一种多策略门限群签名方案的密码学分析

门限群签名是一种特殊而重要的数字签名，但普通的门限群签名方案都存在门限值固定的缺陷。对一种多策略门限群签名方案进行了安全性分析，指出了其中的设计缺陷，并提出了针对该方案的三种攻击，即重放攻击、假冒攻击和合谋攻击。分析结果表明，该方案仍然没有解决门限群签名中门限值固定的问题。

Cryptanalysts of threshold group signature scheme with multi-policy

Threshold group signature is a kind of special and important digital signature.However,common threshold group signature scheme has the weakness that there is only one threshold value.This paper analyzes a threshold group signature scheme with multi-policy,points out its weakness and demonstrates the following three attacks on it：Replay attack,impersonation attack and conspiracy attack.The security analysis indicates that the proposed scheme can’t still resolve the problem that there is only one threshold value in the threshold group signature scheme.