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

• US 5,988,510 A
• Filed: 02/13/1997
• Issued: 11/23/1999
• Est. Priority Date: 02/13/1997
• Status: Expired due to Term

• Current Assignee: Round Rock Research LLC
• Original Assignee: Micron Communications, Inc. (Micron Technology, Inc.)
• Inventors: Tuttle, John R., Wood, Clifton W. Jr., McCabe, Arthur Barney
• Primary Examiner(s): Lee, Michael G
• Assistant Examiner(s): SHERR, DANIEL H
• Application Number:
  US08/800,037
• Time in Patent Office: 1,013 Days
• Field of Search: 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 method of protecting data stored in a smart card, the method comprising:

providing a housing including first and second portions;

providing a volatile memory in the housing;

providing a battery in the housing; and

connecting the battery to the memory, using a conductor including conductive epoxy, such that power to the memory is interrupted and data in the memory is erased if the first portion of the housing is moved relative to the second portion of the housing.

2. A method in accordance with claim 1 wherein the step of providing a housing comprises providing a polymeric film to define the first housing portion, providing a flowable material on the first housing portion to define the second housing portion, and causing the flowable material to harden.

3. A method in accordance with claim 1 wherein the step of employing a volatile memory and the step of providing a battery comprises mounting the volatile memory and the battery to the first housing portion and coupling the battery to the volatile memory using a conductor fixed to the first housing portion.

4. A method in accordance with claim 1 wherein the step of providing a battery comprises mounting the battery to the second housing portion.

5. A method in accordance with claim 1 and further comprising the step of providing a magnetic stripe on the outside of the housing.

6. 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 of conductive epoxy supported by and movable with the second housing portion.

7. A method in accordance with claim 6 wherein the step of employing a volatile memory comprises the step of providing a random access memory.

8. A method in accordance with claim 6 wherein the step of employing a volatile memory and the step of providing a power supply comprises mounting the volatile memory and the power supply to the first housing portion.

9. A method in accordance with claim 6 wherein the step of providing a power supply comprises mounting the power supply to the second housing portion.

10. A method in accordance with claim 6 wherein the step of employing a volatile memory comprises the step of providing a static random access memory.

11. A method in accordance with claim 6 wherein the step of employing a volatile memory comprises providing an integrated circuit including a microprocessor and a static random access memory, and wherein the connecting step comprises connecting the power supply to the integrated circuit.

12. A method in accordance with claim 6 wherein the step of employing a power supply comprises the step of providing a thin profile battery.

13. A method in accordance with claim 6 wherein the step of providing a housing comprises providing a housing having a width of about 3.375 inches and a height of about 2.125 inches.

14. A method in accordance with claim 6 wherein the step of providing a housing comprises providing a housing having a width of about 3.375 inches, a height of about 2.125 inches, and a thickness less than or equal to about 0.0625 inches.

15. A method in accordance with claim 6 wherein the connecting step comprises printing a conductor on the second housing portion.

16. A method in accordance with claim 6 and further comprising the step of providing 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 method in accordance with claim 6 and further comprising the step of embossing the housing.

18. A method of protecting data in a smart card from unauthorized access, the method comprising:

providing first and second housing portions having respective conductors fixed thereto, the conductor fixed to the second housing portion being formed of conductive epoxy;

providing a volatile memory for storing the data, and fixing the volatile memory to the first housing portion;

providing a battery having first and second terminals, the battery maintaining the data in the volatile memory while the power supply is connected to the volatile memory, fixing the battery to the first housing portion with the conductor on the first housing portion connecting the first terminal of the battery to the volatile memory; and

joining the second housing portion with the first housing portion to define a housing having the conductor fixed to the second housing portion connecting 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 attached to the second housing portion.

19. A method in accordance with claim 18 wherein the step of providing a volatile memory comprises the step of providing a random access memory.

20. A method in accordance with claim 18 wherein the step of providing a volatile memory comprises the step of providing a static random access memory.

21. A method in accordance with claim 18 wherein the step of providing a volatile memory comprises providing an integrated circuit including a microprocessor and a static random access memory.

22. A method in accordance with claim 18 wherein the step of providing a battery comprises the step of providing a thin profile battery having a thickness less than 1.6 millimeters.

23. A method in accordance with claim 18 wherein the step of attaching the second housing portion to the first housing portion results in the housing having a thickness less than or equal to 0.0625 inches.

24. A method in accordance with claim 18 wherein the step of attaching the second housing portion to the first housing portion results in the housing having a width and a height in accordance with ISO 7816.

25. A method of protecting data in a smart card from unauthorized access, the method comprising:

providing first and second housing portions having respective conductors fixed thereto;

providing a volatile memory for storing the data, and fixing the volatile memory to the first housing portion;

providing a battery having first and second terminals, the battery maintaining the data in the volatile memory while the power supply is connected to the volatile memory, fixing the battery to the first housing portion with the conductor on the first housing portion connecting the first terminal of the battery to the volatile memory; and

providing the second housing portion joined with the first housing portion to define a housing having the conductor fixed to the second housing portion connecting 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 attached to the second housing portion, wherein providing first and second housing portions having respective conductors fixed thereto comprises providing a sheet of translucent polyester film having interior and exterior sides, painting ink on the interior side of the polyester film, the ink being visible from outside the card, and printing a conductor on the ink to define the first housing portion.

26. A method in accordance with claim 25 wherein the step of providing first and second housing portions having respective conductors thereon comprises forming conductive epoxy on at least one of the first and second housing portions.

27. A method in accordance with claim 25 wherein the step of providing first and second housing portions having respective conductors thereon comprises forming a conductor of clear epoxy on at least one of the first and second housing portions.

28. A method in accordance with claim 25 and further comprising the step of providing a magnetic stripe on the outside of the housing.

29. A method in accordance with claim 25 and further comprising the step of providing 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 method in accordance with claim 25 and further comprising the step of providing 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 method in accordance with claim 25 and further comprising the step of embossing the housing.

32. A method in accordance with claim 25 and further comprising the step of embossing the housing in accordance with ISO 3885.

33. A method of protecting data stored in a smart card against repetitive attacks, the method comprising:

providing a housing including first and second portions;

providing a volatile memory in the housing;

providing a battery in the housing;

connecting the battery to the memory, using a conductor including conductive epoxy, such that power to the memory is lost and data in the memory is erased if the first portion of the housing is moved relative to the second portion of the housing; and

storing medical data in the volatile memory.

34. A method of protecting data in accordance with claim 33 wherein providing a housing comprises providing a polymeric film to define the first housing portion, providing a flowable material on the first housing portion to define the second housing portion, and causing the flowable material to harden.

35. 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 including conductive epoxy and 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 integrated circuit so that data held in the random access memory is erased.

36. A smart card in accordance with claim 35 wherein one of the housing portions comprises a polymeric film.

37. A smart card in accordance with claim 35 and further comprising a magnetic stripe on the outside of the housing.