一个代理盲签名体制的安全性分析

Security Analysis of Proxy Blind Signature Scheme

代理签名是指原始签名人将签名权力委托给代理签名人,由代理签名人代表原始签名人对消息进行签名.盲签名是指签名人不知道所签消息的具体内容.Tan和Liu结合代理签名和盲签名的特性提出了一种代理盲签名,该文指出Tan和Liu提出的代理盲签名方案存在广泛的伪造攻击、原始签名人的伪造攻击和消息拥有者的伪造攻击等安全缺陷,并提出了改进的方案,改进后的方案可以有效地避免原始签名人和消息拥有者的伪造攻击.

Proxy signature allows an original signer to delegate his/her signing power to a proxy signer such that the proxy signer can sign messages on behalf of the original signer. Blind signature allows a user to have a given message signed by the signer without revealing any information about the message. Recently Tan et al proposed a proxy blind signature on the combination of the proxy signature and blind signature. However, this paper shows that the proposed scheme suffers with a universal＂forgery attack, original signer＇ s forgery attack and message owner＇ s forgery attack. This paper proposes an improved scheme that can avoid original signer＇ s and message owner＇ s forgery attack effectively and efficiently.