System for authenticating an authorized user of an IC card

Claim 1

An authentication system comprising a combination of: (a) an IC card which includes (a-1) memory means for storing ID data, (a-2) first signal exchange means for exchanging signals with a terminal unit, (a-3) first timer means for measuring a first time interval and generating a first control signal if the first time interval expires, the first timer means including means for clearing the first timer means in response to a first reset signal, (a-4) a keypad having a plurality of keys, and (a-5) first control means, electrically coupled to the memory means, the first signal exchange means, the first timer means, and the keypad, for activating the IC card when the ID data stored in the memory means is identical to ID data manually entered on the keypad, and for deactivating the IC card in response to the first control signal; and (b) a terminal unit which includes (b-1) IC card receiving means for accepting the IC card, the IC card receiving means including second signal exchange means for providing electrical coupling with the first signal exchange means of the IC card, (b-2) second timer means for measuring a second time interval and generating a second control signal if the second time interval expires, the second timer means including means for clearing the second timer means in response to a second reset signal, and (b-3) second control means, electrically coupled to the second timer means and to the second signal exchange means, for communicating with the first control means in the IC card, for generating the second reset signal in response to any terminal operations, the second reset signal being conveyed to the IC card and to the second timer means in the terminal unit, and for terminating a transaction at the terminal unit if the IC card is deactivated or the second timer means generates the second control signal.

Claim 5

A method for operating an authentication system which includes an IC card and a terminal unit which receives the IC card, the IC card including a memory, a keypad, and a first timer and the terminal unit including a second timer, said method comprising the steps of: (a) activating the IC card if ID data stored in the memory matches ID data manually entered on the keyboard; (b) deactivating the IC card if the first timer measures a first time period and if a reset signal has not been received from the terminal unit; (c) terminating a transaction after the terminal unit receives an activated IC card if the second timer measures a second time interval and no terminal operations have been conducted; and (d) resetting the first and second timer in response to any terminal operations while the IC card is activated.

Claim 6

A method for operating an authentication system which includes an IC card and a terminal unit which receives the IC card, the IC card including a memory, a keypad, and a first timer and the terminal unit including a second timer, said method comprising the steps of: (a) activating the IC card if ID data stored in the memory matches ID data manually entered on the keyboard; (b) deactivating the IC card if the first timer measures a first time period and if a reset signal has not been received from the terminal unit; (c) terminating a transaction after the terminal unit receives an activated IC card if the second timer measures a second time interval and no terminal operations have been conducted; and (d) resetting the first and second timer in response to any terminal operations while the IC card is activated.