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Payment Method Negotiation Service: Framework and Programming Interface

Alireza Bahreman and Rajkuman Narayanaswamy, EIT

Payment Method Negotiation is one of the five services of GEPS. The purpose of Payment Method Negotiation is for a merchant and a customer to come to an agreement on all details of the method of payment when they wish to transfer funds. The service deals with a variety of details about a payment, not just the choice of cash or credit. Some of the motivations for using negotiation are to make good payment method choices in a situation with too many options and to speed up the payment process through automatic negotiation.

Negotiation can take several rounds. In the prepayment stage, while a customer is shopping but before he wants to make a purchase, he could negotiate with the merchant just to make sure that there is a common payment method between them. This could be done in the background as the customer shops. When it comes time to pay, negotiation should be accomplished quickly. Negotiation could be symmetric, or one party could simply name a method. Then comes a finalization stage, in which the method is picked and the transfer of funds begins.

Related work includes the Joint Electronic Payment Initiative (JEPI), which addresses the protocol used to exchange messages. It includes the Universal Payment Protocol from Cybercash and the Protocol Extension Protocol over HTTP. JEPI is concerned with syntax and message flow, but it is not tied to a particular payment system. It is hoped that the payment method negotiation work will use JEPI for message syntax.

Negotiation is closely linked to the payment preferences and payment capability services in GEPS. It is assumed that both parties in a transaction have GEPS. There are three components in the implementation: input and output, payment negotiation, and a user interface. The user interface is specified, but left to the application to implement.

There are several policy issues. It is not clear who should or would want to reveal their capabilities. Also unknown is how long a negotiation will take. Finally, a method of picking the party who is to choose which payment system will be used has not been defined. Some policy decisions can be controlled by the way the application interacts with GEPS. Specifically, the application can control the order of negotiation, how many or few capabilities to reveal, how long negotiation will take, and in which phase the negotiation is. For further policy control, the GEPS objects can be subclassed.

Implementation of this system is in progress, though currently, the emphasis is on promoting the system. Alireza hopes that a very large and influential company will adopt GEPS as a standard, urging other companies to adopt it as well.

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Next: Session V: Atomic Transactions Up: Session IV: Standard Payment Previous: U-PAI: A Universal Payment
Alma Whitten