JP2008269032A - Management system, management method and use device for digital content data - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To properly restrict the unauthorized playback of content by verifying the identity of managed known digital content data with unknown digital content data to be played back at a user side. <P>SOLUTION: A first function calculation means 111 calculates element data D11 and D12 from known or unknown digital content data D1 and D2 by calculating a first function, a second function calculation means 112 calculates digest data D21 and D22 from the known or unknown digital content data D1 and D2 by calculating a second function, a first comparison means 121 compares the identify of the element data and a second comparing means 122 compares the identity of the digest data, and the identity of the known digital content data and unknown digital content data is judged according to the comparison result. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a technique for verifying the identity between known digital content data and unknown digital content data. For example, the present invention decompresses digital data that has been compressed using a technique for irreversibly compressing digital data, and then compresses again. The present invention relates to a digital content data management system, a management method, and a utilization apparatus for verifying the above.

  In recent years, when compressing digital contents, lossless compression has resulted in a large compression ratio and data size reduction technology has been developed, and there are a large amount of data in limited bandwidth transmission lines and storage media. Digital content can be transmitted and recorded, and the development of communication networks makes it easy to send and receive digital data via communication networks, and distribution and sales of content via communication networks. Has also become popular.

  By the way, the lossless loss in the digital content business is caused by the irreversible exchange of the irreversibly compressed digital data.

  In this regard, there is a method using a hash function as a method for evaluating the completeness and correctness of digital data having a relatively large size without examining all the contents of the digital data (see, for example, Patent Document 1). In addition, there is a technique for verifying autocorrelation at a certain level or more even when digital data are not completely identical (for example, Patent Document 2), and one of them is a fingerprint technique (for example, Patent Document). 3).

A player device that plays back digital content can play back digital content data compressed by a widely used lossy compression technique. By using the above-described means for verifying the validity, By verifying the legitimacy, it is possible to limit unauthorized management of content managed by a digital content business or the like.
JP 2001-75868 A JP 2006-295473 A JP-T-2004-505328

  However, in the method using the hash function, since the irreversible hash values are compared with each other by a one-way function, the compared contents must be completely the same, and the irreversibly compressed digital content data is decrypted. It was difficult to verify the deteriorated digital data obtained by re-compressing by an arbitrary method later or by digitally converting the content converted into analog data.

  On the other hand, according to the technology for verifying autocorrelation of a certain level or higher, such as the fingerprint technology, by comparing digest data (fingerprints) calculated based on the characteristics of the contents of digital data, The same fingerprint as the original (known) digital data can be detected even from degraded digital data that is not exactly the same, and the identity of these fingerprints is verified by comparing the known and unknown fingerprints. In the player device, it is possible to limit the reproduction of content having a certain level of identity with the managed content.

  However, if only managed content can be played back, and playback of other content is uniformly restricted, for example, there is a problem that content that is not managed by the service or content created by the user cannot be played back. There are many player devices that can reproduce unmanaged digital content in the same way as managed digital content, and it has not been possible to thoroughly restrict the reproduction of illegally distributed content.

  Therefore, the present invention solves the above-described problem, and for the content managed by the content distribution service, the managed known digital content data and the unknown digital data to be reproduced on the user side. It is an object of the present invention to provide a digital content data management system, management method, and utilization device that can verify identity with content data and appropriately limit the reproduction of illegal content.

The present invention is a digital content data management system and management method having a function of verifying the identity of known digital content data and unknown digital content data,
(1) By calculating the first function by the first function calculating means, the element data extracted from the known or unknown digital content data based on the characteristics relating to the contents of the digital content data is calculated; By calculating the second function by the second function calculating means, the digest data extracted based on the bit sequence of the digital content data is calculated from the known or unknown digital content data,
(2) The element data extracted from each of the known and unknown digital content data is compared by the first comparing means, and the known and unknown digital content data is compared by the second comparing means. A comparison step for comparing the sameness between the digest data extracted from (3) the known digital content data and the unknown digital content data by the determination means according to the comparison results of the first and second comparison means, respectively. The identity is determined. For example, when the first comparison means detects a match and the second comparison means detects a mismatch, the known digital content data and the unknown digital content data are similar but identical. It is determined that it is not.

  According to the present invention, first, by using the first function, elements extracted from known digital content data and unknown digital content data to be reproduced based on characteristics relating to the contents of each digital content data By extracting the data and comparing them with the first comparison means, it is possible to determine whether or not the content related to reproduction is the managed content itself or a derivative thereof. As a result, since the content created by the user does not match in the first comparison means, it can be avoided that the reproduction is restricted by mistake.

  When the first comparison means indicates coincidence, the digest data obtained based on the bit arrangement is calculated using the second function, and these are compared by the second comparison means. Control playback. That is, with respect to unknown digital content data that is assumed to be similar derived content from known digital content data, reproduction of digital content data whose bit arrangement matches that of known digital content data is restricted. As a result, when digital content data is illegally taken out from a protected distribution channel storing digital content data that has been properly distributed and copied or distributed, the digital content data is processed in the process. Can be detected and the reproduction of illegal data can be restricted.

  In the above invention, prior to (1) above, when the digital content data is input to the first function by the conversion means, the digital content data input to such an extent that the output value of the first function is not changed. The distribution data and the verification data are generated from the arbitrary digital content data by the third function having the characteristic of modifying the data, and the verification data is converted into the inverse of the third function by the inverse conversion means on the service provider side. Inverse transformation may be performed by a function that performs processing, and the inversely transformed data may be input to the first function computation unit and the second function computation unit as the known digital content data.

  At the same time, in the above (2), the distribution target data is inversely transformed by the verification object acquisition means on the use device side, and the inversely transformed data is converted from the unknown digital content data to the first and The unknown element data and the unknown digest data calculated by the second function are stored and held, the unknown element data is input to the first comparison means, and the unknown digest data is input to the second comparison means To do.

  Here, as the third function and the inverse process, irreversible compression / decompression widely used for compression / decompression of digital contents and the like can be used. For example, compression methods such as ISO / IEC 11172-5, ISO / IEC 13818-5, ISO / IEC 14496-5, ISO / IEC 11172-3, ISO / IEC 13818-7, ISO / IEC 14496-3, etc. Those defined in the MPEG standard or those having similar effects may be used.

Further, by compressing the digital content that has been subjected to compression processing into distribution data, and in the data utilization device that receives this, the decryption processing and the decompression processing for decrypting the encryption are implemented in the data utilization device in a form that is difficult to separate. Prevents unauthorized distribution of unencrypted distribution data from the user device, and always re-compresses the decompressed data if the user replicates data in a compressed format or performs unauthorized distribution. There is no way to. As a result, the element data obtained by inputting into the first function is the same as the data obtained from the distribution data, but the digest data obtained by inputting this into the second function is obtained from the distribution data. By making it different from what is obtained, it is possible to control the reproduction of illegally distributed content.

  Furthermore, in the said invention, you may make it change the conversion conditions at the time of performing the said conversion process regularly or irregularly in the said conversion means. As described above, in the conversion process, for example, by changing the conversion conditions such as the compression method every time, it is possible to make the compression method difficult to analyze, and to make the system safer. Here, changing the compression method means partially changing the assignment of the code amount to each data included in the compressed data by a method such as changing the quantization width of the parameter, or giving a bias. It is desirable that the compression method itself is not changed and the quality of the digital content data after decompression is not significantly impaired.

  Note that there is a case where there is a difference in data to be output even when a compression unit that executes a digital content data compression method that has been widely used has adopted a similar compression method. However, the difference in the data obtained by inputting these different output data to the decompression means can be stored to the extent that the quality is not impaired when a human views it. The third function can be set so that the data obtained by inputting to the first function is the same.

  In the above invention, in the above (1), a plurality of element data of known digital content data extracted by the first function calculation means are stored in the element data storage section, and the known digital data extracted by the second function calculation means is stored. A plurality of digest data of content data is stored in the digest data storage unit, and in the above (2) and (3), the same element data as the element data of the unknown digital content data extracted by the first function calculation means Is stored in the element data storage unit, the data identification information recorded in association with this is read, and the digest data recorded in association with the same data identification information as the read data identification information is digest data. Read from the storage unit, extracted by the read digest data and the second function calculation means Compared to the unknown digest data of the digital content data, it may be controlled playback If they do not match.

  In the above invention, distribution data may be distributed from a distribution device through a transmission path such as a communication network, and element data and digest data may be distributed. In this case, when distributing and selling arbitrary managed content data through the communication network, the digital content data using apparatus according to the above methods (2), (3) and (4) Only when it is not altered, it can be played back, and the digital content data can be managed so that it is properly transmitted and played back.

  In the above invention, from the data use means using the distribution data, the digital content data related to the use, or the element data and the digest data of the digital content data related to the use are transmitted to the verification target acquisition means, and the determination result by the determination means The digital content data related to the use may be output by the output means provided in the data use means according to the obtained determination result. In this case, the element data and digest data are extracted on the data utilization means side such as the player device and transmitted to the management side, so that the utilization means side does not increase the burden on the management side device. It is possible to appropriately manage and restrict the playback of content.

  As described above, according to the present invention, for the content managed by the content distribution service, the identity between the managed digital content data managed and the unknown digital content data to be reproduced on the user side It is possible to appropriately limit the reproduction of unauthorized content.

[First Embodiment]
Exemplary embodiments of a digital content data management system according to the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a conceptual diagram showing an overall configuration of a digital content data system according to the first embodiment.

(Outline of this embodiment)
In this embodiment, the user who uses the distributed digital content data, the element data D12 obtained by executing the first function on the digital content data D2 to be used, and the element on the management side (service providing side) When the data D11 is compared and the two match, the digest data D22 obtained by executing the second function on the digital content data D2 to be used is compared with the digest data D21 on the management side. If not, a system including a digital content data distribution device that can detect that the distributed data D2 has been altered is configured.

  In the present embodiment, the first function sets the quality of the digital content data so as to output a value that does not change even when the input digital content data is modified to the extent that the human content is viewed. It shall have the characteristic which extracts the element which governs. Further, the second function has a characteristic that the value to be output is changed when any one bit of the input digital content data is changed.

  In this embodiment, a recording unit 120 is provided in the digital content data distribution apparatus on the management side, and this recording unit 120 can be accessed by a user who receives the distributed digital content data.

  Then, when distributing the digital content data, a function calculating unit 111 that executes the first function so that a user who receives the distributed digital content data can check whether the received digital content data has been altered. The element data D11 is calculated from the digital content data D1 and recorded in the recording means 120. In addition, the function calculation means 112 that executes the second function calculates the digest data D21 from the digital content data D1 and records it in the recording means 120.

  Then, the user who uses the distributed digital content data, the element data D12 obtained by executing the first function on the digital content data D2 to be used, and the element data D11 recorded in the recording means 120. Are compared with each other, the digest data D22 obtained by executing the second function on the digital content data D2 to be used is compared with the digest data D21 recorded in the recording means 7, If they do not match, it is detected that the distributed data D2 has been altered.

(Configuration of digital content data management system)
Specifically, as shown in FIG. 1, the digital content data management system is a digital content data management system having a function of verifying the identity of known digital content data D1 and unknown digital content data D2. This is a management system, and generally includes a first function calculation unit 111, a second function calculation unit 112, first and second comparison units 121 and 122, and a determination unit 131. The “module” used in the description refers to a functional unit that is configured by hardware such as an apparatus or a device, software having the function, or a combination thereof, and achieves a predetermined operation. .

  The first function calculating unit 111 calculates element data D11 and D12 extracted based on characteristics relating to the contents of the digital content data from the known or unknown digital content data D1 and D2 by calculating the first function, respectively. This is a module to calculate. Specifically, the first function has a characteristic of extracting an element that controls the quality of digital content data when a person views the input digital content data, and is modified so as not to impair the quality. For example, a function that outputs a value that does not change, for example, a function that calculates a value (fingerprint) based on characteristics related to the contents of digital content data such as sound or video can be employed. This first function calculation means 111 uses the same finger as the original digital data even from degraded digital data obtained by decoding compressed digital content data or digitally converting analog-converted content data. The print can be calculated.

  The second function calculation unit 112 calculates digest data D21 and D22 extracted based on the bit arrangement of the digital content data from the known or unknown digital content data D1 and D2 by calculating the second function. It is a module. Specifically, the second function is a function having a characteristic that the value to be output is changed when any one bit of the input digital content data is changed, for example, all the digital data A function that calculates an irreversible value (hash value) unique to the digital data can be employed without examining the contents. Also, the same value is output when data with slight differences that occur when the same compressed data is decoded by different decoding devices, and different values when data with more differences is input. A function that outputs can also be adopted.

  The first comparison means 121 is a module that compares the identity of the element data D11 and D12 extracted from the known and unknown digital content data D1 and D2, respectively, and the second comparison means 122 is a known and unknown This is a module for comparing the sameness of the digest data D21 and D22 extracted from each of the unknown digital content data D1 and D2, and the comparison result in these comparison means is input to the determination means 131.

  The determination unit 131 is a module that determines the identity of the known digital content data D1 and the unknown digital content data D2 according to the comparison results of the first and second comparison units 121 and 122, respectively.

(Digital content data management method)
By operating the digital content data management system having the above configuration, the digital content data management method of the present invention can be implemented. FIG. 2 is a flowchart showing the operation of the digital content data management system according to this embodiment.

  First, the known and unknown digital content data D1 and D2 are acquired and input to the first function calculating unit 111 and the second function calculating unit 112 (S101). In the present embodiment, the digital content data D1 and D2 may be acquired through a communication network such as the Internet or may be read from a recording medium such as a CD-ROM. Further, the known and unknown digital content data D1 and D2 are respectively copied to a set of two files, and the respective digital content data D1 and D2 are input to the first function calculating means 111 and the second function calculating means 112, respectively. .

  Next, a first function is executed by the first function calculation means 111, element data D11 and D12 such as fingerprints are calculated for each of the known and unknown digital content data D1 and D2, and these are compared with the first comparison means. A comparison is made at 121 (S102 and S103). Then, based on the determination result by the first function calculation unit 111, the determination unit 131 performs the first stage determination (S104). Here, if the element data D11 and D12 do not match, it is determined that the unknown digital content data D2 is an unmanaged content (S109). On the other hand, if the element data D11 and D12 match, the process proceeds to step S105.

  In step S105, the second function calculation means 112 executes the second function to calculate digest data D21 and D22 such as hash values for each of the known and unknown digital content data D1 and D2, The comparison unit 122 performs comparison (S105 and S106). Based on the determination result by the second function calculation unit 112, the determination unit 131 performs the second stage determination (S107). Here, if the digest data D21 and D22 match, it is determined that the unknown digital content data D2 is managed content (S108). On the other hand, if the digest data D21 and D22 do not match, it is determined that the management state is unknown (S109).

(Operational effects of this embodiment)
According to the digital content data management system and management method according to this embodiment, first, using the first function, from the known digital content data D1 and the unknown digital content data D2 to be reproduced, Extracting element data D11 and D12 that are extracted based on the characteristics relating to the contents of each digital content data, and comparing them with the first comparison means 121, the content itself in which the content D2 related to reproduction is managed, Or it can be judged whether it is derived from it.

  In other words, in this embodiment, content that is not managed by the service (content distributed from other services) or content created by the user can be excluded from playback restrictions and managed. It is possible to avoid playback restrictions on free content that is not available.

  Next, digest data D21 and D22 obtained by using the second function are calculated according to the comparison result in the first comparison unit 121, and these are compared by the second comparison unit 122 to obtain a known value. Digital content data (managed digital content data) that matches the digital content data D1 can be reproduced. As a result, it is possible to avoid the reproduction of content that is managed or managed but not the same, and as a result, digital content data whose quality has changed due to unauthorized copying and distribution. Can be restricted from being played.

[Second Embodiment]
(Configuration of digital content data management system)
Next, a second embodiment of the present invention will be described. FIG. 3 is a conceptual diagram showing an overall configuration of a digital content data system according to the second embodiment. In the present embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and the functions and the like are the same unless otherwise specified, and the description thereof is omitted.

  In the second embodiment, a content distribution device 10 for performing digital content data sales / distribution services, a content utilization device 30 for viewing digital content data sold / distributed, and viewing by the content utilization device 30 The content data alteration detection device 20 for verifying the legitimacy of the content to be processed is schematically configured.

  The content use device 30 is a device used by a service provider who sells / distributes arbitrary managed digital content data D01. In addition to the first function calculation unit 111 and the second function calculation unit 112 described above, the content use device 30 is verified. A verification module that transmits the content data D02 for distribution and a distribution module that distributes the distribution content data D03.

  The verification module includes a compression unit 101, a decompression unit 102, first and second function calculation units 111 and 112, and a transmission unit 105. Further, the distribution module includes an encryption unit 103 and a distribution unit 104.

  The compression unit 101 is a module that converts arbitrary digital content data D01 by a third function (here, compression processing) to generate distribution data D03 and verification data D02. The third function is such that the output value of the first function is not changed when the digital content data output from the compression unit 101 and expanded by the expansion unit 102 is processed by the first function. Have the property of modifying digital content data. Here, as the third function and the inverse process, irreversible compression / decompression widely used for compression / decompression of digital contents and the like can be used. For example, compression methods such as ISO / IEC 11172-5, ISO / IEC 13818-5, ISO / IEC 14496-5, ISO / IEC 11172-3, ISO / IEC 13818-7, ISO / IEC 14496-3, etc. Those defined in the MPEG standard or those having similar effects may be used.

  The compression unit 101 is connected to a conversion control unit 107 that changes the characteristics of the third function each time digital content data is distributed. By changing the function parameters by the conversion control unit 107, In the compression unit 101, unique conversion can be performed for each content. As described above, in the conversion process, for example, by changing the conversion conditions such as the compression method every time, it is possible to make the compression method difficult to analyze, and to make the system safer. Here, changing the compression method means partially changing the assignment of the code amount to each data included in the compressed data by a method such as changing the quantization width of the parameter, or giving a bias. It is desirable that the compression method itself is not changed and the quality of the digital content data after decompression is not significantly impaired.

  On the other hand, the decompression means 102 inversely processes the verification data D02 to the original data size (here, decompression processing) using a function that performs the inverse processing of the third function, and the inversely transformed data is known. This is a module that inputs the digital content data to the first function calculation means 111 and the second function calculation means 112, and restores the input digital content data.

  The transmission means 105 is a normal communication interface, transmits / receives data through a communication network such as a public telephone line or the Internet, and transmits element data D11 and digest data D21 obtained from the verification content data D02 to known element data. And a module that transmits the digest data to the content data alteration detection device 20.

  The encryption unit 103 is a module that encrypts the distribution content data D03 related to distribution. The distribution unit 104 is a module that distributes the distribution data D03 through a transmission path such as a communication network. For example, in a document system such as WWW (World Wide Web), an HTML (HyperText Markup Language) file, an image file, and a music file Server computer that transmits information such as, or software with its function, which stores information such as HTML documents and images, and through the IP network such as the Internet in response to requests from client software such as Web browsers Send information.

  The content data alteration detection apparatus 20 is an apparatus in which the comparison unit and the determination unit of the first embodiment described above are mainly independent. In addition to the first and second comparison units 221 and 222 and the determination unit 231 described above, a service is provided. Service-related module that acquires element data and digest data of known digital content data from the provider side, and verification target acquisition module that acquires element data and digest data of unknown digital content data that is about to be reproduced on the user side And.

  The service module includes receiving means 201 for receiving element data D11 and digest data D21 of known digital content data (verification content data D02) transmitted from the content distribution apparatus 10. The element data D11 and digest data D21 are accumulated and held in the storage means.

  As the verification target acquisition system module, receiving means 213 for receiving unknown element data D12 and unknown digest data D22 extracted from unknown digital content data D2, and received element data D12 are used as first comparing means 221. The received digest data D22 is input to the second comparison unit 222. Here, the determination unit 231 determines that the comparison unit 221 detects a match and the comparison unit 22 detects a mismatch, and transmits the determination result D3 to the content use apparatus 30 via the transmission unit 214.

  Note that the determination unit 231 according to the present embodiment includes a transmission unit 214 that transmits data D3, which is a determination result, to the content use apparatus 30.

  The content utilization device 30 is a player device that reproduces and outputs data so that the user can view the content. The content utilization device 30 downloads digital content data through a communication network, and a recording medium such as a CD-ROM or a memory card. It is possible to acquire content through the external input means 302 which is a reading device. Specifically, the content utilization apparatus 30 includes a reproduction system module that acquires and reproduces content in addition to the verification system module including the first function calculation unit and the second function calculation unit described above.

  In the playback system module, a storage device 310 that stores digital content received by the receiving unit 301 or input from the external input unit 302, a decoding unit 303 and a decompressing unit 304 that decrypts / decompresses digital content data, and a playback output Means 308.

  As the storage device 310, for example, a device such as a hard disk or a memory card can be employed. The data stored in the storage device 310 includes “managed content” acquired from the content distribution device 10, acquired from other distribution services, or “unmanaged content” created by the user himself / herself. It is included. Therefore, at the time when the digital content data is read from the storage device 310 at the time of reproduction, it is unknown whether the content is managed or not, and it is verified as unknown digital content data. It becomes a target.

  The decrypting unit 303 is a module for decrypting the content read from the storage device 310 if it is encrypted. The decrypted data is input to the decompressing unit 304. The decompressing means 304 is a means for decompressing corresponding to the compression method on the content distribution apparatus 10 side. The decompressed data is the first function computing means 311 and the second function as unknown digital content data D2 to be verified. The data is input to the calculation means 312 and input to the reproduction output means 308 as reproduction data.

Here, it is desirable that the processing performed by the decryption unit 303 and the decompression unit 304 is inseparably implemented, for example, configured by a single chip so that separation is difficult, and thus decryption is performed by the decryption unit 303. It is possible to prevent the compressed data from leaking out.

  A transmission unit 305 is connected to the first function calculation unit 311 and the second function calculation unit 312, and element data D12 and digest data D22 which are processing results of the first function calculation unit 311 and the second function calculation unit 312 are connected. Is transmitted to the verification object acquisition system module of the content data alteration detection device 20.

  The reproduction output unit 308 is a module that outputs audio data from an output device such as a speaker if the content is music data, and outputs video data from an output device such as a display if the content is video. In the present embodiment, the reproduction output unit 308 is connected to a control unit 307 that controls data use according to the determination result in the content data alteration detection device 20. A receiving means 306 is connected to the control means 307, and the determination result D3 transmitted from the content data modification detection device 20 can be received through the communication network. Data usage can be controlled by prohibiting the use (viewing, etc.) of digital content data, or notifying the user through the user interface provided on the user device that the data has been altered. Alternatively, control may be performed such as transmitting information indicating a transmission path through which the digital content data 35 is obtained, such as download URL information, to the management service.

(Method of digital content data management system)
By operating the digital content data management system having the above configuration, the digital content data management method of the present invention can be implemented. 4 to 6 are flowcharts showing the operation of the digital content data management system according to this embodiment.

  First, as shown in FIG. 4, the content distribution apparatus 10 compresses the managed content D01 to generate distribution content data D03 and verification content data D02 (S201). The distribution content data D03 is encrypted by the encryption unit 103, and then distributed to the content use device 30 by the distribution unit 104 (S202 and S203).

  On the other hand, the verification content data D02 is decompressed by the decompressing means 102 (S204) and input to the first function computing means 111 and the second function computing means 112. Next, the first function calculation unit 111 executes the first function, the element data D11 such as the fingerprint is calculated for the verification content data D02, the second function calculation unit 112 executes the second function, Digest data D21 such as a hash value is calculated for each of the verification content data D02 (S205 and 206), and these are transmitted from the transmission means 105 to the content data alteration detection device 20 (S207).

  On the other hand, as shown in FIG. 5, the content use device 30 downloads (receives) the distribution content data D03 by the receiving means 301 and stores it (S301). At the same time, the content use apparatus 30 can acquire content from a recording medium such as a CD-ROM or a memory card through the external input unit 302.

  Then, the reproduction of the content is started according to the user operation (S302). At the time when the digital content data is read from the storage device 310 at the time of reproduction, it is unknown whether the content is managed or not managed, and decrypted as unknown digital content data D2. And decompressed (S303). The expanded data is input to the first function calculation means 311 and the second function calculation means 312 as unknown digital content data D2, and also input to the reproduction output means 308 as reproduction data.

  In the first function calculation means 311 and the second function calculation means 312, element data D12 and digest data D22 are generated by the first function and the second function (S304 and S305), and the element data D12 that is the result of this processing is generated. The digest data D22 is transmitted to the verification target acquisition system module of the content data alteration detection device 20 through the transmission unit 305 (S306).

  On the other hand, as shown in FIG. 6, the content data modification detection device 20 stores the managed digital content data element data D11 and digest data D21 received from the content distribution device 10 in the storage device 210 (S401). The element data D12 and the digest data D22 of unknown digital content data received from the content utilization device 30 are received (S402).

  Then, the element data is compared by the first comparison unit 221 (S403), and based on the comparison result, the determination unit 231 performs the first stage determination (S404). Here, if the element data D11 and D12 do not match, it is determined that the unknown digital content data D2 is an unmanaged content (S409). On the other hand, if the element data D11 and D12 match, the process proceeds to step S405.

  In step S405, the digest data D21 and D22 are read and compared by the second comparison unit 122 (S405 and S406). Based on the comparison result, the determination unit 231 performs the second stage determination (S407). Here, if the digest data D21 and D22 match, it is determined that the unknown digital content data D2 is managed content (S408). On the other hand, if the digest data D21 and D22 do not match, it is determined that the management state is unknown (S410). The determination result is transmitted to the content use device 30 by the transmission unit 214.

  In accordance with the determination result, the content using apparatus 30 controls whether or not the reproduction / output unit 308 can reproduce / output as shown in FIG. 5 (S307 to S311). That is, content that is not managed (S308) or content that maintains the same identity (S309) based on the comparison result of the first comparison unit 121 and the comparison result of the second comparison unit 122. For example, the reproduction is permitted (S311), and if it is managed but the identity is not maintained, the reproduction is restricted (S310).

(Operational effects of this embodiment)
As described above, according to the digital content data management system and management method according to the present embodiment, in addition to the operational effects of the first embodiment described above, further advantageous effects can be obtained. That is, in the present embodiment, when distributing and selling arbitrary managed digital content data D01, when the digital content data is reproduced on the user side on the distribution / sales service side, the content related to the reproduction is sold. By detecting and verifying the data element data D12 and digest data D22, it is detected whether or not the digital content data that the user intends to reproduce is distribution content data D03 distributed and sold by the service. Can do.

  Further, in the present embodiment, element data and digest data are extracted on the data utilization means side and transmitted to the service provider side, so that the burden on the content data modification detection device 20 on the service provider side is not increased. It is possible to appropriately manage and restrict content playback on the use means side.

[Third Embodiment]
(Configuration of digital content data management system)
Next, a third embodiment of the present invention will be described. The third embodiment is characterized in that a function related to data identification information for specifying digital content data is added to the system described in the second embodiment.

  That is, in addition to the above-described modules, the content distribution apparatus 10 is provided with a content ID management unit 106 that issues and manages data identification information associated with digital content data related to distribution, and includes element data of verification content data and When the digest data is transmitted to the content data alteration detection device 20, the data identification information issued in association with these is also transmitted.

  On the other hand, in the present embodiment, the content data alteration detection device 20 is provided with a known data storage unit 210 that stores a plurality of element data and digest data extracted from the verification content data in association with the data identification information. Data selection means 215 for searching and selecting data in the storage unit 210 based on the data identification information is provided.

  The data selection unit 215 selects digest data from the data storage unit 210 based on the data identification information acquired from the data storage unit 210 and data identification information that associates the element data and digest data extracted from the same digital content data. And a module that inputs to the first and second comparison means. More specifically, the known element data D11 that matches (is estimated to be the same as) the unknown element data D12 is identified by the comparison process performed by the first comparison unit 221, and the identified known element is identified. Data identification information associated with the data D11 is read out, digest data D21 specified by the read data identification information is selected, and transferred to the second comparison means 222.

(Method of digital content data management system)
By operating the digital content data management system having the above configuration, the digital content data management method of the present invention can be implemented. The system operation in the present embodiment is substantially the same as that in the second embodiment described above, and will be described with reference to FIGS.

  First, as shown in FIG. 4, the content distribution apparatus 10 compresses the managed content D01 to generate distribution content data D03 and verification content data D02 (S201). In this embodiment, in this embodiment, the content ID management unit 106 issues data identification information that identifies the managed content D01. The distribution content data D03 is encrypted by the encryption unit 103, and then distributed to the content use device 30 by the distribution unit 104 (S202 and S203).

  On the other hand, the verification content data D02 is decompressed by the decompressing means 102 (S204), duplicated into a set of two files of digital content data, and input to the first function computing means 111 and the second function computing means 112. . Next, the first function calculation unit 111 executes the first function, the element data D11 such as the fingerprint is calculated for the verification content data D02, the second function calculation unit 112 executes the second function, Digest data D21 such as a hash value is calculated for each of the verification content data D02 (S205 and 206), and these are transmitted from the transmission means 105 to the content data alteration detection device 20 (S207). In this step S207, data identification information for specifying these is also transmitted in association with the element data and the digest data.

  On the other hand, as shown in FIG. 5, the content use device 30 downloads (receives) the distribution content data D03 by the receiving means 301 and stores it (S301). At the same time, the content use apparatus 30 can acquire content from a recording medium such as a CD-ROM or a memory card through the external input unit 302.

  Then, the reproduction of the content is started according to the user operation (S302). At the time when the digital content data is read from the storage device 310 at the time of reproduction, it is unknown whether the content is managed or not managed, and decrypted as unknown digital content data D2. And decompressed (S303). The expanded data is input to the first function calculation means 311 and the second function calculation means 312 as unknown digital content data D2, and also input to the reproduction output means 308 as reproduction data.

  In the first function calculation means 311 and the second function calculation means 312, element data D12 and digest data D22 are generated by the first function and the second function (S304 and S305), and the element data D12 that is the result of this processing is generated. The digest data D22 is transmitted to the verification object acquisition system module of the content data alteration detection device 20 through the transmission unit 305 (S306).

  On the other hand, as shown in FIG. 6, the content data alteration detection device 20 receives the managed digital content data element data D11 and digest data D21 received from the content distribution device 10 (S401), and the content utilization device 30. The element data D12 and the digest data D22 of the unknown digital content data received from are received (S402). Upon reception from the content distribution apparatus 10 in step S401, in the present embodiment, element data and digest data relating to a plurality of digital content data are received and accumulated, and data identification information associated with these is also acquired, It accumulates as an index of each element data and digest data.

  Then, the element data is compared by the first comparison unit 221 (S403), and based on the comparison result, the determination unit 231 performs the first stage determination (S404). Here, if the element data D11 and D12 do not match, it is determined that the unknown digital content data D2 is an unmanaged content (S409). On the other hand, if the element data D11 and D12 match, the process proceeds to step S405.

  In step S405, the data identification information of the element data to be compared by the first comparison unit 221 is read, the digest data calculated from the same content associated with the element data is searched, and the data identification information is retrieved. The data identification information specified by is read as known digest data D21. The known digest data D21 and unknown digest data D22 are compared by the second comparing means 122 (S405 and S406). Based on the comparison result, the determination unit 231 performs the second stage determination (S407). Here, if the digest data D21 and D22 match, it is determined that the unknown digital content data D2 is managed content (S408). On the other hand, if the digest data D21 and D22 do not match, it is determined that the content is not the same but is similar (S410). The determination result is transmitted to the content use device 30 by the transmission unit 214.

  In accordance with the determination result, the content using apparatus 30 controls whether or not the reproduction / output unit 308 can reproduce / output as shown in FIG. 5 (S307 to S311). That is, the same result as the unmanaged content (S308) or the managed content is maintained by the comparison result of the first comparison unit 121 and the comparison result of the second comparison unit 122. If it is a content (S309), reproduction is permitted (S311) and managed, but if the identity is not maintained, the reproduction is restricted (S310).

(Operational effects of this embodiment)
According to the digital content data management system and management method according to the present embodiment as described above, it is possible to obtain further advantageous effects in addition to the operational effects of the first embodiment described above. That is, in this embodiment, since the data input to the first and second comparison means is selected based on the data identification information, the digest from the element data of the known digital content data related to the verification is performed based on the data identification information. Since the data can be narrowed down, the inspection result of the first stage can be used for the inspection of the second stage, and the processing speed and reliability can be increased.

[Fourth Embodiment]
Next, a fifth embodiment of the present invention will be described. In the second and third embodiments described above, the first function calculation means 311 and the second function calculation means 312 for digital content data related to reproduction are provided on the content utilization device 30 side. However, as shown in FIG. These may be provided on the content data alteration detection device 20 side.

  In this case, the digital content data itself related to reproduction is transmitted from the content use device 30 to the content data alteration detection device 20, and both the calculation and comparison of element data and digest data are performed by the content data alteration detection device 20. Do. Then, the result of determination as to whether or not playback is possible is transmitted to the content utilization device 30 side, and operation control of the playback output means 308 is performed.

[Fifth Embodiment]
Next, a fifth embodiment of the present invention will be described. In the second and third embodiments described above, the content data alteration detection device 20 is an independent device. However, for example, as shown in FIG.

  Also in the present embodiment, the first function outputs the digital content data so as to output a value that does not change even when the digital content data is viewed by humans so that the quality is not impaired. It shall have the characteristic which extracts the element which controls quality. Similarly, it is assumed that the second function has such a characteristic that the output value is changed when any one bit of the input digital content data is changed.

  In the figure, a recording unit 210 is a recording unit that can be accessed from the person (service provider) who distributed the digital content data through the receiving unit 306. The recording unit 210 includes element data D11 obtained by executing the first function on the distribution source digital content data, and digest data obtained by executing the second function on the distribution source digital content data. It is assumed that D21 is recorded.

  The first function calculation unit 311 calculates element data D12 from the distributed digital content data, and the function calculation unit 312 that executes the second function calculates digest data D22. Next, the element data D11 and element data D12 read out from the recording means 210 are compared in the first comparison means 221, and when they are found to match, they are still read out from the recording means 210. The digest data D21 and the digest data D22 are compared by the second comparison means 222.

  In this second comparison, when it is detected that they do not match, it is determined that the distributed digital content data has been altered from the distribution source digital content data (distribution data), and the data use means 30 performs data use. Is limited by the control means 307.

[Example of change]
In addition, this invention is not limited to embodiment mentioned above, A various change can be added. For example, in the first to third embodiments described above, a function for calculating a fingerprint is used as the first function, and a hash function for obtaining a hash value is used as the second function. Those using prints can also be adopted. In this case, it is necessary to make the autocorrelation (width of identity) of the second function more accurate than that of the first function. This is because the same output can be obtained even if data with a slight difference that occurs when different decompression processing is performed on the same compressed data, and when data with a further difference is input. An object is to determine whether or not the digital content data is obtained from the same compressed data regardless of the same decompression process by obtaining functions that output different values.

  In the above embodiment, the first function calculation unit 111 and the second function calculation unit 112 are provided on the content distribution apparatus 10 side for known content. However, the first and second function calculation units are used as the content data alteration detection apparatus. You may make it provide in 20 side. In this case, the distribution device or the utilization device transmits the known or unknown digital content data itself to the content data alteration detection device 20, and both the calculation and comparison of the element data and the digest data are performed on the content data alteration detection device. 20 is performed.

  At this time, the data utilization means 30 notifies the content data modification detection device 20 of the digital content data acquisition destination information such as the download URL information, and separately receives the content data from the content data modification detection device 20. This can be realized by performing processing equivalent to the decoding process 303, the decompression process 304, the first function calculation means 311 and the first function calculation means 312 on the data alteration detection device 20 side.

  The system, apparatus, and method according to the present embodiment described above can be realized by executing a program described in a predetermined language on a computer. That is, by installing this program on a computer such as a user terminal or a Web server or an IC chip and executing it on the CPU, a system having the above-described functions can be easily constructed. This program can be distributed through a communication line, for example, and can be transferred as a package application that operates on a stand-alone computer.

  Such a program can be recorded on a recording medium readable by a general-purpose computer. Specifically, it can be recorded on various recording media such as a RAM card in addition to a magnetic recording medium such as a flexible disk or a cassette tape, or an optical disk such as a CD-ROM or DVD-ROM.

  According to the computer-readable recording medium in which the program is recorded, the above-described system and method can be implemented using a general-purpose computer or a dedicated computer, and the program can be stored, transported, and installed. It can be done easily.

It is a conceptual diagram which shows the whole structure of the digital content data system which concerns on 1st Embodiment. It is a flowchart figure which shows operation | movement of the digital content data management system which concerns on embodiment which concerns on 1st Embodiment. It is a conceptual diagram which shows the whole structure of the digital content data system which concerns on 2nd Embodiment. It is a flowchart figure which shows operation | movement of the content distribution apparatus 10 which concerns on embodiment which concerns on 2nd Embodiment. It is a flowchart figure which shows operation | movement of the content utilization apparatus 30 which concerns on embodiment which concerns on 2nd Embodiment. It is a flowchart figure which shows operation | movement of the content data alteration detection apparatus 20 which concerns on embodiment which concerns on 2nd Embodiment. It is a conceptual diagram which shows the whole structure of the digital content data system which concerns on 3rd Embodiment. It is a conceptual diagram which shows the whole structure of the digital content data system which concerns on 4th Embodiment. It is a conceptual diagram which shows the whole structure of the digital content data system which concerns on 5th Embodiment.

Explanation of symbols

D01 ... Managed digital content data D02 ... Verification content data D03 ... Distribution content data D1 ... Known digital content data D2 ... Unknown digital content data D11 ... Known element data D12 ... Unknown element data D21 ... Known digest Data D22 ... Unknown digest data D3 ... Determination result 10 ... Content distribution device 20 ... Content data alteration detection device 30 ... Content utilization device 101 ... Compression means 102, 304 ... Decompression means 103 ... Encryption means 104 ... Distribution means 106 ... Content ID management unit 107 ... conversion control means 111, 311 ... first function calculation means 112, 312 ... second function calculation means 121, 221 ... first comparison means 122, 222 ... second comparison means 201, 213, 301, 06 ... Receiving means 210 ... Storage means 211 ... Known data storage unit 105, 214, 305 ... Transmission means 215 ... Data selection means 231,131 ... Determination means 302 ... External input means 303 ... Decoding means 307 ... Control means 308 ... Reproduction output Means 310 ... Storage device

Claims (15)

A digital content data management system having a function of verifying the identity of known digital content data and unknown digital content data,
A first function calculating means for calculating element data extracted from the known or unknown digital content data based on characteristics relating to the contents of the digital content data by calculating a first function;
A second function calculating means for calculating digest data extracted from the known or unknown digital content data based on a bit arrangement of the digital content data by calculating a second function;
First comparing means for comparing the identity of element data extracted from each of the known and unknown digital content data;
Second comparing means for comparing the identity of digest data extracted from each of the known and unknown digital content data;
The digital content data includes: a determination unit that determines the identity of the known digital content data and the unknown digital content data according to a comparison result of each of the first and second comparison units. Management system. When the digital content data to be output is input to the first function, the third function having a characteristic of modifying the input digital content data to such an extent that the output value of the first function is not changed is arbitrarily set Conversion means for generating distribution data and verification data from the digital content data of
The verification data is inversely transformed by a function that performs inverse processing of the third function, and the inversely transformed data is input as the known digital content data to the first function computing means and the second function computing means. Reverse conversion means to
The distribution data is inversely transformed, and the inversely transformed data is stored from the unknown digital content data by storing the unknown element data and unknown digest data calculated by the first and second functions. And a verification object acquisition means for inputting the unknown element data to the first comparison means and inputting the unknown digest data to the second comparison means. The digital content data management system described in 1.   The digital content data management system according to claim 2, wherein the conversion unit includes a conversion control unit that periodically or irregularly changes a conversion condition when the conversion process is performed. An element data storage unit for storing a plurality of element data extracted by the first function calculation means;
A digest data storage unit for storing a plurality of digest data extracted by the second function computing means;
When the same element data exists in the element data storage unit, the data identification information recorded in association with this is read, and the digest data recorded in association with the read data identification information is read out. The digital content data management system according to claim 1, further comprising data selection means for reading data from the data. A digital content data management method having a function of verifying the identity of known digital content data and unknown digital content data,
By calculating a first function by a first function calculating means, element data extracted based on characteristics relating to the contents of the digital content data is calculated from the known or unknown digital content data, and second A function calculation step of calculating digest data extracted from the known or unknown digital content data based on a bit arrangement of the digital content data by calculating a second function by a function calculation means;
The first comparison means compares the identity of the element data extracted from each of the known and unknown digital content data, and the second comparison means calculates the identity data from each of the known and unknown digital content data. A comparison step for comparing the identity of the extracted digest data;
And a determination step of determining the identity between the known digital content data and the unknown digital content data by a determination unit according to a comparison result of each of the first and second comparison units. Digital content data management method. Prior to the function calculation step,
When the digital content data to be output is input to the first function by the conversion means, the third function has a characteristic of modifying the input digital content data to such an extent that the output value of the first function is not changed. A conversion step for generating distribution data and verification data from arbitrary digital content data by a function;
In the inverse transformation means, the verification data is inversely transformed by a function for performing the inverse processing of the third function, and the inversely transformed data is used as the known digital content data and the second function computing means and the second function data. Performing an inverse transformation step that is input to the function computing means, and the comparison step comprises:
The distribution data is inversely transformed, and the inversely transformed data is verified from the unknown digital content data by the unknown element data and the unknown digest data calculated by the first and second functions. A verification object acquisition step of storing and holding the acquisition element, inputting the unknown element data to the first comparison unit, and inputting the unknown digest data to the second comparison unit; The digital content data management method according to claim 5.   The digital content data management method according to claim 6, wherein the conversion step includes a conversion control step of changing a conversion condition for performing the conversion process periodically or irregularly. The function calculation step is
An accumulation step of accumulating a plurality of element data extracted by the first function calculating means in an element data accumulating section and accumulating a plurality of digest data extracted by the second function calculating means in a digest data accumulating section;
When the same element data exists in the element data storage unit, the data identification information recorded in association with this is read, and the digest data recorded in association with the read data identification information is read out. The method for managing digital content data according to claim 5, further comprising: a data selection step of reading from the data. In the data utilization means for utilizing the distribution data, a receiving step of receiving the distribution data through the transmission path;
A transmission step of transmitting, from the data use means, digital content data related to use, or element data and digest data of the digital content data related to use to the verification target acquisition means;
An output step of acquiring a determination result by the determination unit, and outputting digital content data related to use by an output unit provided in the data use unit according to the acquired determination result, The digital content data management method according to claim 6. An apparatus for using digital content data having a function of reproducing and outputting digital content data distributed from a service provider,
Transmitting means for transmitting digital content data related to reproduction to the service provider side;
Receiving means for receiving, from the service provider side, a comparison result relating to the identity between the element data and digest data calculated from the content data related to reproduction and the element data and digest data calculated on the service provider side When,
Control means for controlling the reproduction of the digital content data related to the reproduction according to the received comparison result,
The element data is extracted by calculating a first function based on characteristics relating to the content of digital content data related to reproduction or digital content data held on the service provider side,
The digest data is extracted by calculating a second function based on the digital content data related to reproduction or the bit arrangement of the digital content data held on the service provider side. Use device. An apparatus for using digital content data having a function of reproducing and outputting digital content data distributed from a service provider,
A first function calculating means for calculating element data extracted from the digital content data related to reproduction based on characteristics relating to the contents of the digital content data by calculating a first function;
A second function calculating means for calculating digest data extracted from the digital content data related to reproduction based on the bit arrangement of the digital content data by calculating a second function;
Transmitting means for transmitting the element data and the digest data to the service provider side;
Receiving means for receiving, from the service provider side, a comparison result regarding the identity between the element data and digest data and the element data and digest data calculated on the service provider side;
A digital content data utilization apparatus comprising: control means for controlling reproduction of the digital content data related to the reproduction according to the received comparison result. A content use device having a function of reproducing and outputting digital content data distributed from a service provider,
A first function calculating means for calculating element data extracted from the digital content data related to reproduction based on characteristics relating to the contents of the digital content data by calculating a first function;
A second function calculating means for calculating digest data extracted from the digital content data related to reproduction based on the bit arrangement of the digital content data by calculating a second function;
First comparison means for comparing the identity of the element data calculated by the first function calculation means and the element data distributed from the service provider;
Second comparison means for comparing the identity of the digest data calculated by the first function calculation means with the digest data distributed from the service provider;
An apparatus for using digital content data, comprising: a determination unit that determines whether or not to reproduce the digital content data related to the reproduction according to a comparison result of each of the first and second comparison units. The digital content data related to the reproduction is
When digital content data to be output is input to the first function, the digital content data is generated by a third function having a characteristic of modifying the input digital content data to such an extent that the output value of the first function is not changed. Distribution data
The digital content data utilization device comprises:
The distribution data is inversely transformed by a function that performs inverse processing of the third function, and the inversely transformed data is input to the first function computing means and the second function computing means as digital content data for reproduction. The digital content data utilization apparatus according to claim 11 or 12, further comprising: an inverse conversion unit that performs the conversion. When the distribution data is subjected to the conversion process, the conversion conditions are changed regularly or irregularly,
14. The apparatus for using digital content data according to claim 13, wherein the inverse conversion unit can cope with a change in the conversion condition. An element data storage unit for storing a plurality of element data extracted by the first function calculation means;
A digest data storage unit for storing a plurality of digest data extracted by the second function computing means;
When the same element data exists in the element data storage unit, the data identification information recorded in association with the element data is read, and the digest data recorded in association with the read data identification information is stored in the digest data storage 13. The apparatus for using digital content data according to claim 12, further comprising data selection means for reading out from the section.