Tamper resistant smart card and method of protecting data in a smart card

• US 6,273,339 B1
• Filed: 04/19/2000
• Issued: 08/14/2001
• Est. Priority Date: 08/30/1999
• Status: Expired due to Term

• Current Assignee: Round Rock Research LLC
• Original Assignee: Micron Technology, Inc.
• Inventors: McCabe, Arthur Barney, Tuttle, John R., Wood, Clifton W. Jr.
• Primary Examiner(s): Frech, Karl D.
• Assistant Examiner(s): FRANKLIN, JAMARA ALZAIDA
• Application Number:
  US09/552,512
• Time in Patent Office: 482 Days
• Field of Search: 235/487, 235/492, 235/380
• US Class Current: 235/492
• CPC Class Codes: G06K 19/073 Special arrangements for circuits, e.g. for protecting identification code in memory protection against unauthorised use of computer memory G06F12/14
• CPC Class Codes: G06K 19/07372 by detecting tampering with the circuit
• CPC Class Codes: G06K 19/07381 with deactivation or otherwise incapacitation of at least a part of the circuit upon detected tampering

Abstract

A method of protecting data in a smart card from unauthorized access, the method comprising providing a housing defined by first and second housing portions; employing a volatile memory in the smart card for storing the data, and supporting the volatile memory from the first housing portion; providing a power supply in the housing, the power supply maintaining the data in the volatile memory while the power supply is connected to the volatile memory; and connecting the power supply to the volatile memory using a conductor supported by and movable with the second housing portion. A smart card comprising a housing including two opposing major portions that are connected together; an integrated circuit supported in the housing, the integrated circuit including a microprocessor and a random access memory, the random access memory being used to store data; a battery supported in the housing and having first and second terminals, the first terminal being coupled to the integrated circuit; and a conductor coupling the second terminal of the battery to the integrated circuit to complete a circuit, the conductor being supported by the housing such that separation of one of the portions of the housing from the other portion opens the circuit and breaks connection of the battery to the microprocessor so that data held in the random access memory is erased.

Claims

1. A smart card comprising:

a housing including first and second portions;

a volatile memory supported by the housing;

a battery supported by the housing; and

a conductor including conductive epoxy configured to couple the battery to the memory, such that power to the memory is interrupted and data in the memory is erased if the first portion of the housing is moved away from the second portion of the housing.

2. A smart card in accordance with claim 1 wherein the housing comprises a polymeric film defining the first housing portion, and a hardened flowable material on the first housing portion to define the second housing portion.

3. A smart card in accordance with claim 1 wherein the volatile memory and the battery are mounted to the first housing portion, and wherein the conductor couples the battery to the volatile memory and is fixed to the first housing portion.

4. A smart card in accordance with claim 1 wherein the battery is mounted to the second housing portion.

5. A smart card in accordance with claim 1 and further comprising a magnetic stripe on the outside of the housing.

6. A smart card comprising:

a housing defined by first and second housing portions, the first housing portion having a surface facing the second housing portion and a surface facing away from the second portion;

a volatile memory configured to store data, the volatile memory being supported from the surface of the first housing portion that faces the second housing portion;

a power supply in the housing, the power supply being coupled to the volatile memory to maintain the data in the volatile memory while the power supply is coupled to the volatile memory; and

a conductor of conductive epoxy supported by and movable with the second housing portion, coupling the power supply to the volatile memory.

7. A smart card in accordance with claim 6 wherein the volatile memory comprises a random access memory.

8. A smart card in accordance with claim 6 wherein the volatile memory and the power supply are mounted to the surface of the first housing portion that faces the second housing portion.

9. A smart card in accordance with claim 6 wherein the second housing portion has a surface facing the first housing portion and a surface facing away from the first housing portion, and wherein power supply is mounted to the surface of the second housing portion that faces the first housing portion.

10. A smart card in accordance with claim 6 wherein the volatile memory comprises a static random access memory.

11. A smart card in accordance with claim 6 wherein the volatile memory is defined by an integrated circuit including a microprocessor and a static random access memory, and wherein the power supply is coupled to the integrated circuit.

12. A smart card in accordance with claim 6 wherein the power supply comprises a thin profile battery.

13. A smart card in accordance with claim 6 wherein the housing has a width of 3.375 inches and a height of 2.125 inches.

14. A smart card in accordance with claim 6 wherein the housing has a width of 3.375 inches, a height of 2.125 inches, and a thickness less than or equal to 0.0625 inches.

15. A smart card in accordance with claim 6 wherein the conductor is printed on the second housing portion.

16. A smart card comprising:

a housing defined by first and second housing portions, the first housing portion having a surface facing the second housing portion and a surface facing away from the second portion;

a volatile memory configured to store data, the volatile memory being supported from the surface of the first housing portion that faces the second housing portion;

a power supply in the housing, the power supply being coupled to the volatile memory to maintain the data in the volatile memory while the power supply is coupled to the volatile memory;

a conductor of conductive epoxy supported by and movable with the second housing portion, coupling the power supply to the volatile memory; and

a magnetic stripe on the outside of the housing, the magnetic stripe including two read-only magnetic tracks, and one read-write magnetic track, positioned in accordance with ISO 3554, ISO 3885/30, and ISO 3885/40.

17. A smart card in accordance with claim 16 wherein the housing is embossed.

18. A smart card comprising:

first and second conductors;

first and second housing portions respectively supporting the first and second conductors, the conductor supported by at least one of the first and the second housing portions being formed of conductive epoxy;

a volatile memory configured to store data, the volatile memory being supported by the first housing portion; and

a battery having first and second terminals of opposite polarity, the battery being configured to maintain the data in the volatile memory while the battery is coupled to the volatile memory, the battery being supported by the first housing portion, and the conductor on the first housing portion coupling the first terminal of the battery to the volatile memory, the second housing portion being joined with the first housing portion to define the housing, with the conductor supported by the second housing portion coupling the second terminal of the battery to the volatile memory with the battery maintaining the data in the volatile memory only while the first housing portion remains joined to the second housing portion.

19. A smart card in accordance with claim 18 wherein the volatile memory comprises a random access memory.

20. A smart card in accordance with claim 18 wherein the volatile memory comprises a static random access memory.

21. A smart card in accordance with claim 18 wherein the volatile memory comprises an integrated circuit including a microprocessor and a static random access memory coupled to the microprocessor.

22. A smart card in accordance with claim 18 wherein the a battery comprises a thin profile battery having a thickness less than 1.6 millimeters.

23. A smart card in accordance with claim 18 wherein the housing has a thickness less than or equal to 0.0625 inches.

24. A smart card in accordance with claim 18 wherein the housing has a width and a height in accordance with ISO 7816.

25. A smart card comprising:

first and second conductors;

first and second housing portions respectively supporting the first and second conductors, the conductor supported by at least one of the first and the second housing portions being formed of conductive epoxy;

a volatile memory configured to store data, the volatile memory being supported by the first housing portion; and

a battery having first and second terminals of opposite polarity, the battery being configured to maintain the data in the volatile memory while the battery is coupled to the volatile memory, the battery being supported by the first housing portion, and the conductor on the first housing portion coupling the first terminal of the battery to the volatile memory, the second housing portion being joined with the first housing portion to define the housing, with the conductor supported by the second housing portion coupling the second terminal of the battery to the volatile memory with the battery maintaining the data in the volatile memory only while the first housing portion remains joined to the second housing portion, wherein the first housing portion comprises a sheet of translucent polyester film having interior and exterior sides, ink painted on the interior side of the polyester film, the ink being visible from outside the card, and wherein the first conductor is printing on the ink.

26. A smart card in accordance with claim 25 wherein the first conductor comprises conductive epoxy on the first housing portion.

27. A smart card in accordance with claim 25 wherein the first conductor comprises a conductor of clear epoxy on the first housing portion.

28. A smart card in accordance with claim 25 and further comprising a magnetic stripe on the outside of the housing.

29. A smart card in accordance with claim 25 and further comprising a magnetic stripe on the outside of the housing, the magnetic stripe including two read-only magnetic tracks, and one read-write magnetic track.

30. A smart card in accordance with claim 25 and further comprising a magnetic stripe on the outside of the housing, the magnetic stripe including two read-only magnetic tracks, and one read-write magnetic track, positioned in accordance with ISO 3554, ISO 3885/30, and ISO 3885/40.

31. A smart card in accordance with claim 25 wherein the housing is embossed.

32. A smart card in accordance with claim 25 wherein the housing is embossed in accordance with ISO 3885.