Method and system for transferring content information and supplemental information relating thereto

• US 6,209,092 B1
• Filed: 01/27/1998
• Issued: 03/27/2001
• Est. Priority Date: 01/27/1997
• Status: Expired due to Fees

• Current Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Original Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Inventors: Linnartz, Johan P. M. G.
• Primary Examiner(s): Swann, Tod R.
• Assistant Examiner(s): Smithers, Matthew
• Application Number:
  US09/014,170
• Time in Patent Office: 1,155 Days
• Field of Search: 380/201, 380/202, 380/203, 705/57, 711/76
• US Class Current: 713/176
• CPC Class Codes: G06T 1/0021 Image watermarking
• CPC Class Codes: G06T 1/0042 Fragile watermarking, e.g. so as to detect tampering
• 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 20/00884 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 19/00 Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
• 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 2005/91335 the copy protection signal being a watermark
• CPC Class Codes: H04N 2005/91342 the copy protection signal being an authentication signal
• CPC Class Codes: H04N 2005/91364 the video signal being scrambled
• 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 5/913 for scrambling ; for copy protection

Abstract

A method and system for recording and reproducing, such as on a record carrier, content information and supplemental information relating thereto. The content information may be audio and/or video, and the supplemental information may provide author identification and/or copy control status. An encoded signal is generated representing the content information and which includes a watermark pattern representing the supplemental information. The watermark pattern cannot be changed without impairing the quality of the content information during reproduction. The supplemental information also includes a control pattern, the watermark being generated by applying a one-way function to such control pattern. This has the advantage that any alteration of the watermark or the control pattern can be detected easily, because it is not computationally feasible to calculate a new control pattern for an altered watermark. Therefore, the supplemental information is well protected against unauthorized manipulation. An attempt to fully replace the watermark pattern will affect the quality of reproduction of the content information. In a copy control method allowing a first generation copy (“copy-once”), the original control pattern is processed several times by the one-way function for generating the watermark. Each player or recorder processes the control pattern once before outputting/recording it, thus forming a cryptographically protected down-counter.

Claims

1. A method of recording and reproducing content information and supplemental information relating thereto, in which:

an encoded signal representing the content information and a watermark pattern representing the supplemental information is recorded,

a control signal is also recorded, representing a control pattern, the watermark pattern and the control pattern in combination constituting the supplemental information, and

the watermark pattern corresponds to the result obtained by applying a one-way function to the control pattern.

2. A method of encoding content information and supplemental information relating thereto, comprising:

generating an encoded signal by encoding the content information in accordance with a watermark pattern representing the supplemental information,

generating a control signal representing a control pattern, the watermark pattern and the control pattern in combination constituting the supplemental information, and

generating the watermark pattern by applying a one-way function to the control pattern.

3. A method of retrieving supplemental information related to content information, comprising:

retrieving a watermark pattern representing supplemental information from an encoded signal representing the content information and the watermark pattern, the watermark pattern and a control pattern in combination constituting the supplemental information,

processing the control pattern by a one-way function, and

verifying the supplemental information by comparing the watermark pattern and the processed control pattern.

4. A system for transferring content information and related supplemental information from a system input to a system output via a transfer signal which includes an encoded signal, the system comprising:

a transmitter at the system input for transmitting the transfer signal, said transmitter including encoding means for generating the encoded signal by encoding the content information in accordance with a watermark pattern representing the supplemental information, and

a receiver at the system output for receiving the transfer signal, said receiver including means for retrieving the watermark pattern,

the transfer signal further including a control signal representing a control pattern, the watermark pattern and the control pattern in combination constituting the supplemental information,

the transmitter further including a first one-way function means for generating the watermark pattern in dependence on the control pattern, and

the receiver further including a second one-way function means for processing said control pattern and comparator means for verifying the supplemental information by comparing the watermark pattern and the processed control pattern.

5. An arrangement for generating an encoded signal for recording, which arrangement comprises:

encoding means for generating the encoded signal by encoding content information in accordance with a watermark pattern,

control means for generating a control signal representing a control pattern, the watermark pattern and the control pattern in combination constituting supplemental information, and

one-way function means for generating the watermark pattern in dependence on the control pattern.

6. The encoded signal generating arrangement as claimed in claim 5, in which the one-way function means is also adapted to generate a n-time processed control pattern by passing the control pattern n times through a cryptographic one-way function, n being an integer >

0.

7. The encoded signal generating arrangement as claimed in claim 6, in which n=3, thereby indicating that one generation of copies is allowed.

8. The encoded signal generating arrangement as claimed in claim 5, further comprising identification means for including a recorder identification code in the supplemental information.

9. An arrangement for read-out of a recorded encoded signal representing content information as well as a watermark pattern combined with a control pattern, said combination constituting supplemental information, which read-out arrangement comprises:

a retrieval unit for retrieving the watermark pattern,

control means for deriving a control signal from the control pattern,

one-way function means for generating from the control signal a processed control pattern, and

comparator means for verifying the supplemental information by comparing the watermark pattern with the processed control pattern.

10. The read-out arrangement as claimed in claim 9, in which the one-way function means is also adapted to generate a n-time processed control pattern by passing the control pattern n times through a cryptographic one-way function, n being an integer >

0.

11. The read-out arrangement as claimed in claim 10, in which:

the control pattern includes a first part and a second part, and

the arrangement further comprises means for combining the n-time processed control pattern and the second part of the (n−

1)-time processed control pattern, the output of the combining means being coupled to an input of the one-way function means.

12. The read-out arrangement as claimed in claim 10, further comprising control means for outputting a further control signal representing the n-time processed control pattern, n being equal to 1.

13. The read-out arrangement as claimed in claim 10, in which the comparator means is also adapted to determine a value m by:

a first comparison of the watermark pattern and the n-time processed control pattern at n=1; and

at least one further comparison of the watermark pattern and the n-time processed control pattern at n>

1, m being the value of n which results in a successful comparison.

14. The read-out arrangement as claimed in claim 13, further comprising output means for producing an output signal representing the content information in dependence on the supplemental information.

15. The read-out arrangement as claimed in claim 14, in which the output means includes means for recording the output signal on a record carrier.

16. The read-out arrangement as claimed in claim 15, in which the recording means is also adapted to record a further control signal representing the n-time processed control pattern.

17. The read-out arrangement as claimed in claim 14, in which the output means is also adapted to provide the output signal if m=1 or m=3.

18. The read-out arrangement as claimed in claim 15, in which the recording means is also adapted for recording if m=2.

19. The read-out arrangement as claimed in claim 9, further comprising playback means for inputting the encoded signal from a record carrier.

20. The read-out arrangement as claimed in claim 9, further comprising:

carrier pattern read means for retrieving a carrier pattern from a record carrier on which the encoded signal is recorded,

one-way function means for generating a processed carrier pattern, and

a comparator for comparing the watermark pattern and the processed carrier pattern.

26. The read-out arrangement of claim 9 in which:

the one-way function means is further adapted to generate a n-time processed control pattern by passing the control pattern n times through a cryptographic one-way function, n being an integer >

0,

said arrangement further comprises further control means for outputting a further control signal representing the n-time processed control pattern, n being equal to 1,

the comparator is also adapted to determine a value m by a first comparison of the watermark pattern and the n-time processed control pattern at n=1 and at least one further comparison of the watermark pattern and the n-time processed control pattern at n>

1, m being the value of n resulting in a successful comparison,

said arrangement further comprises output means for producing an output signal representing the content information in dependence on the supplemental information,

the output means includes means for recording the output signal on a record carrier,

the recording means is also adapted to record the further control signal,

the output means is also adapted to output the output signal if m=1 or m=3, and

the recording means is also adapted to record if m=2.

21. An encoded signal for use in a recording signal generating arrangement in which the encoded signal represents content information and a watermark pattern, the watermark pattern being the result of a control pattern processed by a one-way function, the watermark pattern and the control pattern in combination constituting supplemental information.

22. A control signal for use in a recording signal generating arrangement, in which:

the control signal represents a control pattern for controlling an encoded signal representing content information as well as a watermark pattern,

the control pattern and the watermark pattern in combination constitute supplemental information, and

the watermark pattern corresponds to the result of processing the control pattern in accordance with a one-way function.

23. A record carrier having recorded thereon an encoded signal in the form of a watermark pattern and a control pattern, and in which:

the watermark pattern is indicative of said control pattern after n-times processing, and

the n-times processing of the control pattern is by a cryptographic one-way function, n being an integer >

0.

24. The record carrier as claimed in claim 23, wherein:

the encoded signal is represented by a first modulation pattern of variations of a physical parameter, and

the record carrier includes a second pattern of variations of a physical parameter representing the carrier pattern in a different way than the representation of the encoded signal.

25. The record carrier as claimed in claim 23, in which:

the record carrier is of an optically readable type, and

the encoded signal is represented by a modulation pattern of optically detectable marks in a track.