Magnet-URI has to be created for this file.
This process includes encryption and is considered as
simple as possible: If the user is chatting with a friend in a
pop-up chat window (see images in the chat section), there
is a button “Share StarBeam”. The user can simply click this,
then select the file to be sent from the hard disk and it is
already securely encrypted transmitted over the Echo con-
nection to the friend.
File-Sharing: with StarBeam
153
Figure 63: Spot-On 1:1-chat pop-up window with file transfer
With this integration the user can easily and securely trans-
fer a ZIP with confidential contract documents to family
members or business partners via the chat window or the
StarBeam tab.
To send a file to an entire group, the user can also post
the Magnet-link into the group chat. This will then be au-
tomatically added to the downloads (see checkbox in the
menu options: Buzz / e’IRC-Chat: accept Magnets).
Because of the Echo Protocol, the individual packages are
also “swarmed”, i.e. the encrypted packets that pass by the
user, are even shared with friends and neighbors. They can
unpack and read it successfully if they have the right key.
The file-sharing StarBeam tab consists of three sub-tabs:
one for uploading, one for downloading, and one for creat-
ing or adding StarBeam Magnets.
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154
Figure 64: StarBeam with its three sub-tabs
11.1 Creating StarBeam Magnets with crypto-
graphic values
A Magnet-URI is a standard known from many file-sharing
programs (many in the Gnutella network) or for torrent
links and also corresponds to eDonkey / Emule ed2k links
(e.g., as given in the Shareaza client).
The further development of the Magnet-URI standard by
the Spot-On Encryption Suite lies in the design of the Mag-
net-URI with cryptographic values. Magnets are used to
create or hold together a bundle of cryptographic infor-
mation.
Between the nodes in the Echo Network is thus created
an end-to-end encrypted channel through which a file can
then be sent. However, any further file can be sent as well.
The Magnet is thus not associated with a particular file. The
StarBeam-Magnet is like a channel through which an in-
stance can continuously and permanently send files - or
there is a one-time Magnet created, which is deleted im-
mediately after the single use.
This architecture does not allow a Magnet to be associat-
ed with a single file or IP address. Also, a filename does not
appear in the StarBeam-Magnet (as it is the case even with
the also more advanced links, for example, from OFFSystem
or RetroShare compared to Gnutella, Emule, and Torrent
links). Thus, it becomes clear that no specific file is ex-
changed in StarBeam, but only encrypted channels are ex-
File-Sharing: with StarBeam
155
changed. A “wormhole”, so to speak, to stick to the popular
concept of the “Star Trek” movie. And this channel is de-
fined by a Magnet-URI link and its cryptographic values.
Figure 65: Magnet-URI standard with cryptographic values for
file transfer
While many opinions see the linking of Gnutella, Edonkey,
and Torrent links on the Web as critical, there is no reason
to scrutinize those values in a collection of encryption val-
ues. A homepage or independent portal with StarBeam and
Magnet-URI links present an advanced concept. In addition
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156
to the conceptual choices of selecting a link standard, the
usage aspect is also about the security of the file transfer
between two private users.
In summary: To send a file, an encrypted channel must be
created. This works with the creation of a Magnet, marked
at the end by the suffix “URN=StarBeam”. Then the file is
transmitted encrypted - packet by packet - over this chan-
nel using the HTTPS Echo Protocol (which can be based on
TCP, UDP, DTLS and also SCTP or even Bluetooth connec-
tions). It is therefore an interesting question for a practical
test, whether a transfer of a large, encrypted file via Star-
Beam via the Echo Protocol based on SCTP, TCP or UDP
connections is ceteris paribus transmitted error-free and
fastest?
For the process of private file transfer from friend to friend
some more notes:
11.1.1 Option “NOVA”: Encrypt the file before trans-
ferring the file!
Before the user sends a file, the user can consider whether
he simply attaches it to an e-mail within the Spot-On e-mail
function. This is the variant of choice if the file is smaller
than 10 MB. Larger files should only be transferred to a
friend via the StarBeam feature or in the 1:1-chat window.
Before transferring, the user may also consider encrypt-
ing the file on the hard disk (further encryption layer). To
do this, the Spot-On Software provides a tool for file en-
cryption, found in the main menu under tools (see the sec-
tion below: Spot-On-File-Encryptor). A double passphrase
encodes the file in it.
Of course, this tool, the Spot-On-File-Encryptor can also
be used if the user wants to upload a file somewhere to an
online-hoster within the cloud or transfer it via another
path, another messenger or any e-mail.
However, as these online hosting sites like Dropbox may
control files and mark encrypted files with a question mark,
even though it should be an exclamation mark, it makes
sense to transfer the encrypted file from point to point,
File-Sharing: with StarBeam
157
from friend to friend, directly via Spot-On and to use no
external or foreign intermediate caches as a host.
Some pack the files in a zip and encrypt it before sending
or uploading. However, zip encryption is very easy to crack
with 96 bits, so the user should use a key recommended for
RSA - today for RSA with at least 3072 bits, better even
more bits. And the user can also use the McEliece algorithm
instead of RSA, which is regarded more secure despite the
attacks known from fast Quantum Computing.
No matter how the user prepares and transfers the file:
(1) as a plain binary file, or (2) encrypted with the Spot-On
File-Encryptor tool via StarBeam or (3) as a file with an ad-
ditional NOVA password (see below) as a protection meth-
od in the Star Beam process - in any case, it will in turn be
encrypted several times using the Echo Protocol. However,
this architecture provides an optimum of encryption and a
variety of options, which cover numerous requirements.
Just like a user can put an additional password on an e-mail
(see above, called “Goldbug” in the e-mail function), the
user can also set another password on the file - respective
on the used Magnet-URI for the file transfer: This is called
“NOVA”.
Figure 66: NOVA Password on file transfers
The NOVA Password on file transfers
Optional: A NOVA password for the additional encryption of
the file: Finally, the user can still decide whether he wants
to put on the transfer an additional password - as described
above: a “NOVA”. The friend can open the file only if he en-
ters the NOVA password. It is an additional symmetric en-
cryption to secure a file transfer.
Then the user presses the “Transmit” button.
(Tech Note: Since the Echo is transmitted as HTTPS Post or HTTPS
Get, the transfer is the same as a web page. The chunk size can be
left as predefined, as it is in the minimum view Spot-On interface
hidden. In case the pulse size is made larger, the web page being
transferred becomes longer, so to speak.)
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158
Even if the file transfer is successful or even a third un-
known party could crack the previous multiple encryption
(which is not to be assumed), the NOVA password introduc-
es end-to-end encryption, which is secure as long as the
shared password is exclusive to both partners.
Because, if the transmission of the StarBeam-Magnet
should be intercepted - the user somehow has to transfer
the Magnet online to his friend - then anyone who knows
the Magnet can also receive the file as well. Therefore, it
makes sense to protect the file with a “NOVA” - a password
that both friends have exchanged, possibly orally, in the
past or via a second channel.
The NOVA is also built on the end-to-end encryption
standard AES (that means the password string is generated
by the computer, if the user does not think up his own
passphrase).
As mentioned, the ability to create an own end-to-end
encrypting password yourself and manually enter it – is
known in the science as “Customer Supplied Encryption
Keys” (#CEKS) – it is so far implemented only in a very few
applications such as Spot-On Encryption Suite or Smoke
Mobile Crypto Chat.
And please note: The NOVA must have been deposited in
the node of the recipient - before - the file transfer begins!
11.1.2 Using a one-time Magnet
Ideally, the user has his own Magnet-URI for each file. That
would then be a one-time-Magnet (OTM), a Magnet that is
used only once for a file. (OTM is the same as the idea of an
OTP - a one-time pad: a string that is used only once.) OTP
is often considered essential in cryptographic processes to
provide security.)
The user can also use a Magnet permanently, then it is
like a subscribed video channel in which, for example, a
new file is sent every Monday.
This also opens completely new possibilities for torrent
portals, for example: there does not even have to be a web
portal in which thousands of links are linked! The portal
File-Sharing: with StarBeam
159
itself needs only a single Magnet in a decentralized net-
work, then consecutively, one by one, it is possible to send
one file after the other through the wormhole. (It would be
even possible to send a magnet (in a text file) through the
channel of a file-transfer magnet. This would add forward
secrecy to file sharing.)
As soon as the user has transferred a file via the Magnet,
the user can delete or retain the Magnet-URI. If the user
creates the Magnet as an OTM and activates the checkbox
for OTM, it deletes itself after file transfer. This is similar to
the movie Mission Impossible or apps for pictures where
messages and pictures destroy itself - The Magnet is, so to
speak, a StarBeam wormhole that closes again after a single
use.
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11.1.3 Overview of Magnet-URI standards for crypto-
graphic values
The following overview explains the usual cryptographic
values in the Magnet-URI standard.
Figure 67: Cryptographic values for the Magnet-URI standard
Abbreviation Example Description
rn &rn=Spot-On_Developer_Channel_Key Roomname
xf &xf=10000 Exact Frequency
xs &xs=Spot-On_Developer_Channel_Salt Exact Salt
ct &ct=aes256 Cipher Type
hk &hk=Spot-
On_Developer_Channel_Hash_Key Hash Key
ht &ht=sha512 Hash Type
xt=urn:buzz &xt=urn:buzz Magnet for IRC Chat
xt=urn:starbeam &xt=urn:starbeam Magnet for filetransfer
xt=urn:institution &xt=urn:institution Magnet for the virtual E-
Mail-Postbox
This standard is used to exchange symmetric keys for group
chat or e-mail institutions or even file transfers with Star-
Beam.
Figure 68: Example of a Magnet-URI with cryptographic values
(here for a group chat channel)
Magnet-URI with cryptographical values
Magnet:?rn=Spot-On_Developer_Channel_Key
&xf=10000
&xs=Spot-On_Developer_Channel_Salt
&ct=aes256
&hk=Spot-On_Developer_Channel_Hash_Key
&ht=sha512
&xt=urn:buzz
File-Sharing: with StarBeam
161
The Magnet-URI standard has been further developed into
a format to pass on encryption values similar to a blood
count sheet. Encryption with very individual DNA-values
provide the highest possible security. They are bundled in
the Magnet-URI.
11.1.4 Rewind function
If a recipient has received a file packet, a chunk (or in the
Spot-On kernel also called “link”), the user is able to upload
it again - even in other Magnet-URI channels. - Or the file
can be sent again into the same URI channel. This is similar
to a rewind function: the file is simply played again via the
Echo Network - like on a cassette recorder or MP3 player.
The file can also be sent many hours or days later. Anyone
who has received a copy via the Magnet-URI channel be-
comes a satellite, and can re-import the data into the de-
fined channel, or better, via a StarBeam Magnet.
11.1.5 Comparison with Turtle-Hopping
Turtle-Hopping (see Glossary and: Popescu et al. 2004,
Matejka 2004, as implemented in RetroShare) will pass the
file packages from friends to friends until they reach a de-
fined destination. It is a transformation of a peer-to-peer
(P2P) network into a friend-to-friend (F2F) network. How-
ever, it might have the consideration that friends with little
upload speed to the next friend in the chain form a bottle-
neck and slow down the transport:
The Turtle-Hopping Protocol is first connected only to
nodes that have been defined as friends and here in this
chain of friends can be a friend, which performs only with a
small bandwidth. This then could act as a bottleneck and
senders and recipients of the file must necessarily send
through this bottleneck.
The transmission of a file in the StarBeam function via
the Echo Protocol is therefore probably (to be practical
measured) also more effective than using a Protocol similar
to “Turtle-Hopping” (currently only implemented in the
T
h
e
b
o
t
t
l
e
n
e
c
k
in a Turtle Hoppin
g
chain is a user wit
h
low bandwidth.
Spot-On.sf.net Encryption Suite - Handbook and User Manual
162
RetroShare program), because here, depending on the de-
sign of the Echo Network (Full Echo, Half Echo, Adaptive
Echo) the nodes with low bandwidth do not have to act as a
bottleneck, they optimize the desired download speed via
other Echo paths.
When sending files via the Echo Protocol, therefore, oth-
er nodes such as peers or paths via other graph-options can
be included in the hopping over intermediate stations if
there is a faster route somewhere:
The Echo Protocol automatically creates the flow in the
network of nodes (simply by allowing each node to send
encrypted file packets to each linked node) and therefore
also chooses the fastest path of all possible graphs to the
desired node. A practical measurement must be defined
and tested though.
11.2 StarBeam upload: transferring a file
As described above, sending a file from the chat window to
a single friend is very simple: with the Share-StarBeam but-
ton the user just have to choose one file and it will be
transferred to the referring friend.
In the following, we now look at the upload process with its
technical details in the sub-tabulator “Uploads” of the Star-
Beam tab.
If the user has defined and generated a Magnet-URI, it
will appear not only in the sub-tab for the Magnets, but
also in the table in the sub tab for the upload/seed.
Hence, from here the upload of a file can be started. To
do this, the user selects with the check box a Magnet in this
sub-tab for the upload. Likewise, the file is selected.
File-Sharing: with StarBeam
163
Figure 69: Starbeam file transfer: uploading files
Finally, the user copies the Magnet-URI and sends it to his
friend. The user can copy the Magnet URI via the context
menu button.
If the other friend has pasted the Magnet into the own
instance, the user can start the transfer by deactivating the
pause function (check box “Pause” in the table).
Then the file is transferred to the friend.
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11.3 StarBeam downloads
As written above - it’s the other way around from the per-
spective of the receiver of a file: To load a file with Star-
Beam, the user needs the StarBeam Magnet of the file. The
user receives this from the friend, who wants to send a file.
The user then simply copies the Magnetic URI into the
sub-tab for the Magnetic URIs. Before that, the user should
activate the checkbox “Receiving” in the download sub-tab.
This is deactivated in advance by default, so that no un-
wanted files are received.
The user then tells the friend that he has inserted the Mag-
net URI and then the friend can start the transmission. The
download starts as soon as a transmitter sends the file via
the Echo and through the cryptographic channel of the
Magnet.
With the additional settings on this tab for the upload,
the user can still define the size and the path for the down-
load area.
Successfully downloaded parts are called “Mosaic”s with-
in StarBeam and stored in the same path of the installation
on the hard disk. Similar to a puzzle, the mosaic pieces are
assembled into a full mosaic, the resulting file.
The still-to-be-transferred file parts are called “links” in
StarBeam (see also the term “chunks” in the old EDonkey
network or the term “blocks” in the Gnutella network,
which was coined by the use of the then there used Tiger–
Tree-Hashes).
File-Sharing: with StarBeam
165
Figure 70: StarBeam File Transfer - Incoming Files
11.3.1 Tool: StarBeam Analyzer
If a file was not successfully transferred 100%, it can be
checked with the StarBeam Analyzer tool. This determines
if all mosaic parts are present or if any links / chunks /
blocks or packages still to be transferred are missing. If any
Spot-On.sf.net Encryption Suite - Handbook and User Manual
166
links are missing, the SB Analyzer will create a Magnet URI
that the friend can re-enter in his upload tab. Then only the
missing links or mosaics are sent again.
Figure 71: File transfer using StarBeam: Analysis tool for the
chunks
The file would also complete if the sender sends it three
times a day over the Echo with the “Rewind” function.
It should be noted that a Magnet is a channel, and exist-
ing files in the local mosaic path will then be renewed if no
One-Time-Magnet is used and they are sent again in the
same channel. A renewed shipment of the file by the up-
loader will thus overwrite the file received by the user
again - if the user has not set a lock option in the transfer
table. The checkbox “Lock” then would not allow to delete
the file that the user received.
File-Sharing: with StarBeam
167
11.3.2 Outlook for Cryptographic Torrents
Because of encryption, nobody can see what file a user is
downloading, because nobody knows if the user was able
to successfully decrypt the package - and even if, nobody
knows if the user created or saved the file in total from it.
The upload is similar. The upload is only visible from a
neighbor IP, if this neighbor knows the Magnet of the file.
In this case, if the user wants to load public StarBeam Mag-
nets, it is best to connect only to neighbors or chat servers
that the user trusts or has define as friend through account
access.
Also, the above-mentioned variant of setting a NOVA
password on the file and the distribution of the physical
blocks in time before granting the access rights to the NOVA
password in a second process can offer new perspectives in
technical, procedural or even legal considerations.
This means e.g. that the transfer of the file takes place in
the past and the transfer of the decryption option with the
NOVA password takes place in a future, separate and down-
stream process.
Then, using the Echo Protocol, StarBeam Magnet-URIs
can play a role in new ways of thinking about developing
and using “crypto-torrents” discussed in the file-sharing
community.
Encryption basically means that unauthorized persons do
not know what is in the encrypted packet and that the
owner of the key decides himself when to perform the de-
cryption. That is, encryption has been logically applied to
the file transfer and the sovereignty of the user.
Questions and further Research & Development Fields
Test the speed of a file transfer over TCP versus SCTP.
Transfer a file with a one-time Magnet.
Compare Cryptographic Torrents to regular tracker-
based Torrents.
C
r
y
p
t
o
g
r
a
p
h
i
c
Torrents are base
d
on the Magnet-URI
-
Scheme with
cryptographic
values.
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12 Open Source web search engine
with encrypted URL database
With the integrated function of a web search Spot-On is
also an open source p2p web search engine due to its used
architecture of the kernel.
Spot-On is the only (and so far) one of the few handiest
p2p distributed search engines like YaCy, Arado.sf.net or
Grub (which was once known by Wikia-Search), which is
able to handle the transfer of the URLs over encrypted con-
nections into a distributed F2F or P2P network.
The idea of the web search function in Spot-On is not on-
ly to offer an open source programming of the search en-
gine or the sorting algorithm, but also to handle the reposi-
tory of URLs open source, so that each participant can
download the entire URL-Database. Third, finally, transfers
and database storage take place in an encrypted environ-
ment. An innovative and exemplary model for search in
encrypted databases (that means within cipher text).
Website titles, keywords and the URL itself are stored en-
crypted in a SQLite or PostgreSQL database and linked to-
gether via the Echo Protocol (or via the PostgreSQL net-
working and cluster function).
A user can use a crawler or RSS feed to store own web
pages and URLs in a searchable database repository and
share them with other nodes.
Spot
-
On We
bse
arch
is not only open
source for
the
search engine code,
the sorting alg
o-
rithm, but
also the
URL-Database.
Open Source web search engine with encrypted URL database
169
Figure 72: Web search with Spot-On in the URL database
The user can now design an own search engine: for exam-
ple, with 15 GB of URLs in the database on the own ma-
chine, the user can certainly achieve interesting search re-
sults for new websites that a friend finds interesting and
has received via the p2p network.
Spot-On.sf.net Encryption Suite - Handbook and User Manual
170
But also, as a local database for own bookmarks or an
own crawl of a dedicated domain, the URL database can be
used.
The web search in the URL repository remains anony-
mous, because the Spot-On URL search generates in other
nodes no announcement of the search words, so-called
“query hits”.
Spot-On converts the search words into a hash and
searches the local databases to see if it contains this hash.
Then there is also the hash of the URLs that contain this
keyword. The URL database is then searched for the hash of
the URL.
The databases are also encrypted, so that after the
search process also a decryption process is connected. Fi-
nally, the search results are generated and shown to the
user. The UI currently sorts the results for one or more
search words for simplicity, such that the most recent URLs
are displayed first at the top.
If the user wants to create an open source search algo-
rithm for sorting URL results, Spot-On will provide the open
source code base for this function in order not only to de-
velop an own algorithm model, but also to subject it to a
practical test.
The distribution of website URLs does not happen via
central servers, but is organized via the encrypted Echo Pro-
tocol decentralized between the participants: Two or more
users exchange their URL keys and then take part in the p2p
exchange of website URLs, such as own bookmarks, with all
friends. The online exchanged URLs are first collected in
main memory and then written to the local database every
10 seconds.
There is also the option of manually importing new URLs
into your own local database. This requires the web brows-
er Dooble.sf.net. The first icon in the URL line of the brows-
er allows storing a single URL in an intermediate database:
Shared.db. This is then imported by Spot-On with just one
click. The Shared.db must be in the installation path of
Spot-On and both programs, Spot-On and Dooble, must
define in the settings the path of this file.
Se
arch in
encryp
ted
databases with ci-
pher text
is a young
research field.
Open Source web search engine with encrypted URL database
171
In order to import an URL of the web page that a user is
currently reading from the Web Browser Dooble into Spot-
On’s own URL database, the user simply has to click on the
first icon in the URL line of the browser to start the URL to
be stored in the URL-DB: Shared.db. Then, in Spot-On, the
user clicks on the tab “Import” in the tab of the web search.
However, the newer version of the browser Dooble
(Dooble 2.0) no longer supports this import function of a
single URL in Spot-On. Because the new version of the
browser Dooble represents a complete reprogramming.
which became necessary due to the change in Qt regarding
the Webkit module.
In the still available source code of the old Dooble
Browser, however, this option can be reactivated with an
own compilation. This option should only be mentioned
here for a short sentence since other developers may also
want to import an URL from a (or any) browser into an en-
crypted bookmark database and look at this model.
The idea of making bookmarks shared with friends
searchable and locally storable for own history thus re-
mains current.
More efficient, however, are the other methods to im-
port numerous URLs using a crawler (Pandamonium Crawl-
er) or the RSS feed in Spot-On.
But first let’s look how to setup the URL database in Spot-
On.
12.1 URL Database Setup
The URLs can optionally be stored in a SQLite or PostgreSQL
database. SQLite is the automatically configured database
that is also recommended for users with less experience in
setting up databases. More advanced users can also contact
a PostgreSQL database facility. This has advantages in the
network access, the administration of user rights and the
handling of large URL data stocks. Spot-On is therefore suit-
able for creating an own web search, even for teaching
purposes, in case those learners are interested in setting up
databases.
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The URLs are stored in 26x26 or 36x36 databases (2 (16 ^
2) = 512 tables), which are encrypted. This means that the
search takes place in an encrypted database (URLs.db).
Searching in encrypted databases is a field of research that
has so far received little attention.
12.1.1 SQLite
SQLite is a program library that contains a relational data-
base system. The entire database is in a single file. A client-
server architecture is therefore not available.
Figure 73: Installing the URL database for the URL/Web search
The SQLite library can be directly integrated into appropri-
ate applications so that no additional server software is
required. This is also the ultimate difference from other
database systems. Integrating the library extends the appli-
cation with database functionality without relying on exter-
nal software packages.
SQLite has some special features over other databases:
The library is only a few hundred kilobytes in size. A SQLite
Open Source web search engine with encrypted URL database
173
database consists of a single file that contains all tables,
indexes, views, triggers, and so on. This simplifies the ex-
change between different systems.
12.1.2 PostgreSQL
PostgreSQL - also known as Postgres - is a free, object-
relational database management system (ORDBMS). Its
development originated in the 1980s from a database de-
velopment of the University of California at Berkeley, since
1997, the software is developed by an open source com-
munity.
PostgreSQL is largely compliant with the ANSI SQL 2008
SQL standard. PostgreSQL is fully ACID compliant, and sup-
ports extensible data types, operators, functions, and ag-
gregates.
Most Linux distributions contain PostgreSQL - Windows
and Mac OS X are also supported. Since the setup process
of the PostgreSQL database is more extensive, it should also
be referred to the manuals of this database also regarding
its own p2p capability outside the p2p Echo Network.
12.2 URL-Filter
If the user now participates in the p2p process of URL ex-
change with friends and peers, the user gets all the URLs
that others have added to the system. To exclude malicious
URLs, the user can also delete URLs in the web search with
a single click - or else the user uses the URL filter right from
the beginning, which can be found in its own tab.
URL filters - so-called distillers - can filter incoming, out-
going and imported data with a blacklist or whitelist. For
example, the user can define that only URLs from the do-
main www.wikipedia.org are allowed or that uploads of
URLs to friends only take place from the domain of his uni-
versity. Also, the user can specify that he does not want to
receive URLs of a particular country domain.
Spot-On.sf.net Encryption Suite - Handbook and User Manual
174
In case the user does not want to receive URLs, he just sets
the distiller filter to “http: //” with the value “Deny” for the
downloads, then these URLs will not be accepted.
Figure 74: URL Options: Import and Export Filters: URL Distiller
Open Source web search engine with encrypted URL database
175
Very important: To have the filter active, the filter should
be set to “Active” with the check box at the top.
12.3 URL-Community: Open Source URL-Database
To be able to exchange URLs and letting the own database
grow for web search, the user can either manually paste
the URL key at the tab “URL Filter” into the participant ta-
ble; or, the second option is to send the own URL key to a
community.
If the user’s friend is also online, and the user uses the
“EPKS” tool - Echo Public Key Share - to send his URL key to
the “Spot-On URL Community” defined there, his friend
receives the URL key of the User automatically transferred
online.
This transfer is encrypted using the Echo Protocol and us-
es the name of the URL community as symmetric encryp-
tion. It is similar to a group chat room (e’IRC/Buzz function)
where the URL keys are then sent out and automatically
integrated (see as already described AutoCrypt as a deriva-
tion from this invention). How EPKS works is described in
more detail below in the tools section.
Figure 75: Echo Public Key Sharing (EPKS)
E
P
K
S
o
f
f
e
r
s
auto-
matic key sharing.
Hence it is
A
utoCrypt.
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176
12.4 Pandamonium Webcrawler
Another import option for URLs is to use the crawler “Pan-
damonium”.
The Christmas release 2015 of Spot-On was the “Panda-
monium Web crawler release” and referred to the web
crawler named Pandamonium, which has been added as a
tool to the URL database feature.
The web crawler scans a domain for all linked URLs and
can then index new URLs on the discovered websites and
add these to the crawl or index. Pandamonium works (as
well as the import from the Dooble Web Browser) via an
intermediate Shared.db. The web crawler Pandamonium is
also open source and can be downloaded from this URL:
https://github.com/textbrowser/pandamonium
It is also pre-compiled for Windows in the GoldBug Zip for
Windows under http://goldbug.sf.net.
Figure 76: Pandamonium Web Crawler
The URLs added in this way are then also shared with the
friends via encrypted connections or stored encrypted in
the own local database as well.
Open Source web search engine with encrypted URL database
177
For example, the Pandamonium crawler offers the possi-
bility of importing large amounts of web pages of desired
domains for a web search in the client Spot-On.
In addition to the URL, Pandamonium also stores the
website as rich text (that means without images) in the da-
tabase and these database entries can also be shared with
friends. Web browsing in Spot-On enables the user to
browse web pages locally without having to contact the
Internet or the domain to reveal own IP information.
It is almost a new kind and advanced idea of the anony-
mization network Tor: No longer the website is contacted
live via a p2p proxy network, but the URL is searched in a
p2p web search or database and the same website can be
loaded as rich text, browsed and read locally, such as from a
browser cache or proxy.
Java scripts, images and referral URLs as well as IP infor-
mation are not included. The user is thus protected from
the disclosure of own data and can still read the desired
web page of an URL if it is present in the shared data. While
web pages can also call additional links or leave traces on
the anonymization tool Tor - due to Javascript, it is prefera-
ble for the web crawler Pandamonium to avoid such securi-
ty risks and provide only rich text in ascii.
Various revisions of web pages at different call times of
the website (Memento) are also supported – for both, in
the crawler as well as in the web search of the Spot-On cli-
ent. The page viewer of the web search in Spot-On displays
various revisions of the web page, if they exist. That is like
having a kind of GIT added to a new kind of Tor.
The setup of the SQLite database for importing the URLs
from the Pandamonium Web crawler via the shared.db is
done in a few steps:
The user creates a SQLite database in the Spot-On pro-
gram under Web Search / Settings.
The user now enters a password for “Common Creden-
tials”. This is a password feature in case third or further ap-
plications provide URLs for import.
Then the user verifies all inputs and starts the import
from shared.db, into which the user has previously stored
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178
the URLs collected by the Pandamonium Webcraler: The
import process retrieves the URLs from this file and adds
the URLs to the URL database in the Spot-On client
(URLs.db).
Any imported URLs may be shared with the user’s friends
online peer-to-peer. To do this, the friend’s URL Key has to
be entered by the user in the Add Participant window (sub-
set from main menu), or the user should use the URL shar-
ing community as described above to swap the URL key.
12.5 RSS reader and URL import
The RSS function extends the Spot-On client to a RSS reader.
RSS 2.0 feeds are supported. News-URLs are displayed in a
timeline so that the most recent message is always on top.
In addition, the news-URLs are indexed, i.e. prepared for
local web search in Spot-On. The import of the encrypted
RSS database into the encrypted URL database can be done
automatically periodically, or even via a manual import but-
ton only on action of the user.
The RSS feature not only makes it easy to read selected
news portals on a news page, but also manually or auto-
matically import the new URLs into an own local URL data-
base.
As far as known, Spot-On is the only News-Feed-Reader
with an encrypted database, which enables the user to
search in own News-Feeds and provides also a searchable
index for the full news website even with revisions.
The indexing of the website uses the 50 longest words of
the website-text (or even more according the user’s setting)
to prepare these words for the search index of the URL da-
tabase during import.
For the timeline, the titles of the RSS-messages are pro-
vided with a hyperlink only when indexing has taken place.
The status line shows statistics on how many RSS feeds are
subscribed, how many URLs are already indexed, how many
URLs from the RSS database were imported into the web
search URL database - as well as the total readable messag-
es or URLs in the RSS window.
Spot
-
On is a
RSS
-
Feed-Reader wh
ich
has a search engin
e
for all
received
and
read URLs.
Even more:
The
Website
respective
f
ull message can
be
read from the
da-
tabase cache.
Open Source web search engine with encrypted URL database
179
Figure 77: RSS feed reader for importing URLs into the URL
database/web search
The messages are read in a Page Viewer, which does not
display the messages in a browser, but for reasons of safety
only in text form. As already indicated: Java scripts, images
and advertising are removed from the pages, it will be dis-
played only the ASCII characters of the website and the hy-
perlinks to other websites. With the context menu, URLs
and hyperlinks can be manually copied out for a view into
the (external) browser.
The RSS reader is proxy-capable and can therefore also
preserve the content of the websites behind restrictive en-
vironments and then make them available for storage and
searching in Spot-On.
A feature that today certainly is also offered by some
browsers: to look up or offer the URL history and web pages
searchable from the cache of the user. Spot-On provides
this in an encrypted and p2p environment for local storage
in a dedicated URL repository.
As a simple use case a user can be described, who wants to
crawl all websites with the key word e.g. “Falun Gong“ (a
kind of meditation practice, which has been censored later
Spot-On.sf.net Encryption Suite - Handbook and User Manual
180
on by the Chinese regime). If the user wants to have an
own saving and indexing of all these websites, then Spot-On
is the right instrument to create such a database containing
public websites, and an URL- and keyword-index for it with
a p2p sharing option for this database to friends over en-
crypted connections.
Questions and further Research & Development Fields
Define RSS feeds into the feedreader of Spot-On.
Share URL-Key with your friends over EPKS.
Provide a URL.db based on SQLite with Wikipedia URLs
and pages.
Try to measure the speed of an URLs transfer over an
Echo Connection compared to a PostgreSQL direct con-
nection to another instance.
Test the revision function of webpages included in the
database based on Wikipedia page entries, which have
been updated.
Crawl a website of a school or university with Panda-
monium Webcrawler.
Describe pro and cons for the use of SQLite and Post-
greSQL
Compare Spot-On websearch with YaCy in regard of en-
cryption and Queryhits
Program an import / export from YaCy to Spot-On or
vice versa or program a query of Spot-On in the YaCy
Network with saved results in the Spot-On database.
Create a web interface to URLs.db - using Python,
Apache, Javascript, PHP etc. and set up a website for it.
Develop an algorithm to sort and display Spot-On URL
results.
Setting-up an own server – for chat and p2p e-mail
181
13 Setting-up an own server – for
chat and p2p e-mail
Secure Chat is not about the Client and its GUI, it is about
an easy to install open source chat server in own hands.
Setting up a chat server or Spot-On kernel means setting
up a so-called “listener”, according to this technical term.
If the user is in the minimal view of the user interface, a
chat & e-mail server or listener is set up as quickly as the
tab further above shown establishes an IP connection to a
server or neighbor.
The user does not need advanced server administration
skills to run a Spot-On node on the own web server, to set
up a chat server, or even to set up an e-mail inbox for
friends and own purposes.
In Spot-On only a so-called listener at a defined port must
be defined. And that’s possible with just a few clicks. Prob-
ably the simplest chat server administration ever compared
to other server setups.
13.1 Set up the chat / e-mail server via a listener
As a reminder, on the Connect tab, the user connects the
own Spot-On to another node or neighbor, and with the
chat server listener tab, the user creates a server or listener
so that others can connect to it. No matter which method,
messages can always be sent if the second or third LED in
the status line is green and a neighbor is connected: Either
to the other user as a server/listener or, the user as a client
to the neighbor which offers a listener.
The right (third) LED in the status bar thus indicates that
the user has set up an own chat server on the own com-
puter.
To do this, the user must enter the local IP address of the
own machine in the “Chat Server” tab. This is not the (ex-
ternal) IP address of the router, but the local network IP
C
o
m
p
a
r
i
n
g
C
h
a
t
A
pps is partly non-
sense.
Open Source Server
Software for en-
crypted chat must
be compared.
Spot-On.sf.net Encryption Suite - Handbook and User Manual
182
address of the device where Spot-On is installed. Again, the
user gets over the pull-down menu a selection, the IP is
displayed directly, and the user can then select the local IP.
The port 4710 is then automatically defined again.
Then the user presses the button “Set” and the entry of
the listener was successful when the third LED of the status
bar is green. Just make it reachable over your router by port
forwarding and probably DynDNS.
13.1.1 Server broadcast
If the user has a client connected to his listener, or the user
in the “connect-neighbor” tab is connected to another chat
server or friend on his own, then the user can also right-
click the command in the table “Publish information”.
Thus, this chat server address is communicated over the
existing connections to the friends and neighbors as well as
friends of friends. “Publish server” means “Broadcast IP +
Port” of the own chat server to its (connected) friends and
neighbors. Then the friends can also automatically connect
to this chat server. In this case, the user no longer must
communicate an IP address or needs to let the friends enter
the dedicated IP address manually. Everything runs auto-
matically, and the user’s server is available as a peer to the
friends and their friends. It’s that easy to create a chat
server and communicate it to others on the network.
The listener or chat server is set up by default for the TCP
Protocol, furthermore Spot-On is also equipped to set up a
listener via the UDP, DTLS or even the SCTP Protocol. Both
latter Protocols are ideal for VOIP or streams. Further, a
chat server/listener via Bluetooth is possible, see the sec-
tions below.
Therefore, the connection options can also be used to
define whether the user’s client should connect to the TCP
neighbor or another server via UDP, SCTP or Bluetooth.
The neighbor or listener of the server can do without SSL
connections, then the transmission is regulated not over
HTTPS, but only over HTTP.
Setting-up an own server – for chat and p2p e-mail
183
Figure 78: Setting up a chat server
This means that an encrypted layer is not required, the en-
crypted Echo capsule is not sent through the HTTPS tunnel,
but via HTTP - and still remains encrypted because the Echo
capsule itself is already encrypted.
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13.1.2 Security options
For sure, there are further setting options:
For example, a listener may set the security option to
generate a permanent SSL certificate. Thus, the Diffie-
Hellman key exchange or negotiation process existing in SSL
is not renegotiated in every session, but an attacker would
already have to know a negotiation process in the past to
intervene here.
However, it may be that the server or listener renews its
SSL certificate, so it may make sense to allow exceptions if
the user wants to make a connection easier and does not
want to perfect that extra level of security.
Likewise, one can define the key size for the SSL connec-
tion and determine that connections below a certain SSL
key size are not established at all. One time it is defined,
what the neighbor should offer in regard of the SSL key size,
and the other time is defined, which key size the user ex-
pects from a server or neighbor.
Finally, there is the option that the client determines if it
connects to the neighbor with Full Echo or Half Echo. At
Half Echo, the message packet is - as known - only sent to
the neighbor one hop over the direct connection. Assuming
the user’s friend has the web server set up and sitting in
front of it and the user does not want the own Echo packets
to go to third parties and their friends, then the user can
define with the Half Echo that own packets received by the
server are not be distributed further. In practice: The two
users chat via a direct IP connection. Both participants see
the IP address of the friend and of the chat partner at Half
Echo. In the Full Echo, the chat friend does not have to be
an administrator of the node but can connect multiple cli-
ents like a central chat server.
Further security options allow the user to define the SSL
key size when creating a chat server/listener, as well as
maintaining a permanent SSL certificate.
Also, the user – if there is a permanent, stable IP address
– can integrate this into the SSL certificate.
Setting-up an own server – for chat and p2p e-mail
185
These three measures make it harder for attackers to ex-
change or “fake” the SSL certificate - because it would be
immediately recognized if a different certificate was to be
used as the original one: for example, the client would ex-
pect not be a new, but the old permanent certificate. Or the
IP address is missing or inconsistent within the SSL certifi-
cate. The SSL key size also defines additional security.
13.1.3 Proxy and firewall annotations
If the user wants to run Spot-On as a client via a proxy in
the company, behind a firewall or a proxy of the university
or via the anonymization network Tor, the user can insert
the proxy details for the neighbor.
As a client, the user can connect to any IT environment
thanks to the HTTP Protocol if the user is able to surf in that
environment with a browser.
That’s the advantage of the Spot-On program, which
means that wherever users can surf with their browsers,
they can also e-mail and chat with Spot-On Encryption Suite
because of the HTTPS or POPTASTIC Protocol they use.
Many other programs cannot do this, depending on the
firewall settings – e.g. from the workplace or in the student
residence.
If the user wants to use or test out a proxy e.g. in the
company or university with the Spot-On Encryption Suite,
then this is uncritical, because a SSL/TLS or HTTPS connec-
tion is established - which is hardly different for the proxy
administrators like any other SSL/HTTPS connection to an
HTTPS website when doing banking or logging into a web e-
mail provider.
It is just essential to address a listening node in the web
with the own Spot-On, which may not be limited by the
port through a firewall or the proxy. If so, the user may ask
the friend to set up the Spot-On chat server on port 80 or
port 443 instead of 4710 and provide it with login infor-
mation for an Echo Account, if available and deliverable.
Encrypted traffic remains encrypted traffic, and any Spot-
On friend or chat server can be reached on the web
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through ports 443 or 80 or ports, which are regularly
opened in the firewall.
Since the Echo Protocol only requires a simple HTTP con-
nection to a neighbor (and not necessarily a Stun server or
a DHT etc.), and thus ideally can be mapped through a
proxy, through a firewall or over the Tor network, it’s a very
simple architecture to operate chat securely through a
proxy or a proxy network.
If the user wants to define an additional feature, a further
often-used function is that of the Echo Account.
To do this, the user in the table marks the listener that
was created and then enters the account credentials, i.e.
the name and password. The user then tells the friend what
the account name and password are, and when the friend
establishes the neighbor contact, the friend will be asked
via a pop-up window to enter these credentials. In case not
everyone should be able to address to the Echo Server (e.g.
behind Tor), then the Echo Account can authenticate a ded-
icated user.
Furthermore, the user can also choose between IPV4 and
IPV6 if he wants to create a listener/chat server. Also, mul-
tiple chat servers can be created by choosing a different
port. The user can create different listeners with port 4710
or 80 or 443 and decide whether he wants to define these
listeners for friends with an Echo Account (friend mode), or
for easier to build connections that runs in peer mode
without account login.
Echo Accounts thus define whether the user builds an
F2F network or a P2P network, because with the account
credentials the user creates a web-of-trust with which only
his trusted friends can connect with the defined login pass-
word. (A SmokeStack server on Android by the way also
provides the feature of a private server for defined friends).
Setting-up an own server – for chat and p2p e-mail
187
13.1.4 Spot-On as LAN Messenger
If the user operates a peer, for example, at a LAN party of a
closed network with the IP broadcast function, he can in-
form all participants that his node has opened a listener for
the guests. Thanks to the UDP Protocol, however, the Spot-
On Messenger also works directly like a LAN messenger
within a closed user group of the LAN.
For this, the LAN listener is already defined as a neighbor
in the neighbor table (defined IP: 239.255.43.21). This has
just to be activated and other Spot-On installations in the
same Windows network are then automatically found for a
connection. Besides the many options the original Spot-On
client offers, it is a nice Qt-Exercise for a university task to
code an own simple LAN messenger with this architecture
and a compact GUI as own client for the university or stu-
dents home LAN.
13.2 Server / Listener Creation at home behind a
router / Nat
If the user does not have his own server on the web or does
not find a general neighbor with a listener on the web, it is
also recommended to set up an own chat server at home
behind the own router and to forward the port in the rout-
er. The friends then can connect directly to this defined
listener as a client.
However, one of the friends has to create a listener if
both friends sit behind a firewall or do not use a chat server
on the web. So, if the user wants to create a server behind
his router/Nat at home, as mentioned the local IP address
of the machine for the listener is to take, e.g.
192.168.121.1. Then the user must also forward the port in
his router, i.e. port 4710 must be forwarded by the router
to 192.168.121.1: 4710. Furthermore, the kernel - Spot-on-
Kernel.exe - as well as the Spot-On.exe should be allowed as
an exception in the (Windows) Firewall. If the user has for-
warded everything correctly, the friend can connect to the
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client’s (external) IP address (see, for example,
www.whatismyip.com) and port 4710.
It is only important that the router of the user forwards
the contact attempt from the Internet at the defined port
to the own local machine. This is a common and secure
procedure and does not open any access to a computer, but
over the port and the application is defined (as with many
other programs that only packages in this sense are al-
lowed).
The user can and must define this by himself and Spot-On
does not contain any code that automatically forwards
ports in the router or opens or even automatically sets up a
listener!
Thus, in Spot-On it is more secure, as there are more op-
tions to be decided by the user than in other applications,
which configure itself in the interest of user-friendliness
and reduce the effort and provision of background automa-
tion. – Convenience appears as a security risk for those us-
ers, who know the technical details of port forwarding with-
in the own router and for the creation of a listener, and
need no automatic definition, opening and forwarding of
ports. Once known and done, the own listening server at
home is quickly administered.
13.3 Use of Spot-On in the Tor network
If the user wants to operate the own Spot-On chat through
the Tor network, this will also be worth a test. The Tor exit
node should only see the cipher text of the communication.
Here, the chat server is again in the normal web outside the
Tor network.
So far, Tor cannot establish HTTPS connections at the exit
node of the Tor network, but a pass-through of encrypted
packets from two Spot-On instances should be possible:
Spot-On -> Tor -> Internet -> Tor -> Spot-On. A HTTP listener
can also be set up for the TOR network. This is an ideal test
environment of both applications. So far no one has pub-
lished about Echo over Tor (while Tor is being the overlay
Setting-up an own server – for chat and p2p e-mail
189
network for it). Also, other networks can be tested, e.g. like
the Matrix.org.
Figure 79: Testing Proxy and Pass-Through capabilities
Testing Proxy & Pass-Through capabilities
Messaging through a Proxy
Spot-On => Proxy (Entry) => Internet [=> Proxy (Entry)] Spot-On
Messaging over Tor
Spot-On => Tor (Entry) => Internet => Tor (Exit) => Spot-On
Echo through the Echo
GoldBug => Spot-On => Tor (Entry) => Internet => Tor (Exit) =>
Spot-On => GoldBug
Gopher passing through the Echo
Gopher => Spot-On (Pass-through) => Internet => Spot-On (Pass-
through) => Gopher
Compare:
Gopher over Matrix.org is untested and assumed to fail
Gopher => Matrix (Entry) => Internet => Matrix (Exit) => Gopher
Next to a proxy it is also possible to use the pass-through
functionality of Spot-On, here Spot-On is not connected to a
proxy, but is becoming a proxy on localhost, to which other
applications can be tied. That means one can send from a
Gopher App to Spot-On and to the network and then from
Spot-On at the other end back to Gopher. This is possible as
the function is not tied to a special protocol or library
(compare a test with Tor or the Matrix network, which re-
quire special protocol/library implementations).
13.4 Spot-On Kernel Server
As currently described, the software to set up a chat server
is currently described according to the application Spot-On.
As an alternative User Interface to Spot-On, there is also the
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190
GoldBug interface and server software. A chat server listen-
er can be set up with both applications referring to the
Spot-On Kernel. But there are even some more ways, appli-
cations and methods to set up a server for communication:
13.5 Spot-On Lite Server as Deamon
If the user wants to administer a chat server without a user
interface, thus using the chat server as a kernel daemon on
a web server, one can view at the other Lite server software
for Echo clients at: github.com/textbrowser/spot-on-lite.
Figure 80: Bluetooth chat server architecture model
13.6 SmokeStack Server on Android
The simplest option at home in the LAN or even with port
forwarding in the router to set up a chat server is to install
Setting-up an own server – for chat and p2p e-mail
191
the App SmokeStack on an Android device. This Android
server can also forward the Echo packages of Spot-On Echo
clients. Available at: github.com/textbrowser/smokestack.
13.7 Spot-On Bluetooth Server
Finally, a chat server/listener via Bluetooth is also possible
(depending on Qt currently only for Linux). With Bluetooth,
it is possible, for example, to connect the devices BT-
wirelessly via the Echo Protocol at a LAN party. This option
can be very crucial if there is no Internet or infrastructure
left.
13.8 Spot-On UDP Server
The User Datagram Protocol, UDP for short, is a minimal,
connectionless network Protocol that belongs to the
transport layer of the Internet Protocol family.
The development of UDP began when a simpler Protocol
was required for the transmission of speech than the previ-
ous connection-oriented TCP. A Protocol was needed that
was only addressing, without securing the data transmis-
sion, as this would cause delays in voice transmission.
A three-way handshake, such as TCP (the Transmission
Control Protocol) for establishing the connection, would
create unnecessary overhead in this case.
UDP is therefore a connectionless, non-reliable and unse-
cured as well as unprotected transmission Protocol. That is,
there is no guarantee that a packet once sent will also ar-
rive, that packets arrive in the same order in which they
were sent, or that a packet arrives only once at the receiver.
An application that uses UDP, therefore, must be insensitive
to lost and unsorted packages or even provide appropriate
corrective measures and, if necessary, safeguards.
For the Echo Protocol an interesting basis, since the
packets are indeed rather undirected in the flow of the
network and lost UDP packets are then not lost because of
the multiplication and redundancy within each node.
S
m
o
k
e
S
t
a
c
k
i
s
a
n
elaborated
Chat Server for
encrypted chat for
the Android
operating system.
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13.9 Spot-On DTLS Server
A DTLS Server is also possible: Datagram Transport Layer
Security (DTLS) is a communications protocol that provides
security for datagram-based applications by allowing them
to communicate in a way that is designed to prevent eaves-
dropping, tampering, or message forgery. The DTLS proto-
col is based on the stream-oriented Transport Layer Securi-
ty (TLS) protocol and is intended to provide similar security
guarantees. The DTLS protocol datagram preserves the se-
mantics of the underlying transport—the application does
not suffer from the delays associated with stream proto-
cols, but because it uses UDP, the application has to deal
with packet reordering, loss of datagram and data larger
than the size of a datagram network packet. As DTLS can be
used also for audio streaming, this is a basis for encrypted
voice and audio over Spot-On (e.g. Spot-On-Sender (Analog
Audio) => Amazon Echo => Internet => Amazon Echo =>
(Analog Audio) Spot-On-Receiver).
13.10 Spot-On SCTP Server
The Stream Control Transmission Protocol (SCTP) is a relia-
ble, connection-oriented network Protocol. As a transport
Protocol, SCTP is at the same level of the TCP / IP reference
model as TCP and UDP.
SCTP realizes the concept of an association: Here, a con-
nection is set up in which several message data streams are
transported in order-preserving (with each other but poten-
tially non-order-preserving). In addition, individual, for ex-
ample, urgent, datagrams may be sent separately and out
of line, possibly “overhauling” the in-order data streams.
Also, to use this Protocol for the transmission of Echo
packets is very interesting for the research, since the rather
undirected Echo packets may experience a more secure
transmission with this Protocol compared to UDP.
This Protocol can also be used to set up a chat server
within Spot-On.
Setting-up an own server – for chat and p2p e-mail
193
13.11 Spot-On Ncat connection
While other applications always require a server that may
be difficult to replicate, install or manage, Spot-On also can
do without any dedicated server software. For this purpose,
Ncat can be used as follows:
In one exercise, two devices are connected to Spot-On
through a RaspberryPi running Debian using NCat. It re-
quires a working network, a RaspberryPi and two devices
each with Spot-On.
(1) First, ncat will be installed on the Pi:
sudo aptitude install nmap
(2) Then some SSL material is generated:
openssl req -new -x509 -keyout server-key.pem -out server-
cert.pem
(3) Then ncat is called:
ncat -broker -ssl -ssl-cert server-cert.pem -ssl-key server-
key.pem -k -l 192.168.178.130 4710
(4) Now the user visits the neighbor / server tab in Spot-On
and defines the remote server at 192.168.178.130.
If the neighboring devices have been activated and the ker-
nels are turned on, the connection already exists.
A nice exercise to test a network and Ncat for encrypted
communication.
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Questions and further Research & Development Fields
Setup an own Spot-On-Listener at home with DynDNS.
Connect a Spot-On client with a SmokeStack server on
Android.
Define a Half Echo Listener for Spot-On.
Use the Debian Installer for Spot-On on a RaspberryPi as
a server.
Setup the SmokeStack server on an Android TV-Box
from Ebay.
Test a Bluetooth Server with Spot-On under Linux.
Compare a Spot-On Listener or Echo Server creation
with the setup of a Matrix or XMPP or Signal Server. De-
scribe both processes in detail and compare.
Integrated Encryption Tools
195
14 Integrated Encryption Tools
In addition to the regular functions, Spot-On Encryption
Suite also has several tools that offer further useful fea-
tures. These include, in particular, the functions of file en-
cryption (File Encryptor), another tool for converting nor-
mal text and cipher text (Rosetta-CryptoPad), and the EPKS
tool, with which the public keys for encryption are transmit-
ted online in a secure channel to a friend or to a communi-
ty. Furthermore, the pass-through functionality as well as
the tools for statistics and analyzes should be mentioned.
14.1 Tool: Encryption of files with Spot-On FileEn-
cryptor
Spot-On has additional encryption tools. In the main menu
under tools the user finds the tool for encrypting files on
the own hard disk (“File Encryption Tool”).
Figure 81: File Encryptor - file encryption tool
This allows the user to specify a file from the hard drive,
then specify the same path and choose any extension or
change of file name - then enter password and pin (both of
course again with at least 16 characters) and define with
the radio select buttons, whether the file should be en-
crypted or decrypted.
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Cipher and hash-type are also definable as well as that a
signature in the encryption can optionally be installed to
ensure that the encryption was made only by the defined
user (and nobody else).
The file encryption tool is an offer to replace potentially
insecure Truecrypt containers, or to encrypt or to back up
individual files before the user transfers the files - whether
as an e-mail in Spot-On, via StarBeam file transfer in Spot-
On or over conventional, insecure ways - or simply to en-
crypt the files on the hard disk or when stored in online
cloud stores like Dropbox or other.
14.2 Tool: The Rosetta CryptoPad for text conver-
sion in Spot-On
The tool Rosetta CryptoPad takes its name from the “Stone
of Rosette”, which stands in the museum in London. It is
considered a translation tool for Egyptian hieroglyphs in
other languages.
The Rosetta CryptoPad included in Spot-On has its own
key - as well as chat and e-mail and all other functions have
their own keys like this.
The user also exchanges the Rosetta key with a friend,
then enters text into the CryptoPad, selects the friend and,
whether it is encryption or decryption, - and press the
“Convert” button.
Then the bottom of the window of the output is dis-
played as cipher text. The user can easily copy it with the
copy function and sends it via conventional online commu-
nication channels such as @-e-mail or another chat. Web
boards or paste bins can also be used by the user as a place
for encrypted communication.
It is, so to speak, “slow chat” by a manually clicked en-
cryption of the chat text (although the encryption is faster
than the copy/paste-process into other instances).
The Rosetta CryptoPad is an alternative to other solu-
tions, as it is based on a-symmetric encryption (PKI).
Integrated Encryption Tools
197
Figure 82: Encryption of text with the Rosetta Crypto Pad
This method of slow chat also shows that applications that
rely on encrypting each individual e-mail are an inconven-
ient method. Who wants to select the recipient for every e-
mail and chat message, encrypt the message, decide
whether the signature key should still be added or not be-
fore the message is sent?
Spot-On has the general advantage of exchanging the key
just once with the friend during set up and then everything
is encrypted at all times and the entire communication is
transferred within the chosen encryption, with temporary
keys and end-to-end passphrases can be renewed instanta-
R
o
s
e
t
t
a
C
r
y
p
t
o
P
a
d
derives its name
f
rom the “Stone of
Rosette” in the
Museum of London.
Spot-On.sf.net Encryption Suite - Handbook and User Manual
198
neously at any time (e.g. with the Cryptographic Calling
function).
14.3 Tool: Echo Public Key Share (EPKS) & Au-
toCrypt
When it comes to encryption, there is always the central
question of how to safely transport the key to the friend.
Some architectures use key servers in which the user can
store their public keys. This seems logical, after all it is a
public key. Nevertheless, the key servers also have massive
disadvantages, so we do not know if one has found the
right key in it or if this is even up to date.
Instead, the Echo Public Key Share (EPKS) function makes
it very easy to transfer keys in the Spot-On Encryption Suite.
Figure 83:
EPKS - Echo Public Key Sharing
For this purpose, a symmetric key is defined with a com-
munity name in the p2p network of the Echo Protocol,
through which all participants - who know the community
name - can exchange the public keys.
Integrated Encryption Tools
199
The tool is linked via the main menu and opens a new
pop-up window.
An example of a community is already there by default
for the exchange of URL keys. The user sends the own URL
key to this community and all other subscribers who are
currently online in the p2p network receive this key.
It is a key exchange over a symmetric encrypted channel,
where the password for end-to-end encryption is the name
of the community. All users who know the name of the
community will be able to receive and add the keys that
users put into the secure channel to their Spot-On program.
14.4 Pass-Through functionality (“Patch-Points”)
If two Spot-On clients have an existing connection over the
Internet, this connection can be used as a tunnel to pass
the data of another application through this tunnel. It has
been mentioned a bit already above.
For this, a kind of proxy function of Spot-On is addressed
with this pass-through functionality.
This is an interesting feature to protect two clients of an-
other program without encryption over the Internet with
the encrypted connection via Spot-On.
Originally a pass-through was also named in the develop-
er forum as a “Patch-Point”.
Application => Spot-On => Spot-On-Server => Spot-On =>
Application
For another application, so to speak, a VPN tunnel is set up,
which can even be equipped even with the McEliece algo-
rithm or one of the other encryption algorithms. As long as
no VPN provider offers McEliece encryption from start to
end, the pass-through functionality is the right choice for a
test. Spot-On represents here a kind of VPN tool. So far, no
further tunnel software is known which applies McEliece.
The application to be connected should be tolerant to the
order of the sent packets. It is an interesting research field
P
a
t
c
h
P
o
i
n
t
s
describe a
p
ass-through
f
unctionality.
Spot-On.sf.net Encryption Suite - Handbook and User Manual
200
that can be conducted with several possible applications
and tests.
Figure 84:
Spot-On as proxy: pass-through
14.5 Statistics & Analyzing Tools
In addition to statistics overviews also analysis tools are
included in Spot-On, such as the above-mentioned Star-
Beam Analyzer. The listener and server tables also contain a
lot of data information about sent packets, as well as statis-
tics for the URL database.
Integrated Encryption Tools
201
Figure 85:
Display of statistics
In addition to the usual user interface, Spot-On can also be
installed in console form e.g. on a RasperryPi and retrieve
the statistics overview with a corresponding command.
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Figure 86:
Statistics console on a Raspberry Pi
The Pandamonium URL Web crawler also has correspond-
ing statistics.
The Encryption Suite Spot-On is ideal for tests and learnings
with this provided insight for different functions.
Questions and further Research & Development Fields
Test the speed and measure the time to encrypt a movie
file with FileEncryptor.
Test the pass-through function with Gopher.
Test a pass-through with any other network, e.g. Tor, I2P
or Matrix.
Test the pass-through function to send Echo packets
through the Echo.
Test the Rosetta CryptoPad for generating ciphertext.
Define a Key Sharing Community in EPKS.
Integrated Encryption Tools
203
Figure 87:
Pandamonium Web Crawler Stats
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15 BIG SEVEN STUDY: Crypto-
Messenger-Audit
In the Study BIG SEVEN Crypto Messengers (2016) for Desk-
top Computers by David Adams and Ann-Kathrin Spot-On,
respective the GoldBug Messenger GUI, was considered
among seven open source Messengers. This international
IT-audit-oriented evaluation regarded the software “more
than audit-compliant” in more than 20 dimensions and
“overall trustworthy”. Also, the numerous code reviews
gave hints in regard of an excellent programming.
The ‘‘10 Trends in Crypto-Messaging’’ have been identi-
fied by all seven messengers core competencies – and
found all very elaborated within the research software of
GoldBug and the underlaying Spot-On-Kernel architecture.
The following ten items to be considered in cryptographic
programming have been pointed out:
1. Consolidation of chat and e-mail encryption: Messag-
ing consolidates between chat and e-mail, the POP-
TASTIC protocol is an ideal example, where e-mail
servers are utilized for chat.
2. Storage of Data on the Hard Disc only encrypted: All
data containers in the Spot-On architecture are fully
encrypted as known from a truecrypt/veracrypt con-
tainer.
3. SMP with zero-knowledge-proof processes for authen-
tication: While the Socialist-Millionaire-Protocol is
used to authenticate a friend, Secret Streams within
the Spot-On architecture show how a bunch of
ephemeral keys derived from the SMP process can se-
cure end-to-end encryption without transferring the
keys over the Internet.
T
he
B
I
G
SEVEN
Study provides not
only a security au-
dit of the Spot-On
Source code, but
derives also 10
Trends in Crypto-
graphic Messaging
from
several ana-
lyzed Messengers.
BIG SEVEN STUDY: Crypto-Messenger-Audit
205
4. Multi-Encryption: Several layers of encryption are pro-
vided e.g. with the Echo Protocol or with individual
functions e.g. like a Nova-password on files.
5. Easy and decentral server setup: A listener for the
Spot-On Server setup is created within a few clicks.
6. IPFS with Cryptographic Calling: Instant Perfect For-
warding Secrecy has been elaborated with several
methods of Cryptographic Calling and even for Fiasco
Forwarding a full bunch of keys will be transferred and
tested.
7. Individual Crypto-DNA: Magnet-URI links contain many
cryptographic values, which are bundled in the link of
the Magnet-URI standard.
8. Manual definition of end-to-end encryption keys:
#CSEK – Customer Supplied Encryption Keys – The user
is requested to manually and individually define the
passphrase for an end to end encryption key.
9. Avoiding of Metadata: With the graph theory within
the Echo Network packets flood in every direction, so
that meta data is hard to record.
10. Alternatives to RSA: e.g. McEliece Algorithm – As RSA
is regarded officially as broken by NIST (2016) software
needs to start to use alternative Algorithms, like NTRU
or McEliece.
Spot-On covers these trends identified by the comparison
of seven well known crypto messenger very elaborated. The
procedures of the software are in each field still advanced
of not leading. Research needs to (1) analyze further com-
parisons of applications and (2) implementations and
standards, software development with cryptographic pro-
cedures needs to reach.
The ten fields with “Trends in Encrypting Processes” need
to be further deepened also for other encrypting software
besides messaging.
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Figure 88: Big Seven Crypto Study: Trends in Crypto (2016)
BIG SEVEN STUDY: Crypto-Messenger-Audit
207
Next to the auditing of the source code 2016, the architec-
ture and processes of encryption as well as the functions in
Spot-On, there are numerous other topics on which future
research can orientate itself. As an example, the following
questions should be mentioned for further evaluations and
research needs, which may play a role in comparison with
other processes and applications:
C
r
i
t
e
r
i
o
n
/
Q
u
e
s
t
i
o
n
Spot-On Lettera Riot Smoke Signal GoldBug Retro-
Share
Is the application open source?
Is it a tiered application: kernel and user interface processes?
Are there proxy capabilities?
Is it possible to send E-Mail messages to offline friends?
Is it possible to send E-Mail with encrypted attachments?
Are there different keys for different functions in place like
Chat, E-Mail, CryptoPad, Filetransfer etc.?
Is the key stuck to the IP Address of the user?
How is mutual access authentication defined?
Are there alternatives to RSA, like McEliece or NTRU? Can a
NTRU-user chat to a RSA-user? With which library is McEliece
implemented?
Are there selectable SSL ciphers?
Are there selectable hash algorithms?
Is just connectivity needed, i.e. no key exchange is needed, are
keys optional?
Is trust needed, or can it be added as the user defines it?
What about technical simplicity?
Is it possible to determine, who is reading which message? Can
a sent message be deleted?
Local databases store all information in encrypted .db’s?
Is the authentication of messages optional?
Can the user communicate without public keys, e.g. using Mag-
nets?
Support for TCP and UDP and SCTP communications?
Support of multi-layers of encryption?
Are multiple listeners possible?
Is a multi-threaded kernel given?
Spot-On.sf.net Encryption Suite - Handbook and User Manual
208
Are there IRC-like group chat channels?
What about simple IP-based firewalls?
Do scramblers send out fake messages?
Is it possible to store messages in friends?
Is there the option to use an individually defined and manually
inserted end-to-end key for communication?
Is there the option to renew the end-to-end key each time a us-
er wants (not only session based)?
Encrypted file transfer Protocol - Using a onetime Magnet
(OTM) for a crypto channel?
Having IPv6 support?
Having Qt 5 and up deployed? Also a Java client in place?
Sending a message to a friend to his dedicated connection and
not to all or central connections?
Hiding the key exchange online over encrypted solutions (e.g.
REPLEO or EPKS channel)?
Using different encryption keys for one file transfer?
Adding a passphrase to a to be transferred file?
Questions and further Research & Development Fields
Lookup the 20 audit criteria for the evaluation of IT
Software according the Big 7 Study (2016).
Go through the code of the latest Spot-On and note
your findings.
Choose one Trend-Dimension and analyze two applica-
tions in comparison in this regard.
As it is not about the Application to compare, but the
open source chat server to compare, please compare
the two open source server applications for encrypted
chat.
Create a concept for a Crypto-Party evening to set up an
own server. Note the questions of the guests and work
out a procedure with recommendations for the server
set up.
Outlook with Graph-Theory: Initial Welcome in the New Era of Exponential Encryption
209
16 Outlook with Graph-Theory: In-
itial Welcome in the New Era of
Exponential Encryption
The term "Era of Exponential Encryption" has been coined
by Mele Gasakis and Max Schmidt in their book "Beyond
Cryptographic Routing". Herein they describe the develop-
ment within cryptography to multiply several methods, val-
ues and constants. Based on the therein provided analyzes
and recent innovations in cryptography they provide a vi-
sion that can demonstrate an increasing multiplication of
options for encryption and decryption processes: Also re-
ferred to their analysis of the Echo Protocol, especially if it
is regarded in the context of Graph-Theory.
Similar to a grain of rice that doubles exponentially in every
field of a chessboard, more and more newer concepts and
programming in the area of cryptography like the Echo Pro-
tocol increase these manifolds: both, encryption and de-
cryption, require more session-related and multiple keys, so
that numerous options exist for configuring encryption:
with different keys and algorithms, symmetric and a-
symmetrical methods, or even modern multiple encryption,
with that cipher text is converted again and again to cipher
text. It is also analyzed how a handful of newer applications
and open source software programming implements these
encryption mechanisms.
16.1 Multiplication towards Exponential
Next to hybrid-encryption, which means to apply both,
symmetric and a-symmetric encryption or vice versa, also
multi-encryption is mentioned, in which a cipher text is en-
crypted to cipher text and, again, several times to cipher
text - possibly and intended with different methods or algo-
T
h
e
E
r
a
o
f
Exponential
Encryption:
Beyond
Cryptographic
Routing.
Spot-On.sf.net Encryption Suite - Handbook and User Manual
210
rithms. Further is mentioned the turn back from session
keys, so called ephemeral keys, towards a renewal of the
session key by instant options for the user: to renew the
key several times within the dedicated session. That has
forwarded the term of "Perfect Forward Secrecy" to "In-
stant Perfect Forward Secrecy" (IPFS) – as we already know
by end of this Handbook and User Manual.
But even more, if in advance a bunch of keys is sent, a
decoding of a message has to consider not only one present
session key, but also over dozens of keys sent prior before
the message arrives. The new paradigm of IPFS has already
turned into the newer concept of these Fiasco Keys. Fiasco
Keys are keys, which provide over a dozen possible ephem-
eral keys within one session and define Fiasco Forwarding,
the approach, which complements and follows IPFS.
Fiasco Keys have been coded into several applications like
Smoke (Client) and SmokeStack (Chatserver). They provide
in contrast to other more static and schematic Protocols
like the Signal Protocol a vision into a more volatile world of
encryption.
And further, adding routing- and graph theory to the en-
cryption process, which is a constant part of the also in this
Handbook in detail described Echo Protocol, an encrypted
packet might take different graphs and routes within the
network. This and the sum off all the mentioned innova-
tions and development features described within the book
"Beyond Cryptographic Routing" multiply also the options
an invader against a defined encryption has to consider -
and shifts the current status to a new age: The Era of Expo-
nential Encryption, so the vision and description of the au-
thors.
That means: If cipher text is now sent over the Internet,
there exist also the manifold options in the networks of the
analyzed applications that messages take undefined routes
or even routes defined with cryptographic tokens. If the
routing- and graph-theory is paired with encryption, the
network theory of computer science gets quite new dimen-
sions:
The Echo P
rotocol
is
Beyond
Crypto-
graphic Routing.
Outlook with Graph-Theory: Initial Welcome in the New Era of Exponential Encryption
211
Based on the development of various proxy- or mix-
networks, such as the well-known Tor-network (and further
analyzed in their book), a development from so-called "On-
ion Routing" to "Echo Discovery" is described: That means
the route of a packet to be sent can no longer be defined,
as each node in the network independently decides the
next hop.
On the other hand: The special case of a "sprinkling net-
work" describes the learning of servers and nodes based on
these cryptographic tokens. This Adaptive Echo offers ad-
vantages and disadvantages compared to the previous mix
networks.
It is therefore not spoken in these flooding networks
from the concept of "routing", as we know it from the well-
known TCP Protocol, but of "discovery": If the cryptograph-
ic token is matching, the message belongs to me. The Echo
Protocol is an example of the change from Onion Routing to
Cryptographic Discovery.
Is it also a new option for new, better encryption in the
network? If routing does not require destination infor-
mation but is replaced by cryptographic insights, then it is
"beyond cryptographic routing". Will servers within the
network learn in the future through cryptographic tokens,
which route a packet takes within the Internet and to which
recipient it should be delivered and which recipient it
should not be forwarded to? Well-known alternatives to
popular messengers have announced that they will replace
the sender with a cryptographic token, and thereby ap-
proach this property of the Echo that has existed for many
years. Servers will learn now based on Cryptographic Dis-
covery: The Artificial Intelligence – the learning of comput-
ers – will be steered in the future by Cryptographic Discov-
ery? It can be spoken of Cryptographic Artificial Intelli-
gence, in short: CAI.
At the same time, some are also analyzing and realizing a
new way of thinking and working in the time after the
Snowden Papers, - especially within the open source com-
munity - which differs from industrial development work
for encryption programs to community-oriented open
S
p
o
t
-
O
n
a
s
I
n
i
t
i
a
l
Welcome in the Era
of Exponential
Encryption (EEE)
W
i
l
l
s
e
r
v
e
r
s
w
i
t
h
i
n
a network learn
soon by crypto-
graphic tokens?
The SECRED
Protocol of the
Sprinkling Effect is
one element of
Cryptographic
Discovery.
Spot-On.sf.net Encryption Suite - Handbook and User Manual
212
source developments. These in particular have, can and will
arise innovations in cryptography (probably detached from
the known insider circles of experts).
A prominent example of such an innovation is such of
Cryptographic Calling: In this process, numerous keys for
end-to-end encryption are promptly and several times
within one push of a button individually defined and re-
newed after a user request. Only a few programs can do
this so far.
The Echo Protocol, which is applied in a handful of soft-
ware applications, is in this regard an initial welcome within
the Era of Exponential Encryption. Encryption and Graph-
Theory have been brought together. According to this, eve-
ry message is encrypted several times and each network
node sends a packet to all known neighbors. This compares
and transforms classic mix networks like Tor or I2P and oth-
er to a new kind of flooding networks. A complex chaos is
coming.
16.2 Four Arms within the Era of Exponential En-
cryption
There are four arms to be identified within the "Era of Ex-
ponential Encryption", which refer to (1) multi-encryption:
the conversion from cipher text to cipher text to cipher
text, (2) meta-data resistance, and (3) third, the increasing
diversification of cryptographic parameters: Key variables or
applied algorithms, as well as (4) the trend towards new
algorithms such as NTRU and McEliece, which are so far
considered to be particularly more secure against the at-
tacks of the fast Quantum Computing:
Multi-Encryption as a result of numerous disruptive
innovations in cryptography: Multi-Encryption is the
conversion of cipher text to cipher text, if both a-
symmetric and symmetric methods are used, hybrid
multi-encryption can be defined.
Avoiding Meta-data & Resistance to Meta-data Analy-
sis: Big user data has become a gray fog or noise fac-
Four
Arms
:
Multi-
Encryption
Avoiding Meta-
Data
Value-
Diversification
New Algorithms
Cryptographic
Artifi
cial
Intelligence (CAI)
is defined by
Cryptographic
Discovery and
Machine Learning.
Outlook with Graph-Theory: Initial Welcome in the New Era of Exponential Encryption
213
tor, which makes it difficult to decipher and in which a
user may also hide with secret messages.
Diversification of the user-defined cryptographic pa-
rameters: Users can use numerous algorithms, the in-
dividual cryptographic-DNA has been highly individual-
ized.
Switching from RSA Algorithm to NTRU and McEliece
as a strengthening of Resistance to Quantum Compu-
ting: Since 2016, RSA has been officially insecure.
Short, but fact. Switching to NTRU and McEliece plays
a central role.
These research results and assumptions in the concept pro-
posal of the NEW EEE-ERA is strengthening the ten crypto
trends found proposed by Adams/Maier in 2016.
16.3 Implications
From these developments, social, legal, political and eco-
nomic recommendations are derived, which are to be dis-
cussed more intensely, especially in educational processes:
Our schools need more teaching and learning processes
that understand and convey the beginning of the increas-
ingly exponential cryptography.
Social implications:
"'The liberty of the other begins with the acceptance of his
or her cipher text' - if the known quotation from Rosa Lux-
emburg (1918) may be applied to the next century in this
wording. If it is difficult to accept the limits of the readable
opinion of the other, how easily should one fall to accept
the limits of the unreadable opinion of the other?", has to
be asked. Combined with a suggestion, that multipliers
within social groups help others to get a common under-
standing for cryptographic processes in society and for pri-
vate people.
Legal implications:
The new status in the Era of Exponential Encryption shows
that the legal requirements to judge cases are becoming
S
o
c
i
a
l
,
l
e
g
a
l
,
p
olitical and
economic
implications.
Spot-On.sf.net Encryption Suite - Handbook and User Manual
214
more complex: e.g. if non-license-free material is forwarded
in an encrypted packet or if only "non-routed" communica-
tion content has to be decoded in a legal case – or if an In-
ternet Service Provider should be able to decrypt at all? -
The authors suggest to provide professional education al-
ready at high school for all law concerned professions.
Political implications:
Here the question is raised, how much competence devel-
opment in a particular nation should this nation request?
and how can political processes steer this? The authors
suggest that encryption must be a well accepted science
and practical process in politics and by politicians. A nation
needs own research results in cryptography.
Economic implications:
Encryption is the basic process of the digital economy. The
authors suggest that an initiative should equal the open
source software with proprietary encryption solutions.
16.4 Outlook
A pleading for the compulsory subject computer-science
already in school? - In any case, the so-called "digital immi-
grants" as well as members of the "Generation Y", who
have grown up with the mobile phones, continue to devel-
op the content of the cryptography in the curricula of
schools and discuss the described innovations and ques-
tions towards the "Era of Exponential Encryption ".
It is necessary to develop teaching concepts that lead
non-MIT and non-math students to cryptology & cryptog-
raphy and, secondly, to address also the other group of
non-students: technically interested people who have never
seen a university from inside but are interested in technical
development and its social discussion of the consequences
of technology and/or not learning and applying of new
technology.
Here, in the area of encryption, every reader and user is
asked to consider how to learn, how to deepen the existing
Outlook with Graph-Theory: Initial Welcome in the New Era of Exponential Encryption
215
knowledge and to be learned content as well as practical
application of the know-how of encryption.
The context content appeals to interested persons of
computer science, math, and cryptography as well as to
students who want to discuss new cryptographic innova-
tions in tutorials and crypto-parties.
Questions and further Research & Development Fields
Why are multi-encryption and individual Cryptographic
DNA values influencing the multiplication of options?
How is graph theory and networking within the Echo
Protocol related to multiplied and exponential Encryp-
tion?
What are the four arms of the New Era of Exponential
Encryption?
Which implications derive from the New Era of Expo-
nential Encryption for the next Crypto-Party of stu-
dents?
Provide an action plan to update educational processes
for one educational class curriculum, school or universi-
ty based on 10 chapters of this handbook.
Discuss Life-Cycle-Management for a RSA application
and provide a start-up business-plan for a McEliece ap-
plication. How has Chance Management to be steered
of companies offering both software products?
How can developers paid by government and working
for public domain provide an open source alternative
for WhatsApp based on open source chat server soft-
ware everyone can install and use?
Spot-On.sf.net Encryption Suite - Handbook and User Manual
216
17 Digital Encryption of Private
Communication in the Context
of …
This user manual is not only intended to technically de-
scribe the handling of encryption, its processes or the use
of the individual tabs and buttons, but also to illustrate the
meaning of the encryption as it stands in the light of various
basic laws for the protection of private freedom and com-
munication. The following basic laws should therefore be
pointed out, which refer to them in their original texts.
17.1 Principles of the protection of private
speech, communication and life: Universal
Declaration of Human Rights, 1948 (Art. 12)
No one shall be subjected to arbitrary interference with his
privacy, family, home or correspondence, nor to attacks
upon his honor and reputation. Everyone has the right to
the protection of the law against such interference or at-
tacks.
http://www.un.org/en/documents/udhr/index.shtml#a12
Universal Declaration of Human Rights.
17.2 International Covenant on Civil & Political
Rights, 1966 (Art. 17)
1. No one shall be subjected to arbitrary or unlawful
interference with his privacy, family, home or cor-
respondence, nor to unlawful attacks on his hon-
our and reputation.
2. Everyone has the right to the protection of the
law against such interference or attacks.
Digital Encryption of Private Communication in the Context of …
217
http://www.ohchr.org/EN/ProfessionalInterest/Pages/
CCPR.aspx International Covenant on Civil and Political
Rights.
17.3 European Convention on Human Rights,
1950 (Art. 8)
1. Everyone has the right to respect for his private
and family life, his home and his correspondence.
2. There shall be no interference by a public authority
with the exercise of this right except such as is in
accordance with the law and is necessary in a
democratic society in the interests of national se-
curity, public safety or the economic well-being of
the country, for the prevention of disorder or
crime, for the protection of health or morals, or for
the protection of the rights and freedoms of oth-
ers.
http://conventions.coe.int/treaty/en/Treaties/Html/005.ht
m / European Convention on Human Rights.
17.4 Charter of Fundamental Rights of the Euro-
pean Union, 2000 (Art. 7, 8)
Article 7 - Respect for private and family life: Everyone has
the right to respect for his or her private and family life,
home and communications.
Article 8. Protection of personal data: 1. Everyone has the
right to the protection of personal data concerning him or
her. 2. Such data must be processed fairly for specified pur-
poses and on the basis of the consent of the person con-
cerned or some other legitimate basis laid down by law.
Everyone has the right of access to data which has been
collected concerning him or her, and the right to have it
rectified. 3. Compliance with these rules shall be subject to
control by an independent authority. Charter of Fundamen-
tal Rights of the European Union - Charter of Fundamental
Rights of the European Union (Wikisource) Charter of Fun-
damental Rights of the European Union.
Spot-On.sf.net Encryption Suite - Handbook and User Manual
218
17.5 Basic Law e.g. for the Federal Republic of
Germany, 1949 (Art. 2 Abs. 1 i. V. m. Art. 1
Abs. 1)
Article 2 - Personal freedoms: (1) Every person shall have
the right to free development of his personality insofar as
he does not violate the rights of others or offend against
the constitutional order or the moral law. Article 1 [Human
dignity – Human rights – Legally binding force of basic
rights] (1) Human dignity shall be inviolable. To respect and
protect it shall be the duty of all state authority.
https://www.btg-bestellservice.de/pdf/80201000.pdf Basic
Law for the Federal Republic of Germany.
Further: Article 1 and Article 10:
Art. 1 Human dignity – Human rights: Legally binding
force of basic rights (1) Human dignity shall be inviolable. To
respect and protect it shall be the duty of all state authori-
ty. (2) The German people therefore acknowledge inviola-
ble and inalienable human rights as the basis of every
community, of peace and of justice in the world. (3) The
following basic rights shall bind the legislature, the execu-
tive and the judiciary as directly applicable law
17.6 Privacy of correspondence, posts and tele-
communications (Art. 10)
Secrecy of correspondence - Fernmeldegeheimnis (Art. 10
Abs. 1 Grundgesetz)
§ 88 Abs. 1 Fernmeldegeheimnis - Telekommunikations-
gesetz: (1) Dem Fernmeldegeheimnis unterliegen der Inhalt
der Telekommunikation und ihre näheren Umstände, insbe-
sondere die Tatsache, ob jemand an einem Telekommunika-
tionsvorgang beteiligt ist oder war. Das Fernmeldegeheim-
nis erstreckt sich auch auf die näheren Umstände erfolglo-
ser Verbindungsversuche. (2) Zur Wahrung des Fernmelde-
geheimnisses ist jeder Diensteanbieter verpflichtet. Die
Pflicht zur Geheimhaltung besteht auch nach dem Ende der
Tätigkeit fort, durch die sie begründet worden ist. (3) Den
nach Absatz 2 Verpflichteten ist es untersagt, sich oder an-
Digital Encryption of Private Communication in the Context of …
219
deren über das für die geschäftsmäßige Erbringung der Te-
lekommunikationsdienste einschließlich des Schutzes ihrer
technischen Systeme erforderliche Maß hinaus Kenntnis
vom Inhalt oder den näheren Umständen der Telekommu-
nikation zu verschaffen. Sie dürfen Kenntnisse über Tatsa-
chen, die dem Fernmeldegeheimnis unterliegen, nur für
den in Satz 1 genannten Zweck verwenden. Eine Verwen-
dung dieser Kenntnisse für andere Zwecke, insbesondere
die Weitergabe an andere, ist nur zulässig, soweit dieses
Gesetz oder eine andere gesetzliche Vorschrift dies vorsieht
und sich dabei ausdrücklich auf Telekommunikationsvor-
gänge bezieht. Die Anzeigepflicht nach § 138 des Strafge-
setzbuches hat Vorrang. (4) Befindet sich die Telekommuni-
kationsanlage an Bord eines Wasser- oder Luftfahrzeugs, so
besteht die Pflicht zur Wahrung des Geheimnisses nicht
gegenüber der Person, die das Fahrzeug führt oder gegen-
über ihrer Stellvertretung.
17.7 Verletzung des Post- oder Fernmeldegeheim-
nisses (§ 206)
(1) Wer unbefugt einer anderen Person eine Mitteilung
über Tatsachen macht, die dem Post- oder Fernmeldege-
heimnis unterliegen und die ihm als Inhaber oder Beschäf-
tigtem eines Unternehmens bekanntgeworden sind, das
geschäftsmäßig Post- oder Telekommunikationsdienste er-
bringt, wird mit Freiheitsstrafe bis zu fünf Jahren oder mit
Geldstrafe bestraft. (2) Ebenso wird bestraft, wer als Inha-
ber oder Beschäftigter eines in Absatz 1 bezeichneten Un-
ternehmens unbefugt 1. eine Sendung, die einem solchen
Unternehmen zur Übermittlung anvertraut worden und
verschlossen ist, öffnet oder sich von ihrem Inhalt ohne
Öffnung des Verschlusses unter Anwendung technischer
Mittel Kenntnis verschafft, 2. eine einem solchen Unter-
nehmen zur Übermittlung anvertraute Sendung unter-
drückt oder 3. eine der in Absatz 1 oder in Nummer 1 oder
2 bezeichneten Handlungen gestattet oder fördert. (3) Die
Absätze 1 und 2 gelten auch für Personen, die 1. Aufgaben
der Aufsicht über ein in Absatz 1 bezeichnetes Unterneh-
Spot-On.sf.net Encryption Suite - Handbook and User Manual
220
men wahrnehmen, 2. von einem solchen Unternehmen
oder mit dessen Ermächtigung mit dem Erbringen von Post-
oder Telekommunikationsdiensten betraut sind oder 3. mit
der Herstellung einer dem Betrieb eines solchen Unter-
nehmens dienenden Anlage oder mit Arbeiten daran be-
traut sind. (4) Wer unbefugt einer anderen Person eine Mit-
teilung über Tatsachen macht, die ihm als außerhalb des
Post- oder Telekommunikationsbereichs tätigem Amtsträger
auf Grund eines befugten oder unbefugten Eingriffs in das
Post- oder Fernmeldegeheimnis bekanntgeworden sind,
wird mit Freiheitsstrafe bis zu zwei Jahren oder mit Geld-
strafe bestraft. (5) Dem Postgeheimnis unterliegen die nä-
heren Umstände des Postverkehrs bestimmter Personen
sowie der Inhalt von Postsendungen. Dem Fernmeldege-
heimnis unterliegen der Inhalt der Telekommunikation und
ihre näheren Umstände, insbesondere die Tatsache, ob je-
mand an einem Telekommunikationsvorgang beteiligt ist
oder war. Das Fernmeldegeheimnis erstreckt sich auch auf
die näheren Umstände erfolgloser Verbindungsversuche.
http://www.gesetze-im-internet.de/gg/art_10.html
Secrecy of correspondence – Briefgeheimnis -
(Fernmeldegeheimnis) - Postgeheimnis
http://www.gesetze-im-internet.de/tkg_2004/__88.html
http://www.gesetze-im-internet.de/stgb/__206.html
17.8 United States Constitution: Search and Sei-
zure (Expectation of Privacy, US Supreme
Court)
The right of the people to be secure in their persons, hous-
es, papers, and effects, against unreasonable searches and
seizures, shall not be violated, and no Warrants shall issue,
but upon probable cause, supported by Oath or affirmation,
and particularly describing the place to be searched, and
the persons or things to be seized.
http://www.usconstitution.net/const.html
History of Program Publications
221
18 History of Program Publica-
tions
The list of publications shows continuous updates and re-
leases of the application over several years. The first publi-
cation dates back to 2013, and before that, another project
also involved several years of research work. The release
dates of the versions show on average almost monthly or at
least quarterly a release. The notes makes it clear which
feature has been added, improved, or published.
The history of the publications since 2013 and earlier can
be found with approx. 40 Program releases in the wiki of
the project page of the GoldBug release history, for Spot-On
the release history is to be analysed in detail by the release
notes, which moved from Sourceforge to Github and have
been arrived there too:
https://github.com/textbrowser/spot-
on/tree/master/branches/Documentation
https://sourceforge.net/p/goldbug/wiki/release-
history/
19 Website
Further information can be found on the website:
http://spot-on.sf.net
https://textbrowser.github.io/spot-on/
Spot-On.sf.net Encryption Suite - Handbook and User Manual
222
20 Open source code & Compila-
tion
The open source code and further compile information can
be found at the repository at Github:
https://github.com/textbrowser/spot-on
The GoldBug GUI source code is also to be found in
the Spot-On repository at Github.
20.1 Compile Information
Anyone who looks on the website of Spot-On, finds here
the current release, especially for Windows. If the user has
advanced computer skills, would like to compile the pro-
gram from the source code or wants to learn from this ex-
ample, this developer will find here more hints on how to
proceed for the operating systems, e.g. Windows.
The compilation from the source code allows the devel-
oper to see how the source code forms into a binary file
(.exe) and which program libraries are to be supplemented
so that the executable file can run.
First, it is to download the Qt tool kit. Choose the offline
(or online) installation of Qt with MingGW: e.g. Qt 5.X for
Windows 32-bit (MinGW 4.9.2, 1.0 GB) at the URL:
http://www.qt.io/download- open-source / # section-2
Then the source code has to be downloaded. For Win-
dows all required dependencies and libraries are already
integrated in the path of the source text. The Spot-On GUI
and the Spot-On Kernel can be found at GitHub at the men-
tioned URL above: https://github.com/textbrowser/spot-on
To download the source code, the developer can download
the master tree on the website as a zip in the browser or
use a GIT client.
For Linux, all these libraries should be installed:
Qt 5.1.x or higher,
Open source code & Compilation
223
libGeoIP 1.5.1,
libcrypto 0.9.8 or later,
libgcrypt 1.5.x, and
libssl 0.9.8 or later.
libsqlite3-dev
libgcrypt11-dev
libssl-dev
libgeoip-dev
libpq-dev,
libeay,
libgpg-error,
libsshgcrypt-dev,
libssh-gcrypt-dev,
libgcrypt-dev,
libgcrypt11-dev,
libgl1-mesa-dev,
libcurlpp-dev,
libcurl4openssl-dev,
libsctp-dev,
libtool,
libtool-dev,
libntl.
The libGeoIP program library is optional and can be by-
passed if the selected Qt-PRO project file is configured ac-
cordingly. It has to be checked, whether for Linux all men-
tioned, or more recent versions of these program libraries
are installed on the machine. For Windows, the necessary
program libraries are already attached to the source code
(DLL files, even if not customary). Further compiling infor-
mation can be found within the source code itself.
After the developer has installed Qt, the user starts the
program Qt-Creator from the Qt directory.
Then the developer selects the relevant .pro file from the
unpacked source code path and compiles the GUI and the
kernel with Qt Creator. For the compilation of Spot-On the
user installs Qt5 and then select the .pro file “Spot-
On.Qt5.win.pro”. This file opens both, kernel and GUI sub-
pro files.
Spot-On.sf.net Encryption Suite - Handbook and User Manual
224
Then in QT-Creator the developer simply clicks on the
green forward arrow and starts the compiling. At the end of
the compilation process from the Qt Creator Spot-On.exe
should then be bootable. If the developer wants to put the
exe.file in a separate path on the own hard-disk, the devel-
oper has to add all needed DLL files (from the selected Qt
version and from all current libraries) as well as the sub-
paths e.g. for the sound or Qt files, as they already exist in
the default installation zip for Spot-On Windows. The li-
brary DLL files for Window are also stored in the source
code of the respective library paths for convenient and easy
use.
The developer can of course compile with the Qt termi-
nal window Spot-On also with manual DOS commands,
without using Qt-Creator.
COMPILING PROCESS with C ++ / Qt:
Windows: qmake -o Makefile Spot-On.win.qt5.pro
make or mingw32-make
or choose in Qt-Creator: Spot-On.win.qt5.pro
Spot-On does not provide checksums for the binary down-
loads as the source is given for those who want to build on
their own. Please notice: Spot-On has a build date in the
GUI so the sums might differ for each compile!
FURTHER INFO for other .pro files:
If header (h) or interface (ui) files have changed, please per-
form a distclean before building the application.
Absolute cleaning: make distclean or mingw32-
make distclean
FreeBSD: qmake -o Makefile spot-on.freebsd.pro
make
Linux: qmake -o Makefile spot-on.pro
make
OS X: qmake -spec macx-g++ -o Makefile spot-
on.osx.pro
make
Open source code & Compilation
225
Windows: qmake -o Makefile spot-on.win.pro
make or mingw32-make
Spot-On.sf.net Encryption Suite - Handbook and User Manual
226
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Index of Figures
241
22 Index of Figures
Figure 1: The tabs in Spot-On Encryption Suite
application ........................................................ 15
Figure 2: How asymmetric encryption with Public
Key Infrastructure (PKI) works .......................... 21
Figure 3: McEliece’s algorithm for advanced
protection against attacks from Quantum
Computing in the Settings Tab .......................... 23
Figure 4: RSA and its alternatives in Spot-On .................. 24
Figure 5: Individual Crypto-DNA: Customizable
cryptography, e.g. based on key size and
further values ................................................... 26
Figure 6: Example of an AES Password string .................. 30
Figure 7: Example of Encapsulation with three levels
of encryption .................................................... 30
Figure 8: Discovering Spot-On’s sent cipher text to a
localhost HTTP-Listener in a browser ............... 31
Figure 9: Message Encryption Format of the Echo
Protocol ............................................................ 34
Figure 10: Threefish implementation ................................ 36
Figure 11: Example of message encryption within the
Echo .................................................................. 37
Figure 12: Graphical depiction of a message within
the Echo Protocol ............................................. 38
Figure 13: Simulacra, Impersonator, Super-Echo ............... 41
Figure 14: Echo Simulation: Each node sends to each
connected node ................................................ 45
Figure 15: Example and Process Description of the
Echo-Match ....................................................... 47
Figure 16: Account Firewall of Spot-On ............................. 49
Figure 17: The Echo Grid Template .................................... 51
Figure 18: Alice, Bob, Ed and Mary in the Echo Grid -
An example of Echo paths and for Graph
Theory ............................................................... 53
Spot-On.sf.net Encryption Suite – Handbook and User Manual
242
Figure 19: Adaptive Echo (AE): The “Hansel and
Gretel” Example of the Adaptive Echo ............. 56
Figure 20: SECRED – Sprinkling Effect (SE) &
Cryptographic Echo Discovery (CRED) via
the Echo Protocol ............................................. 61
Figure 21: Definition of SECRED ........................................ 63
Figure 22: Initial Wizard of Spot-On .................................. 68
Figure 23: Set Passphrase - if not the Wizard is used,
it is found in the settings Tab for kernel
activation - here shown within the
GoldBug GUI ..................................................... 71
Figure 24: Authentication: Login to the application
Spot-On with a passphrase ............................... 72
Figure 25: Virtual Keyboard of the Spot-On
application ........................................................ 74
Figure 26: Options for Display: e.g. change icon set.......... 78
Figure 27: Lock of the user interface in the status bar ...... 79
Figure 28: Activation of the kernel in the Settings Tab ...... 80
Figure 29: Encryption between kernel and GUI and
three LEDs. ........................................................ 80
Figure 30: Creating a connection to a neighbor/server ..... 81
Figure 31: Connected neighbors/ servers .......................... 82
Figure 32: Logo of the GoldBug Crypto Chat
Application ........................................................ 86
Figure 33: 1:1 chat in the pop-up window ........................ 87
Figure 34: Add Friend/Key ................................................. 89
Figure 35: Chat Tab ............................................................ 93
Figure 36: Chat in the pop-up window with the SMP
authentication option ....................................... 94
Figure 37: The MELODICA Button since 2013.................... 95
Figure 38: Definition of Two-way Cryptographic
Calling ............................................................... 99
Figure 39: Two-Way Calling in the context menu from
the friends-list .................................................. 100
Figure 40: SMP Protocol in the pop-up chat window ........ 103
Figure 41: Socialist Millionaire Protocol (SMP) in the
chat window to authenticate the chat
partner .............................................................. 106
Figure 42: Definition of Secret Streams ............................. 107
Index of Figures
243
Figure 43: Secret Streams based on SMP Protocol ............ 108
Figure 44: Definition of Forward Secrecy .......................... 109
Figure 45: Overview of the different types of
Cryptographic Calling with respective
criteria .............................................................. 112
Figure 46: Emoticon list in Spot-On Encryption Suite ........ 114
Figure 47: Tear-off / hook-up of controls ........................... 115
Figure 48: File transfer in the pop-up chat window .......... 116
Figure 49: The e’IRC group chat ......................................... 117
Figure 50: IRC-style group chat within the e’IRC buzz
channel ............................................................. 119
Figure 51: Mobile Smoke Messenger with left-right
chat layout ........................................................ 122
Figure 52: E-Mail - read view (shown here in the
GoldBug GUI) .................................................... 124
Figure 53: POPTASTIC: chat via e-mail server .................... 127
Figure 54: P2P e-mail from the postbox to a friend:
C/O function (shown in the GoldBug
Interface) .......................................................... 131
Figure 55: Database encryption – file email.db ................. 132
Figure 56: URN = Institution (VEMI Method) .................... 134
Figure 57: E-mail with forward secrecy ............................. 138
Figure 58: Implementation of Secret Streams here for
e-mail ................................................................ 143
Figure 59: POPTASTIC Protocol Graphic ............................. 145
Figure 60: POPTASTIC Settings: Encrypted Chat and
Encrypted E-Mail over POP3 and IMAP ............ 148
Figure 61: MOMEDO Analysis Report ................................ 150
Figure 62: GUI Screenshot of the Lettera Application
(Android) with also intended chat over e-
mail servers ...................................................... 151
Figure 63: Spot-On 1:1-chat pop-up window with file
transfer ............................................................. 153
Figure 64: StarBeam with its three sub-tabs ..................... 154
Figure 65: Magnet-URI standard with cryptographic
values for file transfer ....................................... 155
Figure 66: NOVA Password on file transfers ...................... 157
Figure 67: Cryptographic values for the Magnet-URI
standard ............................................................ 160
Spot-On.sf.net Encryption Suite – Handbook and User Manual
244
Figure 68: Example of a Magnet-URI with
cryptographic values (here for a group chat
channel) ............................................................ 160
Figure 69: Starbeam file transfer: uploading files ............. 163
Figure 70: StarBeam File Transfer - Incoming Files ........... 165
Figure 71: File transfer using StarBeam: Analysis tool
for the chunks ................................................... 166
Figure 72: Web search with Spot-On in the URL
database ........................................................... 169
Figure 73: Installing the URL database for the
URL/Web search ............................................... 172
Figure 74: URL Options: Import and Export Filters:
URL Distiller ...................................................... 174
Figure 75: Echo Public Key Sharing (EPKS) ......................... 175
Figure 76: Pandamonium Web Crawler ............................. 176
Figure 77: RSS feed reader for importing URLs into
the URL database/web search .......................... 179
Figure 79: Setting up a chat server .................................... 183
Figure 80: Testing Proxy and Pass-Through capabilities .... 189
Figure 81: Bluetooth chat server architecture model ....... 190
Figure 82: File Encryptor - file encryption tool .................. 195
Figure 83: Encryption of text with the Rosetta Crypto
Pad .................................................................... 197
Figure 84: EPKS - Echo Public Key Sharing ......................... 198
Figure 85: Spot-On as proxy: pass-through ....................... 200
Figure 86: Display of statistics ........................................... 201
Figure 87: Statistics console on a Raspberry Pi ................. 202
Figure 88: Pandamonium Web Crawler Stats .................... 203
Figure 89: Big Seven Crypto Study: Trends in Crypto ........ 206
Glossary
245
23 Glossary
2WIPFS: See: Two-way instant perfect forward secrecy.
4710: Port for the applications Spot-On and other Echo
clients.
Access Controls: means to ensure that access to assets is
authorized and restricted based on business and security
requirements. Related to authorization of users, and as-
sessment of rights.
Adaptive Echo (AE): The Adaptive Echo does not send in
terms of the normal Echo a message-packet to each con-
nected node, instead, for the over giving of a message a
cryptographic token is needed. The Echo-Protocol is
equipped for the Adaptive Echo Modus with a routing in-
formation. Only nodes, which have a certain cryptographic
token available, get the message forwarded.
AES: The Advanced Encryption Standard (AES), also known
as Rijndael (its original name), is a specification for the en-
cryption of electronic data established by the U.S. National
Institute of Standards and Technology (NIST) in 2001. AES is
based on the Rijndael cipher developed by two Belgian
cryptographers, Joan Daemen and Vincent Rijmen, who
submitted a proposal to NIST during the AES selection pro-
cess.
AE-Token: The AE-Token is a cryptographic token used to
deploy the Adaptive Echo (AE) modus. It is a kind of pass-
word or string, which is entered the node, to avoid mes-
sages to be sent to nodes, without the AE-Token. AE-Tokens
can help to create a self-learning, adaptive network. The
token must contain at least thirtv-six characters.
Algorithm: In mathematics and computer science, an algo-
rithm is a self-contained step-by-step set of operations to
be performed. Algorithms exist that perform calculation,
data processing, and automated reasoning.
Spot-On.sf.net Encryption Suite – Handbook and User Manual
246
Android: Android is a mobile operating system which al-
lows to deploy mobile devices similar as an Raspberry Pi
with server software, e.g. like the encrypting chat server
SmokeStack for Android.
Answer Method: The Answer Method is a procedure for
the login into an application. It is applied in the software
Spot-On and GoldBug. Here the login into the application
can be done over a password, or, the password is replaced
by two entry text fields. One string covers the question,
and the other string covers the referring answer to the
question. Both values are hashed and processes in a cryp-
tographic way. The right answers are not stored on the
hard disk in plain text, so that the process provides a dif-
ferent method and offers more security. An attacker does
not know, if a user has used the password or the ques-
tion/answer login method.
Asymmetric Calling: Cryptographic Calling is the immediate
transfer of end-to-end encrypting encryption credentials to
secure a communication channel. Cryptographic calling has
been invented by the Software Project Spot-On. Asymmet-
ric Calling is some modus for Cryptographic Calling, which
sends temporary asymmetric keys for end-to-end encryp-
tion. It refers to send one asymmetric key (pair) through
one secured channel. The Call with asymmetric credentials
refers to ephemeral asymmetric keys, which are used for
the time of the call. This could be one session or even a
shorter part of time of the session. It depends whenever a
communication partner starts to initiate a call. The asym-
metric ephemeral credentials for the call should be trans-
ferred over a secure connection, which is either a symmet-
ric key, over a a-symmetric key (PKI) or over an already ex-
istent call-connection, in this case an ephemeral asymmet-
ric temp-key.
Asymmetric Encryption: In cryptography, encryption is the
process of encoding messages or information in such a way
that only authorized parties can read it. In public-key en-
cryption schemes, the encryption key is published for any-
one to use and encrypt messages. However, only the re-
Glossary
247
ceiving party has access to the decryption key that enables
messages to be read. Public-key encryption was first de-
scribed in a secret document in 1973; before then all en-
cryption schemes were symmetric-key (also called private-
key).
Attack: attempt to destroy, expose, alter, disable, steal or
gain unauthorized access to or make unauthorized use of
an asset.
Audit: systematic, independent and documented process
for obtaining audit evidence and evaluating it objectively to
determine the extent to which the audit criteria are ful-
filled. An audit can be an internal audit (first party) or an
external audit (second party or third party), and it can be a
combined audit (combining two or more disciplines).
Auditing and Logging: Related to auditing of actions, or
logging of problems.
Authentication: provision of assurance that a claimed
characteristic of an entity is correct. Related to the identifi-
cation of users.
Autocrypt: AutoCrypt is an automatic key exchange. This
has originally been invented by the Spot-on Project and re-
fers to the protocol definitions of a REPLEO and the EPKS
protocol. A REPLEO is the method to encrypt the own Pub-
lic Key with the received Public Key of a friend. That hides
the own public key from public by using encryption meth-
od. The EPKS Protocol is the Echo Public Key Sharing Proto-
col, which allows to send the own key over an existing en-
crypted connection to one or several friends. The EPKS
protocol has been invented in the Spot-On project and
GoldBug Project and has been overtaken by other projects
in an automated way for an e-mail reply. That means two
users of the same e-Mail client exchange the public encryp-
tion key and are from that point of time secured for all fur-
ther communication. The EPKS Protocol provides this many
years before the Term AutoCrypt went public. Other pro-
ject also copied this invention under the Name KeySync.
The new process is, that the key is not stored and searched
on a Key server, but sent from node to node in a secure
Spot-On.sf.net Encryption Suite – Handbook and User Manual
248
channel, either by manual sent-out or an automated ex-
change of two nodes, e.g. e-mail-clients or Spot-On Clients
over the EPKS protocol.
Availability: property of being accessible and usable upon
demand by an authorized entity.
Bluetooth: Bluetooth is a wireless technology standard for
exchanging data over short distances (using short-
wavelength UHF radio waves in the ISM band from 2.4 to
2.485 GHz) from fixed and mobile devices and building per-
sonal area networks (PANs).
Broadcast: Broadcast is as term widely known. In Cryptog-
raphy it is known from the Spot-On application to send the
public encryption key over an IP-network connection, so
that all connected nodes can pick-up the sent key. A cryp-
tographic Broadcast is a wider form of AutoCrypt and in-
cludes as well the EPKS channel. It is also possible to send
the Cryptographic Broadcast over a not encrypted connec-
tion, while a broadcast over the Echo Network or the Echo
Public Key Sharing function of the Spot-On Client would
provide always an encrypted connection, e.g. based on the
symmetric key, which allows only people who know the key
to have access.
Button: A button is the most discussed element in an ap-
plication, respective GUI development.
Buzz: Buzz is the name of the libspoton to provide Echoed
IRC(e*IRC). So Buzz is another word for IRC, respective
e*IRC, used by the library.
C/O (Care-of)-Function: “Care of”, used to address a letter
when the letter must pass through an intermediary (also
written C/O). Neighbors are often asked to care of your
postal letters, in case you live with them in one house or
have a relationship to them. As well parcel stations, letter
boxes or just persons e.g. at your home or in the neighbor-
hood provide a local delay of your envelopes and parcels,
in case you are at work and want to receive the parcel or
letter in the evening. The included Email Function of Spot-
On provides such a feature.
Glossary
249
Calling: A “Call” transfers over a public/private key en-
crypted environment a symmetric key (e.g. AES). It is a
password for the session talk, only the two participants
know. With one click you can instantly renew the end-to-
end encryption password for your talk. It is also possible to
manually define the end-to-end encrypted password
(manually defined Calling). There are five further different
ways to call: Asymmetric Calling, Forward Secrecy Calling,
Symmetric Calling, SMP-Calling and 2-Way-Calling. The
term of a “Call” in Cryptography has been introduced by
Spot-on, the integrated library and kernel of the Spot-On
Application, and refers to sending a new end-to-end en-
cryption password to the other participant.
CBC: Cipher Block Chaining – Ehrsam, Meyer, Smith and
Tuchman invented the Cipher Block Chaining (CBC) mode
of operation in 1976. In CBC mode, each block of plaintext
is XORed with the previous ciphertext block before being
encrypted. This way, each ciphertext block depends on all
plaintext blocks processed up to that point.
Cipher text: Cipher text is the result of encryption per-
formed on plaintext using an algorithm, called a cipher. Ci-
pher text is also known as encrypted or encoded infor-
mation because it contains a form of the original plain text
that is unreadable by a human or computer without the
proper cipher to decrypt it. Decryption, the inverse of en-
cryption, is the process of turning ciphertext into readable
plaintext. Cipher text is not to be confused with code-text
because the latter is a result of a code, not a cipher.
Cipher: In cryptography, a cipher is an algorithm for per-
forming encryption or decryption—a series of well-defined
steps that can be followed as a procedure. An alternative,
less common term is encipherment. To encipher or encode
is to convert information into cipher or code. In common
parlance, ‘cipher’ is synonymous with ‘code’. Codes gener-
ally substitute different length strings of characters in the
output, while ciphers generally substitute the same num-
ber of characters as are input.
Spot-On.sf.net Encryption Suite – Handbook and User Manual
250
Clientside Encryption: Client-side encryption is the crypto-
graphic technique of encrypting data before it is transmit-
ted to a server in a computer network. Usually, encryption
is performed with a key that is not known to the server.
Consequently, the service provider is unable to decrypt the
hosted data. In order to access the data, it must always be
decrypted by the client. Client-side encryption allows for
the creation of zero knowledge applications whose provid-
ers cannot access the data its users have stored, thus offer-
ing a high level of privacy.
C-mail: C-mail as a term describing e-mail, that is encrypt-
ed. This term was introduced due to the awareness, that
each e-mail is distributed over Internet servers readable
like a postcard to any admin.
Confidentiality: property that information is not made
available or disclosed to unauthorized individuals, entities,
or processes.
Configuration: Related to security configurations of serv-
ers, devices, or software.
Congestion Control: Congestion control concerns control-
ling traffic entry into a telecommunications network, so as
to avoid congestive collapse by attempting to avoid over-
subscription of any of the processing or link capabilities of
the intermediate nodes and networks and taking resource
reducing steps, such as reducing the rate of sending pack-
ets.
Continuous improvement: recurring activity to enhance
performance.
Corrective action: action to eliminate the cause of a non-
conformity and to prevent recurrence.
Crawler: A Web crawler, sometimes called a spider or spi-
derbot and often shortened to crawler, is an Internet bot
that systematically browses the World Wide Web, typically
for the purpose of Web indexing (web spidering). Web
search engines and some other sites use Web crawling or
spidering software to update their web content or indices
of others sites' web content. Web crawlers copy pages for
Glossary
251
processing by a search engine which indexes the down-
loaded pages so users can search more efficiently.
Cryptogramm: Verbal arithmetic, also known as alphamet-
ics, cryptarithmetic, crypt-arithmetic, cryptarithm,
mprovemen or word addition, is a type of mathematical
game consisting of a mathematical equation among un-
known numbers, whose digits are represented by letters.
The goal is to identify the value of each letter. The name
can be extended to puzzles that use non-alphabetic sym-
bols instead of letters.
Cryptographic Calling: Cryptographic Calling is a way to
provide end-to-end credentials over a secure connection.
The temporary key can be a-symmetric (PKI) or symmetric
(a password string also known as a passphrase). The idea is
to make end-to-end encryption as easy as calling a partner
over a phone, just taking the phone, call, and if the session
has to end, to change the temporary keys again and quit
the call.
Cryptographic Discovery: Cryptographic Discovery de-
scribes the method of an Echo-ing Protocol to find nodes in
an Echo Network. Peers are aware of other peers and their
cryptographic identities based on a cryptographic discovery
within the network. Nodes inform other nodes about their
neighbors, so that they can be addressed.
Cryptographic Routing: Cryptographic Routing is a term,
which has been used as an antagonism for describing the
Echo Protocol, as this is beyond Routing. Echo means for-
warding a message, which is address-less. So no routing is
given within Echo. A Cryptographic Routing would be giv-
en, if a node would have a certain cryptographic token as
identifier. This is the case within Adaptive Echo (AE). Here
in partial one can speak of cryptographic routing, as a tar-
get address might be given.
Cryptographic Torrents: Cryptographic Torrents are defined
by a bunch of cryptographic values, listed in a link to gen-
erate a download of a file. Similar to Torrent Links the
download is started packet by packet, just with the differ-
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ence that all packets are encrypted, and the link contains
an assortment of cryptographic values.
Cryptographic-DNA: Cryptographic DNA is derived as term
– in allusion to the DNA term taken from biology - from
Magnet-URI-Links containing an assortment of specific
cryptographic values. These values describe key size, algo-
rithm, hash, iteration count etc. As each link can be differ-
ent, the term DNA describes the specific uniqueness or
footprint of such a bundle.
Cryptography: Related to mathematical protections for
data.
CryptoPad: A Cryptopad is a tool, to convert plain text to
cipher text. A first suite integrated pad has been developed
by the Spot-On application under the name Rosetta Crypto
Pad. The name derives from the Stone of Rosette in the
Museum of London, which is an index to read hieroglyphs.
The Rosetta CryptoPad uses asymmetric keys, so it is based
on PKI and both participants need to share (and enter) the
public key. It is not based on symmetric key, so that the
other user just has to enter a passphrase-string like some
PDF files are often encrypted.
Crypto-Parties: A Crypto-Party is a grassroots global en-
deavour to introduce the basics of practical cryptography
such as the Tor anonymity network, key signing parties,
disk encryption and virtual private networks to the general
public. The project primarily consists of a series of free
public workshops. Marcin de Kaminski, founding member
of Piratbyrån which in turn founded The Pirate Bay, regards
CryptoParty as the most important civic project in cryptog-
raphy today, and Cory Doctorow has characterized a Cryp-
toParty as being "like a Tupperware party for learning cryp-
to." Der Spiegel in December 2014 mentioned "crypto par-
ties" in the wake of the Edward Snowden leaks in an article
about the NSA.
CSEK: CSEK is the short abbreviation of Customer Supplied
Encryption Keys. This refers to services, Internet offers and
software architecture, which provides the option, that the
user brings in his own keys, either symmetric or asymmet-
Glossary
253
ric. This is especially important for applications providing
end to end encryption that users can insert or define their
own password and use other channels to exchange the
password.
Customer Supplied Encryption Keys (#CECS): Customer
Supplied Encryption Keys have been introduced as term by
google to provide customers to use own keys for the en-
cryption of data within the google cloud.
Data Exposure: Related to unintended exposure of sensi-
tive information.
Data Validation: Related to improper reliance on the struc-
ture or values of data.
Decentralized computing: Decentralized computing is the
allocation of resources, both hardware and software, to
each individual workstation, or office location. Decentral
means, there is no central server nor a web-interface, you
can lof into a service. A client needs to be installed and ad-
justed locally on your device. Another term is: Distributed
computing. Distributed computing is a field of computer
science that studies distributed systems. A distributed sys-
tem is a software system in which components located on
networked computers communicate and coordinate their
actions by passing messages. Based on a “grid model” a
peer-to-peer system, or P2P system, is a collection of appli-
cations run on several local computers, which connect re-
motely to each other to complete a function or a task.
There is no main operating system to which satellite sys-
tems are subordinate. This approach to software develop-
ment (and distribution) affords developers great savings, as
they don’t have to create a central control point. An exam-
ple application is LAN messaging which allows users to
communicate without a central server.
Distributed Hash Table: A Distributed Hash Table (DHT) is a
class of a decentralized distributed system that provides a
lookup service similar to a hash table: (key, value) pairs are
stored in a DHT, and any participating node can efficiently
retrieve the value associated with a given key. Keys are
unique identifiers which map to particular values, which in
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254
turn can be anything from addresses, to documents, to ar-
bitrary data.
DNS: The Domain Name System (DNS) is a hierarchical and
decentralized naming system for computers, services, or
other resources connected to the Internet or a private
network. It associates various information with domain
names assigned to each of the participating entities. Most
prominently, it translates more readily memorized domain
names to the numerical IP addresses needed for locating
and identifying computer services and devices with the
underlying network protocols. By providing a worldwide,
distributed directory service, the Domain Name System has
been an essential component of the functionality of the In-
ternet since 1985.
Documented information: information required to be con-
trolled and maintained by an organization and the medium
on which it is contained. Note: Documented information
can be in any format and media and from any source.
Dooble: Dooble is a free and open source Web browser.
Dooble was created to improve privacy. Currently, Dooble
is available for FreeBSD, Linux, OS X, OS/2, and Windows.
Dooble uses Qt for its user interface and abstraction from
the operating system and processor architecture. As a re-
sult, Dooble should be portable to any system that sup-
ports OpenSSL, POSIX threads, Qt, SQLite, and other librar-
ies.
DTLS: Datagram Transport Layer Security (DTLS) is a com-
munications protocol that provides security for datagram-
based applications by allowing them to communicate in a
way that is designed to prevent eavesdropping, tampering,
or message forgery. The DTLS protocol is based on the
stream-oriented Transport Layer Security (TLS) protocol
and is intended to provide similar security guarantees. The
DTLS protocol datagram preserves the semantics of the
underlying transport—the application does not suffer from
the delays associated with stream protocols, but because it
uses UDP, the application has to deal with packet reorder-
ing, loss of datagram and data larger than the size of a
Glossary
255
datagram network packet. Because DTLS uses UDP rather
than TCP, it avoids the "TCP meltdown problem", when be-
ing used to create a VPN tunnel.
Echo Accounts: Echo Accounts define an authorization
scheme for the access to neighbour-nodes respective to
the listener of a server. At the same time, they can form a
Web-of-Trust. One-Time-Accounts regulate the assignment
of an access, which can be used on time.
Echo Match: The Echo Match is a specific cryptographic
process to check the provided hash of the original plain
text message with the hash of the conversion of the cipher-
text with a specific key. If both hashes are the same, the
right key has been chosen. Because the hash function can-
not be inverted, the provided hash of the original plain text
message does not provide any information about this mes-
sage. Only if both hashes are the same, the conversion
from cipher text to plain text has been successful and the
right user with the right key can read the message. This re-
quires that each given key must be tried out and if the
message cannot be converted successfully, that the mes-
sage has to be provided to all known network connections
and nodes to be tried out there: the message cannot be
read by this node with given keys.
Echo Network: The Echo Network is a network based on
Echo Nodes communicating over the Echo Protocol (and
HTTPS). Often the letters E_C_H_O are used to provide a
template for such a network within graph theory. The Echo
network consists of servers and clients, within the Spot-On
clients the server software is already included, so that
nodes can be in a hybrid position, to be a server connected
to a server, a server connected to a node or a node con-
nected to a server. The Echo Network is speaking of Neigh-
bors for another node.
Echo: Spot-On introduced the Echo. The Echo is a malleable
concept. That is, an implementation does not require rigid
details. Each model may adhere to their own peculiar obli-
gations. The Echo functions on the elementary persuasion
that information is dispersed over multiple or singular pas-
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256
sages and channel endpoints evaluate the suitability of the
received data. Because data may become intolerable, Spot-
On implements its own congestion control algorithm. Re-
ceived messages that meet some basic criteria are labeled
and duplicates are discarded. Advanced models may define
more sophisticated congestion-avoidance algorithms based
upon their interpretations of the Echo. The Echo combines
encryption and graph theory: With the Echo Protocol is
meant - simply put – that first, every message transmission
is encrypted and second, in the Echo Network, each con-
nection node sends each message to each connected
neighbor. As third criterion for the Echo Protocol can be
added, that there is a special feature when unpacking the
encrypted capsule: The capsules have neither a receiver
nor sender information included - and here they are differ-
ent from TCP packets. The message is identified by the
hash of the unencrypted message (compared to the con-
version text of all known keys in the node) as to whether
the message should be displayed and readable to the recip-
ient in the user interface or not. For this so-called “Echo
Match” see even more detailed at referring keyword. Spot-
On provides two modes of operation for the general Echo,
Full Echo and Half Echo. The Full Echo permits absolute da-
ta flow. The Half Echo defines an agreement between two
endpoints. Within this agreement, information from other
endpoints is prohibited from traveling along the private
channel.
Echo-Grid: The Echo-Grid is a graphical representation of a
template for the Echo-protocol, do be able to illustrate dif-
ferent nodes and communicational relations in a graphic
and within graph-theory. For that the letters for the word
ECHO, respective the both characters AE are drawn and
connected on a base-line. All angle corners of each letter
further represent potential nodes in communicational
networks, which can be per letter be consecutively num-
bered, example: E1 … E1 for the six nodes of the letter E.
Then it is possible to talk about the communicational paths
of drawn users from E to O.
Glossary
257
Echo-Protocol: The Echo protocol means from an opera-
tional view: you send only encrypted messages, but you
send your to-be-send-message to all of your connected
friends. They do the same. You maintain your own net-
work, everyone has every message and you try to decrypt
every message. In case you can read and unwrap it, it is a
message for you. Otherwise you share the message with all
your friends and the message remains encrypted. Echo is
very simple, and the principle is over 30 years old – nothing
new. As Echo uses HTTP as a protocol, there is no forward-
ing or routing of messages: no IPs are forwarded, e.g. like it
is if you send your message e.g. from your home laptop to
your webserver. The process starts at each destination new
– as you define it. The Echo protocol provided by spot-on
has nothing to do with RFC 862. A new Echo protocol RFC
has to be written or re-newed and extended – with or
without that RFC-Number it refers to a p2p network.
Edgar Allan Poe: Edgar Allan Poe (1809 – 1849) was an
American writer, editor, and literary critic. Poe is best
known for his poetry and short stories, particularly his tales
of mystery and the macabre. He is widely regarded as a
central figure of Romanticism in the United States and of
American literature as a whole, and he was one of the
country's earliest practitioners of the short story. One very
popular short story was the story of “GoldBug”. Hence, the
software application also named GoldBug as an alternative
GUI for the Spot-On kernel is a reminiscence to this writer.
Poe is generally considered the inventor of the detective
fiction genre and is further credited with contributing to
the emerging genre of science fiction. He was the first well-
known American writer to earn a living through writing
alone, resulting in a financially difficult life and career. Poe
was born in Boston and his works influenced literature
around the world, as well as specialized fields such as cos-
mology and cryptography. He was a popular writer of cryp-
tograms and interested in bringing the knowledge of cryp-
tographic thinking to the population.
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ElGamal: In cryptography, the ElGamal encryption system
is an asymmetric key encryption algorithmfor public-key
cryptography which is based on the Diffie–Hellman key ex-
change. It was described by Taher ElGamal in 1985. El-
Gamal encryption is used in the free GNU Privacy Guard
software, recent versions of PGP, and other cryptosystems.
E-Mail Institution: An E-Mail-institution describes an E-
Mail-Postbox within the p2p network of the Echo protocol.
Per definition of an address-like Description for the institu-
tion, E-Mails of users within the p2p network can tempo-
rarily be stored within one other node. As well it is possi-
ble, to send E-Mail to friends, which are currently offline.
Institutions describe a standard, how to configure an E-
Mail-Postbox within a p2p network – like today POP3 and
IMAP allow to provide a Mailbox. The Mailbox of the E-
Mail-Institution is inserted by a Magnet-URI-Link within the
client, which want to use the Postbox. At the E-Mail-
Institution only the public E-Mail-Encryption-Key of the
postbox-users has to be entered.
Encapsulation: The capsule (like a zip) within the Echo de-
scribes a bundle of message elements, like the cipher text
of the original message, the hash for the plain text of the
message and also further elements like signature keys etc.
In case an Echo Match was not successful, the elements of
the capsule are encapsulated again and sent to further
neighbors.
Encrypt-then-MAC(ETM): The plaintext is first encrypted,
then a MAC is produced based on the resulting ciphertext.
The ciphertext and its MAC are sent together. Used in, e.g.,
Ipsec. The standard method according to ISO/IEC
19772:2009. This is the only method which can reach the
highest definition of security in authenticated encryption,
but this can only be achieved when the MAC used is
“Strongly Unforgeable”. In November 2014, TLS and DTLS
extension for EtM has been published as RFC 7366.
End-to-End: The end-to-end principle is a classic design
principle of computer networking, first explicitly articulated
in a 1981 conference paper by Saltzer, Reed, and Clark. The
Glossary
259
end-to-end principle states that application-specific func-
tions ought to reside in the end hosts of a network rather
than in intermediary nodes – provided they can be imple-
mented “completely and correctly” in the end hosts. In de-
bates about network neutrality, a common interpretation
of the end-to-end principle is that it implies a neutral or
“dumb” network. End-to-end encryption (E2EE) is an unin-
terrupted protection of the confidentiality and integrity of
transmitted data by encoding it at its starting point and de-
coding it at its destination. It involves encrypting clear (red)
data at source with knowledge of the intended recipient,
allowing the encrypted (black) data to travel safely through
vulnerable channels (e.g. public networks) to its recipient
where it can be decrypted (assuming the destination
shares the necessary key-variables and algorithms). An
end-to-end encryption is often reached by providing an en-
cryption with the AES Passphrase.
Ephemeral Keys: Ephemeral Keys are temporarily used
keys for encryption, often used for end-to-end encryption
and/or to provide Forward Secrecy: Temporary keys are
more deniable than permanent keys.
EPKS (Echo Public Key Share): Echo Public Key Share (EPKS)
is a function implemented in Spot-On to share public en-
cryption keys over the Echo Network. This allows a group
to share keys over secure channels so that a classical key
server it not needed. It is a way of key exchange to a group
or one individual user. The key exchange (also known as
“key establishment”) is any method in cryptography by
which cryptographic keys are exchanged between users, al-
lowing use of a cryptographic algorithm. If sender and re-
ceiver wish to exchange encrypted messages, each must be
equipped to encrypt messages to be sent and decrypt mes-
sages received. The nature of the equipping they require
depends on the encryption technique they might use. If
they use a code, both will require a copy of the same
codebook. If they use a cipher, they will need appropriate
keys. If the cipher is a symmetric key cipher, both will need
a copy of the same key. If an asymmetric key cipher with
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the public/private key property, both will need the other’s
public key. The key exchange problem is how to exchange
whatever keys or other information are needed so that no
one else can obtain a copy. Historically, this required trust-
ed couriers, diplomatic bags, or some other secure chan-
nel. With the advent of public key / private key cipher algo-
rithms, the encrypting key (aka public key) could be made
public, since (at least for high quality algorithms) no one
without the decrypting key (aka, the private key) could de-
crypt the message. Diffie–Hellman key exchange: In 1976,
Whitfield Diffie and Martin Hellman published a crypto-
graphic protocol, (Diffie–Hellman key exchange), which al-
lows users to establish ‘secure channels’ on which to ex-
change keys, even if an Opponent is monitoring that com-
munication channel. However, D–H key exchange did not
address the problem of being sure of the actual identity of
the person (or ‘entity’).
Exponential Encryption: Exponential Encryption is a term
coined by the analysts and authors Meke Gasakis and Max
Schmidt in their book about „The New Era of Exponential
Encryption“, in which they analyze based on the Echo Pro-
tocol the trends and their vision to provide exponential op-
tions for encryption and decryption processes in combina-
tion with graph-theory within Echo networks. Here each
node sends each message to each known neighbor, which
multiplicities the options like a rice corn – according to a
popular story - doubling at each field of a chess board.
Fiasco Keys: Fiasco Keys are temporary keys, which were
first introduced within the Smoke Mobile Echo Client.
These keys are a bunch of temporary keys provided in a
cache for end to end encryption. Starting from the newest,
all keys in that cache for Fiasco Forwarding have to be tried
out. This is a more volatile construction than schematic key
transmission known form other protocols.
File Encryption Tool: The File Encryption Tool of Spot-On
has the function to encrypt and decrypt files on the hard
disk. Here as well many values for the encryption details
can be set individually. The tool is useful, in case files have
Glossary
261
to be sent - either over encrypted or unencrypted connec-
tions. As well for the storage of files, either on your local
hard disc or as well remote in the cloud, this tool is very
helpful, to secure own data.
File-Encryptor: File-Encryptor is a tool within the Spot-On
Encryption Suite to encrypt files before they are sent out
over encrypted or unencrypted connection or are stored
within a cloud or foreign storage option.
File-Sharing: File sharing is the practice of distributing or
providing access to digital media, such as computer pro-
grams, multimedia (audio, images and video), documents
or electronic books. File sharing may be achieved in a
number of ways. Common methods of storage, transmis-
sion and dispersion include manual sharing utilizing re-
movable media, (de-)centralized servers on computer net-
works, World Wide Web-based hyperlinked documents,
and the use of (mobile) distributed peer-to-peer network-
ing.
FireChat: FireChat is an IRC-like group chat within the
Smoke Mobile Echo Client and compatible to the BUZZ-
Chat in the
Forward Secrecy (FS): In cryptography, forward secrecy (FS;
also known as perfect forward secrecy) is a property of se-
cure communication protocols: a secure communication
protocol is said to have forward secrecy if compromise of
long-term keys does not compromise past session keys.[2]
FS protects past sessions against future compromises of se-
cret keys or passwords. If forward secrecy is utilized, en-
crypted communications recorded in the past cannot be re-
trieved and decrypted should long-term secret keys or
passwords be compromised in the future.
Forward-Secrecy-Calling: Forward-Secrecy-Calling is some
modus for Cryptographic Calling, which sends temporary
asymmetric keys for end-to-end encryption and is referred
to asymmetric calling. It refers to send several asymmetric
key (pairs) through one secured channel. The symmetric
end-to-end encryption key is sent in the Forward Secrecy
Calling (FSC) not over the permanent (a-symmetric) e.g.
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262
chat key or over the channel of an existing (symmetric)
end-to-end encryption key, but by the new ephemeral,
temporary and a-symmetric (e.g. chat) key. While sending
an end-to-end encryption key over an existing end-to-end
symmetric encrypted channel defines a "symmetric" “in-
stant perfect forward secrecy”, sending an end-to-end en-
crypting key over the ephemeral keys of the initiated “for-
ward secrecy” (in e.g. the chat function) may be considered
an “a-symmetric” one of “Instant Perfect Forward Secrecy”.
Forward Secrecy: Forward Secrecy (FS), also known as per-
fect forward secrecy (PFS), is a feature of specific key
agreement protocols that gives assurances your session
keys will not be compromised even if the private key of the
server is compromised. Forward secrecy protects past ses-
sions against future compromises of secret keys or pass-
words. By generating a unique session key for every session
a user initiates, even the compromise of a single session
key will not affect any data other than that exchanged in
the specific session protected by that particular key.
Friend-to-Friend (F2F): A friend-to-friend (or F2F) comput-
er network is a type of peer-to-peer network in which us-
ers only make direct connections with people they know.
Passwords or digital signatures can be used for authentica-
tion. Unlike other kinds of private P2P, users in a friend-to-
friend network cannot find out who else is participating
beyond their own circle of friends, so F2F networks can
grow in size without compromising their users’ anonymity.
Full Echo: See Echo.
Galois/Counter Mode (GCM)-Algorithm: Galois/Counter
Mode (GCM) is a mode of operation for symmetric key
cryptographic block ciphers that has been widely adopted
because of its efficiency and performance. GCM through-
put rates for state of the art, high speed communication
channels can be achieved with reasonable hardware re-
sources.
Gemini: The Gemini is a feature in Spot-On Secure Instant
Messenger to add another security layer to the chatroom
with an AES Key for end-to-end
Glossary
263
GnuPG: GNU Privacy Guard (GnuPG or GPG), a free-
software replacement for Symantec's PGP cryptographic
software suite, complies with RFC 4880, the IETF stand-
ards-track specification of OpenPGP. Modern versions of
PGP are interoperable with GnuPG and other OpenPGP-
compliant systems. GnuPG is a hybrid-encryption software
program because it uses a combination of conventional
symmetric-key cryptography for speed, and public-key
cryptography for ease of secure key exchange, typically by
using the recipient's public key to encrypt a session key
which is only used once. GnuPG encrypts messages using
asymmetric key pairs individually generated by GnuPG us-
ers. The resulting public keys may be exchanged with other
users in a variety of ways. GnuPG also supports symmetric
encryption algorithms. By default, GnuPG uses the CAST5
symmetrical algorithm.
Gnutella: Gnutella is a large peer-to-peer network. It was
the first decentralized peer-to-peer network of its kind,
leading to other, later networks adopting the model.
GoldBug (Application): The GoldBug Messenger and E-
Mail-Client is a user interface, which offers for the kernel
and the application Spot-On an alternative to the originally
offered user interface of Spot-on, which contains many op-
tions. The GoldBug Graphical User Interface (GUI) therefore
has the approach, to have a more simplified user interface
designed, which is useable not only on the desktop, but al-
so can be deployed for mobile devices.
GoldBug (E-Mail Password): The GoldBug-feature is used
in the integrated email client to add here as well an end-to-
end AES Encryption layer – the GoldBug, or: just a pass-
word, both users use to encrypt their emails once more. So
with the GoldBug, you need a kind of password (e.g. AES-
string) to open the email of a friend or to be able to chat
with him.
Graph-Theory: In mathematics, and more specifically in
graph theory, a graph is a representation of a set of objects
where some pairs of objects are connected by links. The in-
terconnected objects are represented by mathematical ab-
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264
stractions called vertices (also called nodes or points), and
the links that connect some pairs of vertices are called
edges (also called arcs or lines). Typically, a graph is depict-
ed in diagrammatic form as a set of dots for the vertices,
joined by lines or curves for the edges. Graphs are one of
the objects of study in discrete mathematics.
Group chat: The term group chat, or group chat room, is
primarily used to describe any form of synchronous con-
ferencing, occasionally even asynchronous conferencing.
The term can thus mean any technology ranging from real-
time online chat and online interaction with strangers (e.g.,
online rooms) to fully immersive graphical social environ-
ments. The primary use of a group chat room is to share in-
formation via text with a group of other users. Generally
speaking, the ability to converse with multiple people in
the same conversation differentiates group chat rooms
from instant messaging programs, which are more typically
designed for one-to-one communication - though two us-
ers also can define a group for private conversations.
GUI: In computer science, a graphical user interface or GUI
is a type of interface that allows users to interact with elec-
tronic devices through graphical icons and visual indicators
such as secondary notation, as opposed to text-based in-
terfaces, typed command labels or text navigation.
Half Echo: Spot-On provides two modes of operation for
the general Echo, Full Echo and Half Echo. The Full Echo
permits absolute data flow. The Half Echo defines an
agreement between two endpoints. Within this agree-
ment, information from other endpoints is prohibited from
traveling along the private channel. If you use the modus
“half Echo”, then your message is not shared with other,
third participants (Model: A -> B -> C). Only direct connec-
tions are used (Model A -> B). It requires only one direct
connection to one friend. With the modus “Full Echo” your
message is forwarded from friend to friend and so on, until
the recipient could decrypt the envelope and read the
message.
Glossary
265
Hash: A hash function is any function that can be used to
map data of arbitrary size to data of fixed size. The values
returned by a hash function are called hash values, hash
codes, hash sums, or simply hashes. A cryptographic hash
function is a hash function which is considered practically
impossible to invert, that is, to recreate the input data
from its hash value alone. These one-way hash functions
have been called “the workhorses of modern cryptog-
raphy”. The input data is often called the message, and the
hash value is often called the message digest or simply the
digest.
HMAC: HMAC (sometimes expanded as either keyed-hash
message authentication code or hash-based message au-
thentication code) is a specific type of message authentica-
tion code (MAC) involving a cryptographic hash function
and a secret cryptographic key. It may be used to simulta-
neously verify both the data integrity and the authentica-
tion of a message, as with any MAC. Any cryptographic
hash function, such as SHA-256 or SHA-3, may be used in
the calculation of an HMAC; the resulting MAC algorithm is
termed HMAC-X, where X is the hash function used (e.g.
HMAC-SHA256 or HMAC-SHA3). The cryptographic
strength of the HMAC depends upon the cryptographic
strength of the underlying hash function, the size of its
hash output, and the size and quality of the key. HMAC us-
es two passes of hash computation. The secret key is first
used to derive two keys – inner and outer. The first pass of
the algorithm produces an internal hash derived from the
message and the inner key. The second pass produces the
final HMAC code derived from the inner hash result and
the outer key. Thus, the algorithm provides better immuni-
ty against length extension attacks. An iterative hash func-
tion breaks up a message into blocks of a fixed size and it-
erates over them with a compression function. For exam-
ple, SHA-256 operates on 512-bit blocks. The size of the
output of HMAC is the same as that of the underlying hash
function (e.g., 256 and 1600 bits in the case of SHA-256
and SHA-3, respectively), although it can be truncated if
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266
desired. HMAC does not encrypt the message. Instead, the
message (encrypted or not) must be sent alongside the
HMAC hash. Parties with the secret key will hash the mes-
sage again themselves, and if it is authentic, the received
and computed hashes will match. The definition and analy-
sis of the HMAC construction was first published in 1996 in
a paper by Mihir Bellare, Ran Canetti, and Hugo Krawczyk,
and they also wrote RFC 2104 in 1997.
HTTPS: HTTPS (also called HTTP over TLS, HTTP over SSL,
and HTTP Secure) is a protocol for secure communication
over a computer network which is widely used on the In-
ternet. HTTPS consists of communication over Hypertext
Transfer Protocol (HTTP) within a connection encrypted by
Transport Layer Security or its predecessor, Secure Sockets
Layer. The main motivation for HTTPS is authentication of
the visited website and protection of the privacy and integ-
rity of the exchanged data.
Human Rights: Human rights are the basic rights and free-
doms to which all humans are entitled". Examples of rights
and freedoms which are often thought of as human rights
include civil and political rights, such as the right to life,
liberty, and property, freedom of expression, pursuit of
happiness and equality before the law; and social, cultural
and economic rights, including the right to participate in
science and culture, the right to work, and the right to ed-
ucation and the right of privacy.
Hybrid Encryption: See also Multi-Encryption. Hybrid En-
cryption points especially out that symmetric and asym-
metric encryption has been applied either in one applica-
tion or to a plain text.
IMAP: In computing, the Internet Message Access Protocol
(IMAP) is an Internet standard protocol used by e-mail cli-
ents to retrieve e-mail messages from a mail server over a
TCP/IP connection. IMAP is defined by RFC 3501. IMAP was
designed with the goal of permitting complete manage-
ment of an email box by multiple email clients, Therefore,
clients generally leave messages on the server.
Glossary
267
Impersonator: Impersonator is a function, which sends
from the Spot-On Client a message from time to time into
the network, which contains only random characters. With
this method it is made more difficult for attackers to con-
duct time analysis of communications. Also, real cipher
text messages should be harder to recognize and harder to
differ from such messages with random characters.
Information security: information security preservation of
confidentiality, integrity and availability of information
Innovation: Innovation in its modern meaning is a "new
idea, creative thoughts, new imaginations in form of device
or method". Innovation is often also viewed as the applica-
tion of better solutions that meet new requirements, unar-
ticulated needs, or existing market needs. Such innovation
takes place through the provision of more-effective prod-
ucts, processes, services, technologies, or business models
that are made available to markets, governments and soci-
ety. An innovation is something original and more effective
and, as a consequence, new, that "breaks into" the market
or society. Innovation is related to, but not the same as, in-
vention, as innovation is more apt to involve the practical
implementation of an invention (i.e. new/improved ability)
to make a meaningful impact in the market or society, and
not all innovations require an invention.
Instant Perfect Forward Secrecy (IPFS): While Perfect For-
ward Secrecy, often also called only Forward Secrecy, de-
scribes within many applications and as well from a con-
ceptional approach the transmission of ephemeral– this
means temporary - keys, it is implicit connected, that this is
proceeded one time per online session. With Spot-On and
the underlying architecture of the Spot-On Kernel a new
paradigm has been implemented. Forward Secrecy or Per-
fect Forward Secrecy, has developed further to Instant Per-
fect Forward Secrecy (IPFS). While Forward Secrecy means
to be able to neglect to have used a certain key in the past
if one further key is compromised, this concept addresses
to end-to-end encryption. With Instant Perfect Forward
Secrecy the Cryptographic Calling comes into the frame: A
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user is able to renew the end-to-end encrypting credentials
like in a call: Instantly and several times within a session
the user should be able to renew temporary keys for end-
to-end encryption. An even further development of this
concept has been taken place by the development of Fias-
co Forwarding, which sends a full bundle of keys within
one session or with a(n automated) call action for future
sessions.The end-to-end-encryption with temporary keys
can be changed at any time, this means also per any sec-
ond. This describes the term of Instant Perfect Forward Se-
crecy (IPFS). Via a so-called “Call” the end-to-end-
encryption can be renewed. Instantly. Also, the term of a
“call” for the transmission of a to-be-created or to-be-
renewed end-to-end-encryption has been introduced by
Spot-on into cryptography.
Institution: An Institution in Cryptography is an e-mail
postbox to save messages for offline participants within a
peer-to-peer Echo Network. The institution is based on
cryptographic credentials, so that in one node subscribed
participant with their public encryption key can deposit,
save and retrieve messages. The advantage despite other
methods e.g. storing the data within a common friend) is
that the providing node of an Institution need not to give
out the own public encryption key.
Integer factorization: In number theory, integer factoriza-
tion is the decomposition of a composite number into a
product of smaller integers. If these integers are further re-
stricted to prime numbers, the process is called prime fac-
torization. When the numbers are very large, no efficient,
non-quantum integer factorization algorithm is known; an
effort by several researchers concluded in 2009, factoring a
232-digit number (RSA-768), utilizing hundreds of ma-
chines took two years and the researchers estimated that a
1024-bit RSA modulus would take about a thousand times
as long.
Integrity: property of accuracy and completeness.
IPFS: IPFS is the abbreviation of Instant Perfect Forward
Secrecy.
Glossary
269
IRC: Internet Relay Chat (IRC) is an application layer proto-
col that facilitates communication in the form of text. The
chat process works on a client/server networking model.
IRC clients are computer programs that users can install on
their system or web based applications running either lo-
cally in the browser or on 3rd party server. These clients
communicate with chat servers to transfer messages to
other clients. IRC is mainly designed for group communica-
tion in discussion forums, called channels, but also allows
one-on-one communication via private messages as well as
chat and data transfer, including file sharing.
Iteration Function: In mathematics, an iterated function is
a function X? X (that is, a function from some set X to it-
self) which is obtained by composing another function f :
X ? X with itself a certain number of times. The process of
repeatedly applying the same function is called iteration.
Iterated functions are objects of study in computer science,
fractals, dynamical systems, mathematics and renormaliza-
tion group physics.
Java: Java is a general-purpose computer-programming
language that is concurrent, class-based, object-oriented,
and specifically designed to have as few implementation
dependencies as possible. It is intended to let application
developers "write once, run anywhere" (WORA), meaning
that compiled Java code can run on all platforms that sup-
port Java without the need for recompilation.
Kerckhoffs's principle: Kerckhoffs's principle was stated by
Netherlands born cryptographer Auguste Kerckhoffs in the
19th century: A cryptosystem should be secure even if eve-
rything about the system, except the key, is public
knowledge. Kerckhoffs's principle was reformulated (or
possibly independently formulated) by American mathe-
matician Claude Shannon as "the enemy knows the sys-
tem", i.e., "one ought to design systems under the assump-
tion that the enemy will immediately gain full familiarity
with them". In that form, it is called Shannon's maxim.
Kerckhoffs's principle (Shannon's maxim) is widely em-
braced by cryptographers.
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Kernel: In computing, the kernel is a computer program
that manages input/output requests from software and
translates them into data processing instructions for the
central processing unit and other electronic components of
a computer. The kernel is a fundamental part of a modern
computer’s operating system or of applications.
Keyboard: In computing, a computer keyboard is a type-
writer-style device which uses an arrangement of buttons
or keys to act as mechanical levers or electronic switches.
Keyboard keys (buttons) typically have characters engraved
or printed on them, and each press of a key typically corre-
sponds to a single written symbol. Virtual keyboards in
software with encryption prevent that key-loggers record
the typing - as mouse clicks do not indicate, which symbol
has been klicked.
Keyed-Hash Message Authentication Code (HMAC): In
cryptography, a keyed-hash message authentication code
(HMAC) is a specific construction for calculating a message
authentication code (MAC) involving a cryptographic hash
function in combination with a secret cryptographic key. As
with any MAC, it may be used to simultaneously verify
both the data integrity and the authentication of a mes-
sage. Any cryptographic hash function, such as MD5 or
SHA-1, may be used in the calculation of an HMAC; the re-
sulting MAC algorithm is termed HMAC-MD5 or HMAC-
SHA1 accordingly. The cryptographic strength of the HMAC
depends upon the cryptographic strength of the underlying
hash function, the size of its hash output, and on the size
and quality of the key.
KeySync: KeySyc is a term deriving from the context of the
term AutoCrypt, which are both a follow up of the idea of a
REPLEO, respective a key exchange over the EPKS – Echo
Public Key Sharing – Protocol. Here two participants share
over a channel the public keys and integrate the received
keys into the own nodes.
Libcurl: cURL is a computer software project providing a
library and command-line tool for transferring data using
various protocols. The cURL project produces two prod-
Glossary
271
ucts, libcurl and cURL. It was first released in 1997. The
name originally stood for “see URL”.
Listener: A listener is a software design pattern in which an
object maintains a list of its dependents and notifies them
automatically of any state changes, usually by calling one of
their methods. It is mainly used to implement distributed
event handling systems. It is often used for creating or
opening a port on which the service or chat-server then is
“listening” for incoming data connections.
Login: In computer security, logging in (or logging on or
signing in or signing on) is the process by which an individ-
ual gains access to a computer system by identifying and
authenticating themselves. The user credentials are typical-
ly some form of "username" and a matching "password",
and these credentials themselves are sometimes referred
to as a login, (or a logon or a sign-in or a sign-on).
MAC (Message Authentication Code): In cryptography, a
message authentication code (often MAC) is a short piece
of information used to authenticate a message and to pro-
vide integrity and authenticity assurances on the message.
Integrity assurances detect accidental and intentional mes-
sage changes, while authenticity assurances affirm the
message’s origin. A MAC algorithm, sometimes called a
keyed (cryptographic) hash function (however, crypto-
graphic hash function is only one of the possible ways to
generate MACs), accepts as input a secret key and an arbi-
trary-length message to be authenticated, and outputs a
MAC (sometimes known as a tag). The MAC value protects
both a message’s data integrity as well as its authenticity,
by allowing verifiers (who also possess the secret key) to
detect any changes to the message content.
Magnet-URI: The Magnet-URI scheme, defines the format
of Magnet-links, a de facto standard for identifying files by
their content, via cryptographic hash value) rather than by
their location.
McEliece: In cryptography, the McEliece cryptosystem is an
asymmetric encryption algorithm developed in 1978 by
Robert McEliece. It was the first such scheme to use ran-
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domization in the encryption process. The algorithm has
currently not gained much acceptance in the cryptographic
community but is a candidate for “post-quantum cryptog-
raphy”, as it is immune to attacks using Shor’s algorithm
and — more generally — measuring cost states using Fou-
rier sampling. The recommended parameter sizes for the
used Goppa code - which maximizes the adversary’s work
factor - appears to be n = 1024, t = 38, and k = 644.
Measurement: process to determine a value.
MELODICA: With the MELODICA feature in Spot-On Secure
Messenger you call your friend and send him a new Gemi-
ni (AES-256-Key). The Key is sent over your asymmetric en-
cryption of the RSA key. This is a secure way, as all other
plaintext transfers like: email, spoken over phone or in
other messengers, have to be regarded as unsafe and rec-
orded. MELODICA stands for: Multi Encrypted Long Dis-
tance Calling. You call your friend even over a long distance
of the Echo protocol and exchange over secure asymmetric
encryption a Gemini (AES-256 key) to establish an end-to-
end encrypted channel.
Meta-data: Metadata is data [information] that provides
information about other data. Many distinct types of
metadata exist, among these descriptive metadata, struc-
tural metadata, administrative metadata, reference
metadata and statistical metadata. In the Internet meta da-
ta often refers to the recording of when how many data
has been accessed or transferred by whom to whom.
Monitoring: determining the status of a system, a process
or an activity.
Mosaic: A mosaic is the name for a file splitted into smaller
parts. These smaller parts are commonly called “blocks”,
“parts” or “chunks”, here in the Spot-On application they
are called: “links”. All links build the mosaic, which can be
assembled to the file, which has been transferred.
Multi-Encryption: Multiple encryption is the process of
encrypting an already encrypted message one or more
times, either using the same or a different algorithm. It is
Glossary
273
also known as cascade encryption, cascade ciphering, mul-
tiple encryption, and superencipherment. Superencryption
refers to the outer-level encryption of a multiple encryp-
tion. A hybrid cryptosystem is one which combines the
convenience of a public-key cryptosystem with the effi-
ciency of a symmetric-key cryptosystem. A hybrid cryp-
tosystem can be constructed using any two separate cryp-
tosystems: first, a key encapsulation scheme, which is a
public-key cryptosystem, and second a data encapsulation
scheme, which is a symmetric-key cryptosystem. Perhaps
the most commonly used hybrid cryptosystems are the
OpenPGP (RFC 4880) file format and the PKCS #7 (RFC
2315) file format, both used by many different systems.
Multiple encryption is the process of encrypting an already
encrypted message one or more times, either using the
same or a different algorithm. Multiple encryption (Cas-
cade Ciphers) reduces the consequences in the case that
our favorite cipher is already broken and is continuously
exposing our data without our knowledge. When a cipher
is broken (something we will not know), the use of other
ciphers may represent the only security in the system.
Since we cannot scientifically prove that any particular ci-
pher is strong, the question is not whether subsequent ci-
phers are strong, but instead, what would make us believe
that any particular cipher is so strong as to need no added
protection. Folk Theorem: A cascade of ciphers is at least as
at least as difficult to break as any of its component ci-
phers. When a cipher is broken (something we will not
know), the use of other ciphers may represent the only se-
curity in the system. Since we cannot scientifically prove
that any particular cipher is strong, the question is not
whether subsequent ciphers are strong, but instead, what
would make us believe that any particular cipher is so
strong as to need no added protection.
Ncat: Netcat (often abbreviated to nc or Ncat) is a comput-
er networking utility for reading from and writing to net-
work connections using TCP or UDP. Netcat is designed to
be a dependable back-end that can be used directly or
easily driven by other programs and scripts.
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Neighbor: In graph theory, a neighbor of a vertex is anoth-
er vertex that is connected to it by an edge.
Neuland: Neuland is a German term within the context of
the Internet and non-IT-savvy people, deriving as satirical
designation in reference to the sentence of the year 2013
by German chancellor Angela Merkel.
NIST: The National Institute of Standards and Technology
(NIST) is a physical sciences laboratory, and a non-
regulatory agency of the United States Department of
Commerce. Its mission is to promote innovation and indus-
trial competitiveness. NIST's activities are organized into
laboratory programs that include nanoscale science and
technology, engineering, information technology, neutron
research, material measurement, and physical measure-
ment.
NOVA: NOVA describes a password on the to-be-
transferred file. It is a symmetric encryption of the file
scheduled for the transfer. It can be compared with the
term of a GoldBug-Password on an E-Mail. Both are techni-
cally created with an AES-256 (or a user-defined password).
NTRU: NTRU is a patented and open source public-key
cryptosystem that uses lattice-based cryptography to en-
crypt and decrypt data. It consists of two algorithms:
NTRUEncrypt, which is used for encryption, and NTRUSign,
which is used for digital signatures. Unlike other popular
public-key cryptosystems, it is resistant to attacks using
Shor’s algorithm (i.e. by “Quantum Computing”) and its
performance has been shown to be significantly better.
Objective: result to be achieved.
Off-the-record (OTR): Off-the-Record Messaging (OTR) is a
cryptographic protocol that provides encryption for instant
messaging conversations. OTR uses a combination of AES
symmetric-key algorithm with 128 bits key length, the Dif-
fie–Hellman key exchange with 1536 bits group size, and
the SHA-1 hash function. In addition to authentication and
encryption, OTR provides forward secrecy and malleable
encryption.
Glossary
275
One-Time-Magnet (OTM): A One-Time-Magnet (OTM) is a
Magnet, which is deployed for the File-Transfer within the
StarBeam-Function. After sending the File using the cryp-
tographic values included in the Magnet-Link, the Magnet
is deleted within the Spot-On. Other Magnets for the Star-
Beam-Function can be used several times – this means,
several and different files can be transferred to the receiver
through the symmetric Channel (including all users, know-
ing the specific Magnet).
One-Time-Pad (OTP): In cryptography, the one-time pad
(OTP) is an encryption technique that cannot be cracked if
used correctly. In this technique, a plaintext is paired with a
random secret key (also referred to as a one-time pad).
Then, each bit or character of the plaintext is encrypted by
combining it with the corresponding bit or character from
the pad using modular addition. If the key is truly random,
is at least as long as the plaintext, is never reused in whole
or in part, and is kept completely secret, then the resulting
ciphertext will be impossible to decrypt or break.
Open source: Open source is a term denoting that a prod-
uct includes permission to use its source code, design doc-
uments, or content. It most commonly refers to the open-
source model, in which open-source software or other
products are released under an open-source license as part
of the open-source-software movement. Use of the term
originated with software but has expanded beyond the
software sector to cover other open content and forms of
open collaboration. In Cryptography only open source
software allows everyone to proof that the code has no
backdoors implemented.
OpenPGP: The OpenPGP standard (also Pretty Good Priva-
cy) is a data encryption and decryption computer program
that provides cryptographic privacy and authentication for
data communication. PGP is often used for signing, en-
crypting, and decrypting texts, e-mails, files, directories,
and whole disk partitions and to increase the security of e-
mail communications. It was created by Phil Zimmermann
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in 1991.PGP and similar software follow the OpenPGP
standard (RFC 4880) for encrypting and decrypting data.
OpenSSL: In computer networking, OpenSSL is a software
library to be used in applications that need to secure com-
munications against eavesdropping or need to ascertain
the identity of the party at the other end. It has found wide
use in internet web servers, serving a majority of all web
sites. OpenSSL contains an open source implementation of
the SSL and TLS protocols. Transport Layer Security (TLS)
and its predecessor, Secure Sockets Layer (SSL), both of
which are frequently referred to as ‘SSL’, are cryptographic
protocols designed to provide communications security
over a computer network.
OTM: See One-Time-Magnet.
OTR: See Off-the-record.
Ozone Postbox: The Ozone Postbox is a way to reach of-
fline friends within the Smoke Mobile Crypto Client respec-
tive the SmokeStack Communication Server for Android.
The Ozone Postbox serves as a cache for friends, which are
not online. The Ozone is just a passphrase string, which
must be applied in both, the client Smoke and the Server
SmokeStack. The rest is done by the cryptographic keys.
The Ozone can be initialized within the client by using the
dyndns or IP name, port and TCP, e.g.:
dyndns.org:4711:TCP. If the server administrator of Smoke-
Stack applies this string also as one ozone within the serv-
er, the clients will automatically add the string as the ozone
when entering the IP respective dyndns-string of the serv-
er.
P2P: see Peer-to-Peer.
Pandamonium: Pandamonium is a Web-Crawler, with
which URLs of a Domain can be indexed for Spot-On. The
Pandamonium Web Crawler can allocate for the URL-
Search function within the Spot-On Encryption Suite a
bunch of URLs over the Import-function.
Passphrase: A passphrase is a sequence of words or other
text used to control access to a computer system, program
Glossary
277
or data. A passphrase is similar to a password in usage but
is generally longer for added security. Passphrases are of-
ten used to control both access to, and operation of, cryp-
tographic programs and systems. Passphrases are particu-
larly applicable to systems that use the passphrase as an
encryption key. The origin of the term is by analogy with
password. The passphrase in Spot-On must be at least 16
characters long, this is used to create a cryptographic hash,
which is longer and stronger.
Pass-through: The Pass-through method within the appli-
cation Spot-On describes a function for a network path
from an application, e.g. a Gopher client, over two Spot-On
instances to another Gopher Client: Gopher -> Spot-On ->
Internet -> Spot-On – Gopher. This function works similar
as a VPN tunnel or a proxy for the external application. As
the connection from a Spot-On node over the Internet to
another Spot-On node is encrypted, also e.g. with the
McEliece algorithm, even old applications with no encryp-
tion can communicate now secure over the Internet. The
application to tie in must only meet some tolerance for
chaotic transmission, a Gopher client can be ideal used for
such tests.
Password: A password is a word or string of characters
used for user authentication to prove identity or access
approval to gain access to a resource (example: an access
code is a type of password), which is to be kept secret from
those not allowed access. In modern times, user names
and passwords are commonly used by people during a log
in process that controls access to protected computer op-
erating systems, mobile phones, cable TV decoders, auto-
mated teller machines (ATMs), etc.
Patch-Points: Patch-Points describe the entry- and end-
nodes of the pass-through functionality. This functionality
of has been discussed in the Spot-On Developer Forum
originally as Patch-Points, has then be named within the
application as pass-through function. At Patch-Points two
older applications without encryption can communicate
over the secure connection of two Spot-On nodes.
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Peer-to-Peer (P2P): Peer-to-peer (P2P) computing or net-
working is a distributed application architecture that parti-
tions tasks or workloads between peers. Peers make a por-
tion of their resources, such as processing power, disk stor-
age or network bandwidth, directly available to other net-
work participants, without the need for central coordina-
tion by servers or stable hosts. Peers are equally privileged,
equipotent participants in the application. They are said to
form a peer-to-peer network of nodes.
Performance: measurable result. Note: Performance can
relate either to quantitative or qualitative findings.
PKI: A public key infrastructure (PKI) is a set of roles, poli-
cies, and procedures needed to create, manage, distribute,
use, store & revoke digital certificates and manage public-
key encryption. The purpose of a PKI is to facilitate the se-
cure electronic transfer of information for a range of net-
work activities such as e-commerce, internet banking and
confidential email. It is required for activities where simple
passwords are an inadequate authentication method and
more rigorous proof is required to confirm the identity of
the parties involved in the communication and to validate
the information being transferred. In cryptography, a PKI is
an arrangement that binds public keys with respective
identities of entities (like people and organizations). The
binding is established through a process of registration and
issuance of certificates at and by a certificate authority
(CA). Depending on the assurance level of the binding, this
may be carried out by an automated process or under hu-
man supervision.
Plain text: In computing, plain text is a loose term for data
(e.g. file contents) that represent only characters of reada-
ble material but not its graphical representation nor other
objects (floating-point numbers, images, etc.). It may also
include a limited number of characters that control simple
arrangement of text, such as spaces, line breaks, or tabula-
tion characters (although tab characters can "mean" many
different things, so are hardly "plain"). In cryptography,
plain text is the opposite of cipher text.
Glossary
279
Point-to-Point: In telecommunications, a point-to-
point connection refers to a communications connection
between two communication endpoints or nodes. An ex-
ample is a telephone call, in which one telephone is con-
nected with one other, and what is said by one caller can
only be heard by the other. This is contrasted with a point-
to-multipoint or broadcast connection, in which many
nodes can receive information transmitted by one node.
Policy: intentions and direction of a formal entity as for-
mally expressed by its management.
POP3: In computing, the Post Office Protocol (POP) is an
application-layer Internet standard protocol used by local
e-mail clients to retrieve e-mail from a remote server over
a TCP/IP connection. POP has been developed through
several versions, with version 3 (POP3) being the last
standard in common use.
POPTASTIC: POPTASTIC is a function, which enables en-
crypted chat and encrypted E-Mail over the regular
POP3and IMAP-Postboxes of a user. The Spot-On Encryp-
tion Suite recognizes automatically, if the message has to
be regarded as a Chat-Message or an E-Mail-Message. For
that, the POPTASTIC encryption key is used. Once with a
friend exchanged, this key is sending all E-mails between to
E-Mail-Partner only as encrypted E-Mail. Third, POPTASTIC
enables – respective the insertion of the POP3 / IMAP ac-
count information into the settings enables – also an old-
fashioned and unencrypted E-Mail-Communication to @-E-
Mail-Addresses. Spot-On extends the Instant Messaging
with this function to a regular E-Mail-Client and also to an
always encrypting E-Mail-Client over the POPTASTIC Key.
The E-Mail-Addresses for encrypted E-Mails are indicated
with a lock icon. Encrypted Chat is enabled over the free
ports for E-Mail also behind more restrictive Hardware en-
vironments at any time.
PostgreSQL: PostgreSQL, often simply Postgres, is an ob-
ject-relational database management system (ORDBMS)
with an emphasis on extensibility and standards-
compliance. As a database server, its primary function is to
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280
store data securely, supporting best practices, and to allow
for retrieval at the request of other software applications.
It can handle workloads ranging from small single-machine
applications to large Internet-facing applications with many
concurrent users. PostgreSQL implements the majority of
the SQL:2011 standard.
Privacy: Privacy is the ability of an individual or group to
seclude themselves, or information about themselves, and
thereby express themselves selectively. The boundaries
and content of what is considered private differ among cul-
tures and individuals but share common themes. When
something is private to a person, it usually means that
something is inherently special or sensitive to them. The
domain of privacy partially overlaps with security (confi-
dentiality), which can include the concepts of appropriate
use, as well as protection of information. Privacy may also
take the form of bodily integrity. The right not to be sub-
jected to unsanctioned invasions of privacy by the govern-
ment, corporations or individuals is part of many countries'
privacy laws, and in some cases, constitutions. All countries
have laws which in some way limit privacy. An example of
this would be law concerning taxation, which normally re-
quires the sharing of information about personal income or
earnings. In some countries individual privacy may conflict
with freedom of speech laws and some laws may require
public disclosure of information which would be consid-
ered private in other countries and cultures. The right to
privacy is an element of various legal traditions to restrain
governmental and private actions that threaten the privacy
of individuals. Over 150 national constitutions mention the
right to privacy. Since the global surveillance disclosures of
2013, initiated by ex-NSA employee Edward Snowden, the
inalienable human right to privacy has been a subject of in-
ternational debate. Internet privacy involves the right or
mandate of personal privacy concerning the storing, re-
purposing, provision to third parties, and displaying of in-
formation pertaining to oneself via the Internet. Internet
privacy is a subset of data privacy. Privacy concerns have
Glossary
281
been articulated from the beginnings of large-scale com-
puter sharing.
Private Key: Public-key cryptography refers to a set of cryp-
tographic algorithms that are based on mathematical prob-
lems that currently admit no efficient solution. The
strength lies in the “impossibility” (computational imprac-
ticality) for a properly generated private key to be deter-
mined from its corresponding public key. Thus the public
key may be published without compromising security.
Security depends only on keeping the private key private.
Process: set of interrelated or interacting activities which
transforms inputs into outputs
Public Key: Public-key cryptography refers to a set of cryp-
tographic algorithms that are based on mathematical prob-
lems that currently admit no efficient solution – particular-
ly those inherent in certain integer factorization, discrete
logarithm, and elliptic curve relationships. It is computa-
tionally easy for a user to generate a public and private key-
pair and to use it for encryption and decryption. The
strength lies in the “impossibility” (computational imprac-
ticality) for a properly generated private key to be deter-
mined from its corresponding public key. Thus the public
key may be published without compromising security.
Security dependes especially on keeping the private key
private.
Pure Forward Secrecy (PURE FS): Pure Forward Secrecy
refers to a communication in the E-Mail function of Spot-
On, within which the information is not sent over asym-
metrical keys, but over temporary, ephemeral keys, which
generate a symmetric encryption. The ephemeral keys for
Pure Forward Secrecy are exchanged over asymmetric keys,
but then the message is sent exclusively over the tempo-
rary symmetric key. Compare in a different approach of In-
stant Perfect Forward Secrecy, that the messages is en-
crypted and transferred with both, a symmetric key and al-
so with a asymmetric key within the format of the Echo-
protocol.
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Qt: Qt is a cross-platform application framework that is
widely used for developing application software that can
be run on various software and hardware platforms with
little or no change in the underlying codebase, while still
being a native application with the capabilities and speed
thereof. Qt is currently being developed both by the Qt
Company, a subsidiary of Digia, and the Qt Project under
open source governance, involving individual developers
and firms working to advance Qt.
Quantum Computing: Quantum computing is the use of
quantum-mechanical phenomena such as superposition
and entanglement to perform computation. A quantum
computer is used to perform such computation, which can
be implemented theoretically or physically. The field of
Quantum Computing is actually a sub-field of quantum in-
formation science, which includes quantum cryptography
and quantum communication. Quantum Computing was
started in the early 1980s when Richard Feynman and Yuri
Manin expressed the idea that a quantum computer had
the potential to simulate things that a classical computer
could not. In 1994, Peter Shor shocked the world with an
algorithm that had the potential to decrypt all secured
communications.
Random: Randomness is the lack of pattern or predictabil-
ity in events. A random sequence of events, symbols or
steps has no order and does not follow an intelligible pat-
tern or combination. Individual random events are by defi-
nition unpredictable.
Raspberry Pi: The Raspberry Pi is a series of small single-
board computers developed in the United Kingdom by the
Raspberry Pi Foundation to promote teaching of basic
computer science in schools and in developing countries.
The original model became far more popular than antici-
pated.
REPLEO: With a REPLEO the own public key is encrypted
with the already received public key of a friend, so that the
own public key can be transferred to the friend in a pro-
tected way.
Glossary
283
Requirement: Need or expectation that is stated, generally
implied or obligatory; Note: “Generally implied” means
that it is custom or common practice for the organization
and interested parties that the need or expectation under
consideration is implied. A specified requirement is one
that is stated, for example in documented information.
RetroShare: RetroShare is a chat and file sharing applica-
tion based on a Friend-to-Friend Network building a web of
trust. Peers have been replaced in this network by trusted
friends. It is in complementary the old-fashioned way to
connect to a friend in regard to Echo-Accounts, which are
not tied to the public key of a friend.
Review: activity undertaken to determine the suitability,
adequacy and effectiveness of the subject matter to
achieve established objectives
Rewind: Rewind describes a function within the StarBeam-
File-Transfer. With this the Send-out of a file is started for a
second time. It is comparable with a new play from start of
a music file. In case the file has not been completely trans-
ferred, the transmission can be started new or even sched-
uled for a later point of time. In case only some missing
block of the file should be transferred again to the receiver,
the further tool StarBeam-Analyzer is able to generate a
Magnet-URI-Link, which the receiver can send to the send-
er, so that is will send out only the missing blocks again.
Rosetta CryptoPad: The Rosetta-CryptoPad uses an own
Key for the encryption – as also an own key exists for E-
Mail, Chat, URLs or POPTASTIC. With the Rosetta-
CryptoPad a text can be converted into cipher text. It is
used, to encrypt own texts before sending the text out to
the internet or before you Post it somewhere into the Web.
Similar to the File-Encryption-Tool for Files, Rosetta also
converts plaintext into cipher text. Then the text can be
transferred – either over one again secured and encrypted
channel or even unencrypted as Chat or E-mail. Further
messages can be posted to an Internet-Board or a Paste-
Bin-Service as chipper text.
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RSA: RSA is one of the first practical public-key cryptosys-
tems and is widely used for secure data transmission. In
such a cryptosystem, the encryption key is public and dif-
fers from the decryption key which is kept secret. In RSA,
this asymmetry is based on the practical difficulty of factor-
ing the product of two large prime numbers, the factoring
problem. RSA is made of the initial letters of the surnames
of Ron Rivest, Adi Shamir, and Leonard Adleman, who first
publicly described the algorithmin 1977.
Salt, cryptographic: In cryptography, a saltis random data
that is used as an additional input to a one-way function
that hashes a password or passphrase. The primary func-
tion of salts is to defend against dictionary attacks versus a
list of password hashes and against pre-computed rainbow
table attacks.
SCTP: In computer networking, the Stream Control Trans-
mission Protocol (SCTP) is a transport-layer protocol (pro-
tocol number 132), serving in a similar role to the popular
protocols Transmission Control Protocol (TCP) and User
Datagram Protocol (UDP). It provides some of the same
service features of both: it is message-oriented like UDP
and ensures reliable, in-sequence transport of messages
with congestion control like TCP. RFC 4960 defines the pro-
tocol. RFC 3286 provides an introduction.
Secret Streams: Secret Streams are a function within the
Spot-On client and describe a pool of keys, which are pro-
vided by a function deriving ephemeral keys created by the
SMP – Socialist Millionaire Protocol – Process for authenti-
cation of two users. With this zero-knowledge proof at
both user sides keys are generated, which need not to be
transferred over the internet. This invention by the Spot-On
development solved the key transmission problem over the
internet.
Security: Security is freedom from, or resilience against,
potential harm (or other unwanted coercive change)
caused by others. Beneficiaries (technically referents) of
security may be of persons and social groups, objects and
institutions, ecosystems or any other entity or phenome-
Glossary
285
non vulnerable to unwanted change by its environment.
Security mostly refers to protection from hostile forces, but
it has a wide range of other senses: for example, as the ab-
sence of harm (e.g. freedom from want); as the presence
of an essential good (e.g. food security); as resilience
against potential damage or harm (e.g. secure founda-
tions); as secrecy (e.g. a secure telephone line); as con-
tainment (e.g. a secure room or cell); and as a state of
mind (e.g. emotional security).
Server: In computing, a server is a computer program or a
device that provides functionality for other programs or
devices, called "clients". This architecture is called the cli-
ent–server model, and a single overall computation is dis-
tributed across multiple processes or devices. Servers can
provide various functionalities, often called "services", such
as sharing data or resources among multiple clients, or per-
forming computation for a client. A single server can serve
multiple clients, and a single client can use multiple serv-
ers. A client process may run on the same device or may
connect over a network to a server on a different device.
Typical servers are database servers, file servers, mail serv-
ers, print servers, web servers, game servers, and applica-
tion servers.
Session Management: Related to the identification of au-
thenticated users
SHA-3: SHA-3 (Secure Hash Algorithm 3) is the latest mem-
ber of the Secure Hash Algorithm family of standards, re-
leased by NIST on August 5, 2015. Although part of the
same series of standards, SHA-3 is internally different from
the MD5-like structure of SHA-1 and SHA-2. SHA-3 is a sub-
set of the broader cryptographic primitive family Keccak.
Keccak's authors have proposed additional uses for the
function, including a stream cipher, an authenticated en-
cryption system, a "tree" hashing scheme for faster hashing
on certain architectures, and AEAD ciphers Keyak and Ket-
je. Keccak is based on a novel approach called sponge con-
struction. Sponge construction is based on a wide random
function or random permutation and allows inputting ("ab-
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286
sorbing" in sponge terminology) any amount of data, and
outputting ("squeezing") any amount of data, while acting
as a pseudorandom function with regard to all previous in-
puts. This leads to great flexibility.
Signature: A digital signature is a mathematical scheme for
demonstrating the authenticity of a digital message or
documents. A valid digital signature gives a recipient rea-
son to believe that the message was created by a known
sender, that the sender cannot deny having sent the mes-
sage (authentication and non-repudiation), and that the
message was not altered in transit (integrity).
Simulacra: The Simulacra function is a similar function
compared to the Impersonator While Impersonator is sim-
ulating a chat of two participants with messages, Simulacra
is just sending out a Fake-Message from time to time. Sim-
ulacra-Messages contain only random characters and have
not the style or goal, to imitate a process of a conversation.
SIP-Hash: SipHash is an add–rotate–xor (ARX) based family
of pseudorandom functions. Although designed for use as
a hash function in the computer science sense, SipHash is
fundamentally different from cryptographic hash functions
like SHA in that it is only suitable as a message authentica-
tion code: a keyed hash function like HMAC. That is, SHA is
designed so that it is difficult for an attacker to find two
messages X and Y such that SHA(X) = SHA(Y), even though
anyone may compute SHA(X). SipHash instead guarantees
that, having seen Xi and SipHash(Xi, k), an attacker who
does not know the key k cannot find (any information
about) k or SipHash(Y, k) for any message Y ∉ {Xi} which
they have not seen before.
Small world phenomenon: Small world phenomenon re-
fers to a a hypothesis, according to which every human be-
ing (social actor) is connected to the world with each other
over a surprisingly short chain of acquaintance relation-
ships. The phenomenon is often referred to as Six Degrees
of Separation. Guglielmo Marconi’s conjectures based on
his radio work in the early 20th century, which were articu-
lated in his 1909 Nobel Prize address, may have inspired
Glossary
287
Hungarian author Frigyes Karinthy to write a challenge to
find another person to whom he could not be connected
through at most five people. This is perhaps the earliest
reference to the concept of six degrees of separation, and
the search for an answer to the small world problem. The
small-world experiment comprised several experiments
conducted by Stanley Milgram and other researchers ex-
amining the average path length for social networks of
people in the United States. The research was ground-
breaking in that it suggested that human society is a small-
world-type network characterized by short path-lengths.
Smoke Crypto Chat App: Smoke Crypto Chat is a mobile
Software Echo Client Application currently for Android,
which is open source, and provides with SmokeStack an
easy to configure and open source server software. The us-
er ID is not based on phone numbers and no friends list is
uploaded to any server. As it provides the secure algorithm
McEliece, Smoke is regarded as worldwide the first mobile
McEliece Messenger.
SmokeStack: SmokeStack is the name of the server soft-
ware for encryption communication over the Smoke Crypto
Chat App. It functions also as a key server and a Postbox for
offline user via the Ozone function. The server is provided
for the operating system Android for mobile devices.
SMP: See Socialist Millionaire Protocol.
SMP-Calling: SMP-Calling is some modus for Cryptographic
Calling, which sends temporary symmetric keys for end-to-
end encryption, which are derived from the Socialist-
Millionaire Protocol for Authentication. SMP-Calling is the
basis for constantly generated temporary keys called Secret
Streams.
SMTP: Simple Mail Transfer Protocol(SMTP) is an Internet
standard for electronic mail (email) transmission. First de-
fined by RFC 821 in 1982, it was last updated in 2008 with
the Extended SMTP additions by RFC 5321—which is the
protocol in widespread use today. SMTP by default uses
TCP port 25. The protocol for mail submission is the same,
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288
but uses port 587. SMTP connections secured by SSL,
known as SMTPS, default to port 465.
Socialist Millionaire Protocol (SMP): In cryptography, the
socialist millionaire problem is one in which two million-
aires want to determine if their wealth is equal without
disclosing any information about their riches to each other.
It is a variant of the Millionaire’s Problem whereby two mil-
lionaires wish to compare their riches to determine who
has the most wealth without disclosing any information
about their riches to each other. It is often used as a cryp-
tographic protocol that allows two parties to verify the
identity of the remote party through the use of a shared
secret, avoiding a man-in-the-middle attack without the in-
convenience of manually comparing public key fingerprints
through an outside channel. In effect, a relatively weak
password/passphrase in natural language can be used.
Spot-On: Spot-On is a very elaborated Encryption Software
Suite with modern encryption functions. It is based on the
Echo Protocol, which sends the encrypted packets address-
and target less.
SQLite: SQLite is a relational database management system
contained in a C programming library. In contrast to many
other database management systems, SQLite is not a cli-
ent–serverdatabase engine. Rather, it is embedded into the
end program.
StarBeam: StarBeam is the function to share a file over two
Echo Clients. All packets are sent encrypted.
StarBeam-Analyser: The StarBeam-Analyzer is a tool, to
analyze a transferred file over the StarBeam-function in
that regard, if all partially blocks of the file have been re-
ceived completely. The tool investigates – in case needed –
the missing blocks of a file and creates a respective Mag-
net-URI-Link with this information. The receiver of the file
can generate the Magnet and send it over to the sender of
the file, who is then able to schedule a new send-out just
of the missing blocks (also named as links or chunks). Over
this procedure not the complete files has to be sent or re-
played new to complete the original first transfer.
Glossary
289
Super-Echo: The Echo protocol consists within these re-
membered characteristics (if we summarize it short), that
each node tries to encrypt each message capsule – if this
succeeds in terms of the hash-comparison, this message is
for the own reading, and will be not again repacked and
transferred further to all other connected online neighbors.
As an online attacker could recognize this, when an incom-
ing message is not sent out again, and thus could assume,
that that it is a message for the receiver at this node. With
Super-Echo the message will be – even if it has been de-
crypted successfully for the own node – sent out again to
the connected nodes and for traveling on further paths.
Just in regard, as this message would not have been de-
termined for the own readings.
Symmetric Calling: Symmetric Calling is some modus for
Cryptographic Calling, which sends temporary symmetric
keys for end-to-end encryption. It refers to send one sym-
metric key (pair) through one secured channel.
Symmetric Encryption: Symmetric-key algorithms are algo-
rithms for cryptography that use the same cryptographic
keys for both encryption of plaintext and decryption of ci-
phertext. The keys may be identical or there may be a sim-
ple transformation to go between the two keys. The keys,
in practice, represent a shared secret between two or more
parties that can be used to maintain a private information
link. This requirement that both parties have access to the
secret key is one of the main drawbacks of symmetric key
encryption, in comparison to public-key encryption (asym-
metric encryption).
Symmetric Key: These keys are used with symmetric key
algorithms to apply confidentiality protection to infor-
mation.
TCP: The Transmission Control Protocol (TCP) is a core pro-
tocol of the Internet protocol suite. It originated in the ini-
tial network implementation in which it complemented the
Internet Protocol (IP). Applications that do not require reli-
able data stream service may use the User Datagram Pro-
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290
tocol (UDP), which provides a connectionless datagram
service that emphasizes reduced latency over reliability.
ThreeFish: Threefish is a symmetric-key tweakable block
cipher designed as part of the Skein hash function, an entry
in the NIST hash function competition. Threefish uses no S-
boxes or other table lookups in order to avoid cache timing
attacks; its nonlinearity comes from alternating additions
with exclusive ORs. In that respect, it is similar to Salsa20,
TEA, and the SHA-3 candidates CubeHash and BLAKE.
Timing: Related to the race conditions, locking, or order of
operations
TLS: Transport Layer Security (TLS), and its now-deprecated
predecessor, Secure Sockets Layer (SSL), are cryptographic
protocols designed to provide communications security
over a computer network. Several versions of the protocols
find widespread use in applications such as web browsing,
email, instant messaging, and voice over IP (VoIP). Web-
sites can use TLS to secure all communications between
their servers and web browsers. The TLS protocol aims
primarily to provide privacy and data integrity between
two or more communicating computer applications.
Token: A security token is a physical device used to gain
access to an electronically restricted resource. The token is
used in addition to or in place of a password. It acts like an
electronic key to access something. Examples include a
wireless keycard opening a locked door, or in the case of a
customer trying to access their bank account online, the
use of a bank-provided token can prove that the customer
is who they claim to be. Some tokens may store crypto-
graphic keys, such as a digital signature, or biometric data,
such as fingerprint details. Some may also store passwords.
Tor: Tor is free and open-source software for enabling
anonymous communication. The name is derived from an
acronym for the original software project name "The Onion
Router". Tor directs Internet traffic through a free, world-
wide, volunteer overlay network consisting of more than
seven thousand relays to conceal a user's location and us-
age from anyone conducting network surveillance or traffic
Glossary
291
analysis. Using Tor makes it more difficult to trace Internet
activity of the user.
Turtle-Hopping: Turtle was a free anonymous peer-to-peer
network project being developed at the Vrije Universiteit in
Amsterdam, involving professor Andrew Tanenbaum. Like
other anonymous P2P software, it allows users to share
files and otherwise communicate without fear of legal
sanctions or censorship. Turtle’s claims of anonymity are
backed by two research papers. Technically, Turtle is a
friend-to-friend (F2F) network. The RetroShare File Sharing
application is based on a F2f and implemented a “Turtle-
Hopping” feature which was inspired by Turtle.
Two-way-Calling: Two-Way-Calling is some modus for
Cryptographic Calling, which creates temporary symmetric
keys for end-to-end encryption, which are defined 50:50 by
each of the end-users. In a Two-way Call the user sends an
AES-256 as a passphrase for the future end-to-end encryp-
tion to the friend, and the friend also sends an own gener-
ated AES-256 to the first user in response. Now the first
half of the AES of the first user and the second half of the
AES of the second user are taken, respectively, and assem-
bled into a common AES-256. It refers to the method of 2-
way safety.
UDP: The User Datagram Protocol (UDP) is one of the core
members of the Internet protocol suite. The protocol was
designed by David P. Reed in 1980 and formally defined
in RFC 768. UDP uses a simple connectionless transmission
model with a minimum of protocol mechanism. It has no
handshaking dialogues, and thus exposes the user’s pro-
gram to any unreliability of the underlying network proto-
col. There is no guarantee of delivery, ordering, or dupli-
cate protection. Time-sensitive applications often use UDP
because dropping packets is preferable to waiting for de-
layed packets, which may not be an option in a real-time
system.
URL: A Uniform Resource Locator (URL), colloquially
termed a web address, is a reference to a web resource
that specifies its location on a computer network and a
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292
mechanism for retrieving it. A URL is a specific type of Uni-
form Resource Identifier (URI), although many people use
the two terms interchangeably. URLs occur most common-
ly to reference web pages (https) but are also used for file
transfer (ftp), email (mailto), database access (JDBC), and
many other applications.
URL-Distiller: URL-Distillers are filter rules, with which the
downloaded, uploaded or imported URLS will be filtered.
For example, one can configure his URL-Distillers in such a
way, that all URLs are loaded into the own Database, but
only specific URLS from one defined Domain, e.g. Wikipe-
dia, are uploaded. Also e.g. a university can distribute only
URLs out of the own database to its connected students,
which refer to the own web-domain. URLs and URIs of
Magnets, ED2K-Links and Torrent-URLs are currently not
supported in the own URL-Database respective filter rules.
The distillers refer to Web-URLs and also to FTP and Go-
pher.
URN: A Uniform Resource Name (URN) is a Uniform Re-
source Identifier (URI) that uses the urn scheme. URNs
were originally conceived to be part of a three-part infor-
mation architecture for the Internet, along with Uniform
Resource Locators (URLs) and Uniform Resource Character-
istics (URCs), a metadata framework. URNs were distin-
guished from URLs, which identify resources by specifying
their locations in the context of a particular access proto-
col, such as HTTP or FTP. In contrast, URNs were conceived
as persistent, location-independent identifiers assigned
within defined namespaces, so that they are globally
unique and persistent over long periods of time, even after
the resource which they identify ceases to exist or be-
comes unavailable.
VEMI: VEMI stands for Virtual E-Mail Institution. See Insti-
tution.
Web-of-Trust: In cryptography, a Web-of-Trust is a concept
used in PGP, GnuPG, and other OpenPGP-compatible sys-
tems to establish the authenticity of the binding between a
public key and its owner. Its decentralized trust model is an
Glossary
293
alternative to the centralized trust model of a public key in-
frastructure (PKI), which relies exclusively on a certificate
authority (or a hierarchy of such). As with computer net-
works, there are many independent webs of trust, and any
user (through their identity certificate) can be a part of,
and a link between, multiple webs.
Wide Lanes: One of the many obligations of a Spot-On-
Kernel process is to receive, process, and forward data to
one or more nodes. The mechanism that performs this task
is similar to both a network hub and a network switch.
Wide Lanes allow node operators to assign listener lane
widths. Let's consider a basic example, a listener having a
lane width of 20,000 bytes. The kernel, if necessary, will
forward packets via the listener's clients if the sizes of the
forwarded packets do not exceed 20,000 bytes. Optionally,
clients may negotiate different lane widths with their
peers. All network communications beyond the interface
and the kernel must and will adhere to the configured lim-
its.
YaCy: YaCy (pronounced "ya see") is a free distributed
search engine, built on principles of peer-to-peer (P2P)
networks. Its core is a computer program written in Java
distributed on several hundred computers, as of Septem-
ber 2006, so-called YaCy-peers. Each YaCy-peer inde-
pendently crawls through the Internet, analyzes and index-
es found web pages, and stores indexing results in a com-
mon database (so called index) which is shared with other
YaCy-peers using principles of P2P networks. It is a free
search engine that everyone can use to build a search por-
tal for their intranet and to help search the public internet
clearly.
Zero-knowledge-proof: A zero-knowledge proof or zero-
knowledge protocol is a method by which one party (the
prover) can prove to another party (the verifier) that they
know a value x, without conveying any information apart
from the fact that they know the value x. The essence of
zero-knowledge proofs is that it is trivial to prove that one
possesses knowledge of certain information by simply re-
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294
vealing it; the challenge is to prove such possession with-
out revealing the information itself or any additional in-
formation. If proving a statement requires that the prover
possess some secret information, then the verifier will not
be able to prove the statement to anyone else without
possessing the secret information. The statement being
proved must include the assertion that the prover has such
knowledge, but not the knowledge itself. Otherwise, the
statement would not be proved in zero-knowledge because
it provides the verifier with additional information about
the statement by the end of the protocol. Interactive zero-
knowledge proofs require interaction between the individ-
ual (or computer system) proving their knowledge and the
individual validating the proof.
Keywords
295
24 Keywords
#CEKS ............................ 158
2WIPFS ......................... 101
4710 ....................................
82, 83, 182, 185, 186,
187, 193
Adaptive Echo .....................
39, 52, 55, 56, 57, 58, 67,
162, 211
AES ......................................
21, 22, 30, 31, 32, 33,
35, 37, 39, 47, 50, 95, 98,
99, 107, 109, 113, 139,
140, 158
Algorithm ............................
15, 23, 24, 25, 31, 35,
39, 49, 52, 75, 77, 102,
168, 170
Android ...............................
. 114, 121, 190, 191, 239
Answer Method ..................
............................. 72, 73
Artificial Intelligence ...........
................................ 211
A-symmetric .......................
21, 24, 25, 30, 31, 32,
33, 39, 45, 75, 95, 97,
98, 109, 110, 111, 113,
120, 136, 137, 138, 139,
140, 142, 144, 209, 212
Asymmetric Calling .............
...........................97, 113
Audit .............. 204, 226, 238
Authenticate .......................
............... 34, 35, 93, 103
Authenticity .............. 33, 35
Autocrypt ........................ 14
Basic Law ...................... 218
Bluetooth ............................
......... 156, 182, 190, 191
Broadcast .............. 182, 187
Browser ..............................
14, 31, 73, 122, 128,
146, 170, 171, 177, 179,
185, 222
Button .................................
69, 78, 79, 81, 82, 88,
89, 91, 92, 95, 97, 103,
109, 111, 114, 115, 118,
119, 126, 152, 162, 163,
178, 182, 196, 212
Buzz ....................................
16, 54, 118, 121, 135,
153, 175
C/O .......... 16, 131, 132, 134
C++ ........................ 121, 235
Care-Of ................. 131, 132
Chaos ............................ 212
Charter of Fundamental
Rights of the European
Union ...................... 217
Chat ....................................
13, 19, 20, 25, 37, 41, 42,
44, 53, 54, 56, 58, 69,
75, 76, 80, 81, 82, 87, 90,
91, 92, 95, 97, 98, 102,
103, 109, 110, 113, 114,
115, 117, 118, 119, 120,
121, 122, 127, 128, 129,
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296
131, 136, 138, 140, 142,
143, 144, 145, 146, 147,
149, 152, 153, 156, 162,
167, 181, 182, 183, 184,
185, 186, 187, 188, 190,
191, 192, 196, 197, 207
Cipher text ..........................
13, 14, 20, 31, 39, 46,
75, 84, 129, 132, 139,
195, 196, 209, 210, 212,
213
C-mail ........................ 17, 85
Congestion Control .............
...................... 40, 45, 54
Crawler ................................
13, 168, 171, 176, 177,
202
Cryptographic ......................
20, 25, 26, 35, 49, 50,
51, 52, 55, 57, 68, 72, 76,
142, 152, 210, 211, 212,
213, 215
Cryptographic Calling ..........
32, 95, 96, 97, 107, 109,
111, 112
Cryptographic Discovery .....
.................... 51, 59, 211
Cryptographic Routing ... 51,
211
Cryptographic Torrents . 167
Cryptographic-DNA ....... 213
CryptoPad ....... 14, 195, 196
Crypto-parties ............... 215
Customer Supplied
Encryption Keys ....... 158
Democracy ...................... 18
Diffie-Hellmann ............... 29
DNS ................. 83, 237, 240
Dooble ........................... 170
Echo ................................ 17
Echo Accounts ..... 39, 48, 54
Echo Grid ................... 51, 55
Echo Match ..................... 38
Echo Network ......................
16, 37, 41, 42, 54, 90,
154, 159, 161, 162, 173
Edgar Allan Poe ............... 84
Elgamal ................................
15, 23, 24, 25, 27, 30,
31, 37, 98, 99, 102, 207
Elliptic Curve ................... 29
E-mail ..................................
13, 14, 17, 19, 20, 25,
44, 53, 54, 55, 69, 75, 76,
88, 91, 109, 117, 123,
125, 126, 127, 128, 129,
130, 131, 132, 133, 134,
135, 136, 137, 138, 139,
140, 142, 143, 144, 145,
146, 147, 148, 149, 156,
157, 160, 181, 185, 196,
197
Emoticons ..................... 114
Encapsulation ............ 30, 34
Encryption ...........................
13, 14, 15, 18, 20, 21,
22, 23, 24, 25, 26, 27, 30,
31, 32, 33, 34, 35, 36,
39, 41, 45, 46, 48, 50,
52, 53, 54, 72, 73, 74, 75,
76, 80, 85, 88, 95, 97, 98,
99, 100, 101, 102, 103,
107, 109, 110, 111, 112,
113, 117, 118, 119, 128,
130, 135, 136, 137, 139,
140, 143, 144, 146, 149,
154, 155, 156, 157, 158,
161, 162, 167, 175, 188,
Keywords
297
195, 196, 197, 198, 199,
207, 208, 209, 210, 211,
212, 214, 216
Encrypt-then-MAC ..............
............................ 35, 39
End-to-End ..........................
32, 92, 95, 97, 98, 99,
100, 101, 102, 107, 109,
110, 111, 112, 113, 117,
136, 137, 138, 140, 145,
146, 154, 158, 197, 199,
208, 212
Ephemeral ..........................
109, 110, 113, 138, 139,
140, 141, 142, 144, 210
EPKS ....................................
14, 17, 90, 120, 175,
195, 198
Era of Exponential
Encryption .....................
209, 210, 212, 213, 214,
231
European Convention on
Human Rights .......... 217
Exponential Encryption ......
.................................. 20
File transfer ........................
13, 54, 115, 133, 136,
152, 156, 157, 158, 159,
163, 167, 208
File-Encryptor ......... 14, 156
File-Sharing ...... 92, 152, 153
FireChat ........................ 121
Forward Secrecy .................
97, 101, 108, 109, 110,
112, 137, 138, 139, 140,
141, 142, 144, 146, 210,
235
Forward Secrecy Calling110,
113
Friend-to-Friend .................
..................... 37, 43, 161
FSC ................................ 110
Full Echo ...... 39, 48, 56, 184
Gemini ................................
30, 95, 97, 98, 99, 102,
107, 109, 110, 113, 136,
146
GnuPG ............................ 15
Gnutella ..............................
. 152, 154, 155, 164, 238
GoldBug ..............................
83, 84, 85, 226, 227,
229, 230, 231, 232, 233,
234, 236, 237, 238, 239,
240
Graph ..................................
....... 52, 57, 58, 162, 210
Group chat ..........................
13, 14, 117, 118, 121,
134, 135, 153, 160, 175,
208
Half Echo ............ 39, 55, 184
Hashtype ................... 26, 75
HMAC ........................ 72, 73
HTTPS .................................
31, 47, 156, 182, 185,
188
Human rights .......... 18, 218
Hybrid .................................
15, 18, 33, 145, 209, 212
IMAP ...................................
14, 16, 55, 118, 123,
125, 126, 127, 128, 129,
131, 135, 136, 145, 146,
148, 149
Impersonator ............ 41, 42
Spot-On.sf.net Encryption Suite – Handbook and User Manual
298
innovation ...........................
19, 35, 90, 145, 212, 228
Instant Perfect Forward
Secrecy .............. 97, 110
Institution ...........................
55, 133, 134, 135, 136,
160
International Covenant on
Civil and Political Rights
........................ 216, 217
IPFS .....................................
97, 101, 112, 141, 146,
210
IRC ......................................
14, 16, 54, 117, 118,
119, 120, 121, 135, 153,
160, 175, 208
Iteration .................... 26, 75
Java ....... 121, 122, 177, 179
Kerckhoffs's principle .... 120
Key ......................................
14, 21, 23, 24, 25, 26,
30, 31, 32, 34, 35, 39,
45, 46, 48, 49, 50, 52,
53, 54, 55, 69, 72, 73, 74,
75, 76, 77, 78, 87, 88, 90,
91, 92, 95, 97, 98, 102,
109, 110, 112, 113, 117,
118, 120, 121, 128, 129,
133, 134, 135, 136, 137,
138, 139, 140, 141, 142,
144, 147, 157, 167, 175,
178, 184, 185, 193, 196,
197, 198, 199, 207, 208,
210
Keyboard ................... 73, 95
KeySync ..................... 14, 90
LAN ......... 83, 187, 190, 191
LED ...... 80, 82, 87, 181, 182
Listener ...............................
31, 48, 54, 80, 82, 83,
121, 181, 182, 184, 186,
187, 188, 190, 191, 200
Login ....................................
16, 70, 72, 75, 78, 79, 87,
88, 185, 186
Magnet ................................
54, 55, 118, 119, 120,
134, 135, 152, 153, 154,
157, 158, 159, 160, 161,
163, 164, 166, 208
Magnet-URI .........................
118, 119, 120, 133, 152,
154, 155, 158, 159, 160,
161, 162, 163
McEliece ..............................
15, 21, 22, 23, 24, 37,
75, 77, 98, 102, 157,
199, 207, 212, 213
MELODICA ................. 95, 97
Meta-data ....... 42, 130, 212
Mosaic ........................... 164
Multi-encryption .................
14, 15, 18, 33, 34, 39,
47, 57, 98, 158, 207, 209,
210, 212
Ncat ............................... 193
Neighbor .............................
37, 40, 51, 54, 58, 69, 80,
81, 82, 83, 87, 90, 92,
167, 181, 182, 184, 185,
186, 187, 193
Neuland ........................... 85
NIST ..................... 15, 22, 35
NOVA ...................................
. 136, 156, 157, 158, 167
NTRU ...................................
15, 21, 22, 23, 24, 35,
Keywords
299
37, 75, 77, 98, 99, 102,
105, 207, 212, 213
One-Time-Magnet ........ 166
Open source .......................
15, 26, 32, 41, 73, 74,
121, 168, 170, 173, 176,
204, 207, 209, 212, 214,
222, 226, 238
OpenPGP ........................ 15
OpenSSL .......................... 15
OTM ....... 120, 158, 159, 208
OTR ....................... 102, 144
Ozone Postbox .............. 135
P2P......................................
14, 47, 76, 117, 123,
128, 129, 130, 133, 168,
169, 170, 173, 177, 178,
179, 198, 199
Pandamonium ....................
176, 177, 178, 202, 203,
236
Passphrase ..........................
30, 32, 49, 50, 55, 56, 57,
68, 70, 71, 72, 79, 95, 97,
99, 102, 104, 112, 113,
156, 158, 208
Passphrase method ........ 71
Pass-through .......................
.................188, 195, 199
Password ............................
16, 17, 21, 30, 31, 39,
49, 50, 70, 71, 72, 73,
79, 87, 88, 90, 93, 95, 97,
98, 99, 100, 102, 103,
107, 108, 113, 117, 136,
137, 139, 142, 143, 157,
158, 167, 177, 186, 195,
199
Patch-Points .................. 199
Peer-to-Peer .......................
. 13, 37, 43, 48, 130, 161
PKI ........... 22, 23, 30, 33, 37
Plain text .............................
17, 20, 45, 46, 47, 48, 75,
126, 139
Point-to-Point ........... 32, 98
POP3 ...................................
14, 16, 55, 118, 123,
125, 126, 127, 128, 129,
131, 135, 136, 145, 146,
148, 234
POPTASTIC ..........................
17, 75, 125, 127, 128,
129, 135, 139, 143, 144,
145, 146, 147, 148, 149,
185
PostgreSQL14, 168, 171,
173
Privacy .................... 18, 216
Qt ......................................
76, 114, 171, 191, 208,
222, 223, 224, 237
Quantum Computing15, 22,
23, 212, 213
Random ......... 41, 42, 46, 70
Raspberry Pi ......... 121, 132
REPLEO ...............................
. 14, 90, 91, 92, 120, 128
RetroShare ..........................
..... 48, 52, 154, 162, 233
Rewind function ........... 161
Rosetta ................................
14, 75, 128, 195, 196,
197
RSA .....................................
15, 22, 23, 24, 25, 27,
29, 30, 31, 33, 37, 39,
Spot-On.sf.net Encryption Suite – Handbook and User Manual
300
54, 75, 77, 96, 98, 99,
102, 113, 157, 207, 213
RSS .. 14, 168, 171, 178, 179
Salt .... 26, 49, 50, 71, 72, 75
Salted hash ................ 72, 73
SCTP ...... 156, 182, 192, 207
Search .................................
13, 14, 15, 48, 50, 53,
75, 76, 125, 168, 169,
170, 171, 172, 173, 175,
177, 178
Secret Streams ....................
................ 108, 142, 143
Security ...............................
20, 22, 34, 74, 76, 83, 95,
101, 102, 109, 118, 125,
127, 128, 136, 148, 156,
158, 161, 177, 184, 217
Server ..................................
13, 16, 17, 32, 37, 44, 50,
55, 56, 58, 69, 75, 79,
80, 81, 82, 83, 87, 90, 92,
117, 119, 120, 121, 122,
123, 125, 126, 127, 128,
129, 130, 131, 133, 145,
146, 148, 149, 172, 181,
182, 184, 185, 186, 187,
188, 190, 191, 192, 193,
200
SHA-3 .............................. 35
Shor's algorithm .............. 29
Simple Mail Transfer
Protocol ................... 125
Simulacra .................. 41, 42
SIP hash ......................... 121
Small world phenomenon ...
.................................. 43
Smoke .................................
114, 121, 122, 135, 158,
210, 231, 239
SmokeStack .........................
121, 135, 190, 191, 210,
231
SMP .....................................
93, 102, 103, 106, 107,
108, 113, 142, 143
SMP-Calling ................... 113
SMTP ............. 123, 125, 147
Snowden ................. 20, 211
Socialist Millionaire Protocol
................... 93, 102, 142
Spot-On ...............................
13, 14, 15, 17, 19, 20,
21, 23, 24, 25, 26, 30,
32, 33, 34, 35, 36, 41,
42, 48, 50, 51, 53, 67,
69, 70, 75, 76, 77, 78, 80,
81, 83, 88, 91, 95, 96,
97, 98, 100, 102, 103,
107, 109, 111, 114, 117,
118, 120, 121, 122, 123,
125, 126, 128, 129, 130,
133, 135, 136, 137, 139,
140, 145, 146, 147, 149,
152, 154, 156, 157, 158,
160, 168, 170, 171, 175,
176, 177, 178, 179, 181,
182, 185, 187, 188, 189,
190, 191, 192, 193, 195,
196, 197, 198, 199, 200,
201, 207, 221, 222, 223,
224
SQL .......................... 14, 173
SQLite .... 168, 171, 172, 177
StarBeam .............................
16, 54, 92, 115, 133,
Keywords
301
134, 136, 152, 153, 154,
155, 156, 157, 159, 160,
161, 162, 164, 165, 167,
196, 200
StarBeam Analyzer ....... 165
Statistics .............................
13, 178, 195, 200, 201,
202
Super-Echo .........................
42, 43, 47, 63, 95, 99,
107, 109, 157, 160, 189
Symmetric ..........................
21, 30, 31, 32, 33, 34,
39, 97, 98, 102, 109,
110, 111, 112, 113, 117,
121, 136, 137, 138, 139,
140, 142, 144, 160, 175,
198, 209, 212
Symmetric Calling ...............
................... 98, 112, 113
TCP ......................................
38, 156, 182, 191, 192,
207, 211
ThreeFish ........................ 35
TLS ......................................
22, 30, 31, 32, 37, 39, 47,
50, 95, 97, 98, 99, 102,
112, 113, 118, 126, 140,
142, 185
Token ..................................
... 39, 55, 56, 57, 58, 211
Tor ......................................
41, 83, 146, 177, 185,
186, 188, 211, 212, 226,
228, 230, 231, 232, 233,
234, 235, 236, 237, 239,
240
Turtle-Hopping ....... 54, 161
Two-way-calling ...... 99, 113
UDP .....................................
156, 182, 187, 191, 192,
207
Universal Declaration of
Human Rights .......... 216
URL .....................................
13, 14, 15, 53, 75, 76,
91, 128, 168, 170, 171,
172, 173, 174, 175, 176,
177, 178, 179, 199, 200,
202, 222
URN ...............118, 134, 156
VEMI ........ 16, 133, 134, 135
Web-of-Trust .......................
......... 39, 48, 54, 58, 186
Wizard ................................
..... 67, 68, 69, 75, 77, 78
YaCy ...................... 168, 236
Zero-knowledge proof ........
....................... 103, 142.
Spot-On Encryption Suite is a secure instant chat messenger
and encrypting e-mail client that also includes additional
features such as group chat, file transfer, and a URL search
based on an implemented URL data-base, which can be peer-to-
peer connected to other nodes. Also, further tools for file
encryption or text conversion to ciphertext etc. are included.
The Spot-On program might currently be regarded as a very
elaborated, up-to-date and diversificated open source
encryption software for Multi-Encryption and Cryptographic
Calling: As it also includes the McEliece algorithm it is thus
described as the first McEliece Encryption Suite worldwide – to
be especially secure against attacks known from Quantum
Computing.
Thus, the three basic functions frequently used by a regular
Internet user in the Internet - communication (chat / e-mail),
web search and file transfer - are now secure over the Internet
within one software suite: Open source for everyone.
This handbook and user manual of Spot-On is a practical
software guide with introductions not only to this application
and its innovative and invented processes, but also into
Encryption, Cryptography, Cryptographic Calling and
Cryptographic Discovery,Graph-Theory, p2p Networking,
NTRU, McEliece, the Echo Protocol and the Democratization of
Multiple and Exponential Encryption also in the regard of the
context of Privacy and Human Rights.
The book covers more than 15 chapters and more than 80
figures with content for presentations within educational
tutorials or for self-learning opportunities about these topics.
