一个无证书的环代理签名方案

无证书公钥密码体制既简化了传统公钥密码体制负担过重的密钥管理问题,又消除了基于身份的公钥密码体制所固有的密钥托管缺陷.基于无证书公钥密码体制提出一个高效的环代理签名方案,其成员私钥不再由密钥生成中心KGC单独产生,而由KGC和用户合作生成.安全性和有效性分析比较,该方案既具有环签名的无条件匿名性,原始签名人能匿名授权代理权限,又满足强代理签名的所有安全特性,能够有效抵制KGC的强伪造攻击；其环代理授权过程,不需要双线性对运算且标量乘运算代价较现有最优方案减少了一半,其效率具有明显优势,适用于需要匿名性且带宽受限的场合.

Certificateless Ring Proxy Signature Scheme

Certificateless public key cryptography reduces the difficult problem of key management in traditional public key cryptography,it also eliminates the key-escrow problem of identity-based cryptography and also preserves all of its advantages.A the lowest calculating time ring proxy signature scheme is proposed,the secret keys of singers in the scheme is generated by members and secret key generation center(KGC) cooperatively.In contrast with other similar scheme in security and efficiency,our scheme can meet with the requirements of unconditional anonymity of the original signer′s proxy delegation,and can resist the strongest forgery attacks from the KGC,and achieves all security attributes of strong proxy signature.Especially,it is more efficient in ring proxy delegation phase because without the computational cost of bilinear pairings,and the computational cost of scalar multiplication required is half of other scheme,so it is suitable to the application of low bandwidth and anonymity.