Secure Multi-party Comparison Protocol and Application

Abstract

The problem of information comparison is always an important field of SMC. In order to effectively solve the fully equal problem of multi-data for all information, a secure two-party multi-data comparison protocol for equality (STMC) is proposed with the aid of the NTRU encryption. The protocol converts multi-data comparison problem for equality to polynomials comparison for equality. Analysis shows that the protocol is correct and security in semi-honest model. Being STMC as basic building block, a secure multi-party multi-data comparison protocol for equality (SMMC) is proposed. SMMC provides a solution which n participants hope to determine the equality of their private input sets, on the condition of no information leaked. This protocol is proved to be collusion-resistance security. The last, computational complexity and communication complexity of the two protocols are analyzed. It is shown that new protocols have low complexity. We also give applications in the secure multi-party information comparison problem and secure multi-party polynomial comparison problem.