Copyright protection system for data storage and transmission

• US 20050078937A1
• Filed: 08/13/2004
• Published: 04/14/2005
• Est. Priority Date: 02/26/1999
• Status: Active Grant

• Current Assignee: JVC Kenwood Corporation
• Original Assignee: Victor Company of Japan Limited (JVC Kenwood Corporation)
• Inventors: Sugahara, Takayuki, Higurashi, Seiji
• Granted Patent: US 7,239,703 B2
• Time in Patent Office: Days
• US Class Current: 386/234
• 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

1-40. -40. (canceled)

41. A method of recording digital data possible to 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 impossible to be outputted 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 possible to be outputted 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 in the recording format, 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 in the recording format, 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.

42. A method according to claim 41, wherein the recording format comprises an unrewritable area, and the first value is recorded in the unrewritable area of the recording medium.

43. 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 in the recording format and to place the portion of the content data at a position apart from the sync data by a second distance in the recording format 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 impossible to be outputted 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 possible to be outputted as playback signals from the playback apparatus.

44. 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 impossible to be outputted 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 possible to be outputted as playback signals from the playback apparatus, the second value being placed at a position apart from the sync data by a first distance in the recording format, a portion of the content data being placed at a position apart from the sync data by a second distance in the recording format, 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.

45. 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 impossible to be outputted as a playback signal and a group of content data, sync data and a second value recorded as data possible to be outputted as a playback signal, wherein the second value is placed at a position apart from the sync data by a first distance in the recording format, wherein a portion of the content data is placed at a position apart from the sync data by a second distance in the recording format, 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.

46. A recording medium, which is of a magnetically recordable and writable type and is formed in a tape or disc shape, which is of a type writable by means of an optical beam and is formed in a disc shape, or which acts as a memory, the recording medium comprises:

a first area in which a first value is recorded in a recording format as data impossible to be outputted as a playback signal from a playback apparatus used for the recording medium; and

a second area in which content data prepared to be played back, sync data and a second value are recorded in the recording format as data possible to be outputted as playback signals from the playback apparatus so as to place the second value at a position apart from the sync data by a first distance in the recording format and to place a portion of the content data having a length of a predetermined number of bits at a position apart from the sync data by a second distance in the recording format,

wherein the second value is set to equal a predetermined value determined according to a predetermined formula from the first value, the portion of the content data and an authenticator having a preset value.

47. A recording medium according to claim 46, wherein the content data is compressed and encoded according to an MPEG (moving picture experts group), the second value is recorded in a user data field prescribed by the MPEG, a private data byte field prescribed by the MPEG or a data packet defined as a private stream.

48. A recording medium according to claim 46, wherein the first area denotes an unrewritable area, and the second area denotes a rewritable area.

49. A recording medium according to claim 46, wherein the recording medium is a read only medium, and the first value is recorded in a user-unwritable area for which handling of a user is not permitted.