基于双线性对的无证书签名与群签名方案

Certificateless Signature and Group Signature Schemes Based on Bilinear Pairings

传统数字签名方案的证书存储和管理开销较大，基于身份的数字签名方案无法解决其固有的密钥托管问题，而无证书签名方案无需使用公钥证书，且没有密钥托管问题。为此，提出一个基于双线性映射的无证书签名方案，并在随机预言机模型下证明其安全性。在此基础上设计一个无证书群签名方案，其安全性建立在计算Diffie—Hellman问题的困难性假设上。性能分析表明，2种签名方案在保证安全性的前提下，具有较高的执行效率。

Traditional digital signature schemes need much more storage and management overhead for the use of certificates, while the identity-based digital signature schemes fail to solve the inherent key-escrow problem. Certificateless signature schemes need no certificates and can solve the key-escrow problem. This paper presents a certificateless signature scheme from bilinear pairings, and verifies its security under the random oracle machine. It designs a certificateless group signature scheme from the certificateless signature scheme, and its security is founded under the assumption of the computational Diffie-Hellman problem. Performance analysis shows that both signature schemes are secure and have high performing efficiency.