| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide high security wherein unauthorized use of a card by a third party other than a card holder is minimized and a password is prevented from being easily penetrated by entering the password on hand, and to further provide smooth room entering/leaving management by eliminating a need for stopping for entering the password. <P>SOLUTION: The card holder enters the password on the card when using the card, giving the validity to the password for a predetermined time as the password is stored in a memory in the card for the predetermined time. As the predetermined time passes after entering the password, the password is deleted from the memory in the card as a means to invalidate the password of the card. This improves security of a lost card or a stolen card. <P>COPYRIGHT: (C)2003,JPO |
