CARD WITH INTEGRATED CIRCUIT, PORTABLE COMMUNICATION TERMINAL, TRANSACTION SYSTEM AND UNAUTHORIZED USE PREVENTIVE METHOD THEREFOR

PROBLEM TO BE SOLVED: To suppress unauthorized card use by a third person and thus to obviate the occurrence of unexpected disadvantages for a valid card owner, even if a card with an integrated circuit and its code number have slipped out to the third person. SOLUTION: An IC card 200 is provided with: an authentication information acquisition means for acquiring authentication information from a mobile phone 100 possessed by a user of the IC card 200 before transfer of card identification information to an ATM 300; an authentication processing section 213 for authenticating whether or not the user is a valid user of the IC card 200 based on the authentication information acquired with the authentication information acquisition means; and a control section 216 for controlling so as to approve transactions with the ATM 300 if the authentication processing section 213 has authenticated the user as the valid user, or to disapprove transactions with the ATM 300 if the user has not been authenticated as the valid user. COPYRIGHT: (C)2007,JPO&INPIT