Radio transceiver or other encryption device having secure tamper-detection module

• US 8,006,101 B2
• Filed: 06/20/2008
• Issued: 08/23/2011
• Est. Priority Date: 06/20/2008
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: General Instrument Corporation (CommScope Holding Company, Inc.)
• Inventors: Crawford, Nathan J.
• Primary Examiner(s): Song; Hosuk
• Application Number:
  US12/142,932
• Publication Number:
  US 20100017621A1
• Time in Patent Office: 1,159 Days
• Field of Search: 380/273, 380/277, 380/44, 380/46, 713/189, 713192-194
• US Class Current: 713/189
• CPC Class Codes: G06F 21/72 in cryptographic circuits

Abstract

An encryption device includes a system processor having a first key for encrypting information. The system processor periodically generates random data strings that are also encrypted using the first key. The encryption device also includes a first output for communicating the encrypted information to an external location and a tamper detection module for receiving on a periodic basis the random data strings generated by the system processor. The tamper detection module includes a second key that is the same as the first key, an encryption engine for encrypting the random data strings using the second key, and a second output for communicating the encrypted data strings to the system processor. The tamper detection module is configured to alter the second key upon detection of a tampering event so that the second key is different from the first key.

Claims

1. An encryption device, comprising:

a system processor that includes a first key for encrypting information and for periodically generating random data strings that are also encrypted using the first key;

a first output for communicating the encrypted information to an external location;

a tamper detection module for receiving on a periodic basis the random data strings generated by the system processor, wherein the tamper detection module includes;

a second key that is the same as the first key;

an encryption engine for encrypting the random data strings using the second key;

a second output for communicating the encrypted data strings to the system processor; and

wherein the tamper detection module is configured to alter the second key upon detection of a tampering event so that the second key is different from the first key.

2. The encryption device of claim 1 wherein the periodic basis on which the random data strings are received by the tamper detection module ranges from about 1000 times/second to once every five minutes.

3. The encryption device of claim 1 wherein the tamper detection module further includes a tamper detector for detecting tampering events.

4. The encryption device of claim 3 wherein the tamper detection module further includes a key alteration unit that permanently alters at least one bit of the first key upon detection of a tamper event by the tamper detector.

5. The encryption device of claim 1 wherein the tamper detection module further includes a storage unit in which the second key is located, the storage unit having an interface accessible to only the tamper detection unit and the encryption engine.

6. The encryption device of claim 1 wherein the second key is configured to be non-user-rekeyable.

7. The encryption device of claim 1 wherein the system processor includes a comparator for comparing encrypted data streams it encrypts using the first key with the encrypted data streams received from the tamper detection module.

8. The encryption device of claim 7 wherein the system processor is configured to perform a predetermined action if the comparator determines that one of the encrypted data streams encrypted using the first key is different from a corresponding one of the encrypted data streams received from the tamper detection module.

9. The encryption device of claim 8 wherein the predetermined action causes the encryption device to be inoperable.

10. The encryption device of claim 8 wherein the predetermined action causes a third party to be notified that a tamper event has occurred.

11. At least one non-transitory computer-readable medium encoded with instructions which, when executed by a processor, performs a method including:

periodically generating a random data string;

encrypting each of the data strings using a first encryption key that is user-rekeyable;

encrypting each of the data strigs using a second encryption key that is not user-rekeyable and which is initially the same as the first key;

altering the second key if a tamper event is detected;

comparing each of the data strings encrypted by the first key with the same data string encrypted by the second key; and

responding by performing a predetermined action if one of the data strings encrypted by the first key is different from the same data string encrypted by the second key.

12. The non-transitory computer-readable medium of claim 11 wherein the predetermined action includes disabling the device.

13. The non-transitory computer-readable medium of claim 11 wherein the predetermined action includes reporting the tampering event to a third party.

14. The non-transitory computer-readable medium of claim 11 further comprising transferring the random data string from a processing module in which the first key is located to a tamper detection module in which the second key is located.

15. The non-transitory computer-readable medium of claim 14 further comprising transferring the data string encrypted by the second key to the processing module for performing the comparison therein.

16. The non-transitory computer-readable medium of claim 14 further comprising detecting a tamper event when a housing is opened in which the processing module and the tamper detection module are located.

17. The non-transitory computer-readable medium of claim 11 wherein the random data strings are periodically generated within a range of about 1000 times/second to once every five minutes.

18. The non-transitory computer-readable medium of claim 11 wherein comparisons of encrypted data strings are performed within a range of about 1000 times/second to once every five minutes.

19. The non-transitory computer-readable medium of claim 11 wherein the second key is permanently altered if a tamper event is detected.