Abstract: Based on the Paterson’s identity-based signature scheme, this paper proposes a provable secure identity-based threshold proxy signature scheme. The scheme is existentially unforgeable against adaptive chosen message attacks under the computational Diffie-Hellman assumption in the standard model. Compared with other threshold proxy signature schemes based on public key cryptosystem, the new scheme is more secure. Compared with other identity-based threshold proxy signature schemes in the random oracle model, the new scheme is more meaningful.

Key words: threshold proxy signature, identity-based cryptography, standard model, Computation Diffie-Hellman（CDH） problem

摘要： 在Paterson基于身份的签名方案基础上，提出一个在标准模型下可证安全的基于身份的门限代理签名方案。新方案具有在自适应选择消息攻击下存在不可伪造性，其安全性在标准模型下可归约为CDH问题假定，与基于公钥密码体制的门限代理签名方案相比，新方案的安全性更高。同时，相对随机预言模型下基于身份的门限签名方案，新方案更具有实际意义。

关键词: 门限代理签名, 基于身份密码体制, 标准模型, CDH问题