Dynamic Electronic Payment Agreement Protocol

Abstract

This thesis covers design, implementation and verification of an electronic payment protocol called Dynamic Electronic Payment Agreement Protocol (DePaP). The DePaP addresses the general online payment scenario where client and merchant use their agents as intermediates. So DePaP allows Client Agent, Merchant and Merchant Agent to agree on a payment and eventually all the parties get an electronic document as a proof for the agreement. However DePaP does not facilitate the Client to Client Agent authentication and lets the Client Agent to use own authentication mechanism as the Client Agent wishes. Client Agent may use an existing mechanism like a simple password based approach, a token based approach or any other approach. DePaP is a request-response based protocol. DePaP needs a message transfer protocol which supports request-response model. HTTP (Hypertext Transfer Protocol)/HTTPS (Hypertext Transfer Protocol Secure) would be a good candidate for the transfer protocol. However the role of the transfer protocol is similar to role of the transfer protocol in SOAP (Simple Object Access Protocol). So any mechanism which supports request-response model can be used as the transfer protocol. Client Agent, Merchant Agent and Merchant exchange several request-response messages among each other and finally everyone gets digitally certified facts so that they can prove the agreement. DePaP specifies the standards for message contents, message formats, message processing, message verification and rules for a valid agreement. DePaP can make any kind of payments possible as long as Client Agent and Merchant Agent have a medium to clear the payment among them.