Copyright protection system for data storage and transmission

• US 7,239,703 B2
• Filed: 08/13/2004
• Issued: 07/03/2007
• Est. Priority Date: 02/26/1999
• Status: Expired due to Term

• Current Assignee: JVC Kenwood Corporation
• Original Assignee: Victor Company of Japan Limited (JVC Kenwood Corporation)
• Inventors: Sugahara, Takayuki, Higurashi, Seiji
• Primary Examiner(s): Moise; Emmanuel L.
• Assistant Examiner(s): CALLAHAN, PAUL E
• Application Number:
  US10/917,489
• Publication Number:
  US 20050078937A1
• Time in Patent Office: 1,054 Days
• Field of Search: 380/201, 380/203, 380/239, 380/37, 380/240, 380/31, 705/57, 369/47.1, 369/47.12, 726/26, 726/30, 726/31, 725/31
• US Class Current: 380/203
• CPC Class Codes: H04L 12/40104 Security; Encryption; Content protection cryptographic protocols H04L9/00; protocols for network security H04L63/00
• CPC Class Codes: H04L 12/40117 Interconnection of audio or video/imaging devices home automation networks H04L12/2803; bitstream network arrangements specially adapted for distribution of digital video signals H04N7/24
• 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 2005/91364 the video signal being scrambled
• CPC Class Codes: H04N 5/913 for scrambling ; for copy protection
• CPC Class Codes: H04N 9/8042 involving data reduction

Abstract

The invention provides a recording media player and a recording media recorder provided with a high-security copy protection system of less complexity. A recording media player and/or recorder provided with a copy protection system stubborn to attacks and highly flexible in dealing with recording media of various copy conditions. For this purpose, various distributed copyright protection information (DCPI) values are used. The DCPI values include water marks in case of an MPEG stream, Copy Generation Management System (CGMS) codes, EMI (encryption mode indicator) in case of an IEEE1394-1995 interface, and user defined DCPI values. The recording is achieved such that DCPI values are recorded in user-unrewritable (or user-inaccessible) areas of the recording medium as long as possible.

Claims

1. A method of recording digital data that may be authenticated into a recording medium in a recording format, the method comprising the steps of:

recording in advance a first value into the recording medium in the recording format as data that cannot be output as a playback signal from a playback apparatus used for the recording medium; and

recording content data prepared to be played back, sync data and a second value into the recording medium in the recording format as the digital data that may be output as playback signals from the playback apparatus;

wherein the second value is placed at a position apart from the sync data by a first distance, a portion of the content data having a length of a predetermined number of bits is placed at a position apart from the sync data by a second distance, a value of an authenticator is determined according to a predetermined formula from the first value, the portion of the content data and the second value, and the second value is set so as to have the value of the authenticator equal a predetermined value.

2. The method according to claim 1, wherein the recording format comprises a non-rewritable area, and the first value is recorded in the non-rewritable area of the recording medium.

3. An apparatus for recording digital data into a recording medium, the apparatus comprising:

a sync data generator for generating sync data;

a first value generator for generating a first value in synchronization with the sync data;

a content data detector for detecting a portion of content data from a predetermined portion of a data stream in response to the sync data, the portion of content data having a length of a predetermined number of bits;

a second value generator for calculating a second value from the first value generated by the first value generator, the portion of content data detected by the content data detector and an authenticator preset at a predetermined value according to a predetermined formula;

formatting means for receiving the first value from the first value generator, the second value from the second value generator, the sync data from the sync data generator and the content data as the digital data, and formatting the first value, the second value, the sync data and the content data in a recording format by inserting the sync data and the second value into the content data so as to place the second value at a position apart from the sync data by a first distance and to place the portion of the content data at a position apart from the sync data by a second distance and by placing the first value at a predetermined position in the recording format; and

data recording means for recording the first value formatted by the formatting means into the recording medium as data that cannot be output as a playback signal from a playback apparatus used for the recording medium, and recording the content data, the sync data and the second value formatted by the formatting means into the recording medium as data that may be output as playback signals from the playback apparatus.

4. A method of playing back digital data of a recording medium by means of a playback apparatus, the method comprising the steps of:

detecting a first value which is recorded into the recording medium as data that cannot be output as a playback signal from the playback apparatus;

detecting sync data, content data and a second value which are recorded into the recording medium as the digital data that may be output as playback signals from the playback apparatus, the second value being placed at a position apart from the sync data by a first distance, a portion of the content data being placed at a position apart from the sync data by a second distance, a value of an authenticator being determined according to a predetermined formula from the first value, the portion of the content data and the second value, and the second value being set so as to have the value of the authenticator equal a predetermined value;

determining a calculated value of the authenticator calculated from the detected first value, the detected second value and the portion of the detected content data;

playing back the detected content data when the calculated value of the authenticator is equal to the predetermined value; and

prohibiting the playback apparatus from playing back the content data when the calculated value of the authenticator is not equal to the predetermined value.

5. An apparatus for playing back a recorded signal recorded into a recording medium in a recording format, wherein the recorded signal includes a first value recorded as data that cannot be output as a playback signal and a group of content data, sync data and a second value recorded as data that may be output as a playback signal, wherein the second value is placed at a position apart from the sync data by a first distance, wherein a portion of the content data is placed at a position apart from the sync data by a second distance, wherein a value of an authenticator is determined according to a predetermined formula from the first value, the portion of the content data and the second value, and wherein the second value is set so as to have the value of the authenticator equal a predetermined value, the apparatus comprising:

reading means for reading out the recorded signal from the recording medium;

a first value detector for detecting the first value from the record signal read out by the reading means;

a sync data detector for detecting the sync data from the recorded signal read out by the reading means;

a content data detector for detecting the portion of the content data from the recorded signal read out by the reading means in response to the sync data from the sync data detector;

a second value detector for detecting the second value from the record signal read out by the reading means in response to the sync data from the sync data detector;

a decoder for decoding the content data of the recorded signal read out by the reading means;

an authenticator calculator for calculating a value of an authenticator from the first value detected by the first value detector, the second value detected by the second value detector and the portion of the content data detected by the content data detector; and

a controller for outputting the content data decoded by the decoder when the calculated value of the authenticator is equal to the predetermined value, and prohibiting the outputting of the content data when the calculated value of the authenticator is not equal to the predetermined value.