Transaction method using one time card information

In a payment transaction method using one time card information in the present invention, card information is not stored in a payment device such as a smart phone and a mobile phone, and the payment transaction is processed using one time card information provided by a credit card company server, thereby utilizing the existing payment network which connects a card reader device and a relay server as well as enhancing the security of a mobile payment system. To do so, in the present invention, a relay server and a payment device are connected in a network, and the card information of a real card corresponding to the payment device is included in a payment system. The present invention includes a step for receiving an expected payment message from a payment device; a step for opening the bank information number (BIN) in response to the expected payment message, generating one time card information which does not include the card information about a real card, and providing the generated one time card information to the payment device; a step for examining the validity of a payment approval message sent from a relay server depending on whether the difference between the first time interval in which the one time card information is returned through the relay server and the second time interval in which the one time card information is provided to the payment device meets the predetermined reference time interval; and a step for determining approval on a payment request message according to the validity determination result. [Reference numerals] (50) Card reader;(AA,CC) OTC/D-TRACK 2 information;(BB) Request one time card information [payment device identifier];(DD) Wireless transmission (NFC);(EE) First-dimension bar code;(FF) QR code;(GG) Payment approval message;(HH) Write payment approval message;(II) Identifier-card information matching;(JJ) OTC table inquiry/allocation;(KK) OTC-card information matching;(LL) D-TRACK 2 decoding