一种无随机预言机的无证书广义签密方案

研究在无证书公钥密码系统下的广义签密问题,提出了无证书广义签密方案的形式化定义,并定义其较为完全的安全模型.该安全模型下的第2类攻击者是恶意但被动的攻击者.同时,利用双线性映射设计了一个高效的无证书广义签密方案.其安全性基于计算Diffie-Hellman问题和判定性Bilinear Diffie-Hellman问题的困难性,并在标准模型下给出正式的安全性证明.鉴于该方案具有安全高效和无证书的优点,它可以广泛地应用于电子商务、防火墙和密钥分配等领域.

Certificateless Generalized Signcryption Scheme without Random Oracles

This paper studies generalized signcryptions in the certificateless public key settings.The paper proposes the formal definition and security model of certificateless generalized signcryption.The Type II adversary in the security model is malicious,but a passive Type II attacker.Also an efficient construction of certificateless generalized signcryption scheme using bilinear maps is also implemented.The security of proposed scheme is based on the infeasibility of the Computational Diffie-Hellman problem and Decision Bilinear Diffie-Hellman problem.The scheme is formally proven without random oracles under the security model of certificateless generalized signcryption schemes.Due to its security,high efficiency and freedom from certificate management,it may have practical applications in electronic cash payment,firewall and key distribution,etc.