Secure Multiparty Computation To The Study Of A Number Of Issues

Secure Multi party Computation first put forward by A.C.Y ao, simplydescribed as follows: P={P1, P2,...Pn} is a set of n participants,they want tosecurely compute a given function f(x1, x2,..., xn)=(y1, y2,..., yn) by transmissionof information each other. The n inputs of function f are provided by n participantsseparately.Requring P1, P2,...Pnobtain y1, y2,..., ynseparately after computation,security mainly means that Pi(i=1,2,..., n) can not get anything about informationxiand yi(j=1,2,..., i1, i+1,..., n) except the information implied by xiand yi.SMC is electronic elections, electronic auction and threshold signature, andmany other applications to the realization of important cryptography basis. SMCprotocol involves many of the ground floor of the password agreement, at present theproposed solutions use to secret sharing, public and private key encryption, homo-morphisms encryption and casual transmission, and many other common algorithmand security agreement. In recent years, people for multi-party computation madeextensive and in-depth research on the problems including confidentiality is the sizeof the two Numbers, confidential data mining, confidential database query, confi-dential auction, confidential scientific computing, confidential statistical analysis,confidential geometric calculations, etc.The main job of this paper is as following:1.The security definition of privately compare information protocol with anobvious third party is given. We anlyse the safety, accuracy and fairness of QINJing's protocol which based on-hinding assumption and homomorphic encryption;2.We propose an efcient protocol based on symmetric encryption. Commu-nication complexity, computational complexity, and security of the protocol basedon-hinding assumption and QIN Jing's protocol based on symmetric encryptionwere analyzed and compared, the fomer is more theoretical while the latter is morepractical;3.We propose a protocol based on RSA homomorphic encryption and OT pro- tocol to solve secret sequencing problem. This protocol satisfy safety, fairness andefciency comparing using A.C.Y ao's protocol repeatedly.