Data containing important information are stored in DB cards separable from
terminals. The terminals and mediums are placed in corresponding relationship.
Multi-security measures are taken to prevent a third party not authorized to access
one of the DB cards from accessing the card and its data due to loss and robbery
of the DB card and the third party's malice to thereby prevent the information
from leaking out from the DB card. To this end, when the terminal accesses the
DB card, the terminal compares its own hardware identification number with that
of the card to determine whether the terminal is authorized to access the DB card.
When it is, the terminal 2 further compares its own software identification
number with that of the card to determine whether the terminal is further authorized
to access a mobile DB in the card.
