Content protection
AssigneeNagravision Sarl
InventorsChristian Schwarz, Andre Nicoulin, Didier Hunacek
Life of this patent
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Abstract
Devices, servers, systems and methods for content protection are provided. Disclosed embodiments improve temporal granularity of controlling access to the protected content and increase resilience against attacks attempting to prevent re-evaluation of conditions of access. Enforcement of re-evaluation may be based on the receipt and/or verification of tokens. In some embodiments, re-evaluation is enforced by periodically rendering content keys required for content decryption unuseable and/or clearing content keys already in use.
Claims21
(canceled)
An apparatus for decrypting encrypted media content, the apparatus comprising:
- at least one memory;
- and
- at least one processor coupled to the at least one memory and configured to:
- receive and store an encrypted content key;
- receive encrypted media content;
- evaluate an access condition after a first interval;
- and
- in response to the access condition being met within the first interval:
- decrypt the encrypted content key to obtain the content key;
- and
- enable a descrambler to use the content key to decrypt the encrypted media content.
A method for decrypting encrypted media content, the method comprising:
- receiving and storing an encrypted content key;
- receiving encrypted media content;
- evaluating an access condition after a first interval;
- and
- in response to the access condition being met within the first interval:
- decrypting the encrypted content key to obtain the content key;
- and
- enabling a descrambler to use the content key to decrypt the encrypted media content.
Dependencies are inferred from the claim text.