IC memory card system for authenticating an IC memory card, and IC memory card used for the same
First Claim
1. An IC memory card system comprising a terminal device and an IC memory card connected thereto,the terminal device selecting a key value,calculating a first value based on the key value using a particular calculating method,calculating a second value based on the key value using a different particular calculating method, andsupplying the key value and first calculated value to the IC memory card;
- the IC memory card calculating a third value and a fourth value using different particular methods based on the key value from the terminal device,comparing the first value received from the terminal device with the calculated third value, andsupplying the calculated fourth value to the terminal device if the compared first and third values are a same value;
wherein the terminal device compares the second value calculated by the terminal device with the fourth value supplied from the IC memory card, andprohibits use of the connected IC memory card if the compared values are not the same.
1 Assignment
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Accused Products
Abstract
An IC memory card and an IC memory card system prevent the use of unauthorized or illegal copies or forgeries of IC memory cards storing original content. Using a key value selected by a terminal device of the IC memory card system, the terminal device calculates a first value and the IC memory card separately calculates a third value by applying a particular method to the key value. Second and fourth values are similarly calculated using a different particular method. The IC memory card then determines whether the first and third values are the same. The terminal device separately determines whether the second and fourth values are the same. Only if the first and third values are confirmed to match, and then the second and fourth values are also confirmed to match, does the terminal device recognize the IC memory card as an authentic IC memory card and not an unauthorized or illegal copy or forgery.
27 Citations
12 Claims
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1. An IC memory card system comprising a terminal device and an IC memory card connected thereto,
the terminal device selecting a key value, calculating a first value based on the key value using a particular calculating method, calculating a second value based on the key value using a different particular calculating method, and supplying the key value and first calculated value to the IC memory card; -
the IC memory card calculating a third value and a fourth value using different particular methods based on the key value from the terminal device, comparing the first value received from the terminal device with the calculated third value, and supplying the calculated fourth value to the terminal device if the compared first and third values are a same value; wherein the terminal device compares the second value calculated by the terminal device with the fourth value supplied from the IC memory card, and prohibits use of the connected IC memory card if the compared values are not the same. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. An IC memory card for use in an IC memory card system,
said IC memory card system comprising an information processing device or other type of terminal device with an IC memory card connected thereto, said IC memory card comprising: -
key value storage for storing a selected key value supplied from the terminal device; first value storage for storing a first value calculated and supplied by the terminal device based on the key value; a third value operator for calculating a third value using a particular method based on the key value stored to the key value storage; a fourth value operator for calculating a fourth value based on the key value using a different particular method; fourth value storage for storing the fourth value calculated by the fourth value operator; and a comparator for detecting whether the first value stored to the first value storage and the third value calculated by the third value operator are a same value, and prohibiting output of the fourth value stored to the fourth value storage to the terminal device when said compared values are determined to be different. - View Dependent Claims (9, 10, 11, 12)
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Specification