典型代理多重签名方案的分析与改进

Analysis and improvement for proxy multi-signature scheme

YBX代理多重签名方案是不安全的,攻击者在不知道原始签名者密钥的情况下,能够伪造代理签名密钥,假冒代理签名者对文件进行签名。在全面分析攻击方案的基础上,构造了一种增强的代理多重签名方案。新方案克服了YBX方案的代理转移、不具有强不可否认性等缺陷,除了具有普通签名方案的安全性外,还具有接收方可查的时控代理多重签名方案的性质。

The proxy multi-signature scheme called YBX is not safe. An attacker can forge the key pair of proxy signature without the original private key, and disguise himself as proxy to sign document. Based on the analysis of attack scheme, an improved proxy multi-signature scheme was proposed. The new scheme overcomes the defects of YBX scheme such as proxy transferring and not having strong undeniability. The new scheme is safe. Moreover, the original signer can set up the time limit of the proxy power holding by the proxy signer and can trace the receiver of the signature.