认证群密钥协商协议的安全性分析与改进

对Tseng协议构造了一种有效的中间人伪造攻击，敌手可以成功获得群会话密钥，因此Tseng协议不满足密钥认证性。然后基于Tseng协议的安全缺陷，提出改进协议，并进行安全性分析和性能分析。改进协议实现了通信节点之间的双向认证，不但满足前向安全性、密钥认证性，还能有效抵抗被动攻击和中间人伪造攻击。改进协议中的低能量节点计算出会话密钥的时间只需2.03s，高能量节点的计算时间仅为原协议的1/2，并且通信开销减小了40%，更适用于能量受限，带宽受限的移动通信系统。

Analysis and Improvement of an Authenticated Group Key Agreement Protocol

An authenticated group key agreement protocol for resource-limited mobile devices was proposed by Tseng Y.M. It is demonstrated that this protocol has security vulnerabilities by mounting a man-in-middle attack against it. The protocol can not achieve key authentication in the presence of an active attacker. This paper presents an improved protocol which achieves mutual authentication. It provides not only the capability of forward secrecy and key authentication, but also the capability against passive attack and man-in-middle attack. The analysis shows that the presented protocol has lower computation cost and communication cost compared with Tseng's protocol.