Interlock Protocol - Brief History

Brief History

Most cryptographic protocols rely on the prior establishment of secret or public keys or passwords. However, the Diffie-Hellman key exchange protocol introduced the concept of two parties establishing a secure channel (that is, with at least some desirable security properties) without any such prior agreement. Unauthenticated Diffie-Hellman, as an anonymous key agreement protocol, has long been known to be subject to man in the middle attack. However, the dream of a "zipless" mutually authenticated secure channel remained.

The Interlock Protocol was described as a method to expose a middle-man who might try to compromise two parties that use anonymous key agreement to secure their conversation.