title: Secure multiparty computation of a comparison problem.
abstract: Private comparison is fundamental to secure multiparty computation. In this study, we propose novel protocols to privately determine [Formula: see text], or [Formula: see text] in one execution. First, a 0-1-vector encoding method is introduced to encode a number into a vector, and the Goldwasser-Micali encryption scheme is used to compare integers privately. Then, we propose a protocol by using a geometric method to compare rational numbers privately, and the protocol is information-theoretical secure. Using the simulation paradigm, we prove the privacy-preserving property of our protocols in the semi-honest model. The complexity analysis shows that our protocols are more efficient than previous solutions.
authors.affiliation: School of Computer Science, Shaanxi Normal University, Xi'an, 710062 China ; School of Information Engineering, Inner Mongolia University of Science and Technology, Baotou, 014010 China.
authors.forename: Xin
authors.initials: X
authors.lastname: Liu
authors.affiliation: School of Computer Science, Shaanxi Normal University, Xi'an, 710062 China.
authors.forename: Shundong
authors.initials: S
authors.lastname: Li
authors.affiliation: School of Communication and Information Engineering, Nanjing University of Posts and Telecommunications, Nanjing, 210003 China.
authors.forename: Jian
authors.initials: J
authors.lastname: Liu
authors.affiliation: Information Security Center, State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, Beijing, 100876 China.
authors.forename: Xiubo
authors.initials: X
authors.lastname: Chen
authors.affiliation: School of Software Engineering, Beijing University of Posts and Telecommunications, Beijing, 100876 China.
authors.forename: Gang
authors.initials: G
authors.lastname: Xu
keywords: Comparison problem; GM encryption scheme; Secure multiparty computation; Vector encoding method