为实现混合密码体制下不同用户之间的代理权,给出了基于身份的原始签名者和基于证书的代理签名者的代理签名体制(PSS-ID-CER)的定义,并利用双线性对的双线性及基于公钥证书的密码体制的密钥和基于身份的密码体制的密钥生成特点,给出了相应方案的构造.为证明方案的安全性,定义了此类方案在适应性选择PKG、ID、代理、代理签名者公钥、代理密钥和消息攻击下的一般化安全模型.在随机预言机模型和计算Diffie-Hellman问题困难假下,方案是可证明安全的.
To realize delegation between different users in a mixed cryptosystem,a proxy signature scheme for ID-based original signers and certificated-based proxy signers(PSS-ID-CER)is defined.Using the bilinear properties of the pairings and the characters of key generations of certificate-based cryptosystems and ID-based cryptosystems,a construction for such a scheme is also presented.To prove the security of the proposed scheme,a general security model for this scheme under adaptive chosen-PKG,chosen-ID,chosen-delegation,chosen-ProxySigner-public-key,chosen-proxy-key and chosen-message attack is defined.The proposed scheme is provably secure under the random oracle model and the hardness assumption of computational Diffie-Hellman problem.