【摘要】 签名算法的安全性依赖于签名密钥的安全性.密钥一旦泄漏,攻击者便可以成功伪造此前的所有签名,这会对整个签名系统造成无法弥补的损失.针对门限代理签名中的密钥泄漏问题,将前向安全引入其中,提出一种具有前向安全特性的指定验证者(t,n)门限代理签名方案.安全性分析表明,新方案真正实现了前向安全.即使当前时段所有成员的密钥被泄漏,也不会影响之前生成的签名的有效性.新方案具有指定验证者的特性,能够确保签名只被预先指定的验证人验证,可以很好地保护原始签名者的隐私.签名具有消息恢复的特性,在传输签名时不用传输明文消息本身,能够减小传输签名时的通信代价.更多还原

【Abstract】 The signature scheme’s security depends on the security of the secret key. Once the secret key is revealed,the adversary can forge all the previous generated signatures. And it is a great loss to the w hole signature system. According to the threshold proxy signature’s key exposure problem,the forw ard security is integrated into it to propose a forw ard secure( t,n) threshold proxy signature scheme w ith designated verifier. Security analysis show s that the new scheme achieves a truly forw ard security. Even if all the signers’ current secret keys are revealed also w on’t affect the previous generated signatures’ validity. The new scheme has a designated verifier,so the signature can only be verified by him,w hich can protect the original signer’s privacy w ell. And the signature has the properties of message recovery,so it can be transmitted w ithout the plain message w hich reduces the communication costs of the signature transmission.更多还原