RFID readers and RFID tags exchanging encrypted password

• US 7,245,213 B1
• Filed: 01/10/2005
• Issued: 07/17/2007
• Est. Priority Date: 05/24/2004
• Status: Active Grant

• Current Assignee: Impinj, Inc.
• Original Assignee: Impinj, Inc.
• Inventors: Diorio, Christopher J., Humes, Todd E., Esterberg, Aanand
• Primary Examiner(s): Crosland; Donnie L.
• Application Number:
  US11/033,028
• Time in Patent Office: 918 Days
• Field of Search: 340/539.12
• US Class Current: 340/539.12
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• CPC Class Codes: H04L 63/0492 by using a location-limited connection, e.g. near-field communication or limited proximity of entities
• CPC Class Codes: H04L 63/083 using passwords cryptographic mechanisms or cryptographic arrangements for entity authentication using a predetermined code H04L9/3226

Abstract

RFID system components, such as readers and tags, communicate where at least a portion of data or a password is transmitted in encrypted form. The reader transmits a command, along with data or a password encrypted using an encryption kernel. In some instances, the tag itself has sent the kernel.

Claims

1. A radio frequency identification (RFID) reader, comprising:

an antenna arranged to transmit a transmission wave; and

circuitry arranged to modulate on the transmission wave symbols encoding a tag command and a callout associated with the command, the callout containing data and at least one portion of a preset password, the data and the at least one password portion having been encrypted using a preset kernel.

2. The reader of claim 1, wherein

the command includes a payload, and at least a portion of the callout is included in the payload.

3. The reader of claim 1, wherein

the callout is transmitted in a plurality of portions, and

the callout contains the entire password.

4. The reader of claim 1, wherein the circuitry is further arranged to:

determine the password.

5. The reader of claim 1, wherein the circuitry is further arranged to:

determine the password from a database.

6. The reader of claim 1, wherein the circuitry is further arranged to:

encrypt the one of the data and the portion of the password.

7. The reader of claim 1, wherein

encryption is by XORing.

8. The reader of claim 1, wherein

the antenna is further arranged to receive a reception wave, and

the circuitry is further arranged to parse at least a portion of the kernel from the reception wave prior to the callout being transmitted.

9. The reader of claim 8, wherein

the circuitry is further arranged to parse a remaining portion of the kernel from the reception wave.

10. The reader of claim 8, wherein

the circuitry arranged to modulate on the transmission wave symbols encoding a kernel request, and

wherein the kernel portion is received in response to the kernel request.

11. The reader of claim 10, wherein

the kernel request is a random-number request.

12. An RFID component device comprising:

means for transmitting a wireless signal; and

means for modulating onto the signal a tag command, and a callout associated with the command, the callout containing data and at least one portion of a preset password, the data and the at least one password portion having been encrypted using a preset kernel.

13. A method for an RFID reader, comprising:

transmitting a tag command; and

transmitting a callout associated with the command, the callout containing data and at least one portion of a preset password, the data and the at least one password portion having been encrypted using a preset kernel.

14. The method of claim 13, wherein

the command includes a payload, and

at least a portion of the callout is included in the payload.

15. The method of claim 13, wherein

the callout is transmitted in a plurality of portions, and

the callout contains the entire password.

16. The method of claim 13, further comprising:

determining the password.

17. The method of claim 13, wherein

the password is determined from a database.

18. The method of claim 13, further comprising:

encrypting the one of the data and the portion of the password.

19. The method of claim 13, wherein

encryption is by XORing.

20. The method of claim 13, further comprising:

receiving at least a portion of the kernel prior to transmitting the callout.

21. The method of claim 20, further comprising:

receiving a remaining portion of the kernel.

22. The method of claim 20, further comprising:

transmitting a kernel request, and

wherein the kernel portion is received in response to the kernel request.

23. The method of claim 22, wherein

the kernel request is a random-number request.

24. The method of claim 22, further comprising:

singulating a tag from a plurality of tags, and

wherein the kernel request is transmitted after singulating.

25. The method of claim 24, further comprising:

transmitting a handle to prevent the other tags from responding to the command.

26. The method of claim 25, further comprising:

receiving the handle.

27. The method of claim 26, further comprising:

requesting the handle.

28. A radio frequency identification (RFID) tag, comprising:

an antenna arranged to receive a wave; and

a processing block arranged to

parse from the wave a command and a callout associated with the command, and

decrypt the callout using at least a portion of a preset encryption kernel to derive one of data and a password.

29. The tag of claim 28, wherein

the processing block is further arranged to

perform an action that conforms to the command if the decrypted password is in accordance with a preset password.

30. The tag of claim 28, wherein

the processing block is further arranged to

perform an action that conforms to the command and uses the data, if data has also been derived from the callout.

31. The tag of claim 28, wherein

the command includes a payload, and

at least a portion of the callout is included in the payload.

32. The tag of claim 28, wherein

the callout is received in a plurality of portions, and

the callout contains the entire password.

33. The tag of claim 28, wherein

decrypting is performed by XORing.

34. The tag of claim 28, wherein

the antenna is further arranged to transmit wirelessly a wave that encodes at least one portion of the kernel prior to receiving the callout.

35. The tag of claim 34, wherein

the kernel is a random number.

36. The tag of claim 28, wherein

the processing block is further arranged to further parse a kernel request from the wave, and

wherein the kernel is transmitted in response to the kernel request.

37. An RFID component device comprising:

means for receiving a wireless signal;

means for parsing out of the signal a command;

means for parsing out of the signal a command and a callout associated with the command; and

means for decrypting the callout using at least a portion of a preset encryption kernel to derive one of data and a password.

38. A method for an RFID tag, comprising:

receiving a command;

receiving a callout associated with the command; and

decrypting the callout using at least a portion of a preset encryption kernel to derive one of data and a password.

39. The method of claim 38, further comprising:

performing an action that conforms to the command if the decrypted password is in accordance with a preset password.

40. The method of claim 38, further comprising:

deriving also data from the callout, and

performing an action that conforms to the command and uses the data.

41. The method of claim 38, wherein

the command includes a payload, and

at least a portion of the callout is included in the payload.

42. The method of claim 38, wherein

the callout is received in a plurality of portions, and

the callout contains the entire password.

43. The method of claim 38, wherein

decrypting is performed by XORing.

44. The method of claim 38, further comprising:

transmitting the at least one portion of the kernel prior to receiving the callout.

45. The method of claim 44, further comprising:

transmitting a remainder of the kernel.

46. The method of claim 44, wherein

the kernel is a random number.

47. The method of claim 38, further comprising:

receiving a kernel request, and

wherein the kernel portion is transmitted in response to the kernel request.

48. The method of claim 47, further comprising:

being singulated from a plurality of other tags, and

wherein the kernel request is received after being singulated.

49. The method of claim 48, further comprising:

determining a valid handle, and

wherein the action is performed only if the callout further includes the handle.

50. The method of claim 49, further comprising:

transmitting the handle.

51. The method of claim 50, further comprising:

receiving a request for the handle and

wherein transmitting is performed responsive to receiving the request.

52. A circuit for a radio frequency identification (RFID) tag that includes an antenna arranged to receive a wave, comprising:

circuitry arranged to derive bits from the wave; and

a processing block arranged to;

parse from the bits a command and a callout associated with the command, and

decrypt the callout using at least a portion of a preset encryption kernel to derive one of data and a password.

53. The circuit of claim 52, wherein

the processing block is further arranged to:

perform an action that conforms to the command if the decrypted password is in accordance with a preset password.

54. The circuit of claim 52, wherein

data is also parsed from the bits, and

the processing block is further arranged to perform an action that conforms to the command and uses the data.

55. The circuit of claim 52, wherein

the command includes a payload, and

at least a portion of the callout is included in the payload.

56. The circuit of claim 52, wherein

the callout is received in a plurality of portions, and

the callout contains the entire password.

57. The circuit of claim 52, wherein

decrypting is performed by XORing.

58. The circuit of claim 52, wherein

the antenna is further arranged to transmit wirelessly a wave that encodes at least one portion of the kernel prior to receiving the callout.

59. The circuit of claim 58, wherein

the kernel is a random number.

60. The circuit of claim 52, wherein

the processing block is further arranged to further parse a kernel request from the wave, and

wherein the kernel is transmitted in response to the kernel request.