无证书聚合签名方案

聚合签名通过聚合n个签名(n个不同签名者对n个不同消息生成)为一个签名, 节省带宽和提高签名验证效率. 无证书公钥密码体制解决了传统公钥密码体制中的证书管理问题以及基于身份密码体制中的密钥托管问题. 该文基于双线性对提出一个新的高效的无证书聚合签名方案. 分析表明, 在随机预言机模型中计算性Diffie-Hellman假设下, 所提方案能够抵抗适应性选择消息攻击下的存在性伪造攻击, 同时所提方案签名长度独立于签名者的数量仅为2个群元素, 签名验证中仅需要4个对和n个标量乘运算, 因此该方案更加适合资源受限网络环境中的应用.

Certificateless Aggregate Signature Scheme

Aggregate signatures allow an efficient algorithm to aggregate n signatures of n distinct messages from n different signers into one single signature. Aggregate signature is useful to save bandwidth and improve the efficiency in verification phase. Certificateless public key cryptography overcomes the complicated certificate management in traditional public key cryptography and key escrow problem in identity based cryptography. In this paper, we present a new efficient certificateless aggregate signature scheme based on the bilinear pairing. The analysis shows that the proposed scheme is proven existentially unforgeable against adaptive chosen message attacks under the computational Diffie-Hellman assumption in the random oracle model. The signature length is only two group elements, which is independent of the number of signers, and the signature needs only four pairings and n scalar multiplications computations in verification phase. Thus, the proposed scheme is more suitable for the applications, in resource-constrained environment.