Date Added: Sep 2009
Implementing an electronic payment system involves striking a balance between usability and security. Systems that allow payments to be completed with little effort on the part of the consumer, such as smart cards, carry a higher probability of incorrect payments. Systems that eliminate the possibility of incorrect payments by requiring explicit approval from the consumer, such as credit cards, make the system too cumbersome for small payments. This paper models the usability and security tradeoff as a problem of minimizing the transaction cost imposed by the payment system on the consumer.