Research On Application Of Secure Multi-party Geometry And Information Matching Computing

Secure multi-party computing(SMC)is a high-level application protocol of Cyberspace Security.This kind of advanced application protocol solves the problem that some protocol participants work out the result of a function together without leaking their privacy information in an open network environment.The application scenarios of SMC mainly include electronic voting,data mining,computational geometry and intelligent medical.At present,most of the solutions of this kind of application scenario rely on trusted third party(TTP),but TTP is very sensitive and vulnerable in the real environment,and it costs a lot to maintain TTP.Because of the above shortcomings,SMC is proposed for a new and low-coupling IT service solution.When designing this kind of application protocol,it is necessary to ensure that each participant does not disclose its own input value,that is,each participant can not get input of other participants,and the result of the protocol must be correct.The key technologies used mainly involve homomorphic encryption,zero knowledge proof and so on.This thesis focuses on secure multi-party computing application protocol,and research on the geometric computation of privacy protection in mobile environment and information matching of privacy protection in medical large data environment.By using homomorphic encryption computing technology to determine the relationship between points and lines,a new privacy protection solution is designed.Experiments show that the scheme is lighter and more suitable for practical application than the existing scheme.On the basis of the above schemes,a method for determining points and arbitrary polygons is designed.This method remedies the weakness of other schemes that can only judge convex polygons,and gives the analysis of computational complexity.The computational complexity analysis results show that this method is more efficient.Because of the nesting of the above new method to determine the relationship between points and lines,it has more practical advantages.At the same time,aiming at the problem of privacy-preserving information matching in large medical data environment,a zeroknowledge proof-based information matching scheme is proposed.This scheme can not only resist the opponent to construct false data attack protocols,but also put forward new possibilities for the existing medical information system architecture.The formal security proof of the above scheme is given.The main contributions is as follows:1.The basic knowledge and related technologies of secure multi-party computing are analyzed and discussed.2.Aiming at the problem of determining the relationship between the point and arbitrary polygon for privacy protection,a new secure multi-party computing scheme is designed,which has better efficiency.3.In the medical big data environment,a privacy-preserving data matching scheme is proposed.This scheme aims at the medical big data environment,and can resist the construction of false data by the adversary to participate in information matching.