Fair e-payment protocols

This paper presents two new protocols for e-payment. The first scheme is an improvement version of the art used widely at present and it does not need the strong trust between customer and merchant in the protocol. In the second scheme, a distrusted third party is introduced to provide a fair commerce environment. He takes part in the protocol on-line, but isn´t leaked any secure information. Entire scheme is based on nonconfidence. An advantage of this scheme is that this approach does not require the intervention of the third party in case of dispute, if one user cheats or simply crashes. The fairness of our schemes significantly surpasses that of prior art.