An anonymity-revoking e-payment system with a smart card

Abstract.

An untraceable offline e-payment system can offer a degree of customer anonymity; however, it also presents criminals with opportunities, such as laundering money, corruption, and kidnapping. In this paper, we improve on the e-payment system with a smart card proposed by S. Brands, and present an anonymity-revoking e-payment system. On the one hand, the customer’s privacy cannot be compromised by the bank or by the payee. On the other hand, anonymity can be removed by a trusted third party (trustee) with the help of the bank. In this case, the third party can link a payment to a corresponding withdrawal and prevent money laundering and blackmailing.