System and method for copy protection for digital signals

• US 7,778,418 B1
• Filed: 01/07/1999
• Issued: 08/17/2010
• Est. Priority Date: 01/08/1998
• Status: Expired due to Fees

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Chaney, Jack
• Primary Examiner(s): Pyzocha; Michael
• Assistant Examiner(s): CALLAHAN, PAUL E
• Application Number:
  US09/226,577
• Time in Patent Office: 4,240 Days
• Field of Search: 380/201, 380/203, 380/205, 380/208, 380/210, 380/281, 705/51, 705/57, 726/26, 725/31
• US Class Current: 380/203
• CPC Class Codes: G11B 20/00086 Circuits for prevention of unauthorised reproduction or copying, e.g. piracy indicating unauthorised use of record carriers in general G11B23/28; scrambling for television signal recording H04N5/913; network architectures or network protocols for network security H04L63/00; cryptographic mechanisms or cryptographic arrangements for secret or secure communication H04L9/00
• CPC Class Codes: G11B 20/00855 involving a step of exchanging information with a remote server
• CPC Class Codes: G11B 2020/10537 Audio or video recording
• CPC Class Codes: G11B 23/28 Indicating or preventing prior or unauthorised use, e.g. cassettes with sealing or locking means, write-protect devices for discs write-protect devices for tapes G11B23/042, G11B23/08714; dummy cassettes for locking in the drive G11B33/005
• CPC Class Codes: G11B 23/284 on the record carrier
• CPC Class Codes: H04N 2005/91364 the video signal being scrambled
• CPC Class Codes: H04N 21/2347 involving video stream encryption
• 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 21/4408 involving video stream encryption, e.g. re-encrypting a decrypted video stream for redistribution in a home network
• CPC Class Codes: H04N 21/8355 involving usage data, e.g. number of copies or viewings allowed
• CPC Class Codes: H04N 5/913 for scrambling ; for copy protection
• CPC Class Codes: H04N 7/163 by receiver means only
• 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

Embodiments of the present invention provide for the copy protection of distributed material after conditional access is applied, regardless of where the material is distributed. The solutions described provide the advantage of being sufficiently simple in implementation to qualify as “curb high” solutions. “Curb high” solutions provide a range of security from minimal security to a high level of security while requiring relatively fewer system resources to implement than prior approaches.

Claims

1. A method of copy-protecting a digital audio-visual signal, comprising:

encoding the digital audio-visual signal to obtain an encoded signal;

converting the encoded signal into a copy protected signal using a copy protection function that utilizes a copy protection data signal to prevent using the digital audio-visual signal without access to the copy protection data signal;

scrambling the copy protected signal to obtain a scrambled signal;

transmitting the scrambled signal and said copy protection data signal to a receiver as a single signal for subsequent recovery of said digital audio-visual signal;

employing a processor for;

recovering said scrambled signal from the single signal;

descrambling the recovered scrambled signal to regain said copy protected signal;

reconverting the regained copy protected signal back into said encoded signal using an inverse copy protection function, wherein the inverse function utilizes copy protection data represented by the copy protection data signal.

2. The method of claim 1, wherein transmitting further comprises combining the scrambled signal and said copy protection data signal into said single signal.

3. The method of claim 1, further comprising:

receiving said single signal in a receiver;

removing said copy protection data signal from the single signal, and storing the copy protection data represented by the copy protection data signal in a memory device; and

decoding the encoded signal obtained by the reconverting of the regained copy protected signal to recover said digital audio-visual signal.

4. The method of claim 1, further comprising:

descrambling the scrambled signal to recover said copy protected signal;

reconverting the recovered copy protected signal back into said encoded signal using an inverse copy protection function, wherein the inverse function utilizes the copy protection data from said copy protection data signal; and

decoding the converted encoded signal to recover said digital audio-visual signal.

5. The method of claim 1, wherein the copy protected signal cannot be usably viewed, displayed, copied or recorded without access to the copy protection data.

6. A method of recovering an audio-visual signal from a digital signal including a scrambled signal and a copy protection data signal representing copy protection data, comprising the steps of:

(a) extracting said data signal from the digital signal;

(b) storing the copy protection data from said copy protection data signal in a memory device;

(c) extracting the scrambled signal from the digital signal;

(d) descrambling the scrambled signal to recover a copy protected signal;

(e) reconverting the copy protected signal into an encoded signal using an inverse copy protection function, wherein the inverse function utilizes said stored copy protection data; and

(f) decoding the encoded signal to recover said audio-visual signal,

wherein the copy protected signal prevents use of the audio-visual signal without access to the copy protection data.

7. The method of claim 6, wherein the copy protected signal cannot be usably viewed, displayed, copied or recorded without access to the copy protection data.

8. A system for copy-protecting a digital audio-visual signal, comprising:

an encoder configured to encode the digital audio-visual signal to obtain an encoded signal;

a converter configured to convert the encoded signal into a copy protected signal using a computer program product comprising a computer usable medium for copy protection including a computer readable program, wherein the computer readable program when executed on a computer causes the computer to;

use a copy protection data signal representing copy protection data to prevent using the digital audio-visual signal without access to the copy protection data;

a scrambler configured to scramble the copy protected signal into a scrambled signal;

a transmitter configured to transmit the scrambled signal and the copy protection data signal as a single signal to a receiver for subsequent recovery of said digital audio\-visual signal;

a hardware processor including a computer program product comprising a computer usable medium including a computer readable program, wherein the computer readable program when executed on the processor causes the processor to;

recover said scrambled signal from the single signal;

a descrambler configured to descramble the recovered scrambled signal to regain said copy protected signal; and

a reconverter configured to convert the regained copy protected signal back into said encoded signal using an inverse copy protection function, wherein the inverse function utilizes said stored copy protection data.

9. The system of claim 8, further comprising a combiner for combining the scrambled signal and said data signal into said single signal, wherein the transmitter transmits said single signal to the receiver.

10. The system of claim 8, further comprising:

a receiver configured to receive said single signal in a receiver;

the computer readable program

a decoder configured to decode the encoded signal to recover said digital audio-visual signal,

wherein the processor further causes the processor to;

remove said copy protection data signal from the single signal, and store the copy protection data in a memory device.

11. The system of claim 8, further comprising:

the descrambler further configured to descramble the scrambled signal to recover said copy protected signal;

the reconverter further configured to convert the recovered copy protected signal back into said encoded signal using an inverse copy protection function, wherein the inverse function utilizes the copy protection data; and

a decoder configured to decode the converted encoded signal to recover said digital audio-visual signal.

12. The system of claim 8, wherein the copy protected signal cannot be usably viewed, displayed, copied or recorded without access to the copy protection data.

13. A system for recovering an audio-visual signal from a digital signal including a scrambled signal and a copy protection data signal representing copy protection data, the system comprising:

(a) a processor for;

(1) removing said copy protection data signal from the digital signal, and storing the copy protection data in a memory device, and (2) recovering said scrambled signal from the digital signal;

(b) a descrambler for descrambling the recovered scrambled signal to recover a copy protected signal;

(c) a reconverter for converting the recovered copy protected signal back into said encoded signal using an inverse copy protection function, wherein the inverse function utilizes said stored copy protection data; and

(d) a decoder for decoding the encoded signal to recover said audio-visual signal,

wherein the copy protected signal prevents use of the audio-visual signal without access to the copy protection data.

14. The system of claim 13, wherein the copy protected signal cannot be usably viewed, displayed, copied or recorded without access to the copy protection data.

15. A system for recovering an audio-visual signal from a single digital signal including a scrambled signal and a copy protection data signal representing copy protection data, the system comprising:

a processor configured to;

separate said copy protection data signal and said scrambled signal from the digital signal;

store copy protection data in a memory;

descramble the separated scrambled signal to recover a copy protected signal; and

reconvert the recovered copy protected signal back into an encoded signal using an inverse copy protection function, wherein the inverse function utilizes said stored copy protection data; and

decode the encoded signal to recover said audio-visual signal, wherein the copy protected signal prevents use of the audio-visual signal without access to the copy protection data.