Smart Card-Based Three-Party Key Exchange without Server´s Assisitance

Three-party password-authenticated key exchange protocol is a cryptographic tool that allows two clients to share a common session key using different passwords by the help of a trusted server. In a three-party key exchange protocol, the server should charge some cost to participate in an execution of the protocol between two clients, and the cost can be heavy burden on the server when many users want to establish a session key. In this paper, we propose a smart card-based three-party key exchange protocol which permits two clients to establish a common session key without the server´s aid.