Abstract: Recently, an efficient identity-based partially blind signature scheme was put forward by Cui and Xin et al. First of all, it was pointed out that Cui-Xin's scheme suffered from the forgery attack in which a requester could change the pre-agreed common information illegally, and the reason why Cui-Xin's scheme could not resist the forgery attack was discussed. Secondly, an improved scheme was put forth to overcome the security flaw of Cui-Xin's scheme, and it was strictly proved to be unforgeable. Compared with the existing schemes, the results show that the proposed scheme is an efficient identity-based partially blind signature scheme.

Key words: partially signature, identity-based, security model, unforgebility, bilinear map

摘要： 最近崔巍等人提出了一个高效的基于身份的部分盲签名方案(崔-辛方案)。首先指出了在崔-辛方案中请求者能非法修改事先已协商好的公共信息，并讨论了出现这种伪造攻击的原因。然后针对崔-辛方案的安全缺陷提出了一个改进方案，并严格证明了它的不可伪造性。最后将所提方案与现有方案进行了性能比较，比较结果显示所提方案是一个效率较高的基于身份的部分盲签名方案。

关键词: 部分盲签名, 基于身份, 安全模型, 不可伪造性, 双线性映射