Security Proofs for an Ecien t Password-Based Key Exchange
Emmanuel Bresson, Olivier Chevassut, David Pointcheval · 2003
Password-based key exchange schemes are designed to provide entities communicating over a public network, and sharing a (short) password only, with a session key (e.g, the key is used for data integrity and/or conden tiality). The focus of the present paper is on the analysis of very ecien t schemes that have been proposed to the IEEE P1363 Standard working group on password-based authenticated key-exchange methods, but for which actual security was an open problem. We analyze the AuthA key exchange scheme and give a complete proof of its security. Our analysis shows that the AuthA protocol and its multiple modes of operation are provably secure under the computational Die-Hellman intractability assumption, in both the random-oracle and the ideal-cipher models.