一种动态群签名的密码学分析

CRYPTANALYSIS OF A DYNAMIC GROUP SIGNATURE

最近,吴克力等人提出了一种基于双线性对的动态群签名方案[1],该方案具有在增加和删除群成员时,不改变群公钥和群成员的签名私钥的优点。王占君等人对其进行安全性分析[2]后认为,该方案存在非成员伪造群成员证书及陷害攻击的缺陷。分析说明王占君等人的分析并不成立,同时指出原方案存在计算上的缺陷,并给出一种陷害攻击和群成员间的联合攻击。证明原方案是不安全的。

Recently,a dynamic group signature based on bilinear pairing was proposed by Wu Keli.The advantage of the scheme is that it neither changes the public key of the group nor the private signature keys of the group members.Wang Zhanjun analyzed the security of Wu＇s scheme and claimed there was certificate forgery of non-group member and framing attacks in the scheme.This paper proves that the analisis of Wang does not hold and aslo points out there is caculation defeat in the original scheme.What＇s more,a new framing attack and a new coalition attack are present.So it can prove the original scheme is not secure.