Method and apparatus for descrambling content

• US 7,925,016 B2
• Filed: 11/13/2007
• Issued: 04/12/2011
• Est. Priority Date: 03/30/1999
• Status: Expired due to Fees

• 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): Song, Hosuk
• Application Number:
  US11/939,500
• Publication Number:
  US 20100020963A1
• Time in Patent Office: 1,246 Days
• Field of Search: 380/239, 380/241, 380277-278, 380200-203, 713/189, 713192-194, 725114-116
• US Class Current: 380/200
• CPC Class Codes: H04N 21/2347 involving video stream encryption
• CPC Class Codes: H04N 21/2543 Billing , e.g. for subscription services payment schemes, architectures or protocols G06Q20/00; e-commerce G06Q30/00; arrangements for billing for the use of broadcast information or broadcast-related information H04H60/21
• CPC Class Codes: H04N 21/4181 for conditional access
• CPC Class Codes: H04N 21/4367 Establishing a secure communication between the client and a peripheral device or smart card
• CPC Class Codes: H04N 21/4405 involving video stream decryption
• CPC Class Codes: H04N 21/47211 for requesting pay-per-view content payment schemes payment architectures or payment protocols G06Q20/00, G07F
• CPC Class Codes: H04N 21/63345 by transmitting keys key distribution for secret or secure communication H04L9/08; network support of key management H04L63/06
• CPC Class Codes: H04N 7/163 by receiver means only
• CPC Class Codes: H04N 7/167 Systems rendering the television signal unintelligible and subsequently intelligible
• 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

In accordance with one embodiment, a method for securing control words is provided. The method includes receiving scrambled digital content in a descrambler integrated circuit. The method further includes receiving an encrypted control word in the descrambler integrated circuit, decrypting the encrypted control word using a key stored in a register circuit of the descrambler integrated circuit, and descrambling the scrambled digital content in the descrambler integrated circuit using the decrypted control word.

Claims

1. A method of descrambling digital content comprising:

receiving scrambled digital content in a descrambler integrated circuit, the descrambler integrated circuit including a decryption hardware being a hardware circuit without any software control, the descrambler integrated circuit including a decryption block, a register circuit, and a descrambler;

receiving an encrypted control word in the descrambler integrated circuit, the encrypted control word is received from a smart card, wherein encrypted control word is obtained by encrypting a control word in the smart card using a key stored in a register circuit of the smart card, wherein the key stored in the register circuit of the smart card is associated with a key stored in the register circuit of the descrambler integrated circuit;

decrypting the encrypted control word by the decryption block using the key stored in the register circuit of the descrambler integrated circuit; and

descrambling the scrambled digital content in the descrambler integrated circuit using the decrypted control word.

2. The method of claim 1, wherein the digital content is content contained in a television transmission.

3. The method of claim 1, wherein the digital content is content downloaded from the Internet.

4. The method of claim 1, wherein the control word is decrypted using Triple DES.

5. A descrambler integrated circuit adapted for implementation in a conditional access unit, comprising:

a memory to permanently store a key uniquely assigned to the descrambler integrated circuit;

decryption logic coupled to the memory, the decryption logic being hardware without software control that decrypts an encrypted data using the key completely within the descrambler integrated circuit without accessing any information external to the decryption logic, the encrypted data being a service key; and

a descrambler coupled to the decryption logic, the descrambler to descramble incoming scrambled, digital program data within the descrambler integrated circuit using data recovered by decrypting the encrypted data, wherein the descrambler is being controlled by a processor in communications with a transmitter implemented within the conditional access unit, the transmitter to transmit a request for the service key in the encrypted format to a headend.

6. The descrambler integrated circuit of claim 5, wherein the memory is a one-time programmable non-volatile memory.

7. The descrambler integrated circuit of claim 5, wherein the encrypted data is the service key in an encrypted format being valid for a prescribed period of time, the encrypted service key, when decrypted, to descramble the scrambled digital program data if the digital program data belongs to a selected group of programs each of which capable of being descrambled by the service key.

8. An apparatus comprising:

a first interface to receive encrypted data; and

a descrambler integrated circuit in communication with the first interface, the descrambler integrated circuit comprises

a memory to store a key uniquely assigned to the descrambler integrated circuit,

decryption logic to decrypt the encrypted data using the key within the descrambler integrated circuit, the decryption logic being hardware that independently performs the decrypt operation without accessing any information external to the decryption logic, and

a descrambler to descramble incoming scrambled, digital content within the descrambler integrated circuit using data recovered by decrypting the encrypted data, wherein the descrambler is being controlled by a processor in communications with a transmitter implemented within the apparatus, the transmitter to transmit a request for the encrypted data to a headend.

9. The apparatus of claim 8, wherein the first interface includes an expansion slot to receive a smart card.

10. The apparatus of claim 8, wherein the encrypted data is an encrypted control word.

11. The apparatus of claim 8, wherein the memory of the descrambler integrated circuit is configured to prevent the permanent key from being overwritten or from being read by a source external to the descrambler integrated circuit.

12. The apparatus of claim 8, wherein the descrambler integrated circuit is devoid of a central processing unit, software or firmware.

13. The apparatus of claim 8 is a conditional access unit.