ABSTRACT
In a token-based payment system, electronic money stands for physical money that the customer exchanges with electronic tokens that he uses to pay for products and services. A merchant collects the tokens and sends them appropriately to a trusted third party (the bank, for example) to redeem the money (by means of money transfer to the merchant’s account, for example). In a token-based payment system, the owner is not required to have a payment authorization from the bank for every payment operation. Thus, token-based payment systems would have a lower operational cost compared to account-based systems. Two schemes are known to work under the token-based mode: electronic cash (Yu, 2001) and micropayment systems (Yen, 2001).
