| 摘要 |
PURPOSE:To disable a card to be used illegally even when vertification information leaks to the 3rd party by calculating the verification information from variable information of the card by a calculation expression of a card holder and a calculation expression of a system and identifying the card holder. CONSTITUTION:When the variable information 3 on, for example, the remaining amount of money which varies in shopping is denoted (a), f=a+123, for example, is specified as the calculation expression 4 of the card holder and then the calculation expression of the system is as shown by a path shown by arrows; and the verification information 5 is calculated from an equation I and its value is stored in the EEPROM in the IC card 1. Then, when the holder 2 uses this IC card, the calculation result of the same verification information 5 is obtained by specifying the same expression as the calculation expression 4 of the holder, so the holder is identified. |
