门限签名方案的研究及其安全性分析

Research on threshold signature scheme and its security analysis

对谢君琴等人提出的无可信中心的门限签名方案进行了安全性分析,指出了该方案不能抵抗合谋攻击和已知消息攻击,不具有可追踪性。针对上述问题,在谢君琴等人的方案的基础上提出了一个无可信中心的门限签名方案:由签名组织者发起对消息的签名,限制门限签名的发布权于签名组织者,从而抵抗合谋攻击和已知消息攻击;建立追踪方程,实现签名者的追踪。通过安全性分析,证明了所提出的方案具有抗合谋攻击、在已知消息攻击下和选择消息攻击下的存在性不可伪造性、可追踪性等安全性能。与谢君琴等人的方案相比,所提出的方案降低了计算复杂度,提高了签名执行效率。

A threshold signature scheme without trusted party is analyzed by Xie Junqin et al. It is pointed out that it can not resist against collusion attack and known-message attack, and it is not traceable. To solve the above problems, a threshold signature scheme without a trusted party is proposed based on Xie＇s scheme. In detail, to resist against collusion attack and known-message attack, the signature of the message is initiated and published by the signing organizer. To trace the identity of the signer, tracking equations are established. Security analyses are conducted and results show that the proposed scheme owns the security properties such as anti-collusion, unforgeability under known-message attack and chosenmessage attach and traceability. Finally, in comparison with Xie＇s scheme, the proposed scheme has less computational complexity.