Methods and systems for recognizing tamper events

• US 8,284,387 B2
• Filed: 02/08/2007
• Issued: 10/09/2012
• Est. Priority Date: 02/08/2007
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Tucker, James L., Warrensford, Kara L., Dalzell, William J., Fleischman, Scott G.
• Primary Examiner(s): NGUYEN, TU T
• Application Number:
  US11/672,642
• Publication Number:
  US 20080192240A1
• Time in Patent Office: 2,070 Days
• Field of Search: None
• US Class Current: 356/73.1
• CPC Class Codes: G01M 11/3109 Reflectometers detecting the back-scattered light in the time-domain, e.g. OTDR
• CPC Class Codes: G06F 21/87 by means of encapsulation, e.g. for integrated circuits
• CPC Class Codes: G06F 2221/2101 Auditing as a secondary aspect
• CPC Class Codes: G06F 2221/2143 Clearing memory, e.g. to prevent the data from being stolen
• CPC Class Codes: G08B 13/186 using light guides, e.g. optical fibres

Abstract

A method of recognizing a tamper event is provided. The method uses an optical medium having a unique signature, and transmits at least one light wave into the optical medium. The light wave is altered by the unique signature of the optical medium and at least one property of the light wave is measured. Access to at least a portion of a system is conditioned based on the at least one property of the light wave.

Claims

1. A method comprising:

transmitting a first light wave into a first optical medium, the first optical medium having a first unique signature;

after transmitting the first light wave into the first optical medium, measuring at least one property of the first light wave, wherein the first light wave was altered by the first unique signature;

transmitting a second light wave into a second optical medium, the second optical medium having a second unique signature;

after transmitting the second light wave into the second optical medium, measuring at least one property of the second light wave, wherein the second light wave was altered by the second unique signature; and

conditioning access to at least a portion of a system based on a differential between the at least one property of the first light wave and the at least one property of the second light wave.

2. The method of claim 1, wherein conditioning access further comprises:

allowing access only if the differential between the at least one property of the first light wave and the at least one property of the second light wave is unchanged.

3. The method of claim 1, further comprising:

receiving the first light wave at one end of the first optical medium, wherein measuring the at least one property of the first light wave comprises measuring a property of the first light wave received.

4. The method of claim 1, further comprising:

receiving the first light wave at an end of the first optical medium which is opposite of an end in which the first light wave was transmitted.

5. The method of claim 1, further comprising:

receiving at least one reflection of the transmitted first light wave or second light wave at a same end of the first or second optical medium, respectively, in which the first light wave or second light wave was transmitted.

6. The method of claim 1, wherein conditioning access further comprises:

generating an encryption key from the differential between the at least one property of the first light wave and the at least one property of the second light wave.

7. The method of claim 6, wherein conditioning access further comprises:

decrypting stored data with the encryption key.

8. An apparatus comprising:

an optical medium configured to have a unique signature, wherein the unique signature is configured to alter a property of a light wave traveling through the optical medium;

a light emitter in optical communication with the optical medium;

an opto-electrical component coupled to the optical medium and operable to measure at least one property of a light wave that has traveled in the optical medium;

wherein the apparatus is configured to determine whether the at least one property of the light wave that has traveled in the optical medium has been altered; and

an access system operable to condition access to at least a portion of the apparatus based on the at least one property of the light wave that has traveled in the optical medium.

9. The apparatus of claim 8, wherein the access system is unique and is configured to generate a generic key from the at least one property of the light wave that traveled in the optical medium.

10. The apparatus of claim 8, wherein the optical medium comprises one or more optical fibers.

11. The apparatus of claim 8, wherein the optical medium is fixed permanently in place.

12. The apparatus of claim 8, further comprising:

protected electronics; and

a capsule covering the protected electronics, wherein the optical medium is disposed about the capsule.

13. The apparatus of claim 12, wherein the capsule also covers the opto-electrical component and the access system.

14. A method comprising:

measuring at least one value relating to a first optical property of a first optical fiber;

measuring at least one value relating to a second optical property of a second optical fiber;

calculating a differential between the at least one value relating to the first optical property and the at least one value relating to the second optical property; and

conditioning access to a system based on the differential.

15. The method of claim 14, further comprising:

generating a key from the differential.

16. The method of claim 14, further comprising:

forming the first optical fiber to have a first unique signature; and

forming the second optical fiber to have a second unique signature.

17. The method of claim 16, wherein forming the first optical fiber to have a unique signature comprises bending the first optical fiber.

18. The method of claim 16, wherein forming the first optical fiber to have a unique signature comprises cutting the first optical fiber.

19. The method of claim 16, wherein forming the first optical fiber to have a unique signature comprises imbedding at least one material in the first optical fiber.