基于身份代理盲签名方案的密码学分析

Cryptanalysis of Identity-based Proxy Blind Signature Schemes

盲性,也称不可追踪性,是盲签名的一个重要特性。张学军分别对蔡光兴和农强提出的基于身份的代理盲签名方案进行分析(计算机工程,2009年,第3期和第23期),指出这2个方案都不满足盲性,是可追踪的,并分别提出改进的满足盲性的方案。针对张学军对蔡光兴和农强的方案的可追踪性分析进行研究,发现张学军提出的可追踪性分析方法存在缺陷,并采用构造的方法证明代理签名人不能根据签名建立过程中记录的签名参数追踪签名,因此蔡光兴和农强提出的方案仍满足盲性,是不可追踪的。

Blindness,namely unlinkability,is an important property of blind signature.Zhang Xuejun analyzed identity-based proxy blind signature schemes proposed respectively by Cai Guangxing and Nong Qiang,pointed out that the two schemes did not satisfy blindness property and they were linkable,and proposed improved schemes with blindness.This paper researches Zhang Xuejun＇s linkability analysis to Cai Guangxing and Nong Qiang＇ schemes,finds that Zhang Xuejun＇s analysis method of linkability has drawbacks,and then uses construction method to prove that proxy signer can not use the parameters generated during the signing to track the signature.So Cai Guangxing and Nong Qiang＇ schemes still satisfy the blindness property and they are unlinkable.