摘要： 在使用安全媒介(SEM)实现无证书签名撤销时,SEM存储了大量用户的秘密信息,降低了签名方案的安全性和可靠性。为此,根据时间更新密钥的思想,设计一种新的可撤销无证书签名方案。在随机预言模型下,基于CDH困难问题,证明方案的安全性,并可抵抗一般用户的公钥替换攻击、密钥生成中心攻击和已撤销用户攻击。分析结果表明,该方案只需要3个双线性对运算,具有较高的运算效率。

关键词: 无证书签名, 用户撤销机制, 时间更新密钥, 随机预言模型, 不可伪造性

Abstract: Using Security Mediator(SEM) to realize the revocation of certificateless signature,SEM stores a lot of users’ secret information,and reduces the security and reliability of certificateless signature scheme.In order to overcome this shortcoming,this paper proposes an efficiently Revocable Certificateless Signature(RCLS) scheme based on the idea of time update key.In the random oracle model,based on the assumption of Computational Differ-Hellman(CDH) problem,the scheme which is proved to be secure can resist three types of attacks:the attack of user’s replace public key,the attack of Key Generation Center(KGC) and the attack of revocatory users.Analysis results show that this scheme has great computation efficiency as it only needs 3 bilinear pairing computation.

Key words: certificateless signature, user revocable mechanism, time update key, random oracle model, unforgeability

中图分类号: 

• TP309