METHODS AND SYSTEMS FOR ENABLING LEGAL-INTERCEPT MODE FOR A TARGETED SECURE ELEMENT

• US 20170237780A1
• Filed: 06/14/2016
• Published: 08/17/2017
• Est. Priority Date: 02/17/2016
• Status: Active Grant

• Current Assignee: Nagravision SA (Kudelski SA)
• Original Assignee: Nagravision SA (Kudelski SA)
• Inventors: Benoit, Bernard, Fournier, Jean-Claude, Gauteron, Laurent, Zhao, Yishan, Fer, Francois
• Granted Patent: US 10,237,305 B2
• Time in Patent Office: Days
• CPC Class Codes: H04L 2209/80 Wireless network architectures or network communication protocols for wireless network security H04W12/00
• CPC Class Codes: H04L 63/06 for supporting key management in a packet data network cryptographic mechanisms or cryptographic arrangements for key management H04L9/08
• CPC Class Codes: H04L 63/205 involving negotiation or determination of the one or more network security mechanisms to be used, e.g. by negotiation between the client and the server or between peers or by selection according to the capabilities of the entities involved negotiation of communication capabilities H04L69/24
• CPC Class Codes: H04L 63/306 intercepting packet switched data communications, e.g. Web, Internet or IMS communications
• CPC Class Codes: H04L 9/0816 Key establishment, i.e. cryptographic processes or cryptographic protocols whereby a shared secret becomes available to two or more parties, for subsequent use
• CPC Class Codes: H04L 9/0838 Key agreement, i.e. key establishment technique in which a shared key is derived by parties as a function of information contributed by, or associated with, each of these network architectures or network communication protocols for key exchange in a packet data network H04L63/061
• CPC Class Codes: H04W 12/041 Key generation or derivation

Abstract

Disclosed herein are methods and systems for enabling legal-intercept mode for a targeted secure element. In an embodiment, a method includes embedding a first key-negotiation parameter associated with a target client device into an intercept secure encryption element; configuring an encryption-management device to receive the intercept secure encryption element and to receive a second key-negotiation parameter associated with the target client device and obtained from a service-provider system, the encryption-management device configured to embed the second key-negotiation parameter into the intercept secure encryption element; and providing the intercept secure encryption element to a communications-intercept system configured to obtain intercepted messages associated with the target client device, the intercepted messages comprising session-key-negotiation messages and associated data messages encrypted with a corresponding negotiated session key, wherein the intercept secure encryption element is configured to (i) identify the negotiated session key based on the session-key-negotiation messages and the first and second key-negotiation parameters and (ii) decrypt the data messages with the negotiated session key.

Claims

1. A method comprising:

embedding a first key-negotiation parameter associated with a target client device into an intercept secure encryption element;

configuring an encryption-management device to receive the intercept secure encryption element and to receive a second key-negotiation parameter associated with the target client device and obtained from a service-provider system, the encryption-management device configured to embed the second key-negotiation parameter into the intercept secure encryption element; and

providing the intercept secure encryption element to a communications-intercept system configured to obtain intercepted messages associated with the target client device, the intercepted messages comprising session-key-negotiation messages and associated data messages encrypted with a corresponding negotiated session key, wherein the intercept secure encryption element is configured to (i) identify the negotiated session key based on the session-key-negotiation messages and the first and second key-negotiation parameters and (ii) decrypt the data messages with the negotiated session key.

2. The method of claim 1, further comprising configuring the encryption-management device to provide the first and second key-negotiation parameters to a target secure encryption element associated with the target client device.

3. The method of claim 1, wherein a target secure encryption element associated with the target client device is preconfigured with the first and second key-negotiation parameters.

4. The method of claim 1, wherein the negotiated session key is based on a first secret key associated with the target client device and a second secret key associated with a second client device, wherein a target secure encryption element associated with the target client device is selectively configured to use, as the first secret key, a pseudorandom secret key that is based on the first and second key-negotiation parameters.

5. The method of claim 4, wherein each of the target secure encryption element and the intercept secure encryption element is configured with a respective pseudorandom generator that generates the pseudorandom secret key based on the first and second key-negotiation parameters.

6. The method of claim 4, further comprising transmitting a configuration command to the target secure encryption element to selectively configure the target secure encryption element to generate the pseudorandom secret key.

7. The method of claim 4, wherein either or both of the target secure encryption element and the intercept secure encryption element have at least one tamper-resistant safeguard.

8. The method of claim 1, further comprising configuring the encryption-management device to obtain the second key-negotiation parameter from the service-provider system responsive to receiving the intercept secure encryption element.

9. The method of claim 1, further comprising configuring the encryption-management device to obtain the second key-negotiation parameter via a user interface.

10. A method comprising:

receiving an intercept secure encryption element containing an embedded first key-negotiation parameter associated with a target client device;

obtaining, from a service-provider system, a second key-negotiation parameter associated with the target client device;

embedding the second key-negotiation parameter into the intercept secure encryption element;

obtaining intercepted messages associated with the target client device, the intercepted messages comprising session-key-negotiation messages and associated data messages encrypted with a corresponding negotiated session key;

identifying, with the intercept secure encryption element, the negotiated session key based on the session-key-negotiation messages and the first and second key-negotiation parameters; and

decrypting the data messages with the intercept secure encryption element and the negotiated session key.

11. The method of claim 10, further comprising providing the first and second key-negotiation parameters to a target secure encryption element associated with the target client device.

12. The method of claim 10, wherein a target secure encryption element associated with the target client device is preconfigured with the first and second key-negotiation parameters.

13. The method of claim 10, wherein the negotiated session key is based on a first secret key associated with the target client device and a second secret key associated with a second client device, wherein a target secure encryption element associated with the target client device is selectively configured to use, as the first secret key, a pseudorandom secret key that is based on the first and second key-negotiation parameters.

14. The method of claim 13, wherein each of the target secure encryption element and the intercept secure encryption element is configured with a respective pseudorandom generator that generates the pseudorandom secret key based on the first and second key-negotiation parameters.

15. The method of claim 13, further comprising transmitting a configuration command to the target secure encryption element to selectively configure the target secure encryption element to generate the pseudorandom secret key.

16. The method of claim 13, wherein either or both of the target secure encryption element and the intercept secure encryption element have at least one tamper-resistant safeguard.

17. The method of claim 10, wherein the second key-negotiation parameter is obtained from the service-provided system responsive to receiving the intercept secure encryption element.

18. A method comprising:

negotiating cryptographic session keys with remote devices using randomly generated secret keys, and encrypting and decrypting data with the negotiated session keys during communication sessions with the remote devices; and

receiving and authenticating an intercept-mode command, and responsively negotiating a predictable cryptographic session key at least in part by;

accessing a first key-negotiation parameter originating in a secure-encryption-element provider and a second key-negotiation parameter originating in a service provider;

generating a pseudorandom secret key based on the first and second key-negotiation parameters;

generating and sharing a first shared intermediate value based on the pseudorandom secret key;

receiving a second shared intermediate value;

generating the predictable cryptographic session key based on the pseudorandom secret key and the second shared intermediate value; and

encrypting and decrypting data with the generated predictable cryptographic session key during a communication session with a remote device.

19. The method of claim 18, wherein the first shared intermediate value is generated using a discrete-logarithm function or an elliptical-curve function.

20. The method of claim 19, wherein the discrete-logarithm function comprises an exponential multiplication of the pseudorandom secret key into a product, followed by a modulo reduction of the product.