초록
As credit cards are more convenient than cash of heavy and volume, they are used widely in on_line (internet) and off_line in nowadays. A head of the economically active population had 4.8 credit cards in the third quarter 2011. The economically active population in their 20's and 30's may have more than 10 credit cards. If the membership card and point card are included, the count rise to 20 cards in a man. Therefore, the their purse become thick by several cards. Nowadays, the smart-phone is widely used. Therefore, a lot of credit cards are come in smarty-phone from analog form to digital form. In this paper, we study a method of digital credit cards management in smart-phone. For the method, the hardware need in small and existing system have a few change. All kinds of credit cards are used in smarty-phone. We compare the method with Moneta card and NFC of smarty-phone. The digital credit cards feature a light, safety and convenience of mobile users in several ways.