!!! Overview [{$pagename}] is a [cryptographic] [protocol] that provides [encryption] for [Instant Messaging] [Applications]. [{$pagename}] uses a combination of [AES] [symmetric Key] [algorithm] with 128 bits key length, the [Diffie-Hellman] [key-Exchange] with 1536 bits group size, and the [SHA-1] [hash Function]. In addition to [authentication] and [encryption], [{$pagename}] provides [Perfect Forward Secrecy] and [Homomorphic Encryption]. The primary motivation behind the protocol was providing [Repudiation] for the conversation participants while keeping conversations [confidential], like a private conversation in real life, or off the record in journalism sourcing. This is in contrast with [cryptography] tools that produce output which can be later used as a verifiable record of the communication event and [non-Repudiation] identities of the participants. The [{$pagename}] [protocol] was designed by cryptographers Ian Goldberg and Nikita Borisov and released on 26 October [2004|Year 2004].[2] They provide a client library to facilitate support for instant messaging client developers who want to implement the [protocol]. A Pidgin and Kopete plugin exists that allows OTR to be used over any IM [protocol] supported by Pidgin or Kopete, offering an auto-detection feature that starts the [OTR] session with the buddies that have it enabled, without interfering with regular, unencrypted conversations. [{$pagename}] provides:[2] * [Encryption] - No one else can read your instant [messages]. * [Authentication] - You are assured the correspondent is who you think it is. * [Deniability|Reputation] - The [messages] you send do not have [Digital Signatures] that are checkable by a [third-party]. Anyone can forge messages after a conversation to make them look like they came from you. However, during a conversation, your correspondent is assured the [messages] he sees are authentic and unmodified. * [Perfect Forward Secrecy] - If you lose control of your [Private Keys], no previous conversation is compromised. !! More Information There might be more information for this subject on one of the following: [{ReferringPagesPlugin before='*' after='\n' }] ---- * [#1] - [Off-the-Record_Messaging|Wikipedia:Off-the-Record_Messaging|target='_blank'] - based on information obtained 2017-05-21- * [#2] - [Off-the-Record_Messaging|https://otr.cypherpunks.ca/|target='_blank'] - based on information obtained 2017-05-21-