| 摘要 |
The invention concerns a method of using a chip card (4) bearing a switch mechanism (4b) which has at least four states (00, 10, 11, 01). In each authentication process a state value present at the beginning of the process is also taken into account when nominal value and actual value response signals are generated, such that these signals are each inter alia a function of this state value. The first state (00) is a defined initial state of the switch mechanism (4b) which the latter assumes whenever the chip card supply has been switched on (Pon). The second state (10) is the state assumed when a first authentication process (AUT0) has been triggered; the third state (11) is the state assumed when the monetary value of the chip card has been reduced for the first time ( DELTA GW0); and the fourth state (01) is the state assumed when a further authentication process (AUTn) has been triggered. The method prevents automatic vending machine operators who are not the chip card vendors from being charged excessive amounts when the chip card is misused for fraudulent ends. |
