Off-the-Record Messaging is unclaimed —

Off-the-Record Messaging

otr.cypherpunks.ca

Off-the-Record (OTR) Messaging is a protocol and software (a core library, a Pidgin plugin, and related tools) that lets users have private conversations over instant messaging. It provides encryption so messages cannot be read by others, authentication of the correspondent's identity, deniability (no checkable digital signatures), and perfect forward secrecy so past conversations remain secure even if private keys are later compromised.

What it's for

having private conversations over instant messagingencrypting instant messages so no one else can read themauthenticating the identity of an IM correspondentforging messages after a conversation using the included toolkitadding OTR support to other IM applications via the libraryadding OTR support to Java applications via the Java OTR libraryusing OTR with AIM/ICQ clients via a localhost proxy (no longer supported)

Features 14

Authentication of conversation correspondent
Deniability (no checkable digital signatures)
Encryption of instant messages
Java OTR library for developers
libotr portable OTR Messaging Library
Mailing lists for announcements, users, and developers
Multiple language translations (Spanish, German, Norwegian Bokmål, Danish)
OTR localhost AIM proxy (no longer supported)
OTR Toolkit for forging messages
Perfect forward secrecy
pidgin-otr plugin implementing OTR over any IM network Pidgin supports
Protocol documentation (version 2 and version 3)
Public git source repository and bugtracker
Socialist Millionaire Protocol (SMP) authentication fix mentioned

At a glance

open sourceAPI

TypePlugin / add-on

DeploymentInstalled (local)

PlatformsWindows, macOS, Linux

LanguagesEnglish, Spanish, German, Norwegian Bokmål, Danish

Fordevelopers of Java applications, instant messaging users

Integrations

PidginAIMICQ

Resources

Docs