异构签密方案能够为不同安全域之间的数据通信提供机密性和认证性。分析现有的异构签密方案,都是在随机预言模型下可证安全的。基于此,该文提出一个在标准模型下从基于身份的密码到传统公钥设施的签密方案,利用计算Diffie-Hellman问题和判定双线性Diffie-Hellman问题的困难性,对该方案的机密性和不可伪造性进行了证明。通过理论和实验分析,该方案在计算成本和通信成本方面具有更高的效率。
Heterogeneous signcryption scheme can ensure the confidentiality and the authentication for data communication between different security domains. Some existing heterogeneous signcryption schemes are analyzed to be secure in the random oracle model. Based on this problem, an Identity-Based Cryptography (IBC) to Public Key Infrastructure (PKI) signcryption scheme is proposed. The proposed scheme has the confidentiality and the unforgeability under the Computational Diffie-Hellman (CDH) problem and the Decisional Bilinear Diffie-HellmanB (DBDH) problem. Through the theoretical and experimental analysis, both the computational costs and the communication overheads of the proposed scheme are more efficient.