Abstract
A key exchange protocol allows two parties to establish a common session key. In 1990, Gunther proposed a key exchange protocol based on user’s identity. An identity-based key exchange protocol is a protocol that uses user’s identity to achieve user authentication and key exchange. Recently, Saeednia proposed a modification of Gunther’s identity-base key exchange protocol in order to reduce the communication cost. In this paper, we propose a slight modification of Saeednia’s identity-based key exchange protocol such that the computation cost in Saeednia’s protocol can be further reduced. The improved protocol is as secure as Saeednia’s protocol against various attacks