Abstract: The exchangeable key solutions and homomorphic encryption solutions were analyzed. Meanwhile, the deficiencies of these two solutions on the computational complexity were pointed out. On the basis of that, two new solutions were put forward: one was based on chaotic encryption solution, and the other was asymmetric encryption solution which introduced the incredible third party. The correctness, security and complexity of them were analyzed and verified. The comparison between the proposed solutions and the existing ones was given. The experimental results show that the new solutions can reduce the complexity of the algorithm, and greatly improve the execution efficiency of algorithm.

Key words: secure multiparty computation, collection member decision, chaotic encrytion, exchangeable encryption, incredible third party

摘要： 对可交换密钥解决方案与同态加密解决方案进行了分析，并指出了二者在计算复杂度上的不足。在此基础上，提出了另外两种解决方案，一种是基于混沌加密解决方案，另一种是引入不可信第三方参与的非对称加密解决方案，并分析证明了这两种方案的正确性、安全性和复杂性。将提出的新方案与现有的方案进行实验对比，结果证实了新方案能降低算法的复杂度，极大地提高了算法的执行效率。

关键词: 安全多方计算, 集合成员判定, 混沌加密, 可交换加密, 不可信第三方