The Study On Some Discrete Problems On Secure Mutilparty Computation Protocol

Generally speaking, a secure multiparty computation (SMC) problem deals with computing a function on any input a distributed network where each participant holds one of the inputs, and that no more information is revealed to a participant in the computation than can be inferred from that participant's input and output.Special secure multi-party computation protocol is an important area in cryptography in recent year. It's the basis of many distributed cryptographic protocols such as electronic voting, cooperation server online and electronic auction, etc. In fact, almost all protocols in distributed environment can be viewed as a special case of secure multiparty computation. It is based on many basic cryptographic protocols and some basic protocols such as homomorphic encryption scheme, secret sharing and omitting transaction.It's a very meaningful work to design security efficient and practical protocol in secure multi-party computation area, such as secure two-party scalar product protocol, secure multi-party set intersection protocol, symmetrically private information retrieval etc.We will introduce our research on this area detailed, firstly the paper classify the research results like private information retrieval Matrix Calculation, statistical analysis, computational geometry and data mining. Secondly summary the innovations of this thesis as following:1. An efficient secure two-party scalar product protocol is proposed and its correctness, security and complexity are analyzed.2. A privacy-preserving subspace-containing determination protocol based on secure two-party scalar product protocol is proposed and its correctness, security and complexity are analyzed3. A privacy-preserving protocol in computation of set intersection and a protocol of secure multi-party set rank based on Paillier encryption are designed and their correctness, security and complexity are analyzed.4. Research the problem of secure multi-party computational geometry and Summary the development and results. Then propose a protocol of privacy-preserving triangle inequality determination, lastly apply it in the secure multi-party computational geometry area.5 Research the problem of private information retrieval and propose an efficient protocol of one-item symmetrically private information retrieval (SPIR) based on the secret sharing. A multi-item SPIR protocol is derived form the one-item SPIR. Detailed analysis of correctness, security and complexity to the scheme is also given. In addition, an improved scheme of privacy-preserving computing the Kth value of database is proposed.