基于PKI和IBC的双向匿名异构签密方案

摘要

现有的基于传统公钥密码体制(PKI,public key infrastructure)和基于身份的密码体制(IBC,identity-based cryptosystem)之间的异构签密方案都有一定的缺陷,基于此,提出一种新的双向的基于PKI和IBC的异构签密方案.在随机预言模型中和在基于计算性Diffie-Hellman困难问题(CDHP,computational Diffie-Hellman problem)、q-Diffie-Hellman逆问题(q-DHIP,q-Diffie-Hellman inversion problem)和双线性Diffie-Hellman困难问题(BDHP,bilinear Diffie-Hellman problem)的假设下,该方案满足机密性和不可伪造性.同时,该方案还满足密文的无连接性和匿名性.与已有同类异构签密方案对比,该方案不仅实现了签密的双向性,而且在PKI和IBC生成系统参数时不作限制,更加符合实际的应用环境.模拟实验表明,该方案具有可行性,并且满足用户对系统响应时间的要求.%Exiting heterogeneous signcryption schemes which were between public key infrastructure (PKI) and identi-ty-based cryptosystem (IBC) have some limitations. A new heterogeneous signcryption scheme between PKI and IBC was proposed. In the random oracle mode, the scheme ensured confidentiality and unforgeability on the basis of the as-sumption of computational Diffie-Hellman problem (CDHP), q-Diffie-Hellman inversion problem (q-DHIP) and bilinear Diffie-Hellman problem (BDHP). Simultaneously, the proposed scheme guaranteed unconnectedness and anonymity of the ciphertext. Compared with other heterogeneous schemes, the scheme achieved two-way signcryption, and it generated pa-rameters without restrict, which was suitable for actual situations. Simulation tests show that proposed scheme is feasible.