Security · 1h ago
How OTR Messaging Invented Forward Secrecy and Deniability
In 2004, researchers Borisov, Goldberg, and Brewer proposed Off-the-Record Messaging to fix PGP's flaws for instant messaging. OTR introduced forward secrecy by using ephemeral keys and deniability through malleable encryption and published MAC keys. These ideas now underpin billions of modern messaging apps like Signal and WhatsApp.
Meridian48 take
OTR's design choices are now standard, but the protocol itself faded—a reminder that foundational ideas often outlive their original implementations.
encryptionmessaging-protocols