对一个无证书部分盲签名方案的分析与改进

Cryptanalysis and Improvement of a Certificateless Partially Blind Signature Scheme

摘要: 对汤鹏志等提出的一种无证书部分盲签名方案进行了密码分析,指出方案中签名请求者可以非法修改协商信息.为了有效抵抗篡改协商信息攻击,提出了一种改进的无证书部分盲签名方案.在随机预言机模型下证明了改进方案对无证书密码体制的两类敌手的自适应选择消息和身份攻击是存在性不可伪造的,其安全性可以归约为k-CAA问题和ICDH问题.

Abstract: A certificateless partially blind signature scheme proposed by Tang P Z et al was analyzed and it was pointed out that the signature requester can change the negotiated information illegally.In order to resist tampering attack on negotiated information effectively，an improved certificateless partially blind scheme was proposed and proved to be existentially unforgeable against adaptive chosen message and identity attacks from two types of adversaries in certificateless cryptosystems in random oracle model.The security of the improved scheme is reduced to collusion attack algorithm with k traitors and inverse computational Diffie-Hellman assumption.