Abstract: For the weaknesses of previous threshold signature in against conspiracy attack, combining with the discrete logarithm method, this paper proposes a threshold hybrid proxy multi-signature scheme against conspiracy attack. The scheme, through introducing key parameter [ki], camouflages actual signer’s private key and traces signature memberships, thus effectively against conspiracy attack. Theoretical analysis results show that the scheme not only satisfies strong unforgeability and strong undeniability, but also can effectively against conspiracy attack.

Key words: discrete logarithm, threshold signature, hybrid proxy multi-signature, conspiracy attack

摘要： 针对现有门限签名方案在抵抗合谋攻击方面的弱点，结合离散对数问题，提出一个抗合谋攻击的门限混合代理多重签名方案，通过引入关键参数[ki]，实现对实际签名人的私钥的隐藏和对签名成员身份的可追查性，从而有效地抵抗合谋攻击。理论分析结果表明，该方案满足强不可伪造性和强不可否认性，且能有效地抵抗合谋攻击。

关键词: 离散对数, 门限签名, 混合代理多重签名, 合谋攻击