As the Internet continues to transform the commerce, the method of payment is one of critical components to conduct successful business across the internet. An electronic cash has all characteristics of traditional commodity cash and ensures security for all transactions. Accordingly an internet billing system based electronic cash is expected as the secure and efficient payment method in future electronic commerce. Digital Contents such as digital goods and services have the special characteristic that both the delivery of the goods and the transfer of money ran be accomplished on the same network. This allows the optimizations in the design of an electronic commerce system. In this paper, we propose an electronic payment protocol which is especially designed to purchase digital contents through internet. The proposed protocol guarantees anonymity by using a virtual ID, and minimizes payment processing steps.