1. Introduction

Internet based electronic commerce (e-Commerce) is flourishing, but mostly in the Business-to-Consumer (B2C) world like music, books selling etc. The lack of well-accepted standards is hindering the success in promoting Business-to-Business (B2B) electronic commerce solutions. VAN EDI based solutions are only accessible to large organizations due to the cost factor. Corporate buyers and suppliers, large and small, are looking for Internet based solutions to streamline the procurement procedures and to reduce the cost of establishing trading relationship and the trading transactions. Such demands put forward some fundamental challenge on issue like trust infrastructure on the Internet, standards and inter-operability etc. Open Buying on the Internet (OBI) is a promising emerging standard in meeting some of these challenges.

1.1. Open Buying on the Internet (OBI)
Open Buying on the Internet (OBI) is an e-Commerce standard that has been specified by the OBI Consortium. OBI is "an open, flexible framework for business-to-business Internet commerce solutions. It is intended for the high volume, low-dollar transactions that account for 80% of most organizations' purchasing activity"[1]. It is expected to streamline the non-mission critical procurement processes of organizations (e.g. MRO materials) by specifying a standard set of roles that OBI-compliant selling and buying parties must conform to. Furthermore, the standard is supposed to make it easier to achieve compliance by requiring usage of widely accepted, standards-based technologies such as HTTP, digital certificates (X509), secure sockets layer (SSL), and EDI. The usage of these technologies in the various components of an OBI server (OBI-enabled Net.Commerce server) is discussed later in this paper.

1.2. OBI Components

There are four essential entities involved in an OBI system. The Buying Organization procures items as part of its daily business operations. The Requisitioner, a member of the buying organization, is interested in procuring certain items as part of the non-mission critical process of the organization within his/her command. The Selling Organization supplies goods and services to other businesses. Finally, the Payment Organization, which may not exist in all OBI scenarios, as a clearing-house for all payment and settlement activities between the selling and buying organizations. All the aforementioned entities are assumed to have digital certificates that uniquely and securely establish their identities. Of course, these entities are all assumed to be connecting to the Internet.

1.3. Net.Commerce and OBI
Net.Commerce is one of IBM's leading merchant servers. It already provides powerful cataloging, user management, fulfillment and payment facilities to support Internet e-Commerce. What is needed is a new front end for handling digital certificates based user processing and an additional back-end engine for processing OBI-style transactions. This is very important because a large number of buying organizations would like a simple, standards-based way to interact with their many suppliers and are looking towards standards such as OBI and systems based on such standards to address this issue.