OTR (Off-the-Record) messaging is a cryptographic protocol that provides end-to-end encryption, authentication, deniability, and perfect forward secrecy for instant messaging conversations. Implementing OTR on IRC ensures that private communications remain confidential and secure.

OTR enhances IRC private messages by:

• Encryption: Ensures that messages cannot be read by unauthorized parties.
• Authentication: Confirms the identity of the communicating parties.
• Deniability: Prevents third parties from proving the content of the conversation.
• Perfect Forward Secrecy: Protects past communications even if long-term keys are compromised in the future.

For a comprehensive understanding of OTR, refer to the OTR official website.

Several IRC clients support OTR, either natively or through plugins:

• HexChat: Supports OTR via plugins.
• Irssi: Supports OTR through the irssi-plugin-otr.
• WeeChat: Supports OTR via the python-potr plugin.
• Pidgin: Supports OTR through the pidgin-otr plugin.

For a detailed comparison of IRC clients and their features, visit the Comparison of IRC clients page.

OTR provides several methods to authenticate contacts:

• Question and Answer: Ask a question that only your contact can answer.
• Shared Secret: Share a secret passphrase with your contact.
• Manual Fingerprint Verification: Compare the OTR fingerprints of both parties.

For detailed instructions on authentication methods, refer to the Off-the-Record Messaging guide.

• Verify Fingerprints: Always verify the OTR fingerprints of your contacts to prevent man-in-the-middle attacks.
• Use Strong Passphrases: Ensure that your passphrases are strong and unique.
• Regularly Update Software: Keep your IRC client and OTR plugins up to date to benefit from security patches.
• Be Cautious of Logs: Some clients may log OTR conversations; ensure logging is disabled if privacy is a concern.

• OTR Official Website
• OTR Wikipedia Page
• Off-the-Record Messaging Guide