半诚实模型下关于安全多方求解交集问题的研究

特殊情形下的安全多方计算问题是目前密码学界研究的热点，特殊的安全多方计算协议的设计与分析自然成为当前人们致力研究的热门课题。数据库共享过程中，如何在不暴露各自数据集的前提下计算出交集？一直是我们感兴趣的问题，问题的解决对实现新型、安全、公平的数据共享有着重要的意义。在半诚实模型下我们基于计算不可区分概念以及交换加密的安全性假设，给出了一个用于求解交集的特殊安全双方计算协议。该协议具有公平性、安全性，并借助茫然第三方的参与，使协议简单有效。作为茫然第三方不知道最后结果及参与方的秘密，也不能与参与方串谋作弊。文中对协议的安全性进行了理论证明和分析。该协议在政府文件共享、医疗机构的合作研究、数据挖掘等领域中有着广阔的应用前景。

A RESEARCH OF COMPUTING INTERSECTION ACROSS PRIVATE DATASETS UNDER SEMI-HONEST

Research on secure muhi-party computation is of great interest in modem cryptography. Design and analysis of the special multiparty computation protocols is meaningful and has attracted much interest in this field. Based on the combination of commutative encryption and computationally indistinguishable, a protocol for computing intersection of equality is proposed. The protocol is fair, secure and efficient. The oblivious third party cannot learn any information about the participant private inputs and even about the intersection result, and cannot collude with any participant. A precise proof of security of the protocol is presented. Applications of this protocol may include identification in a number of scenarios and so on. It is believed that the protocol may be of practical significance for selective document sharing, medical research and data mining.