Instant messaging

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The contact list (here using Gajim as an example ) is a typical feature of instant messengers.

Instant Messaging [ ˌɪnstənt mɛsɪdʒɪŋ ] (short IM ; English for instant messaging ) or instant messaging is a communication method , two or more participants to chat via text messages in. The sender triggers the transmission (so-called push procedure) so that the messages arrive at the recipient as immediately as possible. In order for messages to be transmitted, the participants must be connected to a computer program (called a client ) via a network such as the Internet directly or via a server . As a rule, messages can also be sent when the conversation partner is currently not online ; the message is then cached by the server and later delivered to the recipient when he can be reached again.

Many instant messengers also support the transfer of files and audio and video streams .

Users can manage each other in their contact list and then see from the presence information whether the other is ready for a conversation.

The ICQ, launched in 1996, is the first Internet-wide instant messaging service . Instant messaging is a very widespread form of telecommunications, especially as a replacement for SMS ( Short Message Service ) in mobile communications (which is associated with additional costs on the part of the network provider) . With the proliferation of smartphones and mobile Internet access, IM has become one of the most widely used services on mobile devices. The Snowden revelations and Facebook's acquisition of the popular messaging service WhatsApp led to great demand for end-to-end encrypted IM services and the development of numerous new encrypted alternative providers, which are often also available as open source .


The expression "instant message" was coined by Paul Linebarger . In his science fiction stories from the 1960s, he used it to describe messages that could be sent over interstellar distances at faster than light speeds . His "instant news" was considered extremely expensive, and he wrote a few episodes about the unaffordable news.


Users can only communicate with interlocutors who use the same protocol . Most IM services use their own, proprietary protocols such as ICQ , WhatsApp and Skype .

There are also open protocols such as IRC , XMPP , WebRTC and the Echo protocol or Tox . Many are mostly defined in open standards as RFCs . There are a number of different clients for various operating systems for these open protocols. The users are therefore not tied to a specific IM service, but only to an open and standardized protocol. - A comparison with the likewise federated e-mail system can serve as an analogy , in which the user is only bound to open and standardized application protocols such as SMTP , POP3 or IMAP , but not to a specific provider. Instant messaging protocols are increasingly also end-to-end encrypted, as is the case with the open source and very elaborate encryption suite for instant messaging and e-mail called "Spot-On".

See also

Web links

Individual evidence

  1. ^ Tilman Frosch, Christian Mainka, Christoph Bader, Florian Bergsma, Joerg Schwenk, Thorsten Holz: How Secure is TextSecure? 2014 ( [PDF]).
  2. David Adams, Ann-Kathrin Maier: BIG SEVEN Study, open source crypto-messengers to be compared - or: Comprehensive Confidentiality Review & Audit: Encrypting E-Mail-Client & Secure Instant Messenger, Descriptions, tests and analysis reviews of 20 functions of the applications based on the essential fields and methods of evaluation of the eight major international audit manuals for IT security investigations Including 38 figures and 87 tables, . English / German Language, Version 1.1 edition. Tokyo / Munich 2016, p. 305 ( [PDF]).
  3. Gasakis, Mele / Schmidt, Max: Beyond Cryptographic Routing: The Echo Protocol in the new Era of Exponential Encryption (EEE) - A comprehensive essay about the Sprinkling Effect of Cryptographic Echo Discovery (SECRED) and further innovations in cryptography around the Echo Applications Smoke, SmokeStack, Spot-On, Lettera and GoldBug Crypto Chat Messenger addressing Encryption, Graph-Theory, Routing and the change from Mix-Networks like Tor or I2P to Peer-to-Peer-Flooding-Networks like the Echo respective to Friend- to-Friend Trust-Networks like they are built over the POPTASTIC protocol, ISBN 978-3-7481-5198-2 , Norderstedt 2018. English / edition. Norderstedt 2018, p. 304 ( ).
  4. Edwards, Scott / Project (Eds.): Communicating like dolphins with Spot-On Encryption Suite: Democratization of Multiple Encryption & Exponential; 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 , 2019. Norderstedt 2019, p. 306 (English).