An Entanglement-Based Protocol for Simultaneous Reciprocal Information Exchange between 2 Players

Let us consider a situation where two information brokers, whose currency is, of course, information, need to reciprocally exchange information. The two brokers, being somewhat distrustful, would like a third, mutually trusted entity to be involved in the exchange process so as to guarantee the successful completion of the transaction and also verify that it indeed took place. Can this be completed in such a way that both brokers receive their information simultaneously and securely, without the trusted intermediary knowing the exchanged information? This work presents and rigorously analyzes a new quantum entanglement-based protocol that provides a solution to the above problem. The proposed protocol is aptly named the entanglement-based reciprocal simultaneous information exchange protocol. Its security is ultimately based on the assumption of the existence of a third, trusted party. Although the reciprocal information flow is between our two information brokers, the third entity plays a crucial role in mediating this process by being a guarantor and a verifier. The phenomenon of quantum entanglement is the cornerstone of this protocol, as it makes its implementation possible even when all entities are spatially separated and ensures that, upon completion, the trusted third party remains oblivious to the actual information that was exchanged. © 2023 by the authors