Signal recording medium, content signal generation apparatus, content signal reproduction method, and content signal reproduction apparatus

• US 20020159594A1
• Filed: 03/12/2002
• Published: 10/31/2002
• Est. Priority Date: 03/16/2001
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Kori, Teruhiko
• Granted Patent: US 7,003,664 B2
• Time in Patent Office: Days
• US Class Current: 380/203
• CPC Class Codes: G06F 21/10 Protecting distributed programs or content, e.g. vending or licensing of copyrighted material protection in video systems or pay television H04N7/16 ; Digital rights management [DRM]
• 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

Abstract

A content signal having a control signal added thereto indicating whether or not a playback restricting function for restricting reproduction is activated is recorded on a disk. When an encryption key generation section determines at the time of reproduction that the content signal has the control signal added thereto indicating that the playback restricting function is activated, it is determined whether or not a playback permission condition is satisfied. The playback permission condition is read from the disk, or acquired via a communication section if it is not stored on the disk. A correct encryption key Kp is supplied to an encryption processing section only when the playback permission condition is satisfied. The encryption processing section decrypts the encrypted content signal recorded on the disk with the encryption key Kp and the correctly decrypted content signal is outputted from an output control section.

Claims

1. A signal recording medium having a content signal recorded thereon, wherein said content signal including a control signal added thereto indicating whether or not a playback restricting function is activated for restricting reproduction of said content signal.

3. The signal recording medium according to claim 1, wherein said content signal comprises a signal encrypted with a new encryption key generated based on said control signal and a preset encryption key.

5. The signal recording medium according to claim 1, wherein said content signal has a test data added thereto enabling determination as to whether or not decryption has been completed properly.

2. The signal recording medium according to claim l, wherein said content signal is recorded with a condition signal added thereto indicating a playback permission condition of said content signal when said playback restricting function is activated.

4. The signal recording medium according to claim 2, wherein said content signal comprises a signal encrypted with a new encryption key generated based on said control signal, a preset encryption key, and said condition signal.

6. A content signal generation apparatus comprising:

a signal generation control section which sets a playback restricting operation for the content signal by supplying a control signal indicating whether or not a playback restricting function is activated for restricting reproduction of a content signal; and

a signal generation section for adding said control signal supplied from said signal generation control section to said content signal to generate a content signal for content distribution.

7. The content signal generation apparatus according to claim 6, wherein said signal generation control section also generates a condition signal indicating a playback permission condition of said content signal when said playback restricting function is activated, and said signal generation section generates said content signal for content distribution by adding said condition signal as well.

8. The content signal generation apparatus according to claim 6, further comprising:

an encrypting section for encrypting a content signal; and

an encryption key generation section for generating an encryption key for use in encrypting said content signal by said encrypting section based on said control signal and a preset encryption key.

9. The content signal generation apparatus according to claim 7, further comprising:

an encrypting section for encrypting a content signal; and

an encryption key generation section for generating an encryption key for use in encrypting said content signal by said encrypting section based on said control signal, a preset encryption key, and said condition signal.

10. The content signal generation apparatus according to claim 6, further comprising an adding section for adding, to said content signal, test data enabling determination as to whether or not decryption has been completed properly.

11. A method of reproducing a content signal comprising the steps of:

determining, when a content signal is reproduced, whether or not said content signal has a control signal indicating whether or not a playback restricting function is activated for restricting reproduction of said content signal; and

when it is determined that said content signal has said control signal, outputting said content signal when a playback permission condition allowing reproduction of said content signal is satisfied.

12. The method of reproducing a content signal according to claim 11, wherein said content signal is outputted if said content signal has a condition signal indicating a playback permission condition of said content signal when said playback restricting function is activated and if the condition indicated by said condition signal is satisfied.

13. The method of reproducing a content signal according to claim 11, wherein said content signal is outputted if said content signal does not have a condition signal indicating a playback permission condition of said content signal when said playback restricting function is activated and if said playback permission condition is acquired, and the acquired playback permission condition is satisfied.

14. The method of reproducing a content signal according to claim 13, wherein said playback permission condition is acquired via a communication section or from a condition storing section storing said playback permission condition.

15. The method of reproducing a content signal according to claim 11, wherein, when said playback permission condition is satisfied, an encryption key is generated based on said control signal and key information included with said content signal, and a content signal which has been decrypted using said encryption key is outputted.

16. The method of reproducing a content signal according to claim 12, wherein, when said playback permission condition is satisfied, an encryption key is generated based on said control signal, key information included with said content signal and said condition signal, and a content signal which has been decrypted using said encryption key is outputted.

17. The method of reproducing a content signal according to claim 11, wherein, when said content signal is encrypted and has test data added thereto enabling determination as to whether or not decryption has been completed properly, said content signal is outputted when said decryption is performed and it is determined by said test data that said decryption has been properly completed.

18. The method of reproducing a content signal according to claim 17, further comprising the step of notifying that the content signal cannot be outputted when it is not determined by said test data that the decryption has been properly completed.

20. The content signal reproduction apparatus according to claim 19, wherein said setting signal generation section extracts a condition signal indicating said playback permission condition from said content signal and outputs said setting signal when said playback permission condition indicated by said condition signal is satisfied.

21. The content signal reproduction apparatus according to claim 20, further comprising a communication section, wherein said setting signal generation section acquires said condition signal through said communication section when said condition signal cannot be extracted from said content signal.

22. The content signal reproduction apparatus according to claim 20, further comprising a storing section for storing said condition signal, wherein said setting signal generation section acquires said condition signal when said condition signal cannot be extracted from said content signal.

23. The content signal reproduction apparatus according to claim 19, wherein said setting signal generation section outputs an encryption key for correctly decrypting the content signal as said setting signal when a condition indicated by said condition signal is satisfied, and said output processing section performs decryption using said encryption key in outputting said content signal.

24. The content signal reproduction apparatus according to claim 23, wherein, when said content signal has test data added thereto enabling determination as to whether or not decrypting has been completed properly, said output processing section performs decryption and outputs said decrypted content signal when it is determined by said test data that the decryption has been properly completed.

25. The content signal reproduction apparatus according to claim 24, further comprising a notifying section for notifying status of operation, wherein, when said output processing section does not determine, using said test data, that the decryption has been properly completed, said notifying section notifies that a content signal cannot be outputted.

19. A content signal reproduction apparatus comprising:

a setting signal generation section for determining whether or not a content signal has a control signal indicating whether or not a playback restricting function is activated for restricting reproduction of said content signal, and for generating a setting signal enabling correct output of said content signal when it is determined that said content signal has said control signal and a playback permission condition allowing reproduction of said content signal is satisfied; and

an output processing section for performing output processing of said content signal using said setting signal from said setting signal generation section.