支持授权撤销的代理签名分析与改进

摘要

在基于时间戳撤销机制的代理签名方案中,授权服务器(AS)签发的时间戳内并不包含原始签名人的授权信息,使攻击者可以利用该缺陷绕过AS检查,获得合法的时问戳签名.为此,对AS生成时间戳阶段进行改进,使攻击者无法获得能够通过验证的时间戳签名,从而弥补原方案的安全缺陷.%According to in-depth security analyzing of a proxy signature scheme with revocation by the use of timestamp, it points out that the malicious proxy signer can obtain a valid timestamp whatever the original signer revoked the delegation or not because the time-stamp issued by Authentication Sserver(AS) do not bind with the delegation of original signer. Pointing at the problems existed in the timestamp generation phase, this paper proposes a more efficient scheme with fast revocation, which solves the weaknesses of original scheme fundamentally.