US 12,143,692 B2
Secure provisioning, by a client device, cryptographic keys for exploiting services provided by an operator
Yann Bieber, Cheseaux-sur-Lausanne (CH); and André Nicoulin, Cheseaux-sur-Lausanne (CH)
Assigned to NAGRAVISION SARL, Cheseaux-sur-Lausanne (CH)
Filed by NAGRAVISION SARL, Cheseaux-sur-Lausanne (CH)
Filed on Sep. 7, 2023, as Appl. No. 18/463,191.
Application 18/463,191 is a continuation of application No. 17/958,970, filed on Oct. 3, 2022, granted, now 11,785,315.
Application 17/958,970 is a continuation of application No. 17/012,440, filed on Sep. 4, 2020, granted, now 11,575,977, issued on Feb. 7, 2023.
Application 17/012,440 is a continuation of application No. 16/073,752, abandoned, previously published as PCT/EP2016/081822, filed on Dec. 20, 2016.
Claims priority of application No. 15202609 (EP), filed on Dec. 23, 2015.
Prior Publication US 2024/0073490 A1, Feb. 29, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. H04L 9/08 (2006.01); H04L 9/14 (2006.01); H04L 9/16 (2006.01); H04N 7/167 (2011.01); H04N 21/4405 (2011.01); H04N 21/6334 (2011.01); H04N 21/835 (2011.01)
CPC H04N 21/835 (2013.01) [H04L 9/0819 (2013.01); H04L 9/0822 (2013.01); H04L 9/0825 (2013.01); H04L 9/083 (2013.01); H04L 9/088 (2013.01); H04L 9/14 (2013.01); H04L 9/16 (2013.01); H04N 7/1675 (2013.01); H04N 21/4405 (2013.01); H04N 21/63345 (2013.01)] 14 Claims
OG exemplary drawing
 
9. A method of descrambling a scrambled service, the method comprising:
receiving, by an operator server, a first challenge from a client device, the 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 a 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,
a plurality of global operator seeds corresponding to a plurality of cryptographic generations are stored; and
the method further comprises changing a cryptographic generation (1) if a current global operator seed is compromised, or (2) periodically.