基于身份的无可信私钥产生中心的代理签名方案的改进

Improvement of ID-based proxy signature scheme without trusted PKG

发现左卫平等人提出的基于身份无可信私钥产生中心的指定验证人代理签名方案存在一个安全漏洞,即代理人根据原始签名人的授权可计算出原始人的私钥,从而可直接伪造原始签名人的签名或任何授权。针对此方案的缺陷,提出了改进措施,分析表明改进后的方案是安全的,可抵抗代理人恶意的伪造攻击,还可以抵抗代理人和私钥产生中心联合的恶意攻击。

A security defect was detected in ZUO Wei-ping＇s ID-based designated verifier proxy signature scheme without trusted PKG. The proxy signer can compute the original signer＇s private key after receiving his authorization. An improved scheme was presented to overcome the above defect. Analysis indicates that it is secure against the proxy signer＇s forgery attack, and even against the malice attack of the ally of the proxy signer and the PKG.