分析了Wu-Wang提出的基于离散对数问题的盲签名方案的安全性,给出了一个攻击,即签名请求者仅执行一次方案可以同时得到两则不同消息的有效签名。针对该攻击提出一种改进方案,通过在签名阶段引入一个随机数来抵抗此种攻击,使得方案安全性能提高。
The security of blind signature scheme based on the discrete logarithm problem which is proposed by Wu-Wang is analyzed, and a security attack is given, that is, a signature requester can obtain valid signatures of two different messages at the same time through performing only one round of the protocol. A modified scheme is presented, in the signature phrase a random number is used by a s!gner to prevent this kind of attack, and its security is improved.