| 摘要 |
PROBLEM TO BE SOLVED: To provide an individual identification method for certainly preventing the illegal use of a card by the others by using an authentication key which is not necessary for a user himself or herself to memorize with any special labor. SOLUTION: At the time of issuing card, individual information related with private items that only a user himself or herself knows and hardly forget is registered in a device to be directly or indirectly managed by a card issuing organization with a password, and a single or plural questions are selected and extracted at random each time from among the plural questions based on the individual information, and the answer to the question is required to the card user when the card is used, and the answer contents to the question are collated with the contents of the previously registered individual information so that whether or not the card user is a true card owner can be decided. |
