Data reproduction apparatus, data recording apparatus, circuit element, data reproduction method and data recording method

• US 7,327,934 B2
• Filed: 04/14/2003
• Issued: 02/05/2008
• Est. Priority Date: 04/15/2002
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Kitani, Satoshi
• Primary Examiner(s): Tran; Thai Q.
• Assistant Examiner(s): Zhao; Daquan
• Application Number:
  US10/413,026
• Publication Number:
  US 20030231869A1
• Time in Patent Office: 1,758 Days
• Field of Search: 386/1, 386/94, 386125-126, 360/60, 380/201, 380/203
• US Class Current: 386/260
• CPC Class Codes: G11B 19/122 involving the detection of an identification or authentication mark record carriers indicating unauthorised or prior use G11B23/28
• 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 20/00304 the key being stored in the lead-in area [LIA]
• CPC Class Codes: G11B 20/00449 content scrambling system [CSS]
• CPC Class Codes: G11B 20/00507 wherein consecutive physical data units of the record carrier are encrypted with separate encryption keys, e.g. the key changes on a cluster or sector basis
• CPC Class Codes: G11B 20/00688 said measures preventing that a usable copy of recorded data can be made on another medium
• 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 20/00818 wherein the usage restriction limits the signal quality, e.g. by low-pass filtering of audio signals or by reducing the resolution of video signals
• 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 2005/91335 the copy protection signal being a watermark
• CPC Class Codes: H04N 2005/91364 the video signal being scrambled
• CPC Class Codes: H04N 5/85 on discs or drums
• CPC Class Codes: H04N 5/913 for scrambling ; for copy protection
• CPC Class Codes: H04N 9/8042 involving data reduction

Abstract

A circuit element is disclosed which restricts reproduction of an illegally duplicated recording medium and prevents illegal duplication of a recording medium. The circuit element is incorporated in a data reproduction apparatus or a data recording apparatus and includes an encryption discrimination section for discriminating whether or not data recorded on a recording medium is encrypted data, a digital watermark status detection section for detecting digital watermark status from within the data read from the recording medium, a determination section for determining, if it is discriminated that the data recorded on the recording medium is encrypted data, that the read data should not be filtered, but determining, if it is discriminated that the data recorded on the recording medium is not encrypted data, whether or not the read data should be filtered based on the digital watermark status, and a filter processing section for filtering part of the read data based on a result of the determination by the determination section.

Claims

1. A data reproduction apparatus, comprising:

a disc holding unit configured to receive a recording medium on which data including digital watermark status is recorded;

a disc determination unit configured to determine a type of the recording medium received by said disc holding unit;

a read processor configured to read the data including the digital watermark status from the recording medium received by said disc holding unit;

digital watermark status detection element configured to detect the digital watermark status from within the data read from the recording medium by said read processor;

a discrimination circuit configured to determine, if it is determined by said disc determination unit that the recording medium is of a first type, that the data read by said read processor should not be filtered, but determining, if it is determined by said disc determination unit that the recording medium is of a second type, whether or not the data read by said read processor should be filtered based on the digital watermark status detected by said digital watermark status detection element;

a filter unit configured to filter, if it is determined by said discrimination circuit that the data should be filtered, part of the data read by said read processor; and

an output unit configured to output the data filtered by said filter unit and the data read by said read processor but not filtered by said filter unit.

2. The data reproduction apparatus according to claim 1, wherein said disc determination unit discriminates whether or not the recording medium received by said disc holding unit is a recording medium of the first type which is a recording medium for reproduction only or a recording medium of the second type which is a recordable recording medium.

3. The data reproduction apparatus according to claim 1, wherein said disc determination unit determines whether or not the data recorded on the recording medium received by said disc holding unit is encrypted data to make a determination between a disk of the first type which includes encrypted data and a disk of the second type which includes no encrypted data.

4. The data reproduction apparatus according to claim 3, wherein said disc determination unit detects information read out from a lead-in region of the recording medium and detects key information for decrypting the data recorded as encrypted data on the recording medium from within the read out information to determine that the data recorded on the recording medium is encrypted data.

5. The data reproduction apparatus according to claim 1, wherein said filter unit replaces part of the data with dummy data, which does not make sense as information, to filter the data.

6. The data reproduction apparatus according to claim 5, wherein the data replaced with the dummy data is contents data.

7. A data reproduction method, comprising:

receiving a recording medium on which data including digital watermark status is recorded;

discriminating a type of the received recording medium according to information recorded on the recording medium thereof;

reading the data including the digital watermark status from the received recording medium;

detecting the digital watermark status from within the data read from the recording medium;

determining that the read data should not be filtered, when it is discriminated that the received recording medium is of a first type and outputting the read data based on the determination that the read data should not be filtered;

determining whether or not the read data should be filtered based on the detected digital watermark status, when it is discriminated that the received recording medium is of a second type and outputting the read data based on the determination based on the digital watermark status that the read data should not be filtered; and

filtering part of the read data based on the discrimination based on the digital watermark status that the read data should be filtered and outputting the filtered data.

8. The data reproduction method according to claim 7, wherein the step of discriminating the type of the recording medium discriminates whether or not the received recording medium is a recording medium of the first type which is a recording medium for reproduction only or a recording medium of the second type which is a recordable recording medium.

9. The data reproduction method according to claim 7, wherein the step of discriminating the type of the recording medium discriminates whether or not the data recorded on the received recording medium is encrypted data to make a discrimination between a disk of the first type which includes encrypted data and a disk of the second type which includes no encrypted data.

10. The data reproduction method according to claim 9, wherein the step of discriminating the type of the recording medium reads out, in response to the installation of the recording medium, from a lead-in region of the recording medium and detects key information recorded in the lead-in region for decrypting the data recorded as encrypted data on the recording medium to discriminate that the data recorded on the recording medium is encrypted data.

11. The data reproduction method according to claim 7, wherein said filter processing means replaces part of the data with dummy data, which does not make sense as information, to filter the data.

12. The data reproduction method according to claim 11, wherein the data replaced with the dummy data is contents data.