目的 研究了几个无证书的部分盲签名方案,对其中的一个签名方案分析发现其存在严重的安全缺陷,并对出现伪造攻击的原因进行分析.方法 在签名阶段加入公共信息,并在签名时改变签名的形式.结果与结论 分析表明,改进方案不仅满足部分盲性,而且可以防止对公共信息的更改,并在随机预言模型下证明新方案是不可伪造的.
Objective--To analyze one of the certificateless partially blind signature schemes that we found unsecure during our study and the reason why this scheme suffer from the attack. Methods-- By increasing the common information and changing the part of signature form, a new scheme is given. Results and Conclusion--The results show that the new scheme not only satisfies the various security properties of partially blind signature, but also can prevent from the adversary's attack of modifying common information, and the new scheme is proved to be unforgeable under the random oracle model.