标准模型下可证安全的基于身份的高效签名方案

基于身份的公钥密码体制克服了传统公钥密码体制所带来的公钥证书存储和管理开销问题;目前大多数基于身份的数字签名方案的安全性足基于随机预言模型进行证明,但随机预言机的实现方式可能会导致方案的不安全,如Hash函数,往往返回的结果并小是随机的.文中提出一种安全、高效的基于身份的签名方案,并且在标准模型下证明该方案对自适应选择消息攻击是存在不可伪造的,方案的安全性可规约为CDH困难假定.与现有的标准模型下安全的基于身份的签名方案相比,方案的通信代价更小,执行效率更高.

An Efficient and Provably Secure Identity-Based Signature Scheme in the Standard Model

Compared with the traditional public key cryptosystem, identity-based cryptosystem can simplify the key management procedure from the view point of the efficiency and convenience. Most of identity-based signature schemes are secure in the random oracle model, but for which any implementation of the random oracle results in insecure schemes. For example, when random oracle is instantiated with concrete hash functions, the resulting scheme is nonrandom which may not be secure. This paper proposes an efficient and provably secure identity-based signature scheme. The scheme is existentially unforgeable against adaptive chosen message attacks under the computational Diffie-Hellman assumption in the standard model. Compared with the known identity-based scheme secure in the standard model, the scheme enjoys shorter signature length and less operation.