A privacy-preserving angle equality determination protocol and its applications

With the fast growth of the network, more and more cooperation opportunities come out in distributed systems. Privacy attracts extensive attention worldwide. Secure Multi-party Computation (SMC) plays an important role in keep information privacy when cooperating to use each other´s data. Privacy-Preserving Computational Geometry is a new research topic in SMC. In this paper, we devote to investigating the solutions to some secure geometry problems in a cooperative environment. With the help of secure two-party scalar product protocol and secure comparison protocol, two privacy-preserving angle equivalence determination protocol are proposed. At the same time, the correctness and security are also discussed. With the aid of privacy-preserving angle equivalence determination protocols, a four-node on same circle determination problem is solved.