An Improvement of Tseng-Wu Group Key Exchange Protocol

摘要

Based on the group Diffie-Hellman technique, a contributory group key exchange protocol has been proposed by Biswas. Although Biswas claimed the protocol belongs to a contributory group key exchange, Tseng and Wu did not agree with. Then, they proposed an improved group key exchange protocol with a character of verifiably contributory and claimed the proposed protocol could not provide a secure scheme against passive attacks. However, Ling et al. pointed out that it is vulnerable to a man-in-the-middle attack with Tseng-Wu's protocol. The attackers could intercept and modify the messages among the group members. In this article, we will propose an improvement of Tseng-Wu group key exchange protocol. Our protocol could against remedy the man-in-the-middle attack.