| 摘要 |
PURPOSE: To prevent the manufacture of a forged card (a forged key). CONSTITUTION: When a card 12 and a terminal (a lock) 13 correspond to each other, the card 12 transmits an ID code and a check code of itself to a host computer 16. The host computer 16 transmits a response code corresponding to the received check code to the card 12. The host computer 16 judges whether or not the received ID code is stored. Next, the card 12 judges whether or not the response code corresponding to the transmitted check code is received. When both judgments of a judgment of the ID code by the host computer 16 and a judgment of the response code by the card 12 are affirmative, the terminal 13 performs prescribed processing. The check code is made different with every use of the card 12. Therefore, since it becomes extremely difficult for a third person to detect a method to perform the prescribed processing, manufacture of a forged key can be prevented. |
