Copy protection apparatus and method

• US 20020046178A1
• Filed: 10/02/2001
• Published: 04/18/2002
• Est. Priority Date: 03/19/1998
• Status: Active Grant

• Current Assignee: Maxell, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Yoshiura, Hiroshi, Roe, Michael, Morito, Hajime
• Granted Patent: US 6,865,553 B2
• Time in Patent Office: Days
• US Class Current: 705/51
• CPC Class Codes: G06T 1/0021 Image watermarking
• CPC Class Codes: G06T 2201/0064 for copy protection or copy management, e.g. CGMS, copy only once, one-time copy
• 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 20/00768 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 19/467 characterised by the embedded information being invisible, e.g. watermarking
• CPC Class Codes: H04N 2005/91328 the copy protection signal being a copy management signal, e.g. a copy generation management signal [CGMS]
• CPC Class Codes: H04N 21/23892 involving embedding information at multiplex stream level, e.g. embedding a watermark at packet level
• CPC Class Codes: H04N 21/8358 involving watermark protecting executable software by watermarking G06F21/16; image watermarking in general G06T1/0021; watermarks inserted in still images for transmission purposes H04N1/32144; inserting watermarks during video coding H04N19/467
• CPC Class Codes: H04N 5/76 Television signal recording
• CPC Class Codes: H04N 5/913 for scrambling ; for copy protection

Abstract

An apparatus and method of copy protection for use in digital data recorders such as DVD-RAM recorders, which includes embedding transmission time information into a digital data stream by digital watermarking and comparing the transmission time with the current time at the data recorder (30, 50). If the time difference is less than a threshold value it is presumed that the recording is for time-shifting purposes, namely recording a programme to watch later, which is generally allowed by copyright laws. If the time difference is greater than a threshold value it is presumed that the recording is an attempted unauthorised recording such as from a pre-recorded copy, and further recording is prevented.

Claims

1. Copy protection apparatus comprising:

data transmission apparatus including means for associating information related to the transmission time of the data with the data to be transmitted; and

data recording apparatus for recording data received from the transmission apparatus including;

means for comparing the transmission time information with information related to current time so as to determine difference data which is a function of the time-difference between the data transmission time and the current time; and

means for determining on the basis of the difference data whether recording of the received data is to be permitted.

2. Apparatus according to claim 1 wherein the time information associating means comprises means for embedding the transmission time information in the data as a digital watermark.

3. Apparatus according to claim 1 wherein the transmission time information and the current time information are each referenced to the same time origin.

4. Apparatus according to claim 1, including means for providing time information.

5. Apparatus according to claim 1, including means for associating with the data to be transmitted a copy control signal indicating the status of the data.

6. Apparatus according to claim 5, wherein the copy control signal is a Copy-Free, Copy-Once or Never-Copy signal.

7. Apparatus according to claim 5, wherein the copy control signal is embedded in the data as a digital watermark.

8. Apparatus according to claim 5, including means for combining the copy control signal with the transmission time information prior to embedding the combined signal into the data.

9. Data transmission apparatus comprising:

means for associating information related to the transmission time of data with the data to be transmitted, such that when the data is received by corresponding data recording apparatus, the transmission time information can be compared with information related to current time so as to determine difference data which is a function of the time difference between the transmission time and the current time, and to determine on the basis of the difference data whether recording of the data is to be permitted.

10. Apparatus according to claim 9 wherein the time information associating means comprises means for embedding the transmission time information in the data as a digital watermark.

11. Data recording apparatus for recording data transmitted thereto, the data being associated with information related to the data transmission time, comprising:

means for comparing the transmission time information with information related to current time so as to determine difference data which is a function of the time difference between the data transmission time and the current time; and

means for determining on the basis of the difference data whether recording of the data is to be permitted.

12. Apparatus according to claim 11, wherein the transmission time information is embedded in the data as a digital watermark.

13. Apparatus according to claim 11, wherein the transmission time information and the current time information are each referenced to the same predetermined time origin.

14. Apparatus according to claim 11, including means for providing time information.

15. Apparatus according to claim 14, wherein the time provision means includes a GPS receiver.

16. Apparatus according to claim 14, wherein the time provision means includes a time signal broadcast by the transmission apparatus.

17. Apparatus according to claim 11, wherein the recording permission determination means comprises means for preventing recording of the received data if the difference data exceeds a predetermined threshold value.

18. Apparatus according to claim 11, wherein the recording permission determination means comprises means for permitting recording of the received data if the difference data falls below a predetermined threshold value.

19. Apparatus according to claim 11, wherein the difference data comprises the time difference between the data transmission time and the current time.

20. Apparatus according to claim 11, wherein the data recording apparatus includes means for extracting transmission time information from the received data.

21. Apparatus according to claim 11, wherein the data recording apparatus includes means for extracting a copy control signal from the received data.

22. Apparatus according to claim 21, wherein the data recording apparatus further comprises means for deciding, in dependence only on the copy control signal, whether to prevent recording of the data.

23. Apparatus according to claim 11, comprising a digital video recorder.

24. Apparatus according to claim 11, comprising a recordable data storage device for a computer.

25. Apparatus according to claim 11, including means for indicating the copy protection status of the data.

26. Apparatus according to claim 25, wherein the indicating means comprises an indicator lamp.

27. Copy protection apparatus comprising:

data transmission apparatus including processing circuitry configured to associate information related to the transmission time of the data with the data to be transmitted; and

data recording apparatus for recording data received from the transmission apparatus including processing circuitry configured to compare the transmission time information with information related to current time so as to determine difference data which is a function of the time difference between the data transmission time and the current time, and to determine on the basis of the difference data whether recording of the received data is to be permitted.

28. A digital video recorder comprising:

a digital video data receiver for receiving video data with which information related to the data transmission time is associated;

means for recovering the transmission time information associated with the received data;

means for comparing the recovered time information with information related to current time so as to determine difference data which is a function of the time difference between the data transmission time and the current time; and

means for determining on the basis of the difference data whether recording of the received video data is to be permitted.

29. A recordable data storage device for a computer comprising:

means for receiving digital data transmitted thereto, the data being associated with information related to the data transmission time;

means for recovering the transmission time information associated with the received data;

means for comparing the recovered time information with information related to current time so as to determine difference data which is a function of the time difference between the data transmission time and the current time; and

means for determining on the basis of the difference data whether recording of the received data is to be permitted.

30. A method of copy protection for a data recorder comprising:

receiving data with which information related to the data transmission time is associated;

recovering the transmission time information associated with the received data;

comparing the recovered time information with information related to current time so as to determine difference data which is a function of the time difference between the data transmission time and the current time; and

determining on the basis of the difference data whether recording of the received data is to be permitted.

31. A method according to claim 30, including preventing the recording of the received data when the difference data exceeds a predetermined threshold.