From SET to PSET - The Pseudonymous Secure Electronic Transaction Protocol
Marc Rennhard, Sandro Rafaeli, Laurent Mathy · 2001
Credit cards have been the dominant payment method in e-commerce during the past years and it is not expected that this is going to change soon. However, credit card payments as used today are not suited for anonymous or pseudonymous payments. Credit card payments disclose the identity of a customer to the merchant and the issuer of the credit card knows exactly where the customer makes payments. The Secure Electronic Transaction (SET) protocol makes credit card payments over the Internet more secure, but it does not much to protect the privacy of the customer. In this report, we present the Pseudonymous Secure Electronic Transaction (PSET) protocol. PSET is an extension of SET and enables pseudonymous credit card payments over the Internet. Pseudonymous payments mean that none of the involved parties in the payment process can learn the identities of both the customer and the merchant at the same time. This is achieved by distributing the knowledge of the whole transaction among the involved parties. On the other hand, PSET guarantees that it is not possible for any of the involved parties to cheat and that it is possible to unambiguously resolve the identity of a pseudonymous customer in case of a dispute.