System and Method of Lawful Access to Secure Communications

• US 20130182840A1
• Filed: 01/11/2013
• Published: 07/18/2013
• Est. Priority Date: 01/12/2012
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Blackberry Limited, Certicom Corporation (Blackberry Limited)
• Inventors: Buckley, Michael Eoin, Zaverucha, Gregory Marc, Campagna, Matthew John
• Granted Patent: US 9,413,530 B2
• Time in Patent Office: Days
• US Class Current: 380/44
• CPC Class Codes: H04L 2209/80 Wireless network architectures or network communication protocols for wireless network security H04W12/00
• CPC Class Codes: H04L 63/306 intercepting packet switched data communications, e.g. Web, Internet or IMS communications
• CPC Class Codes: H04L 9/0861 Generation of secret information including derivation or calculation of cryptographic keys or passwords

Abstract

The present disclosure relates to systems and methods for secure communications. In some aspects, a method of signalling an interception time period is described. At least one keying information used by a KMF to regenerate a key is stored. A start_interception message is signaled from an ADMF to a CSCF. A halt_message is signaled from the ADMF to the CSCF.

Claims

1. A method of signalling an interception time period, the method comprising:

storing at least one keying information used by a KMF to regenerate a key;

signalling a start_interception message from an ADMF to a CSCF; and

signalling a halt_message from the ADMF to the CSCF.

2. The method of claim 1, further comprising decrypting intercepted packets.

3. The method of claim 1, wherein the at least one keying information is stored by the CSCF.

4. The method of claim 1, wherein the at least one keying information includes a TRANSFER_INIT message.

5. The method of claim 1, wherein the at least one keying information includes a TRANSFER_RESP message.

6. The method of claim 1, wherein the at least one keying information includes at least one of RANDRi, RANDRr, IDRi, IDRr, CS_ID, TGK, MOD, HDR, KEMAC, TGK, and TGK′

.

7. The method of claim 1, wherein the halt_message includes a target user identifier.

8. A method of decrypting an intercepted message, the method comprising:

receiving one or more values used in generation of an encryption key;

storing the one or more values used by a KMF to regenerate the encryption key;

generating the encryption key using the one or more values;

signalling a start_interception message to a CSCF;

decrypting intercepted packets; and

signalling a halt_message from an ADMF to the CSCF.

9. The method of claim 8, wherein the signalling of the start_interception message is from the ADMF to the CSCF.

10. The method of claim 8, wherein the one or more values comprise a crypto session identity (CS ID) and a traffic encryption key generation key (TGK).

11. The method of claim 8, wherein the encryption key is a traffic encryption key (TEK) generated following a MICKEY-TICKET protocol.

12. The method of claim 8, wherein the one or more values are combined with a secret value to generate the encryption key following a key generating algorithm.

13. A method for regenerating an encryption key, the method comprising:

receiving one or more values used in generation of an encryption key;

storing at least one of the one or more values in a repository; and

generating the encryption key using the one or more values, including obtaining at least one of the stored values from the repository.

14. The method of claim 13, wherein the more than one value includes a TRANSFER_INIT message.

15. The method of claim 13, wherein the more than one value includes a TRANSFER_RESP message.

16. The method of claim 13, wherein the storing of at least one of the one or more values in a repository comprises storing a CS ID and a TEK in the repository.

17. The method of claim 16, wherein the storing of at least one of the one or more values in a repository further comprises storing in the repository one or more of:

an IDRi and an IDRr.

18. The method of claim 13, wherein the storing of at least one of the one or more values in a repository comprises storing a RANDRi, a RANDRr, a MOD, an IDRi, an IDRr, a TGK, a SALT and a CS ID in the repository.

19. The method of claim 13, wherein the storing of at least one of the one or more values in a repository comprises storing a RANDRi, a RANDRr, an IDRi, an IDRr, a TGK′

, a SALT and a CS ID in the repository.

20. The method of claim 13, wherein the storing of at least one of the one or more values in a repository comprises storing a RANDRi, a RANDRr, a MOD, an IDRi, an IDRr, a HDR, a KEMAC, a TGK, a TGK′

, a Transfer_Init, Transfer_Resp, a SALT and a CS ID in the repository.