一种异构混合群组签密方案的安全性分析与改进

异构混合群组签密不仅能够解决不同密码体制下数据传输的机密性和不可伪造性，而且还能对任意长度的数据进行加密。该文首先分析了一种异构密码体制下混合群组签密方案的安全性，指出该方案不满足正确性、机密性和不可伪造性。并提出了一种新的高效异构混合群组签密方案。其次在随机预言机模型下证明了该方案是安全的。最后效率分析表明，该方案在实现原方案所有的功能的基础上同时降低了计算代价。

Security Analysis and Improvements of Hybrid Group Signcryption Scheme Based on Heterogeneous Cryptosystem

Heterogeneous hybrid group signcryption can not only solve the confidentiality and unforgeability of data transmission under different cryptosystems, but also encrypt data of any length. Firstly, the security of a hybrid group signcryption scheme under heterogeneous cryptosystem is analyzed, and it is pointed out that the scheme does not satisfy the correctness, confidentiality and unforgeability. And a new efficient heterogeneous hybrid group signcryption scheme is proposed. Secondly, it is proved that the proposed scheme is safe under the random oracle model. Finally, the efficiency analysis shows that the proposed scheme reduces the computational cost while realizing all the functions of the original scheme.