摘要：

在无证书密码学体制中,公钥与持有者之间没有认证关系,可能产生恶意用户替换用户公钥的问题。为此,对无证书签名定义进行改进,提出一种可证安全的无证书短签名方案。方案的安全性基于Inv-CDH问题,并在随机预言机模型下给出完整的安全性证明,证明其在新敌手下的适应性选择消息攻击中抗存在性伪造。利用C语言实现此方案,并将其与经典短签名方案以及近年无证书短签名方案进行性能分析与比较。结果表明,在签名阶段该方案仅需1次倍点运算,在验证阶段需要2次倍点运算和2次双线性对运算,其签名长度短、运算效率高。

关键词: 双线性对, 无证书, 数字签名, 短签名, 可证安全

Abstract:

In the certificateless cryptography system,there is no authentication relationship between the public key and the holder,which may cause a problem that a malicious user replaces the user’s public key.To This end,this paper improves the definition of certificateless signature,and proposes a provably security certificateless short signature scheme.The security of the scheme is based on the Inv-CDH problem,and the complete security proof is given under the stochastic oracle model,and it is proved that the scheme is anti-existence forgery in the adaptive selection message attack under the new adversary.This scheme is implemented by C language,and its performance is analyzed and compared with those of the classical short signature schemes and the certificateless short signature schemes in recent years.Results show that in the signature phase,the scheme only needs one time of multiple-point operation;in the verification phase,the scheme requires two times of multiple-point operation and two times of bilinear pairing operation.The proposed scheme has a short signature length and a high operation efficiency.

Key words: bilinear pairing, certificateless, digital signature, short signature, provably security

中图分类号: 

• TP309.2