Abstract: At present,most group signature is only secure in the standard alone.Its security becomes weak in multiple protocol environment.In view of this,the security of group signature protocol is studied in the multiple concurrent execution under the universally composable framework.Since the protocol can be analyzed modularly under the universally composable framework,an ideal function of group signature protocol is defined in this framework.Then a group signature protocol is proposed to realize the ideal function,and its universally composable security as well as unforgeability is also proved.Furthermore,a concrete instance of this universally composable group signature protocol is given.Analysis results show that this protocol security is suitable for applications in multiple concurrent environment.

Key words: group signature, ideal function, concurrent execution, security, unforgeability

摘要： 目前群签名协议大多只局限于单个协议执行的安全性,在多协议环境下安全性减弱。为此,研究通用可组合模型框架下的群签名在多个协议并发执行时的安全性。由于在通用可组合的模型框架下可以模块化地分析协议,因此利用此框架定义群签名协议的理想函数,提出可以实现此理想函数的群签名协议,并证明此协议的安全性和不可伪造性。基于离散对数问题给出通用可组合的群签名协议实例。分析结果表明,该协议的安全性适用于多协议执行的并发环境。

关键词: 群签名, 理想函数, 并发执行, 安全性, 不可伪造性

CLC Number: 

• TP309