A modified eCK model with stronger security for tripartite authenticated key exchange

Abstract

Since Bellare and Rogaway presented the first formal security model for authenticated key exchange (AKE) protocols in 1993, many formal security models have been proposed. The extended Canetti-Krawczyk (eCK) model proposed by LaMacchia et al. is currently regarded as the strongest security model for two-party AKE protocols. In this paper, we first generalize the eCK model for tripartite AKE protocols, called teCK model, and enhance the security of the new model by adding a new reveal query. In the teCK model, the adversary has stronger powers, and can learn more secret information. Then we present a new tripartite AKE protocol based on the NAXOS protocol, called T-NAXOS protocol, and analyze its security in the teCK model under the random oracle assumption