Classifications

• • G—PHYSICS
  • G11—INFORMATION STORAGE
  • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
  • G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
  • G11B20/10—Digital recording or reproducing
• • G—PHYSICS
  • G11—INFORMATION STORAGE
  • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
  • G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
  • G11B20/00086—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy
  • G11B20/00094—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy involving measures which result in a restriction to authorised record carriers
• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
  • G06T1/00—General purpose image data processing
  • G06T1/0021—Image watermarking
• • G—PHYSICS
  • G11—INFORMATION STORAGE
  • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
  • G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
  • G11B20/00086—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy
• • G—PHYSICS
  • G11—INFORMATION STORAGE
  • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
  • G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
  • G11B20/00086—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy
  • G11B20/00731—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy involving a digital rights management system for enforcing a usage restriction
  • G11B20/00746—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy involving a digital rights management system for enforcing a usage restriction wherein the usage restriction can be expressed as a specific number
  • G11B20/00753—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy involving a digital rights management system for enforcing a usage restriction wherein the usage restriction can be expressed as a specific number wherein the usage restriction limits the number of copies that can be made, e.g. CGMS, SCMS, or CCI flags
  • G11B20/00768—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy involving a digital rights management system for enforcing a usage restriction wherein the usage restriction can be expressed as a specific number wherein the usage restriction limits the number of copies that can be made, e.g. CGMS, SCMS, or CCI flags 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
• • G—PHYSICS
  • G11—INFORMATION STORAGE
  • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
  • G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
  • G11B20/00086—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy
  • G11B20/00884—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy involving a watermark, i.e. a barely perceptible transformation of the original data which can nevertheless be recognised by an algorithm
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N5/00—Details of television systems
  • H04N5/76—Television signal recording
  • H04N5/91—Television signal processing therefor
  • H04N5/913—Television signal processing therefor for scrambling ; for copy protection
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N9/00—Details of colour television systems
  • H04N9/79—Processing of colour television signals in connection with recording
  • H04N9/80—Transformation of the television signal for recording, e.g. modulation, frequency changing; Inverse transformation for playback
  • H04N9/804—Transformation of the television signal for recording, e.g. modulation, frequency changing; Inverse transformation for playback involving pulse code modulation of the colour picture signal components
  • H04N9/8042—Transformation of the television signal for recording, e.g. modulation, frequency changing; Inverse transformation for playback involving pulse code modulation of the colour picture signal components involving data reduction
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N5/00—Details of television systems
  • H04N5/76—Television signal recording
  • H04N5/91—Television signal processing therefor
  • H04N5/913—Television signal processing therefor for scrambling ; for copy protection
  • H04N2005/91307—Television signal processing therefor for scrambling ; for copy protection by adding a copy protection signal to the video signal
  • H04N2005/91314—Television signal processing therefor for scrambling ; for copy protection by adding a copy protection signal to the video signal the copy protection signal being a pulse signal inserted in blanking intervals of the video signal, e.g. pseudo-AGC pulses, pseudo-sync pulses
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N5/00—Details of television systems
  • H04N5/76—Television signal recording
  • H04N5/91—Television signal processing therefor
  • H04N5/913—Television signal processing therefor for scrambling ; for copy protection
  • H04N2005/91307—Television signal processing therefor for scrambling ; for copy protection by adding a copy protection signal to the video signal
  • H04N2005/91321—Television signal processing therefor for scrambling ; for copy protection by adding a copy protection signal to the video signal the copy protection signal being a copy protection control signal, e.g. a record inhibit signal
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N5/00—Details of television systems
  • H04N5/76—Television signal recording
  • H04N5/91—Television signal processing therefor
  • H04N5/913—Television signal processing therefor for scrambling ; for copy protection
  • H04N2005/91307—Television signal processing therefor for scrambling ; for copy protection by adding a copy protection signal to the video signal
  • H04N2005/91328—Television signal processing therefor for scrambling ; for copy protection by adding a copy protection signal to the video signal the copy protection signal being a copy management signal, e.g. a copy generation management signal [CGMS]
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N5/00—Details of television systems
  • H04N5/76—Television signal recording
  • H04N5/91—Television signal processing therefor
  • H04N5/913—Television signal processing therefor for scrambling ; for copy protection
  • H04N2005/91307—Television signal processing therefor for scrambling ; for copy protection by adding a copy protection signal to the video signal
  • H04N2005/91335—Television signal processing therefor for scrambling ; for copy protection by adding a copy protection signal to the video signal the copy protection signal being a watermark

Definitions

• the present invention relates to a method of recording media data on a recording medium, a method and a system for accessing media data stored in the recording medium, and in particular, embedding management information in the media data, It relates to controlling access to data based on this management information at the time of access.
• an object of the present invention is to provide a system that can control access to data and can effectively prevent illegal copying of data.
• a first invention is a method of recording media data on a recording medium, wherein an embedding area for embedding management information for controlling access to the media data is embedded in the media data.
• a step of specifying, and referring to an embedding rule in which the content of the data to be embedded is associated with the state of the embedding area, and operating the state of the embedding area in accordance with the management information. Embedding the data in the data; recording the media and data in which the management information is embedded in the recording medium;
• This management information may be information for controlling the copying or playback of media data, and in this case, the management information indicates whether the copying of media data is prohibited or the copying of media data is permitted. It may be represented by 1 bit. In addition, this management information is represented by a plurality of bits indicating whether to prohibit copying of media 'data, permit copying of media' data, or permit only one-time copying! Good.
• the second invention is a method of accessing media and data stored on a recording medium.
• the step of reading media ⁇ data in which management information for controlling access to media ⁇ ⁇ ⁇ data is read from the recording medium, and the embedding in which management information is embedded from the read media data A step of specifying an area and a step of extracting management information according to the state of the embedding area by referring to an extraction rule corresponding to the content of the data for extracting the state of the embedding area; ⁇ Provided is a method of accessing data, which has a step of outputting read data and outputting data only when the content has a content that permits data access.
• the step of outputting the media data may further include the step of changing the content of the management information in the read media data.
• a step of reading media data in which management information for controlling copying or reproduction of media data is embedded from the recording medium A step of specifying an embedded area in which management information is embedded from the read media and data, and referring to an extraction rule corresponding to the contents of the data for extracting the state of the embedded area. Extracting the management information according to the state of the embedding area; outputting the read media data if the management information has a function of permitting the copying or reproduction of the media data; If there is any content that prohibits the copying or reproduction of the media data, copy the media data The other is to provide the media data of the access method and a step to prohibit playback.
• the method further includes the step of changing the content of the management information in the read media data when the conditions for copying or reproducing the media data change due to the access to the media data. .
• a fourth aspect of the present invention in a system for accessing data of a medium stored on a recording medium, embedded information in which management information for controlling copying or reproduction of the medium data is embedded from the supplied medium data.
• a means for extracting the management information according to the state of the embedding area and a method for extracting the access interference signal Means to generate and, if the management information has contents permitting copying or reproduction of media / data, output a read signal and prohibit the management information from copying or reproducing the media / data.
• Access ⁇ system of media data that has to provide.
• the system may further include a change unit that changes the content of the management information in the read data. Further, when the condition for copying or reproducing the media data is changed by accessing the media data, the changing means changes the content of the management information in the read data.
• this management information is information expressed as 1 bit, which indicates either prohibition of copying of media data or permission of copying of media data
• the management information permits the copying of media and data. It may be the case that it has contents to do.
• management information is embedded in the media data stored in the recording medium.
• This management information includes, for example, conditions for playing or copying media data, history of playing or copying,
• FIG. 1 is a diagram showing a procedure for recording media data on a recording medium.
• FIG. 2 is a diagram for explaining data hiding and extraction using PBC.
• FIG. 3 is a diagram for explaining PCB-based hiding when one pixel is a pixel block.
• FIG. 4 is a diagram showing a procedure for accessing media data recorded on a recording medium.
• Figure 5 is a block diagram of the media 'data access' system.
• FIG. 6 is a diagram for explaining an arrangement state of pictures in the MPEG.
• FIG. 7 is a diagram showing a state of a macro block arranged in a B picture.
• FIG. 8 is a block diagram of a media data access system according to another embodiment.
• FIG. 1 is a diagram showing a procedure for recording media data on a recording medium.
• Media data such as images, sounds, and software are recorded on DVD-ROM media according to the following procedure.
• Analog 'data, media' data is converted to digital data by performing analog / digital conversion processing (step 11).
• the converted digital data is compressed using, for example, a Moving Picture Experts Group (MPEG) (step 12).
• MPEG Moving Picture Experts Group
• the compressed data is further encoded, encrypted (step 13), and modulated (step 14), and recorded on the DVD-ROM medium.
• MPEG Moving Picture Experts Group
• the media data is stored in the DVD-ROM after the management information is embedded in the media and data.
• This management information is used to restrict access to this data when the system accesses media data stored in the DVD-ROM. Based on this management information, the system is controlled. You.
• management information for managing a copy of media data will be described as an example.
• each status is represented by the following 2-bit data.
• the embedding of management information into data is performed, for example, between analog-to-digital conversion (step 11) and MPEG compression (step 12).
• This embedding can be performed by a technique called data hiding.
• a method of embedding management information to be concealed in certain media data and a method of extracting embedded data in the form of pixel block coding (Pixel
• PBC Block Coding
• PBC data hiding and extraction
• media data is processed according to a predetermined conversion rule.
• primary characteristics such as pixel values of two adjacent pixels have a high correlation with each other.
• adjacent pixels are very similar green and have a high correlation with each other. Therefore, even if these pixels are replaced, it will be almost impossible to visually recognize the replacement. That is, even if pixel values having a high correlation are operated according to a certain rule, there is almost no deterioration in visual image quality.
• this algorithm defines an image region having at least one pixel as a pixel 'block (embedded region), and intentionally manipulates the characteristics of adjacent pixel' blocks based on a certain conversion rule. By doing so, it hides 1-bit data.
• the data is expressed as a result of comparing the characteristics of adjacent pixel blocks.
• data is extracted according to the extraction rules determined based on the conversion rules.
• the bit information is expressed by exchanging the characteristics (eg, luminance values) of two adjacent pixel blocks according to the following conversion rules.
• Bit “1” if the value of one pixel 'block (PB 1) characteristic' 14 is greater than the characteristic value of the other pixel (PB 2)
• Bit “0” the pixel of the other side. If the characteristic value of the block (PB1) is smaller than the characteristic value of the other (PB2)! / If the bit information is as follows corresponding to the above conversion rule According to the extraction rules, it is extracted by comparing the characteristic values (eg, brightness values) of two adjacent pixel blocks.
• FIG. 2 is a diagram for explaining data hiding and extraction using PBC. is there.
• Pixel 'blocks PB 1 and PB 2 may be defined as a group of a plurality of pixels, for example, 3 ⁇ 3 pixels, or one pixel may be defined as one pixel block. Adjacent pixel blocks have a high correlation, so we can swap their positions
• the characteristic value in addition to the luminance value as described above, a value relating to the primary characteristic and a value relating to the secondary characteristic of the pixel 'block (embedded area) can be used.
• Primary characteristics are direct parameters of pixel values, such as the luminance and chromaticity of a pixel block.
• the secondary characteristic is obtained by decomposing the primary characteristic, such as a value indicating a statistical property such as an average value and a variance of the parameter.
• the first order characteristic has a high correlation between two adjacent pixel blocks.
• the quadratic characteristic can have a high correlation in two blocks that are not adjacent to each other. Therefore, it should be noted that the pixel block to be subjected to PBC is not necessarily limited to an adjacent block. Below, the pixel 'block
• FIG. 3 is a diagram for explaining embedding of 6-bit data into six pixel blocks using PBC when one pixel is a pixel block.
• the characteristic value is a variance value.
• a pixel block is composed of n x m plane elements, if the pixel brightness value is switched between blocks, the image quality will be greatly degraded, such as the occurrence of stripes on the image. Therefore, it is not preferable to use the pixel value as it is as the characteristic value of the block. Therefore, a method using the variance value of the pixel luminance as the characteristic value is conceivable.
• Pixels When the properties of a block's luminance value are decomposed into an average value h and a variance value d, the effect on image quality even if only the variance value d is replaced with the average value h in the adjacent pixel block Is less. Therefore, by making use of this property, the characteristic value of the pixel block is set as the variance d, and the variance d is replaced according to the conversion rule, whereby the data can be hidden.
• an embedding area in which management information is embedded is specified in the media data. Then, the content of the data to be embedded is
• a conversion rule corresponding to (characteristic) is prepared, and the state (characteristic) of the embedding area is directly manipulated according to the management information with reference to this rule.
• This allows management information to be embedded in media data.
• management information integrated with the original media and data is embedded. Therefore, it is difficult to separate and modify only the management information, so that access control of media and data can be effectively performed.
• PBC is described in detail in a Japanese patent application (Japanese Patent Application No. 8-159330 (internal serial number J A996-044)).
• the management information is embedded using the above PBC, and the media 'data stored in the DVD-ROM is accessed by the following procedure.
• FIG. 4 is a diagram showing a procedure for accessing media data recorded on a recording medium.
• the data supply source is, for example, a storage medium such as DVD-ROM or CD-R, communication such as the Internet, or satellite broadcasting.
• the supplied data is demodulated (step 41) and decoded (step 42). If the data is MPEG compressed,
• Step 4 3 Media 'Extract the management information embedded in the data, change the content of the management information if necessary, and embed it again in the media data. Then, the media 'data is subjected to digital-to-analog conversion processing (step 44), whereby an analog reproduced signal is obtained.
• the embedding area in which the management information is embedded is specified from the read data.
• the management information is extracted according to the state of the embedding area by referring to the extraction rule corresponding to the data content for extracting the state of the embedding area.
• the extracted management information is data “0 0”
• the copying of the media data is permitted according to the above rules.
• the data is "1 1”
• Data "10J means that the media data can be copied conditionally (once), and this means that it is based on the media 'data in the original DVD-ROM.
• a copy is allowed, but further copying based on this copy is prohibited, in which case the media '' controls the access system to allow only one copy of the data, and the copied media.
• the data must be sourced and the media must be further protected from being copied
• the original copy is important because it is important to prohibit further copies based on duplicates of the original Occasionally, the copy conditions indicated by the management information embedded in the original media data can be changed from the data "10" (can be copied only once). And rewrites the chromatography data "1 1" (copy prohibited) as the output signal. In the media data as this output signal, "copy prohibited j
• FIG. 5 is a block diagram of a system for accessing media data stored in the DVD-ROM.
• the management information is embedded in the DVD-ROM 51 set in the media data supply unit 61 by directly operating the media data using the data hiding technology.
• the embedded encrypted and modulated data is stored.
• the data read from the read unit 52 in the media ′ data supply unit 6 1 is converted by the demodulator 53, the encryption / decryption unit 54, and the MPEG decoder 55 into the signal processing system 62. It is processed. This yields the decompressed digital data.
• the management information extractor 56 specifies the embedding area in which the management information is embedded from the decompressed digital data output from the MPEG decoder 55, and adds the content of the data to extract the state of the embedding area. By referring to the associated extraction rule, management information is extracted according to the state of the embedding area.
• the DZA converter 57 in the signal processing system 62 converts the digitized media data from which the management information has been removed into an analog signal, and outputs an analog playback signal (for example, NTSC).
• the management information changer 58 is for changing the copy condition indicated by the management information as necessary as described above.
• the access interference signal (for example, APS such as Macrovision Signal) generated by the access interference signal generator 60 is selectively superimposed on the analog reproduction signal by the switch 59 in the output unit 63.
• the switch 59 is controlled by a control signal from the management information extractor 56.
• the output unit 63 outputs the analog reproduction signal or the superimposed signal as an analog output signal.
• the management information extracted by the management information extractor 56 is the management information extracted by the management information extractor 56
• the management information extractor 56 If the information permits copying of the media 'data, the management information extractor 56 outputs a control signal to turn off the switch 59. In this case, the access interference signal is not superimposed on the analog reproduction signal, and the analog reproduction signal is output as it is. on the other hand. If the management information prohibits the copying of the media 'data, the management information extractor 56 outputs a control signal to turn on the switch 59. In this case, a signal in which the interference signal generated by the access interference signal generator 60 is superimposed on the analog signal from the 08 converter 57 is output.
• the management information changer 58 changes the management information in the read data to “copy prohibited” and replaces the information with the read data. Embed. As a result, subsequent data copying based on the copied data can be effectively prevented.
• management information is not limited to the information related to copy restrictions, but can be applied to various management information that controls the system! Reproduction permission information may be used.
• the playback permission information permits the playback of media / data, the playback of media / data is allowed, and if the playback of media / data is prohibited, the media ⁇ Perform control so that data is not output from the system. If it can be played back only once, the media and data are allowed to be played back, and the embedded playback permission information is changed from data “10” to data “11” using data hiding technology. Change.
• the management information may be an expiration date that defines a period during which the media data can be reproduced or recorded, authentication information for reproducing the media content, a disc key, a title key, and the like. Each piece of information is the data needed to access media data.
• N / A Play OK Copy NG 10 1 "0" in the above additional information indicates that no copy has been made, and "1" indicates that copy has been performed once.
• NZA on ROM-type playback media means that this combination does not exist. That is, in addition to the data 11 (unconditional duplication is not possible), 10 (one-time duplication is possible), and 00 (unconditional duplication is possible), additional information indicating whether or not the force was copied once
• the additional information may be embedded using the same embedding method as the previously embedded data (management information), or may be embedded using another embedding method to enhance security.
• the additional data may be not limited to one bit but may be controlled more variously by using a large number of bits.
• the present invention can be similarly implemented without departing from the essence of the present invention.
• FIG. As shown in this figure, in order to realize bidirectional prediction, MPEG defines three types of frames: I picture, P picture, and B picture.
• the I picture is a picture that has been subjected to intra-coding (intra-coding), and all macroblocks in this picture have been subjected to intra-coding (predictive coding within a frame).
• a P picture is an image that has been subjected to inter-frame forward prediction coding, but some macro blocks in this picture may be intra-coded.
• a B picture is an image that has been subjected to inter-frame bidirectional predictive coding. Macroblocks in a B picture are basically coded by forward prediction, backward prediction, or bidirectional prediction, but may include intra-coding.
• the screen for intra-coding the entire screen is an I picture, and the I picture and P picture are coded in the same order as the moving picture.
• the B picture encodes the B picture inserted between them after processing the I picture and the P picture.
• FIG. 7 is a diagram showing a state of a macro block arranged in a B picture.
• a macroblock is a unit to be encoded. For each macroblock, motion compensation is performed on the luminance block of 16 pixels x 16 pixels, and a motion compensation inter-frame prediction method is performed on a macroblock basis, and information compression based on temporal screen correlation is performed.
• Macroblocks in a B picture can be classified into the following four types of prediction.
• Intra macroblock Intra-frame prediction macroblock This is a macroblock that does not perform inter-frame prediction and is coded using only the information of the screen itself.
• This macroblock is forward-predicted by referencing a past I-picture or P-picture (reference frame). Specifically, a 16-pixel X 16-pixel square area that is the most similar in the past reference frame is searched, and the prediction error ( ⁇ ), which is the difference from the square area, and the spatial relative It has information about the position (motion vector).
• the prediction error ⁇ is expressed as a difference between luminance and chrominance of 16 pixels ⁇ 16 pixels. It is up to the encoder to determine the criteria for selecting a similar square area.
• This macroblock is subjected to backward prediction encoding by referring to a future reference frame in the display order. It searches for the most similar area in the future reference frame, and has information about the prediction error ( ⁇ ), which is the difference with that area, and the spatial relative position (motion vector).
• At least one macroblock to be embedded must be specified in the picture. This may be defined, for example, as each macroblock (embedded area) existing in the first to third lines of a picture, or may be the entire macroblock in a certain frame. As described above, in addition to the format being defined in advance, the format can be determined using an algorithm for generating a position sequence. The algorithm for generating the position sequence can use, for example, the algorithm disclosed in Japanese Patent Application No. 8-159330 (internal reference number JA996-444).
• 1-bit data is embedded into one macroblock based on the embedding rule for the macroblock specified as the target of embedding processing. This embedding rule associates bit information with the type of macroblock prediction, and includes, for example, the following rules.
• Bit information to be embedded Macro inter-frame prediction type bit 1 ”bidirectional prediction macroblock (represented by B) bit, 0” forward prediction (represented by P), or
• Backward prediction macroblock (represented by N) For example, consider a case where management information “1 0 1 0” is embedded. This 4-bit data is transferred to the first to fourth 4
• the prediction type of the leftmost macroblock is determined to be bidirectional prediction (B) according to the embedding rules.
• the prediction error in this case is a prediction error that is a difference between the average of the most similar area in the past reference frame and the average of the most similar area in the future reference frame.
• the next data is bit "0". Therefore, according to the embedding rules, the prediction type of the second macroblock (second embedding region) is either forward prediction (P) or backward prediction macroblock (N).
• the prediction error in the forward prediction and the prediction error in the backward prediction are compared, and a type having a small prediction error is selected.
• the forward prediction (P) is selected because the prediction error in the forward prediction is smaller than that in the backward prediction.
• a similar procedure is repeatedly applied to the third and fourth embedded regions. That is, the prediction type of the third macroblock from the left is bidirectional prediction (B), and the prediction type of the fourth macroblock is backward prediction (N) because the prediction error in backward prediction is smaller. It is determined.
• management information “1100” was embedded in these areas.
• a method of extracting the management information embedded by the above procedure will be described.
• information for specifying the macroblock in which the management information is embedded must be provided. This can be given as information from the outside or embedded in the data itself in advance.
• position of the embedding area is standardized,
• the embedded information is extracted by referring to the extraction rule from the prediction type in the specified embedding area.
• This extraction rule associates the macroblock prediction type with bit information and must be given as information at the time of extraction.
• the rules include, for example, the following rules. Note that the correspondence between the prediction type and the bit information in this extraction rule corresponds to that of the embedding rule described above.
• Bidirectional prediction macroblock Bit "1" Forward prediction (represented by P) or bit, 0 "Backward prediction macroblock As shown in Fig. 7 It is assumed that it is known that the management information is embedded in the first to fourth macroblocks on the left of the first line in FIG. Since the prediction type of the leftmost macroblock is bidirectional prediction (B), bit “1” is extracted by referring to the extraction rule. The prediction type of the second macroblock is forward prediction (P) Therefore, the bit “0” is extracted according to the extraction rule, and the same procedure is repeatedly applied to other macroblocks, so that the bits “1” and “0” are sequentially extracted. It is. As a result, the management information "1 0 1 0" is extracted from the these regions.
• the management information is embedded in the data of the media using the data hiding method, and the management information is embedded when accessing the data of the media (playback, recording, etc.). It is characterized in that it controls the system to manage media data access based on the system. Therefore, it should be particularly noted that the present invention is not limited to the data 'hiding method as disclosed above, but is applicable to various methods.
• the embodiment described here is a one-bit management information that intends to give substantially three statuses to the system. It is.
• the system according to the present embodiment has a controller 81 that detects the state of media data being supplied to the system and controls the output of the system according to the state.
• the media data supply device 82 is for supplying media data in which management information is embedded to the access system.
• Management information Optical systems that read data, and circuits that take data on the Internet into the system.
• the management information is represented by 1-bit data indicating the following information.
• Copy permission 0 Media ⁇ Data supplied from the data supply device 82 is processed by the signal processing system 83 that performs demodulation, encryption decryption, DZA conversion, and the like.
• the management information extraction unit 84 identifies the embedded area in which the management information is embedded from the media data processed by the signal processing system 83, and associates the state of the embedded area with the contents of the data to be extracted.
• the management information is extracted according to the state of the embedding area by referring to the extracted extraction rule.
• the management information extractor 84 outputs a control signal according to the extracted information. This control signal is for controlling the output device 85, and selectively superimposes the access disturbing signal generated by the access disturbing signal generator 86 on the output signal in accordance with the content thereof and outputs it. I do.
• the controller 81 is connected to the media
• Replacement form (Rule 26) It monitors how data is being fed into the access system. Then, even if the management information is bit "0", that is, even if the copying of the media data is permitted, the switch in the output unit 85 is turned on in accordance with the result of the supply state, and the superimposition is performed. The output device 85 is controlled so that the output signal is output. In other words, even though the management information itself permits the copying of media data, the copying of data is forcibly prohibited.
• the specific media data supply state is, for example, "When media data is taken into the access system via a recording medium, the set recording medium can be read, only, and rewritten at the time of copying.
• the type of recording medium can be easily monitored in the non-tamperable area (lead-in 'area) of the recording medium because the system can recognize it as hardware. If data is supplied from a read-only recording medium and data is copied, the controller 81 does not forcibly control the switch.
• the access system operates according to the management information provided, and data can be copied as long as the management information permits copying. On the other hand, if data is to be copied while data is being supplied from a rewritable recording medium, the controller 81 turns on the switch regardless of the contents of the management information. Data cannot be copied from a possible recording medium! / ,.
• the content supplier stores it in the ROM and distributes it. Therefore, the fact that the supply state is in ROM format means that the data is the original, not a duplicate.
• the embedded management information can be represented by one bit instead of two bits, there is no need to consider the order of the bits, other than the problem of the size of the management information.
• the management information is 2 bits, if the bit arrangement is different between "01" and "10", it is necessary to consider the order in extracting the information. Then you don't need this. Therefore, there is an effect that the extraction accuracy of the management information is significantly improved.
• the supply status to be monitored may be "if media data is captured via communication, broadcast, etc., whether or not the access system is connected to the network at the time of copying.” . In this case, if the data is connected to the network at the time of copying, it can be regarded as the original data.
• the provider distributes the content to the general public.
• the access system that receives the content has the function of extracting the management information embedded in the content and controlling the access to the content according to the access conditions defined by the access system. Therefore, access to the content by the recipient, particularly illegal copying of the content by the recipient, can be effectively prohibited in the recipient's system.

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• Engineering & Computer Science (AREA)
• Signal Processing (AREA)
• Computer Security & Cryptography (AREA)
• Multimedia (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Theoretical Computer Science (AREA)
• Television Signal Processing For Recording (AREA)
• Signal Processing For Digital Recording And Reproducing (AREA)
• Storage Device Security (AREA)

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• 1997
  • 1997-06-30 WO PCT/JP1997/002286 patent/WO1998016927A1/ja active Application Filing
  • 1997-08-12 KR KR1019997002167A patent/KR100329897B1/ko not_active IP Right Cessation

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