OTR

OTR (Off-the-Record Messaging) is a cryptographic protocol that provides encryption for instant messaging conversations. It ensures that the communication is private and secure, offering features such as authentication, encryption, deniability, and perfect forward secrecy.

Features

OTR offers several key features that make it a preferred choice for secure communication:

• Encryption: Ensures that the messages are only readable by the intended recipient.
• Authentication: Verifies the identity of the participants in the conversation.
• Deniability: Ensures that the messages cannot be proven to have come from a specific user, providing plausible deniability.
• Perfect Forward Secrecy: Ensures that even if long-term keys are compromised, past communication remains secure.

History

OTR was developed by Ian Goldberg and Nik Unger in 2004. It was designed to address the need for secure and private communication in the context of instant messaging.

Protocol

The OTR protocol operates by establishing a secure channel over an existing instant messaging protocol. It uses a combination of the Diffie-Hellman key exchange and the Advanced Encryption Standard (AES) to encrypt messages. The protocol also employs the SHA-1 hash function for message integrity.

Implementation

OTR can be implemented in various instant messaging clients through plugins or built-in support. Some popular clients that support OTR include Pidgin, Adium, and Jitsi.

Security Considerations

While OTR provides strong security features, it is important to note that it relies on the security of the underlying instant messaging protocol. Users should ensure that their messaging clients and systems are up-to-date and free from vulnerabilities.

See Also

• Cryptography
• Instant messaging
• Diffie-Hellman key exchange
• Advanced Encryption Standard
• SHA-1

Related Pages

• Ian Goldberg
• Nik Unger
• Pidgin (software)
• Adium
• Jitsi