Secure Multi-party Comparison Protocol and Application

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.