Modeling and verification for the server-side Netpay protocol

Many virtual payment systems are available on the world wide web for micropayment. Correctness is important for these payment systems as it deals with money. One such payment system is Netpay. This paper examines the server-side Netpay protocol and provides its formalization as an interface automata model to prove three properties which are double spending, validity of an ecoin location and the absence of the deadlock. We will prove that the protocol is executing according to its description based on the assumption that the customers and vendors are cooperative.