Passive contactless smartcard security system

• US 6,588,660 B1
• Filed: 09/29/2000
• Issued: 07/08/2003
• Est. Priority Date: 09/29/2000
• Status: Expired due to Fees

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Buescher, Timothy W., Manchester, Douglas L.
• Primary Examiner(s): Lee, Michael G.
• Assistant Examiner(s): FRANKLIN, JAMARA ALZAIDA
• Application Number:
  US09/676,021
• Time in Patent Office: 1,012 Days
• Field of Search: 235/382, 235/375, 235/492, 235/487, 235/491, 235/380, 235/384, 340/5.1, 340/5.2, 340/5--, 340/5-1-
• US Class Current: 235/382
• CPC Class Codes: G06K 19/0716 at least one of the integrated circuit chips comprising a sensor or an interface to a sensor
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• CPC Class Codes: G06K 19/07345 by activating or deactivating at least a part of the circuit on the record carrier, e.g. ON/OFF switches

Abstract

A method in a contactless smartcard includes providing a contactless smartcard having an operating frequency higher than a specified transmission frequency of contactless smartcards; bringing the contactless smartcard within a detection range of a smartcard reader; activating the contactless smartcard by applying human body capacitance to the contactless smartcard; and deactivating the contactless smartcard by removing the human body capacitance from the contactless smartcard. When thus operated, the contactless smartcard of the present invention is secured against unknown, unintended, and unauthorized interrogations.

Claims

1. A method for securing a contactless smartcard against unknown and unauthorized interrogations while said smartcard is being carried by a cardholder, comprising:

providing an operating frequency in said contactless smartcard, said operating frequency being higher than a specified transmission frequency of contactless smartcards;

bringing said contactless smartcard within a detection range of a smartcard reader;

maintaining said contactless smartcard in an inactive state as a result of said operating frequency being higher than said specified transmission frequency; and

applying a human body capacitance to said contactless smartcard, thereby activating said contactless smartcard for intended interrogations with said smartcard reader.

2. The method of claim 1, wherein said applying a human body capacitance causes said operating frequency of said smartcard to decrease to match said specified transmission frequency, thereby activating said contactless smartcard.

3. The method of claim 2, wherein said operating frequency is at least 10% higher than said specified transmission frequency.

4. The method of claim 2, wherein said specified transmission frequency is 13.56 MHz and said operating frequency is at least 15 MHz.

5. The method of claim 1, wherein said applying a human body capacitance to said contactless smartcard comprises:

placing a digit of said cardholder on a surface of said contactless smartcard, said human body capacitance being a capacitance of said digit.

6. The method of claim 5, wherein said surface is a top surface of said contactless smartcard.

7. The method of claim 5, wherein said surface is a bottom surface of said contactless smartcard.

8. The method of claim 5, wherein said placing a digit of said cardholder on a surface of said contactless smartcard comprises:

placing said digit in a designated area on said surface of said contactless smartcard.

9. The method of claim 8, wherein said designated area is about 3 cm by 3 cm in dimensions.

10. The method of claim 8, wherein said designated area covers substantially the entire surface area of said contactless smartcard.

11. The method of claim 1, wherein said providing an operating frequency in said contactless smartcard comprises:

providing a tuning circuit in said contactless smartcard, said turning circuit electrically coupled to an electronic circuit for providing power to said electronic circuit, said tuning circuit having a resonance frequency higher than said specified transmission frequency, said resonance frequency being said operating frequency of said contactless smartcard; and

providing a conductive plate in said contactless smartcard, said conductive plate being electrically coupled to said tuning circuit.

12. The method of claim 11, wherein said providing a tuning circuit comprises:

providing an antenna coil, said antenna coil having an inductance and a capacitance for setting said resonance frequency, and said conductive plate being electrically coupled to said antenna coil.

13. The method of claim 12, wherein said providing an antenna coil comprises:

providing a thin wire wrapped in one or more turns inside said contactless smartcard.

14. The method of claim 12, further comprising:

applying a human body capacitance to said contactless smartcard, thereby activating said contactless smartcard for intended interrogations with said smartcard reader.

15. The method of claim 14, wherein said applying a human body capacitance comprises:

adding said human body capacitance to said capacitance of said antenna coil in said contactless smartcard, thereby decreasing said resonance frequency of said tuning circuit to match said specified transmission frequency.

16. The method of claim 15, wherein said applying a human body capacitance further comprises:

placing a digit of said cardholder on a surface of said contactless smartcard, thereby adding said human body capacitance to said capacitance of said antenna coil;

wherein said human body capacitance is a capacitance of said digit.

17. The method of claim 16, wherein said surface is a top surface of said contactless smartcard.

18. The method of claim 16, wherein said surface is a bottom surface of said contactless smartcard.

19. The method of claim 16, wherein said placing a digit of said cardholder on a surface of said contactless smartcard comprises:

placing said digit in a designated area on said surface of said contactless smartcard.

20. The method of claim 19, wherein said designated area is about 3 cm by 3 cm in dimensions.

21. The method of claim 19, wherein said designated area covers substantially the entire surface area of said contactless smartcard.

22. The method of claim 15, wherein said operating frequency is at least 10% higher than said specified transmission frequency.

23. The method of claim 15, wherein said specified transmission frequency is 13.56 MHz and said operating frequency is at least 14 MHz.

24. The method of claim 15, wherein said antenna coil has an inductance of 700 nH and a capacitance of 100 pF, and said human body capacitance is a capacitance of a digit and is about 100 pF.

25. A method in a contactless smartcard, comprising:

providing a contactless smartcard having an operating frequency higher than a specified transmission frequency of contactless smartcards;

bringing said contactless smartcard within a detection range of a smartcard reader;

activating said contactless smartcard by applying human body capacitance to said contactless smartcard;

wherein applying human body capacitance causes said operating frequency of said smartcard to decrease to match said specified transmission frequency, thereby activating said contactless smartcard; and

deactivating said contactless smartcard by removing said human body capacitance from said contactless smartcard.

26. The method of claim 25, wherein said applying human body capacitance comprises:

placing a digit of a cardholder on a surface of said contactless smartcard, said human body capacitance being a capacitance of said digit.

27. The method of claim 25, wherein said operating frequency is at least 10% higher than said specified transmission frequency.

28. The method of claim 25, wherein said specified transmission frequency is 13.56 MHz and said operating frequency is at least 15 MHz.

29. A contactless smartcard, comprising:

a first layer of dielectric material having a bottom surface;

a second layer of dielectric material having a bottom surface;

said first layer and second layer of dielectric material providing a laminate layer;

an electronic circuit;

a tuning circuit having an operating frequency, said tuning circuit being electrically coupled to said electronic circuit for providing power to said electronic circuit;

a conductive plate electronically coupled to said tuning circuit and having a first area;

wherein said tuning circuit, said electronic circuit, and said conductive plate are disposed between said first layer and said second layer of dielectric material;

wherein said operating frequency of said tuning circuit is higher than a specified transmission frequency of contactless smartcards; and

wherein when a human body capacitance is applied to said contactless smartcard, said operating frequency of said tuning circuit decreases to match said specified transmission frequency, thereby activating said contactless smartcard when said contactless smartcard is brought within a detection range of a smartcard reader.

30. The contactless smartcard of claim 29, wherein the value of said operating frequency of said tuning circuit inhibits said contactless smartcard from being activated when said contactless smartcard is brought within a detection range of a smartcard reader.

31. The contactless smartcard of claim 30, wherein said operating frequency is at least 10% higher than said specified transmission frequency.

32. The contactless smartcard of claim 30, wherein said specified transmission frequency is 13.56 MHz and said operating frequency is at least 15 MHz.

33. The contactless smartcard of claim 29, wherein said tuning circuit comprises:

an antenna coil having an inductance and a capacitance for setting a resonance frequency, said resonance frequency being said operating frequency of said tuning circuit.

34. The contactless smartcard of claim 33, wherein said human body capacitance is added to said capacitance of said antenna coil to cause said resonance frequency of said antenna coil to decrease to match said specified transmission frequency.

35. The contactless smartcard of claim 33, wherein said antenna coil has an inductance of 700 nH and a capacitance of 100 pF, and said human body capacitance is a capacitance of a digit and is about 100 pF.

36. The contactless smartcard of claim 29, wherein said operating frequency is at least 10% higher than said specified transmission frequency.

37. The contactless smartcard of claim 29, wherein said specified transmission frequency is 13.56 MHz and said operating frequency is at least 15 MHz.

38. The contactless smartcard of claim 29, further comprises:

a contact area on said top surface of said first layer, said contact area being directly above said conductive plate and having an area substantially equal to said first area of said conductive plate.

39. The contactless smartcard of claim 38, wherein said human body capacitance is applied to said contactless smartcard by placing a digit on said contact area.

40. The contactless smartcard of claim 38, wherein said first area is about 3 cm by 3 cm in dimension.

41. The contactless smartcard of claim 38, wherein said first area covers substantially the entire surface area of said first layer.

42. The contactless smartcard of claim 29, further comprises:

a contact area on said bottom surface of said second layer, said contact area being directly below said conductive plate and having an area substantially equal to said first area of said conductive plate.

43. The contactless smartcard of claim 42, wherein said human body capacitance is applied to said contactless smartcard by placing a digit on said contact area.

44. The contactless smartcard of claim 42, wherein said first area is about 3 cm by 3 cm in dimension.

45. The contactless smartcard of claim 42, wherein said first area covers substantially the entire surface area of said second layer.