Anonymous Internet Credit Cards

In credit based payment systems, con dential data such as PIN and credit card number embedded in an electronic credit card must be protected. The authenticity of an electronic credit card in a payment process is normally achieved through an on-line trusted server such as a nancial institution that runs the payment system. This paper considers some novel secure electronic credit card based payment schemes for the Internet, where the involvement of the on-line nancial institution is reduced to a minimum. Our protocols use the technique of proof of knowledge of discrete logarithms that enables a prover to prove a secret without revealing the secret to the veri er.