Method and apparatus for copy protection

• US 6,523,113 B1
• Filed: 11/09/1998
• Issued: 02/18/2003
• Est. Priority Date: 06/09/1998
• Status: Expired due to Term

• Current Assignee: Apple Inc.
• Original Assignee: Apple Computer Incorporated (Apple Inc.)
• Inventors: Wehrenberg, Paul J.
• Primary Examiner(s): Barrón, Gilberto
• Assistant Examiner(s): Callahan, Paul E.
• Application Number:
  US09/188,917
• Time in Patent Office: 1,562 Days
• Field of Search: 380/201, 380/203, 380/210, 713/176
• US Class Current: 713/176
• 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 20/0021 involving encryption or decryption of contents recorded on or reproduced from a record carrier
• CPC Class Codes: G11B 20/00224 wherein the key is obtained from a remote server
• CPC Class Codes: G11B 20/00246 wherein the key is obtained from a local device, e.g. device key initially stored by the player or by the recorder
• CPC Class Codes: G11B 20/00282 the key being stored in the content area, e.g. program area, data area or user area key stored in a management area G11B20/00297
• CPC Class Codes: G11B 20/00449 content scrambling system [CSS]
• CPC Class Codes: G11B 20/00514 wherein the entire content is encrypted with the same key, e.g. disc key or master key
• CPC Class Codes: G11B 20/00528 wherein each title is encrypted with a separate encryption key for each title, e.g. title key for movie, song or data file
• CPC Class Codes: G11B 20/00673 wherein the erased or nullified data include a cryptographic key
• CPC Class Codes: G11B 20/0071 involving a purchase action
• CPC Class Codes: G11B 20/00753 wherein the usage restriction limits the number of copies that can be made, e.g. CGMS, SCMS, or CCI flags
• CPC Class Codes: G11B 20/00768 wherein copy control information is used, e.g. for indicating whether a content may be copied freely, no more, once, or never, by setting CGMS, SCMS, or CCI flags
• CPC Class Codes: G11B 20/00884 involving a watermark, i.e. a barely perceptible transformation of the original data which can nevertheless be recognised by an algorithm
• CPC Class Codes: H04N 1/32128 attached to the image data, e.g. file header, transmitted message header, information on the same page or in the same computer file as the image for information embedded in the image H04N1/32144
• CPC Class Codes: H04N 2201/3233 of authentication information, e.g. digital signature, watermark
• CPC Class Codes: H04N 2201/3246 of data relating to permitted access or usage, e.g. level of access or usage parameters for digital rights management [DRM] related to still images
• CPC Class Codes: H04N 2201/3278 Transmission

Abstract

Copy protection techniques that utilize a watermark and a permission key are disclosed. The copy protection techniques can provide single-copy copy protection in addition to different levels of copy protection. The permission key and the watermark can also permit the invention to yield variable levels of copy protection. In one embodiment, content including a watermark is transmitted to a recipient. The recipient is allowed to read the content but not record the content unless the recipient possesses a permission key.

Claims

1. A method of copy protecting content comprising:

receiving content to be recorded, the content including a watermark encoded in the content and the watermark indicating that the content is copy protected;

receiving an encrypted permission key;

decrypting the encrypted permission key providing a decrypted permission key;

extracting the watermark from the content;

comparing the decrypted permission key and the watermark to determine if the decrypted permission key and the watermark match; and

permitting the recording of the content if the decrypted permission key and the watermark match and otherwise prohibiting the recording of the content.

2. A method as recited in claim 1, wherein the watermark is embedded in the content such that the watermark is configured to be extracted from the content if the watermark is known, and the watermark is not easily extracted from the content if the watermark is not known.

3. A method as recited in claim 1, wherein a copy protection status of the content indicated by the watermark permits the recipient to read the content but does not allow the recipient to record the content unless the recipient possesses a permission key.

4. A method as recited in claim 3, further comprising:

recording the content and the watermark on a recording medium, wherein the recipient is permitted to read the content and the watermark from the recording medium but not permitted to record the content and the watermark on an other recording medium.

5. A method as recited in claim 3, further comprising:

transmitting the content with the watermark to the recipient; and

transmitting the permission key to the recipient, wherein the permission key is a one time use permission key such that the recipient is permitted to read the content and the watermark and permitted to record the content and the watermark once on a recording medium, and the recipient is not permitted to record the permission key such that the content and the watermark cannot be recorded more than once without the permission key.

6. A method as recited in claim 5, wherein the permission key is a variable permission key that varies over the transmission of the content and the watermark such that more than one permission key is required to record the content and the encoded watermark.

7. A method as recited in claim 5, wherein the recording medium is a digital versatile data disc.

8. A method as recited in claim 1, wherein the content includes at least one of audio and video content.

9. A method as recited in claim 1, wherein the content is digital content.

10. A method as recited in claim 1, wherein the content is digital television content.

11. A method as recited in claim 1, wherein said method further comprises:

authenticating the source of the content before or concurrently with the receiving of the encrypted permission key.

12. A method as recited in claim 1, wherein said method further comprises:

preventing the recording of the encrypted or decrypted permission key.

13. A method as recited in claim 1, wherein the watermark indicates that the content may be copied once.

14. A method as recited in claim 1, wherein the watermark indicates that the content may not be copied.

15. A method as recited in claim 1, wherein the watermark indicates a level to which the content may copied.

16. A computer readable medium including computer program code for copy protecting content, said computer readable medium comprising:

computer program code configured to receive content to be recorded, the content including a watermark encoded in the content and the watermark indicating that the content is copy protected;

computer program code configured to receive an encrypted permission key;

computer program code configured to decrypt the encrypted permission key providing a decrypted permission key;

computer program code configured to extract the watermark from the content;

computer program code configured to compare the decrypted permission key and the watermark to determine if the decrypted permission key and the watermark match; and

computer program code configured to permit the recording of the content if the decrypted permission key and the watermark match and otherwise prohibiting the recording of the content.

17. A computer readable medium as recited in claim 16, wherein said method further comprises:

computer program code configured to authenticate the source of the content before or concurrently with the receiving of the encrypted permission key.

18. A computer readable medium as recited in claim 16, wherein said method further comprises:

computer program code configured to prevent the recording of the encrypted or decrypted permission key.