A secure two-party bartering protocol using privacy-preserving interval operations

Bartering plays a significant role in today´s global economy-both between individuals as well as in B2B settings. However, aside from lacking automation, today´s bartering solutions and supporting platforms typically neglect the privacy needs of their users. In this paper, we present a novel two-party protocol which addresses these shortcomings. The new protocol automatically determines whether the desired and offered commodities and quantities overlap in such a way that both parties are willing to barter. Throughout the protocol, the commodities and quantities as specified by the parties are kept private. We show that the protocol is privacy-preserving in the semi-honest model. As main building blocks, the new bartering protocol uses a novel privacy-preserving protocol for selecting a random subinterval out of the overlap of two intervals as well as a newly-developed secure protocol for input-symmetric strong conditional oblivious transfer.