Regulating E-Commerce through Contract Certificates

Enforcing e-commerce contracts is difficult because an enterprise may be concurrently bound by a very large number of commercial agreements, and because these agreements are likely to change in time or to be annulled. We argue that it is not feasible to establish a dedicated server for each contract; nor it is possible to construct a composition of such commercial agreements. To deal with these problems we propose to embed contracts in certificates. We show that disseminating contracts as certificates facilitates deployment, annulment and revision of contracts. We propose a language for stating contract terms, and present several formal examples. We describe here our implementation, which can be used as an extension to a web server, or as a separate server with interface to application. The proposed model does not require any modification of the current certificate infrastructure, and only minor modifications to servers.