Mechanism for protecting the transfer of digital content

• US 7,724,907 B2
• Filed: 03/12/2003
• Issued: 05/25/2010
• Est. Priority Date: 11/05/2002
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.), Sony Electronics Inc. (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.), Sony Electronics Inc. (Sony Group Corp.)
• Inventors: Candelore, Brant L.
• Primary Examiner(s): Moise, Emmanuel L
• Assistant Examiner(s): Gelagay, Shewaye
• Application Number:
  US10/388,002
• Publication Number:
  US 20040086127A1
• Time in Patent Office: 2,631 Days
• Field of Search: 380/281
• US Class Current: 380/281
• CPC Class Codes: H04N 21/4181 for conditional access
• CPC Class Codes: H04N 21/43607 Interfacing a plurality of external cards, e.g. through a DVB Common Interface [DVB-CI]
• CPC Class Codes: H04N 21/4405 involving video stream decryption
• CPC Class Codes: H04N 21/4408 involving video stream encryption, e.g. re-encrypting a decrypted video stream for redistribution in a home network
• CPC Class Codes: H04N 21/4623 Processing of entitlement messages, e.g. ECM [Entitlement Control Message] or EMM [Entitlement Management Message] arrangements for conditional access to broadcast information or to broadcast-related services H04H60/14
• CPC Class Codes: H04N 7/1675 Providing digital key or authorisation information for generation or regeneration of the scrambling sequence pseudo-random number generators in general G06F7/58

Abstract

According to one embodiment, a method for delivering a mating key to a smart card coupled to a decoding device with a built-in descrambler. The mating key is used by the smart card to encrypt the derived descrambling key for the specific decoder with descrambler. The corresponding mating key is a derivation calculated within the descrambler circuit using a unique value stored in the decoding device, and is of a message that comprises a unique predetermined value that identifies a manufacturer of the decoding device, the digital device targeted to receive the encrypted key data, and the service provider.

Claims

1. A system in communication with a remote source and a digital device, comprising:

means for receiving a mating key in response to a prior transmission of a mating key generator and a serial number of the digital device to the remote source, the mating key being a result produced by performing a cryptographic operation on the mating key generator;

means for encrypting a descrambling key with the mating key, the descrambling key being used for scrambling digital content prior to transmission to the digital device; and

means for transmitting the mating key generator to the digital device.

2. The system of claim 1, wherein the remote source is a mating key server in communication with a plurality of servers each associated with a different manufacturer of digital devices.

3. The system of claim 1, wherein the mating key generator comprises a mating key sequence number being used to migrate from one mating key to the next.

4. The system of claim 1, wherein the mating key generator comprises an identifier of a supplier of the digital content, the supplier being one of a cable provider, a satellite-based provider, a terrestrial-based provider, and an Internet service provider.

5. The system of claim 1, wherein the mating key generator comprises an identifier that identifies a provider of the system itself.

6. The system of claim 1 further comprising:

means for generating and providing an entitlement control message (ECM) and an entitlement management message (EMM) to the digital device alone with the mating key, the EMM comprises at least one key to decrypt the ECM.

7. The system of claim 1 further comprising:

where the descrambling keys are service keys, used to decrypt a channel; and

transmitting the encrypted service keys to the digital device.

8. A method comprising:

performing a cryptographic operation on a mating key generator message by encrypting the mating key generator message with a key to produce a mating key, the mating key generator message comprises a predetermined value that identifies a manufacturer of a digital device;

receiving the mating key; and

encrypting data used for scrambling digital content with the mating key.

9. The method of claim 8, wherein the message further comprises a mating key sequence number being used to migrate from one mating key to the next.

10. The method of claim 9, wherein the message further comprises an identifier that identifies a content provider that supplies the digital content, the content provider being one of a cable provider, a satellite-based provider, a terrestrial-based provider, and an Internet service provider.

11. The method of claim 10, wherein the message further comprises a copy protection status value that identifies (1) whether or not the digital content can be copied, or (2) a number of times the digital content is capable of being played back, or (3) date/time of play back.

12. The method of claim 8 further comprising:

transmitting the encrypted data along with the message to a smart card adapted to a set-top box; and

transmitting the encrypted data and the message from the smart card to a descrambler component located within the set-top box.

13. The method of claim 12 further comprising:

decrypting the encrypted data using the message and an unique key stored within the descrambler component to recover the data in a non-encrypted format, the data being used to descramble the scrambled digital content within the descrambler component.

14. The method of claim 8 further comprising:

producing an entitlement management message (EMM) that comprises the message, the encrypted data being an encrypted service key and a value that indicates a tier of service associated with the encrypted service key; and

providing the EMM to the set-top box.

15. The method of claim 14 further comprising:

providing meta-data with an electronic program guide in an unscrambled format to the set-top box, the meta-data comprises a plurality of tag entries in which one of the tag entries comprising a channel name, a name of the digital content, and a key identifier indicating a tier of service associated with the encrypted service key.

16. The method of claim 8 further comprising:

producing an entitlement management message (EMM) that comprises the message, the encrypted data being an encrypted service key, and a value that indicates a tier of service associated with the encrypted service key.

17. The method of claim 8, wherein the key is a pre-stored key unique to the digital device.

18. An apparatus adapted to receive scrambled content and descramble the scrambled content, comprising:

a removable smart card adapted to (i) receive a mating key generator message and (ii) encrypt a descrambling key with a mating key that is generated using the mating key generator message, the mating key generator message includes at least two of a set-top-box manufacturer identifier, a service provider identifier, a conditional access provider identifier and a sequence number; and

a descrambler component to receive the encrypted descrambling key and the mating key generator message, the descrambler component performs a cryptographic operation on the mating key generator message to produce a key that is equivalent to the mating key and decrypts the encrypted descrambling key using the key to recover a descrambling key, the descrambling key being used for descrambling scrambled content loaded into the apparatus.

19. The apparatus of claim 18, wherein the smart card further receiving an entitlement control message including the encrypted descrambling key and access criteria for a particular channel over which the scrambled content is transmitted.

20. The apparatus of claim 18, wherein the descrambler component is an integrated circuit.

21. The apparatus of claim 19, wherein the mating key generator message received by the descrambler component comprises at least one key to decrypt the entitlement control message to recover the encrypted descrambling key entirely within the descrambler component.

22. The apparatus of claim 18, wherein the smart card is further adapted to perform a cryptographic operation on the mating key generator message to produce a result that is equivalent to the mating key.

23. The apparatus of claim 22, wherein the smart card is further adapted to perform the cryptographic operation by encrypting the mating key generator message to produce the result being equivalent to the mating key.

24. The apparatus of claim 18, wherein the mating key generator message includes an identifier of a manufacturer of the set-top box.

25. The apparatus of claim 18, wherein the mating key generator message includes an identifier of a service provider.

26. The apparatus of claim 18, wherein the mating key generator message includes an identifier of a conditional access (CA) provider.

27. The apparatus of claim 18, wherein the mating key generator message includes a mating key sequence number being used to migrate from the mating key to another mating key.

28. A digital device, comprising:

a network interface to receive scrambled content; and

a descrambler component to (i) receive a mating key generator message including an identifier of a manufacturer of a digital device targeted to receive the scrambled content, at least one encrypted service key and a corresponding key identifier to indicates a tier of service associated with the encrypted service key over the network interface, (ii) perform a cryptographic operation on the mating key generator message to produce a key, (iii) decrypt the encrypted service key using the key to recover a service key, and (iv) descrambling the scrambled content using the service key.

29. The apparatus of claim 28, wherein the access criteria for accessing a channel is supplied by an ECM in-band with the digital content while the encrypted service key and the corresponding key identifier are contained in an entitlement management message (EMM) supplied out-of-hand.

30. The apparatus of claim 28, wherein both the mating key generator message and the corresponding key identifier are supplied by meta-data associated with an electronic program guide data supplied alone with the encrypted service key is contained in an entitlement management message (EMM) in the out-of-band.

31. The digital device of claim 28, wherein the message is an out-of-band message and includes an identifier of a service provider.

32. The digital device of claim 28, wherein the message includes an identifier of a conditional access (CA) provider.

33. The digital device of claim 28, wherein the message includes a mating key sequence number being used to migrate from the mating key to another mating key.