PayFair: a prepaid internet micropayment scheme ensuring customer fairness

A software-based prepaid micropayment scheme is developed. As with existing prepaid micropayment schemes, the profits of the merchants are protected. Furthermore. in this proposed scheme, fairness for the customers is also assured. More precisely, in this new scheme, the merchant, after receiving prepaid money, can only claim that a customer has already spent a specific amount of money by showing the required cryptographic witness which can only be received from that Customer when making a payment. Most importantly, in this new scheme, no public key-signature computation is required. Finally, it will be shown that, owing to its simplicity and high performance, the proposed scheme can also be employed by small pieces of electronic equipment for general-purpose resource-access control.