Secure provisioning, by a client device, cryptographic keys for exploiting services provided by an operator

1. A method of descrambling a scrambled service, comprising:

transmitting, by a client device, a first challenge to an operator server, the first challenge including at least a certificate corresponding to the client device;

receiving, by the client device in response to the first challenge, a license from the operator server, the license including at least a service key encrypted with a unique device-derived key;

determining, by the client device, the unique device-derived key by applying a predetermined algorithm on a global operator seed and a unique device key corresponding to the client device;

decrypting, by the client device, the service key with the determined unique device-derived key;

receiving and descrambling, by the client device, the scrambled service using the service key; and

extracting, by the client device, the global operator seed from a global operator vault.

2. The method according to claim 1 , further comprising:

prior to transmitting the first challenge,

downloading, by the client device from the operator server, the global operator vault that stores the global operator seed;

transmitting a second challenge, by the client device to the operator server, the second challenge including at least a unique identifier of the client device and an identifier of the operator server; and

receiving, by the client device in response to the second challenge, the certificate corresponding to the client device.

3. The method according to claim 1 , wherein to extract the global operator seed from the global operator vault, the method further comprises decrypting the global operator vault with a global operator vault key received from the operator server by the client device with the certificate corresponding to the client device.

4. The method according to claim 2 , wherein the global operator vault is stored in non-volatile memory in the client device.

5. The method according to claim 2 , wherein the global operator vault stores a plurality of global operator seeds corresponding to a plurality of cryptographic generations.

6. The method according to claim 5 , further comprising changing a cryptographic generation (1) if a current global operator seed is compromised, or (2) periodically.

7. The method according to claim 1 , wherein the service key includes a content package key encrypted with the unique device-derived key, and a content key encrypted with the content package key.

8. The method according to claim 7 , further comprising:

decrypting, by the client device, the content package key with the unique device-derived key; and

decrypting, by the client device, the content key with the content package key after the content package key is decrypted.

9. A client device that descrambles a scrambled service, the client device comprising:

circuitry configured to

transmit a first challenge to an operator server, the first challenge including at least a certificate corresponding to the client device;

receive, in response to the first challenge, a license from the operator server, the license including at least a service key encrypted with a unique device-derived key;

determine the unique device-derived key by applying a predetermined algorithm on a global operator seed and a unique device key corresponding to the client device;

decrypt the service key with the determined unique device-derived key;

receive and descramble the scrambled service using the service key; and

extract the global operator seed from a global operator vault.

10. A method of descrambling a scrambled service, comprising:

receiving, by an operator server, a first challenge from a client device, the first challenge including at least an identifier of the client device and an identifier of the operator server;

determining entitlement of the client device to descramble the scrambled service;

when the client device is entitled to descramble the scrambled service determining, by the operator server, a device-derived key by applying a predetermined algorithm to a unique device key corresponding to the client device and a global operator seed corresponding to the operator server;

forming, by the operator server, a unique cryptogram by encrypting the device-derived key with the global operator seed;

transmitting, from the operator server to the client device, a certificate corresponding to the client device, the certificate including the unique cryptogram;

receiving, by the operator server, a second challenge from the client device, the second challenge including at least the certificate corresponding to the client device; and

providing, from the operator server to the client device in response to the second challenge, a license from the operator server, the license including at least a service key encrypted with the device-derived key,

wherein the client device uses the service key in the license to descramble the scrambled service.

11. The method according to claim 10 , further comprising:

providing, from the operator server to the client device, a global operator vault including the global operator seed.

12. The method according to claim 11 , further comprising:

providing, from the operator server to the client device, a plurality of unique cryptograms corresponding to a plurality of encryption generations,

wherein the global operator vault includes a plurality of global operator seeds corresponding to the plurality of encryption generations.

13. The method according to claim 12 , further comprising:

changing a current encryption generation (1) if a current global operator seed is compromised, or (2) periodically.

14. The method according to claim 11 , wherein the global operator vault is encrypted with a global operator vault key.

15. The method according to claim 14 , further comprising transmitting, by the operator server, the global operator vault key to the client device at a time when the certificate corresponding to the client device is transmitted.

16. The method according to claim 10 , wherein the service key includes a content package key encrypted with the device-derived key, and a content key encrypted with the content package key.

17. An operator server, comprising:

circuitry configured to

receive a first challenge from a client device, the first challenge including at least an identifier of the client device and an identifier of the operator server;

determine entitlement of the client device to descramble the scrambled service;

when the client device is entitled to descramble the scrambled service, determine a device-derived key by applying a predetermined algorithm to a unique device key corresponding to the client device and a global operator seed corresponding to the operator server;

form a unique cryptogram by encrypting the device-derived key with the global operator seed;

transmit, to the client device, a certificate corresponding to the client device, the certificate including the unique cryptogram;

receive a second challenge from the client device, the second challenge including at least the certificate corresponding to the client device; and

provide, to the client device in response to the second challenge, a license from the operator server, the license including at least a service key encrypted with the device-derived key,

wherein the client device uses the service key in the license to descramble the scrambled service.

18. An operator server according to claim 17 , wherein the circuitry is further configured to:

provide, to the client device, a plurality of unique cryptograms corresponding to a plurality of encryption generations,

wherein the global operator vault includes a plurality of global operator seeds corresponding to the plurality of encryption generations.

19. The operator server according to claim 18 , wherein the circuitry is further configured to change a current encryption generation (1) if a current global operator seed is compromised, or (2) periodically.