一种动态群签名方案

A DYNAMIC GROUP SIGNATURE SCHEME

最近,Bellare,Shi和Zhang提出一个动态群签名模型。依据该模型,提出了一个基于双线性对的动态群签名方案,它实现了动态群签名模型的各种功能。该方案有下列特点:在建群阶段不需要确定成员的数目并且群公钥固定不变;任何时候实体都能通过群权威加入到群中获得签名私钥并且无需更新其他成员的签名私钥;能通过群权威揭示签名人的身份并且这一过程是可验证的。该方案的安全性是建立在间隙群上计算Diffie-Hellaman问题和离散对数问题均是困难问题的基础上。

Recently, a dynamic group signature model is proposed by Bellare, Shi and Zhang. A new dynamic group signature scheme based on bilinear pairing is presented according to the model,and it realizes the functions of the model. This scheme has three merits. First,the number of group members is not fixed in the setup phase and the group public key is unchanged. Second, an entity can join the group at any time and obtain a private signing key without refashioning other group members＇ private signing key. Third,the identity of the group signature can be open by the authority and the procedure of the tracing can be check by anybody. The security of the dynamic group signature is based on the fact that the gap Difl^e-Hellman problem and discrete logarithm problem are hard problems.