List of mobile instant messengers

from Wikipedia, the free encyclopedia

This list contains information about computer programs (“ apps ”) that are used on mobile devices ( smartphones , tablets ) for instant messaging .

Functions

Encryption Functions Others
Messenger Free software End-to-end Client server Authentication Deniability PFS Picture messages Group chat Asynchronous communication Transfer of contacts Self-hosted server Federation
Bleep No Unknown Unknown Unknown Unknown Unknown Unknown Unknown Unknown Unknown Unknown Unknown
Blackberry Messenger No No Unknown Blackberry PIN Unknown Unknown any files Yes Unknown Optional No No
BLACKPIN No AES 256 TSL / SSL Yes No Yes Yes Yes No No
ChatSecure
(formerly Gibberbot) 		Apache 2.0 (Android), GPLv3 + (iOS) OTR (optional), OMEMO TLS / SSL Yes Yes Yes Yes not enabled by default Yes Unknown Yes (XMPP) Yes
Chiffry No In-house development (256-bit AES-GCM and 512-bit ECDH / ECDSA) Yes Yes Yes Yes Yes Yes (decentralized) Yes No Yes (business version) Unknown
cameoNet AGPLv3 In-house development TLS / SSL Yes No No Yes Yes Yes No Unknown Unknown
Conversations GPLv3 OpenPGP, OMEMO TLS Yes Yes Yes Yes Yes Yes No Yes (XMPP) Yes
Delta chat GPLv3 OpenPGP, Autocrypt TLS / SSL
(see note) 		Yes No No Yes Yes Yes No Yes Yes
FriendCaller No In-house development (
RSA / AES)		 TSL, SSL Yes Unknown Unknown Yes Yes Yes Optional Yes Unknown
Hike No Unknown SSL
(see note) 		Unknown Unknown Unknown Only unencrypted Only unencrypted Only unencrypted Yes No No
Hoccer No In-house development (RSA / AES) TLS / SSL Yes Optional, messages can be signed Yes Yes Yes Yes No No No
ICQ No Unknown SSL Unknown Unknown Unknown Yes Yes Yes Optional No No
IM + Unknown Unknown Unknown Unknown Unknown Unknown Unknown Unknown Unknown Unknown A separate server is possible depending on the choice of protocol The messenger supports several protocols, some of which are federations
Jami (software) GPLv3 Yes All P2P communication with E2E (TSL)
Jongla No Unknown Unknown Unknown Unknown Unknown Unknown Unknown Unknown Yes Unknown Unknown
KakaoTalk No Unknown SSL Unknown Unknown Unknown Yes Unknown Unknown Unknown No No
Kik Unknown Unknown Unknown Unknown Unknown Unknown Yes Yes Unknown Unknown Unknown Unknown
Kontalk GPLv3 OpenPGP TLS / SSL Yes No No Yes Yes Yes Their hashes Yes, other server can be set Yes
Line No Yes Unknown Unknown Unknown Unknown Unknown Unknown Unknown Optional No No
OneTime Messenger No No Yes No No No Yes Yes Unknown Yes No No
Rainbow No Yes TLS Yes Unknown Unknown Yes Yes Yes No No Yes
element Apache 2.0 Double ratchet (optional) Unknown Yes Unknown Unknown Yes Yes Yes Optional Yes Yes
SecureChat No Axolotl TLS / SSL Yes Yes Yes Yes Yes Unknown Yes Unknown Unknown
For sure No In-house development TLS / SSL Unknown Unknown No Yes Yes Yes Yes Unknown Unknown
signal GPLv3 Signal protocol TLS / SSL Yes Yes Yes Yes Yes Yes Their hashes Yes (without voice calls) No
SIMSme No In-house development (RSA / AES) SSL Yes No No Yes Yes Yes Their hashes No No
Skype No Unknown Unknown No Unknown Unknown Yes Yes Yes Yes No No
Surespot GPLv3 In-house development SSL No No No Yes No Yes No Unknown Unknown
Telegram GPLv2 (partially) In-house development (optional) In-house development Optional Unknown Optional Yes Client-server encrypted only Yes Yes No No
Threema crypto library only NaCl library TLS / SSL Yes No Server client only Yes Yes Yes Optional, their hashes No No
Tigase Messenger AGPL Unknown Unknown Yes Unknown Unknown Yes Yes Unknown No Yes (XMPP) Yes
TextNow No Unknown Unknown Unknown Unknown Unknown Unknown Unknown Unknown Yes Unknown Unknown
Viber No No Unknown Unknown Unknown Unknown Yes Unknown Unknown Yes No No
Whatsapp No only from version 2.16.14 In-house development Yes Yes Yes Yes only from version 2.16.14 Yes Yes No No
Wickr No In-house development (AES256, ECDH521, RSA4096) TLS / SSL Unknown Unknown Unknown Yes Unknown Unknown Unknown Unknown Unknown
Wire GPL Proteus, Double Ratchet Algorithm, WebRTC ( DTLS ) and SRTP for calls TLS Yes Yes Yes Yes Yes Yes Optional, their hashes Yes No
Xabber GPLv3 OTR (optional) TLS Yes Yes Yes Yes Client-server encrypted only Only unencrypted No Yes (XMPP) Yes

Supported Platforms

The following table shows which messenger apps are supported by which operating systems.

Messenger Android iOS Windows Mobile / Phone BlackBerry Symbian Windows macOS Linux Web Other platforms Info booth
Bleep Yes Yes No No No No No No No December 2017
Blackberry Messenger from 2.3 from 6 from 8 OS 5 No No No No No BlackBerry Tablet OS 1 December 2017
BLACKPIN Yes Yes No No No No No No No December 2017
ChatSecure No Yes No No No No No No No further development for Android has been discontinued December 2017
Chiffry Yes Yes Yes Yes No No No No No December 2017
cameoNet Yes No No No No No No No No December 2017
Conversations from 4.4 No No No No No No No No December 2017
Delta chat Yes Yes No No No Yes Yes Yes Yes Can also be used with Mailvelope or unencrypted via the web interface December 2017
FriendCaller Yes Yes No No No No No No Yes Java, Nokia S40 December 2017
Hike from 2.3 Yes No No No No No No No December 2017
Hoccer from 4.0 Yes No No No No No No No December 2017
ICQ Yes Yes Yes Yes Yes Yes Yes Yes Yes Java December 2017
IM + Yes Yes Yes Yes Yes No No No Yes Java December 2017
Jami Yes Yes No No No Yes Yes Yes No Java December 2017
Jongla Yes Yes No No No No No No No December 2017
KakaoTalk Yes Yes No No No Yes Yes No No December 2017
Kik Yes Yes Unknown Unknown Unknown Unknown Unknown Unknown Unknown June 2019
Kontalk Yes No No No No Yes Yes Yes No Platform-independent Java desktop client December 2017
Line Yes Yes Yes † July 3rd, 2017 No Yes Yes No No Chrome December 2017
OneTime Messenger Yes Yes No No No No No No No December 2017
Rainbow Yes Yes No No No Yes Yes No Yes December 2017
Riot from 4.1 from 8.0 No No No Yes Yes Yes Yes Uses the platform-independent matrix protocol December 2017
SecureChat Yes No No No No No No No No December 2017
For sure Yes Yes Yes No No No No No No December 2017
signal from 4.0 from 8.0 No No No Yes Yes Yes No Chrome, Ubuntu Touch December 2017
SIMSme from 4.0 from 8.0 No No No No No No No December 2017
Skype from 4.0.4 from 10 > 10 Discontinued Discontinued from Windows 7 from X 10.10 64-bit versions Yes Skype-enabled phones, Xbox One, PlayStation Vita June 2020
SureSpot Yes Yes No No No No No No No December 2017
Telegram from 4.1 from 9 Yes unofficially No Yes Yes Yes Yes Firefox OS, Ubuntu Touch , Linux Commandline, Sailfish OS June 2020
Threema from 4.0 Yes † June 30th, 2020 No No No No No Yes Web (Web only if the smartphone belonging to the account has an Internet connection with Threema) July 2020
Tigase Messenger Yes Yes No No No No No No No December 2017
Viber Yes Yes Yes Yes No Yes Yes Yes No December 2017
Whatsapp from 2.1 Yes † December 31, 2019 † December 31, 2017 Yes Yes Yes No Yes Nokia S40 (until 31.12.2018), web (web only if a supported smartphone with WhatsApp is connected to the internet at the same time) December 2017
Wickr Yes Yes No No No Yes Yes Yes No December 2017
Wire from 4.2 from 8.0 No No No Yes Yes Yes Yes December 2017
Xabber Yes No No No No No No No Yes December 2017

Notes on the individual columns

Free software

This column provides information on whether the software is made available to the end user under a free or open source license . For applications where security and trust are paramount, viewing the source code is essential to ensure independent control. In contrast to this, there is proprietary software , in which the source text is normally not released and thus security through obscurity prevails, for example .

Encryption

Some messengers offer the transmission of encrypted messages. These columns provide information about which encryption technology or which encryption protocol is used and which special properties are supported.

Further details on the technology of individual messengers can be found in the respective notes below.

End-to-end encryption

When a message is encrypted before it is sent and only decrypted by the recipient, this is known as end-to-end encryption . The message remains illegible on the entire transport route.

Some messengers use new encryption protocols that were specially designed for mobile instant messaging. However, such new protocols are practically never free of errors straight away. The "end-to-end" field of messengers who use new, unchecked encryption protocols is highlighted in yellow in the table. This shows that the security of these messengers has not yet been checked and probably still contains errors.

While security flaws in open source software are generally discovered and corrected quickly because the source code can be checked by many experts, this is not the case with proprietary software. The “end-to-end” field of proprietary messengers is highlighted in red because they cannot be considered secure in the foreseeable future.

Some messengers use encryption protocols that have been in use for some time and have already been checked many times. The "end-to-end" field of these messengers has a green background to show that they offer a high level of security.

The "end-to-end" column uses the following classification:

  • None : The messenger does not support encryption. The field is highlighted in red.
  • In-house development: The process was designed by the manufacturer himself. Depending on whether it was checked and what the check revealed, the field is highlighted in green (can be considered safe), yellow (no check) or red (security deficiencies have been found).
  • Standard procedures Standardized procedures ( OTR , TLS ) are used. The field has a green background.

Client-server encryption

Mobile instant messaging usually involves one or more servers that receive messages, store them temporarily and - immediately or later - deliver them to the recipient. Communication between a client and a server can be encrypted (so-called transport encryption ). In this case, messages cannot be read during transmission from the client to the server or vice versa, but the messages are in clear text on the server. Whether the connection between two servers is encrypted cannot be influenced by the client (here: the messenger) and is therefore not taken into account.

The TLS protocol is normally used for client-server encryption . Some messengers use the outdated SSL protocol or in-house developments.

The "Client-Server Encryption" column uses the following classification:

  • None : The messenger does not support encryption. The field is highlighted in red.
  • In-house development: The process was designed by the manufacturer himself. Depending on whether it was checked and what the check revealed, the field is highlighted in green (can be considered safe), yellow (no check) or red (security deficiencies have been found).
  • Standard procedures Standardized procedures (OTR, TLS) are used. The field has a green background.

Authentication

There are cryptographic methods with which the authenticity of a message can be checked, i.e. H. whether it actually comes from the sender it appears to come from. In this way, man-in-the-middle attacks can be detected.

This column provides information about whether the respective messenger supports the authentication of messages.

Deniability

If the authenticity of messages can be checked (see column "Authentication"), it is usually possible to subsequently assign messages to the sender without any doubt. It can then be proven that the sender actually sent certain messages.

Some messengers offer the option of subsequently credibly denying the sending of a message . The recipient can still be sure that the message is genuine at the moment it is received.

Both the proof of authenticity at the moment of receipt and the later contestability of authenticity are implemented using cryptographic processes.

Perfect Forward Secrecy (PFS)

If all messages are encrypted with the same cryptographic key, this key can also be used to subsequently decrypt older messages. If an attacker gains access to the key, he can also read messages intercepted earlier.

Some messengers offer perfect forward secrecy , which prevents this scenario by encrypting every message with a new short-term key that is derived from a long-term key and is deleted within a short time.

Functions

Picture messages

Indicates whether the messenger supports the sending of picture messages.

Group chat

Some messengers support group communication. Individual users can become members of a group. Messages sent to the group are delivered to all members of that group.

The “Group chat” column provides information on whether the respective messenger supports this type of communication.

Asynchronous communication

Asynchronous communication (or “offline communication”) is used when messages can be sent while the recipient is not online, i.e. cannot receive any messages. The messages are cached on a server until the recipient is ready to receive the messages. The messages can also be received even if the sender is no longer online.

This property is particularly useful in mobile use, since mobile devices usually do not have a constant Internet connection.

Others

Transmission of the connection data

Many messengers use Internet server services from Google (Google Cloud Messaging, now Firebase Cloud Messaging) or Apple. As a result, these companies receive the meta or connection data of the communication. According to secret services and data protection agencies, metadata is at least as intimate or dangerous as content data. A participant acting under a pseudonym can be identified by metadata. Only the content of a message is hidden by the messenger encryption that is sometimes offered here.

Transfer of contacts

Specifies whether the messenger automatically transfers all phone book entries from the mobile phone to the provider in order to facilitate communication with its own contacts. However, this makes it possible for the provider to create social profiles by linking the contact details.

  • Optional : You can choose whether the phone book should be transferred (green)
  • No : Phonebook is not transferred (yellow)
  • Their hashes : only hashes of the contact data are transmitted (yellow)
  • Yes : the phone book is transferred automatically (red)

Self-hosted server

This column indicates whether it is possible for third parties to host a server for the operation of the messenger themselves.

Federation

The column indicates whether accounts on different servers can communicate with each other.

Notes on the individual messengers

Bleep

  • Bleep uses decentralized distributed servers (P2P).

ChatSecure

  • The transmission of images takes place (optionally OTR-encrypted) via the chat channel.
  • An XMPP account is required, which - depending on the server - can be created directly in the app. Alternatively, the client works with any account that was previously created in the browser.

Chiffry

  • End-to-end data encryption of all messages and telephone calls with 256-bit AES in GCM mode.
  • The encryption key is generated anew before each message or each telephone call and transmitted to the recipient according to the mailbox principle using elliptical curve cryptography (512-bit ECDH).
  • Protection against forgery of all messages by means of 512-bit ECDSA signatures and user identification by means of cipher certificates.
  • Data is transmitted via the Chiffry communication server, which is located in the envia TEL data center in Germany.
  • The basic version is free and includes all basic functions such as encrypted sending of text and voice messages, images, videos, locations, contacts and tap-proof telephony.
  • Business version is designed for authorities and companies and includes special solutions such as B. Communication via its own Chiffry server within an authority or company.

Conversations

Conversations
  • Completely open source
  • XMPP client that works with any server for free. A user can also create an account with Conversations for a fee.
  • End-to-end encryption
  • Can also be installed via F-Droid

Delta chat

Delta chat
  • A valid e-mail address is sufficient for use
  • There is no central server
  • The messages are encrypted using Autocrypt ( openPGP )
  • The use of transport encryption (TLS) depends on the email provider used
  • Communication with other e-mail programs is possible without restriction
  • Any attachments can be sent encrypted
  • Completely open source
  • Can also be installed via F-Droid

Hike

  • The transmission of content (text, images, etc.) can optionally be encrypted within a WI-FI connection with 128-bit SSL.

Kontalk

Kontalk
  • The protocol used is XMPP, which is supplemented with its own extensions.
  • As standard, asymmetric encryption using OpenPGP is used: All messages are end-to-end encrypted and signed.

Line

Line
  • Line is an instant messaging service by the Japanese company Line Corporation, part of the Korean Naver Corporation.
  • The app is available in eighteen languages.
  • Line is the most popular messaging application in Japan. Line is also popular in Taiwan, Thailand, Turkmenistan, and Indonesia, and had 700 million users worldwide in 2017.
  • The program can be used to make free VoIP calls and send messages.
  • Line offers a range of extra services such as Line Friends, Line Pay, Line Taxi, Line Wow, Line Man, Line Today, Line TV and Line Shopping.

signal

signal
  • The apps and the server are published under a free license (GPLv3, AGPLv3) as open source software on Github.
  • Whistleblower and former CIA employee Edward Snowden recommended Signal Messenger several times and, according to his own statements, uses it every day.
  • All communication with other signal users (messages, phone calls, group chats) is automatically encrypted end-to-end. The keys for encrypting communication are stored on the end devices (not on the server).
  • The signal encryption protocol is a further development of OTR in order to enable an asynchronous use of this protocol. In the meantime, Whatsapp, Facebook Messenger, Skype and others also use the signal encryption protocol.
  • One of the two Whatsapp founders (Brian Acton) left Whatsapp and donated $ 50 million to the Signal Foundation in 2018.
  • A desktop version exists. Sent and received messages are synchronized with all devices.
  • Registration only with telephone number.
  • Location sharing not with OpenStreetMap, as one would expect, but with Google.

SureSpot

  • The authentication is ensured by public key cryptography. The server signs the public keys of all clients. A client checks the public key of its communication partner by checking the signature of the server. The server signature is built into the client (it should therefore not be possible to operate your own server). The server thus acts as a de facto certification authority.
  • Users cannot check each other's public keys. The keys can be seen, so that a comparison would be possible. However, a user can generate new keys at any time without the attention of other users.
  • Users reported sometimes extremely long delivery times (up to 8 hours).

Telegram

Telegram
  • Telegram uses its own protocol (MTProto), which also regulates the use of cryptography.
  • Registration only with a telephone number, then use optionally with a user name.
  • The group chat does not offer end-to-end encryption, only client-server or server-client.
  • End-to-end encryption is available in “secret chats” that have to be started manually.
  • The "MTProto" protocol used by Telegram is an in-house development and has been criticized for various reasons, see section Security
  • All messages except for "secret chats" are stored centrally on the Telegram servers and synchronized between the user's end devices.

Threema

Threema
  • Threema was originally developed by the Swiss company Kasper Systems GmbH (later Threema GmbH ). The servers are in Switzerland. At the same time, the push service of the respective operating system manufacturer (e.g. Google Cloud Messaging) is used as standard, with no message content or metadata being sent about it, only the information that a message has arrived. Threema can also be installed and used without a Google account.
  • Registration is also possible without a telephone number and email address.
  • Threema lets the user decide whether he wants to upload his entire phone book to the server or just individual contacts. The automatic contact synchronization can also be controlled.
  • The University of Amsterdam subjected Threema to a basic security analysis. For this purpose, the binary code was decompiled , the data management was analyzed and the communication via man-in-the-middle was attacked. No gaps were found, the authors of the study therefore consider Threema to be well implemented and safe.
  • In November 2015, the program was audited by cnlab security AG, an IT security service provider from Switzerland, and found to be secure.
  • Without open source code, however, it cannot be determined whether Threema has become less secure or even insecure through later updates (e.g. through backdoors). The tests can therefore only certify the security of the tested version.

Whatsapp

Whatsapp
  • WhatsApp is very popular.
  • WhatsApp encrypts the connection with end-to-end encryption (since April 2016, according to the manufacturer).
  • WhatsApp's source code is not available for public review.
  • The WhatsApp Messenger transfers its users' phone and address books to WhatsApp and Facebook.
  • Registration with telephone number
  • WhatsApp belongs to Facebook .

Wickr

  • Wickr promises "military-grade encryption". The Android app uses AES 256 bit, ECDH 521 , RSA-4096 and TLS for encryption .

Wire

  • The source code of the clients is available on GitHub . Since the beginning of April 2017, the source code of the server has also been gradually published on GitHub.
  • for smartphones and tablets (Android or iOS) as well as Windows, macOS and Linux computers.
  • WebRTC possible with certain web browsers ( Chrome , Firefox and Opera ).
  • free for private use
  • All communication content on Wire is end-to-end encrypted.

Xabber

  • An iOS version was last announced on February 5, 2013.
  • An XMPP account is required which cannot be created by Xabber.

Messenger that is no longer maintained

  • myEnigma used end-to-end encryption (AES 256 bit) of the messages between the sending and receiving devices and additional TLS encryption of the data on the way to and from the server. The operator was the Swiss company Qnective, the server was located in Switzerland. The service was discontinued in 2016.
  • sayHEY existed from 2014 to 2017. The free and cross-platform app ran on smartphones and desktops and was developed and operated by Simyo .
  • Whistle.im

See also

Web links

Individual evidence

  1. ↑ Bittorrent Labs: bleep ( English ) In: bittorrent.com . Archived from the original on October 8, 2014. Retrieved October 11, 2014.
  2. ↑ a b c d e WhatsApp and alternatives - data protection in the test . In: test.de . February 26, 2014. Retrieved December 23, 2015.
  3. ↑ Prodekted Mobile Teamwork ( English ) In: blackpin.de . Retrieved February 25, 2019.
  4. ↑ About ( English ) In: chatsecure.org . Retrieved December 23, 2015.
  5. ↑ Security: Experts warn against WhatsApp alternative Hike . In: spiegel.de . Spiegel Online . December 10, 2012. Accessed December 23, 2015.
  6. ↑ a b c Hoccer - Data protection and security declaration . In: hoccer.com . Retrieved December 23, 2015.
  7. ↑ ICQ Video chat & Messenger - Android app . In: chip.de . May 5, 2014. Accessed December 23, 2015.
  8. ↑ Jami: Frequently Asked Questions ( English ) In: jami.net . Retrieved April 9, 2020.
  9. ↑ KakaoTalk Bypassing SSL (2) ( English ) In: bpak.org . June 23, 2011. Accessed December 23, 2015.
  10. ↑ Kontalk Messenger - Apps on Google Play . In: play.google.com .
  11. ↑ riot-web / LICENSE ( English ) In: github.com . Riot.im. Retrieved January 3, 2018.
  12. ↑ Security . In: riot.im . Retrieved January 3, 2018.
  13. ↑ advanced cryptographic ratcheting . In: whispersystems.org . November 26, 2013. Retrieved December 23, 2015.
  14. ↑ Markus Beckedahl: Encrypted Whatsapp alternative: New version of Textsecure offers group chat . In: netzpolitik.org . February 25, 2014. Accessed December 23, 2015.
  15. ↑ a b WhisperSystems / TextSecure server . In: github.com . Retrieved December 23, 2015.
  16. ↑ Security . In: sims.me . German Post AG. Archived from the original on August 19, 2014. Retrieved December 23, 2015.
  17. ↑ Ronald Eikesberg: SIMSme: crypto messenger from Deutsche Post . In: heise.de . August 13, 2014. Retrieved April 17, 2017.
  18. ↑ Frequently asked questions . In: threema.ch . Retrieved December 23, 2015.
  19. ↑ Hristo Dimitrov, Jan Laan, Guido Pineda: threema security assessment - Research project for Security of Systems and Networks Master System and Network Engineering (PDF): os3.nl . Retrieved December 23, 2015.
  20. ↑ Frequently asked questions - Threema . In: threema.ch .
  21. ↑ Tigase Messenger ( English ) In: f-droid.org . F-droid.
  22. ↑ Privacy Policy . In: touch.com . Archived from the original on February 27, 2014. Retrieved on December 23, 2015.
  23. ↑ WhatsApp's Signal Protocol integration is now complete . In: whispersystems.org . Open Whisper Systems. April 5, 2016. Retrieved June 15, 2016.
  24. ↑ Tap-proof: WhatsApp receives end-to-end encryption . In: computerbase.de . November 18, 2014. Accessed December 23, 2015.
  25. ↑ Signal >> Blog >> Advanced Cryptographic Ratcheting . In: www.whispersystems.org .
  26. ↑ wireapp / wire-server ( English ) In: github.com . Wire Swiss GmbH. Retrieved July 27, 2020.
  27. ↑ Xabber is released under GNU GPL v3 (30-01-13) In: xabber.com . Retrieved December 23, 2015.
  28. ↑ Frequently Asked Questions ( English ) In: chatsecure.org . Retrieved December 5, 2017.
  29. ↑ desktopclient-java - Releases ( English ) In: github.com . Retrieved December 23, 2015.
  30. ↑ uApp Explorer TextSecure Client ( English ) In: uappexplorer.com . Retrieved on February 28, 2016.  ( Page no longer available , search in web archives )@1@ 2Template: Dead Link / uappexplorer.com
  31. ↑ a b c d e What are the system requirements for Skype? . In: skype.com . Skype Communications SARL. Accessed June 1, 2020.
  32. ↑ a b c Which Skype-enabled devices or platforms are no longer supported? . In: skype.com . Skype Communications SARL. Accessed June 1, 2020.
  33. ↑ a b Which end devices are supported? . In: telegram.org . Accessed June 1, 2020.
  34. ↑ jollagram OpenRepos ( English ) In: openrepos.net . June 23, 2015. Retrieved February 28, 2016.
  35. ↑ a b Bruce Schneier: Crypto-Gram - Secrecy, Security, and Obscurity ( English ) In: schneier.com . Bruce Schneier, Founder and CTO Counterpane Internet Security, Inc. May 15, 2002. Retrieved December 23, 2015.
  36. ↑ ABC News: Ex-NSA Chief: 'We Kill People Based on Metadata' ( English ) In: ABC News . Archived from the original on September 1, 2016. Retrieved August 31, 2016.
  37. ↑ get.chiffry.de . In: chiffry.de .
  38. ↑ 128 bit SSL Encryption: hike ( English ) In: hike.in . Retrieved on December 23, 2015.  ( Page no longer available , search in web archives )@1@ 2Template: dead link / support.hike.in
  39. ↑ Signal Messenger source code ( English ) In: github.com . GitHub Inc.
  40. ↑ Simplifying OTR deniability. ( English ) In: whispersystems.org . July 27, 2013. Accessed December 23, 2015.
  41. ↑ Signal Desktop ( English ) In: github.com . GitHub Inc. Retrieved March 23, 2018.
  42. ↑ Contact . In: threema.ch . Threema GmbH. Retrieved December 23, 2015.
  43. ↑ Can I buy / use Threema without a Google Account? . In: threema.ch . Threema GmbH. Retrieved August 31, 2016.
  44. ↑ Hristo Dimitrov, Jan Laan, Guido Pineda: threema security assessment - Research project for Security of Systems and Networks Master System and Network Engineering ( English , PDF): os3.nl . December 22, 2013. Accessed December 23, 2015.
  45. ↑ Dennis Schirrmacher: Threema audit completed: “End-to-end encryption without weaknesses”. . In: heise.de . Heise online . November 3, 2015. Retrieved November 3, 2015.
  46. ↑ Internet: Facebook buys rival WhatsApp . In: zeit.de . The time . February 20, 2014. Accessed December 23, 2015.
  47. ↑ Ms. Smith: Wickr: Free texting app has military-grade encryption, messages self-destruct ( English ) In: wickr.com . September 17, 2013. Archived from the original on December 31, 2014.
  48. ↑ Wire clients ( English ) In: github.com . Wire Swiss GmbH.
  49. ↑ Wire-Server ( English ) In: github.com . Wire Swiss GmbH.
  50. ↑ Ferdinand Thommes: Instant Messenger Wire reveals server sources . In: pro-linux.de . Pro Linux . April 12, 2017.
  51. ↑ Andrew Nenakhov: Xabber - Question concerning pull requests ( English ) In: xabber.com . February 5, 2013. Archived from the original on April 22, 2013. Retrieved on December 23, 2015: “GNU GPLv3 is incompatible with Apple Appstore terms and we'll definitely have to think of something similar to solve this problem when we release Xabber for iOS (wich we plan to later this year, btw, work is already in process). "