There has been a great deal of research on fairly exchanging two items. But when one considers peer-to-peer systems, efficiency and performance of the fair exchange protocol matters. In the past, we have created an efficient and scalable optimistic fair exchange protocol suitable for use in high-churn peer-to-peer file sharing systems. Currently, we are working on applying fair exchange protocols to other scenarios where needed. These scenarios include secure two-party or multi-party computation, as well as cloud storage systems.
Furthermore, while analyzing the limits of fair exchange protocols, we looked at distributing centralized parties, such as the trusted third party, the arbiter. Our results include impossibility cases and optimality proofs.
We are grateful for the support from TÜBİTAK and European Union COST Action IC1306.