Research Of The Basic Protocols And Its Applications In Secure Multi-party Computation

Information security is one of the biggest threats to the information society.Secure multi-party computation as an important tool to solve the information security problem has aroused people's attention.Secure multi-party computation refers to the problem where two or more parties want to jointly compute a task based on their private inputs,while no party is willing to disclose his privacy to any other one,it is widely used in scientific computing,geometric calculation and so on.This paper mainly studies the two basic problems in scientific computing and geometric calculation,and designs a number of protocols for specific fields.Firstly,this paper studies the norm problem of vector difference,based on homomorphic encryption technique and secure two-party permutation technique,we design a privacy computation of norm protocol of vector difference.since this protocol does not apply to two-dimensional vectors,so based on the idea of inner product protocol constructed by Clifton,another norm protocol of vector difference is designed.Secondly,it studies the millionaires' problem,and we summarizes and analyzes the existing schemes of the problem,aiming at the low efficiency of the existing schemes,an improved scheme is proposed.Subsequently,a new millionaires' protocol is proposed based on the data-disguising techniques and homomorphic encryption algorithms.Compared with the previous schemes,the two schemes of this paper reduce the number of encryption,decryption,and arithmetic operation,which make our schemes more efficient than others.Finally,based on the norm protocol of vector difference,two application problems are solved,including privacy-preserving computation of high-dimensional spatial parallelogram area and data proportional correspondly problem;based on the millionaires' protocol,three application problems are solved,including vector dominance statistic problem,the position relationship between two rectangles and divisibility problem.Then we design these corresponding protocols,and analyze its' correctness,security and efficiency.By comparison,it shows that our protocols are more secure and more efficient.