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US5471045A Expired / Lapsed US ⏱️ 0.0 years remaining

Smart card locking process

Assignee: Gemplus SA
•
Filing: 1992-05-05
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Granted: 1995-11-28
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Expires: 2012-05-05
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Abstract

Abstract A method of locking a smart card to block the operation of at least one protected program stored in a read-only memory or ROM of the smart card, the smart card incorporating a central processor, the ROM, an erasable programmable read-only memory or EPROM and a random access memory or RAM, the method including the steps of: entering a logic lock in the EPROM, making multiple copies of the logic lock in the EPROM, carrying out a logic OR on the logic lock in the EPROM and the multiple copies of the logic lock in the EPROM in order to block the performance of the protected program upon the detection of either (a) the logic lock in the EPROM or (b) at least one of the multiple copies of the logic lock in the EPROM, recopying the logic lock in the RAM, and performing the logic OR on the logic lock in the EPROM, the multiple copies of the logic lock in the EPROM, and the logic lock in the RAM.

Inventors

  • 👤 Francois Geronimi

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-31 22:42
CPC Classifications
G; G07; G07F; G07F7/00; G07F7/08; G07F7/10; G07F7/1008; G06; G06Q; G06Q20/00; G06Q20/30; G06Q20/34; G06Q20/341; G06Q20/357; G01; G01R; G01R31/00; G01R31/28; G01R31/317; G01R31/31719

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 171 words
A method of locking a smart card to block the operation of at least one protected program stored in a read-only memory or ROM of the smart card, the smart card incorporating a central processor, the ROM, an erasable programmable read-only memory or EPROM and a random access memory or RAM, the method comprising the steps of: entering a logic lock in the EPROM, making multiple copies of the logic lock in the EPROM, carrying out a logic OR on the logic lock in the EPROM and the multiple copies of the logic lock in the EPROM in order to block the performance of the protected program upon the detection of either (a) the logic lock in the EPROM or (b) at least one of the multiple copies of the logic lock in the EPROM, recopying the logic lock in the RAM, and performing the logic OR on the logic lock in the EPROM, the multiple copies of the logic lock in the EPROM, and the logic lock in the RAM.
Claim 2
Independent Claim 171 words
A method of locking a smart card to block the operation of at least one protected program stored in a read-only memory or ROM of the smart card, the smart card incorporating a central processor, the ROM, an erasable programmable read-only memory or EPROM and a random access memory or RAM, the method comprising the steps of: entering a logic lock in the EPROM, making multiple copies of the logic lock in the EPROM, carrying out a logic OR on the logic lock in the EPROM and the multiple copies of the logic lock in the EPROM in order to block the performance of the protected program upon the detection of either (a) the logic lock in the EPROM or (b) at least one of the multiple copies of the logic lock in the EPROM, recopying the logic lock in the RAM, and performing the logic OR on the logic lock in the EPROM, the multiple copies of the logic lock in the EPROM, and the logic lock in the RAM.
Claim 3
Dependent Claim 21 words
The method of claim 1, wherein the logic lock in the RAM is updated during the performance of the protected program.
Claim 4
Dependent Claim 14 words
The method of claim 2, wherein the updating is performed at random time intervals.
Claim 5
Independent Claim 158 words
A method of locking a smart card to block the operation of at least one protected program stored in a read-only memory or ROM of the smart card, the smart card incorporating a central processor, the ROM, an erasable programmable read-only memory or EPROM and a random access memory or RAM, the method comprising the steps of: entering a logic lock in the EPROM, making multiple copies of the logic lock in the EPROM, carrying out a logic OR on the logic lock and the multiple copies in order to block the performance of the protected program upon the detection of one of (a) the logic lock and (b) at least one of the multiple copies, and, prior to entering the logic lock in the EPROM, entering a false lock in the RAM in order to instantaneously test the blocking of the protected program, said false lock and the corresponding blocking disappearing when the smart card is deenergized.
Claim 6
Independent Claim 158 words
A method of locking a smart card to block the operation of at least one protected program stored in a read-only memory or ROM of the smart card, the smart card incorporating a central processor, the ROM, an erasable programmable read-only memory or EPROM and a random access memory or RAM, the method comprising the steps of: entering a logic lock in the EPROM, making multiple copies of the logic lock in the EPROM, carrying out a logic OR on the logic lock and the multiple copies in order to block the performance of the protected program upon the detection of one of (a) the logic lock and (b) at least one of the multiple copies, and, prior to entering the logic lock in the EPROM, entering a false lock in the RAM in order to instantaneously test the blocking of the protected program, said false lock and the corresponding blocking disappearing when the smart card is deenergized.
Claim 7
Independent Claim 159 words
A method of locking a smart card to block the operation of at least one protected program stored in a read-only memory or ROM of the smart card, the smart card incorporating a central processor, the ROM, an erasable programmable read-only memory or EPROM, a random access memory or RAM, and an electrically erasable programmable read-only memory or EEPROM the method comprising the steps of: entering a logic lock in the EPROM, making multiple copies of the logic lock in the EPROM, carrying out a logic OR on the logic lock and the multiple copies in order to block the performance of the protected program upon the detection of one of the logic lock and at least one of the multiple copies, and, prior to entering the logic lock in the EPROM, entering a false lock in the EEPROM in order to instantaneously test the blocking of the projected program, then erasing the false lock and the corresponding blocking.
Claim 8
Independent Claim 159 words
A method of locking a smart card to block the operation of at least one protected program stored in a read-only memory or ROM of the smart card, the smart card incorporating a central processor, the ROM, an erasable programmable read-only memory or EPROM, a random access memory or RAM, and an electrically erasable programmable read-only memory or EEPROM the method comprising the steps of: entering a logic lock in the EPROM, making multiple copies of the logic lock in the EPROM, carrying out a logic OR on the logic lock and the multiple copies in order to block the performance of the protected program upon the detection of one of the logic lock and at least one of the multiple copies, and, prior to entering the logic lock in the EPROM, entering a false lock in the EEPROM in order to instantaneously test the blocking of the projected program, then erasing the false lock and the corresponding blocking.

References Cited (Backward Citations)

US4810862A Cited
US4734568A Cited
US4777355A Cited
US4910393A Cited
EP0325506A1 Cited
US4988855A Cited
US5159183A Cited
JPH0452890A Cited
JPH04180188A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1998-11-27 1999-05-29 1999-11-28 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2002-11-27 2003-05-29 2003-11-28 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2006-11-27 2007-05-29 2007-11-28 $7700.00 Window Closed / Lapsed

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