System for authenticating an authorized user of an IC card

• US 5,146,068 A
• Filed: 11/28/1990
• Issued: 09/08/1992
• Est. Priority Date: 12/01/1989
• Status: Expired due to Term

• Current Assignee: OKI Electric Industry Company Limited
• Original Assignee: OKI Electric Industry Company Limited
• Inventors: Ugawa, Akira, Takizawa, Toshio
• Primary Examiner(s): Trafton, David
• Application Number:
  US07/618,287
• Time in Patent Office: 650 Days
• Field of Search: 235/379, 235/380, 235/382, 235/436, 235/441, 235/492
• US Class Current: 235/441
• CPC Class Codes: G06Q 20/341 Active cards, i.e. cards including their own processing means, e.g. including an IC or chip
• CPC Class Codes: G07F 7/1008 Active credit-cards provided with means to personalise their use, e.g. with PIN-introduction/comparison system
• CPC Class Codes: G07F 7/1083 Counting of PIN attempts
• CPC Class Codes: H04L 63/0853 using an additional device, e.g. smartcard, SIM or a different communication terminal cryptographic mechanisms or cryptographic arrangements for entity authentication involving additional secure or trusted devices H04L9/3234

Abstract

An IC card which has a timer circuit that shuts off the IC card within a predetermined time interval is used with a terminal which resets the timer circuit in the IC card in response to any terminal operations. This prevents the IC card from shutting itself off during the terminal operations.

Claims

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.

2. The authentication system of claim 1, wherein the first control means comprises means for generating the first reset signal if the second reset signal is generated by the second control means.

3. The authentication system of claim 1, wherein the first time interval is longer than the second time interval.

4. 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.