基于身份认证的密钥交换改进协议

Improved Identity-based Authenticated Key Exchange Protocols

基于离散对数的困难性假设,Hlbl等人提出了2个基于身份认证的密钥交换协议HW1和HW2(Computer Standards&Interfaces,2009,No.6)。HW1协议能够有效抵抗Tseng等人提出的攻击(Journal of Computers,2002,No.3),HW2协议则具有较高的效率,但Shim等人发现HW1不能抵抗中间人攻击和伪装攻击,HW2不能抵抗伪装攻击(IEEE Communications Letters,2012,No.4)。通过分析Shim等人提出的攻击方案,找出这2个协议能够被篡改的原因,分别提出改进的HW1和HW2协议,利用Hash函数对传输的信息做Hash验证,以防止信息被篡改。对改进协议进行可行性证明和安全性分析,结果表明,2种协议能够有效抵抗中间人攻击和伪装攻击,具有较高的安全性。

Based on the difficulty of the discrete logarithm assumption,Holbl et al（ Computer Standards ＆Interfaces, 2009,No. 6） presented two identity-based authenticated key exchange protocols. The first protocol,denoted by HW1, improved Hsieh et al’ s protocol which makes it immune against Tseng et al’ s attack （ Journal of Computers,2002, No. 3）,while the second protocol,denoted by HW2,improves the efficiency of Tseng’ s protocol. Shim et al analyzes these two protocols, and then shows that the HW1 can not resist the man-in the-middle attack and the impersonation attack,and the HW2 can not resist the impersonation attack（IEEE Communications Letters,2012,No. 4）. This paper conducts a detailed analysis on the flaw, and finds the reason of the protocols are tampered, making use of the Hash function,authenticates the information to prevent the information is tampered,it proposes improved protocols based on these two protocols,and analyzes the security of improved protocols. The results suggest that the improved protocols can resist the man-in-the-middle-attack and the impersonation attacks,they are safe and feasible.