A Multi-Party Protocol For Privacy-Preserving Cooperative Linear Systems Of Equations

The privacy-preserving cooperative linear system of equations (PPC-LSE) problem is an important scientific problem whose solutions find applications in many real-word scenarios, such as banking, manufacturing, and telecommunications. Roughly speaking, in PPC-LSE a set of parties want to jointly compute the solution to a linear system of equations without disclosing their own inputs. The linear system is built through the parties' inputs.In this paper we design a novel protocol for PPC-LSE. Our protocol has simulation-based security in the semi-honest model, assuming that one of the participants is not willing to collude with other parties. Previously to our work, the only known solutions to PPC-LSE were for the two-party case, and the only known other protocol for the multi-party case was less efficient and proven secure in a weaker model.