Research On Some Application Protocols Of Secure Multiparty Computation

As the rapid development and gradually improvement of related basic theory, researchers pay more and more attention to the research on the application of secure multiparty computation. Especially, the application protocol with high efficiency and safety, which also can solve the practical problem in our real life, has become the focus recently. Therefore, in this paper, we focus on the research of the application of secure multiparty computation to study the problems of secure sequencing, privacy-preserving self-helped medical diagnosis, cloud-assisted secure outsourcing computation, the general two-party bi-input private function evaluation and weighing the business strategies between two competitors and propose related solutions. This work is greatly important in the research of secure multiparty computation as well as in our real life.In brief, the major contributions of the dissertation are as follows:1. We propose a secure secure multiparty computation protocol for the privacy-preserving sequencing problem based on the equivalent transformation of two sequences and the fast symmetric homomorphic encryption. It no longer needs to choose so many polynomials and random numbers. Related complexities in computation and communication also have a great improvement. Our result is not only much simpler, but also more efficient.2. We design a privacy-preserving self-helped medical diagnosis scheme based on secure two-party computation where patients can privately diagnose by themselves by inputting a health card into a self-helped medical diagnosis ATM to obtain a diagnostic report just like drawing money from a bank ATM without revealing patients’ health information and doctors’ diagnostic skill. In our scheme, the diagnostic report is based on the Euclidean distance of two vectors and patients can get the report by calling an Oblivious Transfer protocol. It makes securely self-helped disease diagnosis feasible and greatly benefits patients as well as relieving the pressure of public health institutions.3. We focus on how to securely outsource computation task to the cloud and propose a secure outsourcing multiparty computation protocol on lattice-based encrypted data in two cloud servers scenario. Compared with previous research, our protocol is completely non-interactive between any users and both of the computation and communication complexities of each user in our solution are independent of the computing function.4. We further consider a more general case, two-party bi-input private function evaluation, based on the problem of two-party single-input private function evaluation and propose the first constant-round two-party bi-input private function evaluation protocol, which is with linear complexity and without relying on universal circuit or fully homomorphic encryption with strict proof in real-ideal simulation paradigm. The research on this general case is of great value not in theory but also in practice.5. We present a concise secure protocol for the point-segment position problem based on secure scalar product protocol (SPP) and secure comparison protocol (SCP) to weigh the business strategies between two competitors. Compared with precious solutions, which may disclose at least one inside point, our protocol performs better in terms of security. Our main improvement is to eliminate the dependence of the original point. In this way, our protocol will not reveal any inside point, which is crucially significant in some special occasion.