Analysis on Cyclic Multi-party Fair Exchange Protocols

A multi-party fair exchange protocol allows several parties to exchange commodities in such a way that everyone gives an item away if and only if it receives an expected item in return. In this paper, we review an important cyclic multi-party fair exchange protocol and its evolution. We study the property of fairness on these protocols by analyzing the roles of the third party and the algorithms used, and propose some improvements. We also discuss the open problems and future work about cyclic multi-party exchange protocols.