JP2005080145A - Reproducing apparatus management method, content data reproducing apparatus, content data distribution apparatus, and recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem that condition setting is difficult in a status that a specified person uses content data with two or more reproducing apparatuses, and the reproducing apparatus is not specified because a right of using is formerly given to the person. <P>SOLUTION: A domain key 9 related with a specific content data user or a group which consists of content data users, is containerized with encrypted content data 8 which are enciphered content data 6 so as to directly or indirectly decodable using the domain key 9. Furthermore, a content data container 14 which is processed signature in a signature processor 13, is supplied to the reproducing apparatus. The reproducing apparatus limits the content which can be reproduced by limiting a number of keys which can be stored in a key box because the reproducing apparatus stores the domain key in a key box and then decodes the content data. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a playback device management method, a content data playback device, a content data distribution device, and a recording medium. The present invention relates to a management method of a playback device to be restricted, a content data playback device, a content data distribution device, and a recording medium.

  A method in which right-of-use information including an ID unique to a playback device is added to content data in advance, the right-of-use information extracted from the content during playback is compared with the ID of the playback device, and playback control is performed based on the comparison result. is there. According to this, content data can be supplied by designating a playback device in advance, which leads to prevention of unauthorized use of content data by a playback device other than the designated playback device.

  Also, the encrypted information obtained by encrypting the content data, the further encrypted key information for decrypting the encrypted information, and the condition information for decrypting the key information are recorded on the information recording medium. A content data reproducing apparatus that can decrypt encrypted information read from an information recording medium only under a specific condition has also been known (see, for example, Patent Document 1). According to this conventional content data playback device, content data can be supplied by specifying the playback device conditions in advance, and content data can be prevented from being illegally leaked to playback devices other than the specified playback device. Connected.

Japanese Patent Laid-Open No. 10-283268

  However, in the method of comparing with the ID unique to the playback device, since the playback device is designated in advance, the playback device other than the designated playback device cannot use the data, and the right to use is given to a specific person. This is not suitable for situations where a person uses content data on a plurality of playback devices.

  Further, in the conventional content data reproducing apparatus described in Patent Document 1, the right to use is given to a specific person, and the person uses the content data by a plurality of reproducing apparatuses, and those reproducing apparatuses are not specified. In such a situation, setting conditions is difficult.

  The present invention has been made in view of the above points. Regarding the reproduction of content data, there is a right holder specified for each piece of content data, and it is necessary to limit the use of the content data to other than the specific right holder. There is also a playback device that can be used for a system in which it is not necessary to limit the number of playback devices to be used by a specific right holder, even if the playback device is not specified. It is an object of the present invention to provide a management method, a content data reproduction device, a content data distribution device, and a recording medium.

  To achieve the above object, the playback device management method according to the first aspect of the present invention includes identification information associated with a specific content data user or a group of content data users, and direct or indirect using the identification information. Content that has been encrypted so that it can be decrypted by the encrypted content data is input to the playback device, and the playback device decrypts the encrypted content data directly or indirectly using the identification information. In addition to using data, the reproduction apparatus is associated with a specific content data user or a group of content data users using identification information.

  In this invention, the content data is encrypted using the identification information and input to the playback device, and the playback device decrypts the encrypted content data using the input identification information and identifies the playback device using the identification information. Content data users or groups of content data users are associated with each other, so that the playback device administrator himself selects the content data playback device that plays back the content data, so that the content playback device belonging to his / her domain can be selected. Can be defined.

  In order to achieve the above object, the content data reproducing apparatus according to the second invention decrypts the content key using identification information associated with a specific content user or a group of content users and the identification information. An input means for inputting the encrypted content key encrypted by a predetermined method and the encrypted content data encrypted by a predetermined method capable of decrypting the content data using the content key or separately. And a recording means for storing the identification information, and when the identification information input by the input means is not yet recorded in the recording means and new recording is possible, and the same information as the identification information is stored in the recording means. Only when it has already been recorded, the encrypted content key input by the input means is decrypted using the identification information, and the encrypted content key is decrypted. A first decryption unit for obtaining a content key; a second decryption unit for decrypting the encrypted content data input by the input unit using the content key decrypted by the first decryption unit; And reproducing means for reproducing the content data obtained by the second decoding means.

  In the present invention, when the recording capacity of the recording means for recording the identification information is such that new recording of the identification information is possible, the input means uses the encrypted content identification information input by the input means. When the recorded content of the recording means for recording the identification information is almost full without being able to newly record the identification information, the identification information can be obtained. The encrypted content key used cannot be decrypted, and playback is stopped.

  In order to achieve the above object, the content data reproducing apparatus according to the third aspect of the invention is an encryption in which identification information associated with a specific content user or a group of content users is encrypted using a common key. Identification information, an encrypted content key encrypted by a predetermined method that can decrypt the content key using the identification information, and an encryption encrypted by a predetermined method that can decrypt the content data by using the content key The input means for inputting the content data container digitally signed with the first digital certificate for the data combined with the encrypted content data, the recording means for storing the identification information, and the content data container input by the input means Signature verification means for verifying a digital signature using a second digital certificate corresponding to the first digital certificate; The first decryption means for decrypting the encrypted identification information extracted from the content data container whose signature has been successfully verified by the name verification means with the common key, and the identification information obtained by decrypting by the first decryption means It is obtained by decoding only when it is not yet recorded in the recording means and new recording is possible, or when the same information as the identification information is already recorded in the recording means. The second verification unit that obtains the content key by decrypting the encrypted content key extracted from the content data container that has been successfully verified by the signature verification unit using the identification information, and the signature verification by the signature verification unit is successful. The content data obtained by decrypting the encrypted content data extracted from the content data container using the content key obtained by the second decryption means And having obtained a third decoding means, and reproducing means for reproducing the content data obtained by the third decryption means.

  In the present invention, the digital signature of the input content data container is verified, and the encrypted identification information extracted from the content data container that has been successfully verified is decrypted with the common key. Security can be further improved as compared with the content data reproducing apparatus of the invention.

  In order to achieve the above object, the content data distribution apparatus according to the fourth aspect of the present invention provides a predetermined content key that can decrypt a content key using identification information associated with a specific content user or a group of content users. A first encryption unit that encrypts the content data to obtain an encrypted content key, and a second encryption unit that obtains encrypted content data by encrypting the content data using a content key by a predetermined method And a distribution unit that distributes the information, the encrypted content key, and the encrypted content data together as a content data container to the content data reproducing apparatus.

  In the present invention, content data obtained by containerizing an encrypted content key obtained by encrypting a content key using identification information and encrypted content data obtained by encrypting content data with the content key together with the identification information The container can be distributed to the playback apparatus via a wired transmission path, a wireless transmission path, or a communication network, or can be recorded on a recording medium and distributed to the playback apparatus.

  Furthermore, in order to achieve the above object, the recording medium of the fifth invention is capable of decrypting a content key using identification information associated with a specific content user or a group of content users and the identification information. Content in which an encrypted content key encrypted by a predetermined method and encrypted content data encrypted by a predetermined method capable of decrypting the content data using the content key are recorded and the content data is reproduced It is read by a data reproducing apparatus.

  According to the present invention, it is possible to define a content playback device belonging to his or her domain by selecting a content data playback device by which the playback device administrator himself / herself plays content data.

  In addition, according to the present invention, when the recording capacity of the recording means for recording the identification information is substantially full when the identification information cannot be newly recorded, the encrypted content key cannot be decrypted using the identification information. Since the reproduction is stopped, when there is no room for recording the identification information in the recording means, the content data container having the identification information cannot be reproduced, and as a result, the administrator of the content data reproducing apparatus can determine the content data container to be reproduced. The number of right-of-use users can be limited to the number of identification information that can be recorded in the recording means, and unauthorized reproduction of content data can be prevented.

  Further, according to the present invention, even in a situation where the right to use is given to a specific person, the person uses content data with a plurality of playback devices, and those playback devices are not specified. The condition can be set by recording the identification information of the content data container.

  Next, the best mode for carrying out the present invention will be described with reference to the drawings. FIG. 1 shows a block diagram of an embodiment of a content data container generating device for playback by a content data playback device according to the present invention. In the figure, a content data container generating device includes three cryptographic processing units 1, 2, and 3, and a containerization processing unit 4 that synthesizes signals obtained by these three cryptographic processing units 1, 2, and 3. The signature processing unit 5 performs a digital signature on the output of the containerization processing unit 4.

  Next, the operation of the content data container generation device will be described with reference to the flowchart of FIG. First, the first encryption processing unit 1 encrypts the content data 6 with the content key 7 to obtain encrypted content data 8 (step S1). Also, the second encryption processing unit 2 encrypts the content key 7 used in the first encryption processing unit 1 with the domain key 9 to obtain an encrypted content key 10 (step S2). Here, the domain key 9 is identification information associated with a specific content user or a group of content users, and is encrypted so that it can be decrypted when the content is used. The third cryptographic processing unit 3 encrypts the domain key 9 used in the second cryptographic processing unit 2 with the common key 11 common to the entire system to obtain the encrypted domain key 12 (step S3).

  The encrypted content data 8, the encrypted content key 10, and the encrypted domain key 12 generated in this way are combined and containerized by the containerization processing unit 4 (step S4). The containerized encrypted data is digitally signed using the digital certificate 13 that can be trusted by the signature processing unit 5 to form the content data container 14 (step S5). At this time, a digital certificate 13 that is sufficiently trusted by both the content production side and the content reproduction side is used.

  The content data container 14 generated as described above is schematically shown in FIG. In the figure, signature data 15 is data by a digital signature performed by the signature processing unit 5 using the digital certificate 13. The content data container 14 is transmitted to a content data reproducing apparatus to be described later by wire or wireless, is recorded on a recording medium and distributed, or is distributed via a communication network.

  Next, a content data reproducing apparatus according to the present invention will be described. FIG. 4 shows a block diagram of an embodiment of a content data reproducing apparatus according to the present invention. In the figure, the content data reproducing apparatus includes a signature verification processing unit 21, a data extraction processing unit 22, three decryption processing units 23, 24 and 25, a key storage processing unit 26, a key box 27, and content data. And a playback unit 28. The content data reproducing apparatus of the present embodiment is obtained by receiving a wired signal or a wireless signal, reproducing from a loaded recording medium, or downloading a distribution distributed via a communication network. The encrypted content data 8 in the content data container 14 with the digital signature generated by the generating apparatus shown in 1 is decrypted and reproduced.

  Next, the operation of the embodiment of FIG. 4 will be described with reference to the flowcharts of FIGS. The signature verification processing unit 21 in FIG. 4 uses the digital certificate 29 to verify the digital signature applied to the content data container 14 received, reproduced, or downloaded and input as described above (FIG. 5). Step S11). If the verification of the digital signature fails, the reproduction process is stopped (step S12 in FIG. 5).

  On the other hand, if the verification of the digital signature is successful, the data extraction processing unit 22 extracts the encryption domain key 12 from the content data container 14 (step S13 in FIG. 5), and the decryption processing unit 23 acquires the encryption domain key 12 The domain key 34 (corresponding to the domain key 9 in FIG. 1) is obtained by decrypting with the common key 11 (step S14 in FIG. 5). Then, the key storage processing unit 26 starts the operation of storing the domain key 34 in the key box 27 (step S15 in FIG. 5). This operation is performed as follows according to the flowchart of FIG.

  That is, first, the key storage processing unit 26 checks whether or not the same key as the domain key 34 to be stored already exists in the key box 27 (step S151 in FIG. 6). If the same domain key exists, the key storage is terminated as successful key storage (step S152 in FIG. 6). On the other hand, if the same domain key does not exist in the key box 27, it is confirmed whether there is room for further key addition in the key box 27 (step S153 in FIG. 6).

  If there is no more room to store the key, the storage of the domain key is terminated as a key storage failure (step S154 in FIG. 6). If there is room for storing the domain key in the key box 27, the domain key 34 is added or newly stored in the key box 27, and the storage of the domain key 34 is terminated as the key storage is successful (steps S155 and S156 in FIG. 6). .

  As described above, the domain key 34 is stored in the key box 27 by the key storage processing unit 26. If the storage operation fails, the content data reproduction processing is stopped (step S12 in FIG. 5), and the storage operation is performed. If successful, the data retrieval processing unit 22 extracts the encrypted content key 10 from the content data container 14 (step S16 in FIG. 5), and the decryption processing unit 24 decrypts the encrypted content key 10 into the decrypted domain key 34. To obtain the content key 35 (corresponding to the content key 7 in FIG. 1).

  Subsequently, the encrypted content data 8 is extracted from the content data container 14 in the data retrieval processing unit 22 (step S18 in FIG. 5), and the encrypted content data is decrypted in the decryption processing unit 25 using the decrypted content key 35. 8 is decoded (step S19 in FIG. 5). As a result, the decrypted content data 36 (corresponding to the content data 6 in FIG. 1) is extracted from the decryption processing unit 25, supplied to the content data reproduction unit 28 and reproduced (step S20 in FIG. 5).

  Thus, according to the present embodiment, when there is room for storing the decrypted domain key 34 in the key box 27, the domain key 34 is added to or newly stored in the key box 27 and encrypted. However, if there is no room for storing the decrypted domain key 34 in the key box 27, the encrypted content data cannot be decrypted and reproduced. If the number of domain keys that can be stored in the key box 27 is only one, the content data playback apparatus once performs the playback process of the content data having the domain key, and the key box 27 stores the domain key. Since there is no room for storing other domain keys, it becomes impossible to reproduce content data having other domain keys.

  Therefore, in the above case, as a result, the administrator of the content data playback apparatus is limited to the content data container to be played back having only one domain key. Accordingly, only the right holder specified for the content data container can reproduce the content data container, and the reproduction of a person other than the authorized right holder can be suppressed.

  In the present embodiment, the playback device administrator himself / herself can select the content data playback device that plays back the content data container, so that the content data playback device belonging to his / her domain can be defined. Content data can be used in the data reproducing apparatus. In this embodiment, since the content data is encrypted with the content key, even if only the content data portion is extracted and played back, it cannot be decrypted unless the content key corresponding to the content key used for encryption is used. Therefore, the content data itself can be protected.

  The present invention is not limited to the above-described embodiment. For example, the content data container 14 has been described as being input to the content data playback device. However, the encrypted content data 8, the encrypted content key 10, and The encrypted domain keys 12 may be separately input to the content data reproducing apparatus without being combined together.

  The key storage processing unit 26 cancels reproduction without performing additional recording of the domain key 34 in the key box 27 when there is no room for additional recording of the domain key 34 in the key box 27. Even when the domain key 34 is a domain key that is prohibited from being recorded in the key box 27, the reproduction may be stopped without performing additional recording.

It is a block diagram of one Embodiment of the production | generation apparatus of the content data container reproduced | regenerated with this invention apparatus. It is a flowchart for operation | movement description of FIG. It is a schematic diagram of an example of the format of the content data container produced | generated by the production | generation apparatus of FIG. It is a block diagram of one embodiment of a content data reproducing apparatus of the present invention. 5 is a flowchart for explaining the operation of the playback device in FIG. 4. 5 is a flowchart for explaining key storage of the playback device of FIG. 4.

Explanation of symbols

1, 2, 3 Cryptographic processing unit 4 Containerization processing unit 5 Signature processing unit 6, 36 Content data 7, 35 Content key 8 Encrypted content data 9, 34 Domain key 10 Encrypted content key 11 Common key 12 Encrypted domain key DESCRIPTION OF SYMBOLS 13 Digital certificate 14 Content data container 15 Signature data 21 Signature collation processing part 22 Data extraction processing part 23, 24, 25 Decryption processing part 26 Key storage processing part 27 Key box 28 Content data reproduction part 29 Digital certificate

Claims (5)

  Identification information associated with a specific content data user or a group of content data users, and encrypted content data obtained by encrypting the content data so that it can be directly or indirectly decrypted using this identification information Is input to the playback device, and the encrypted content data is directly or indirectly decrypted using the identification information in the playback device, the decrypted content data is used, and the playback device is used using the identification information. Is associated with the specific content data user or a group of content data users. Identification information associated with a specific content user or a group of content users, an encrypted content key encrypted with a predetermined method that can decrypt the content key using the identification information, and the content key An input means for inputting together or separately with the encrypted content data encrypted by a predetermined method capable of decrypting the content data,
Recording means for storing the identification information;
When the identification information input by the input means has not yet been recorded in the recording means and new recording is possible, and when the same information as the identification information has already been recorded in the recording means A first decryption unit that decrypts the encrypted content key input by the input unit using the identification information and obtains the content key,
Second decryption means for decrypting the encrypted content data input by the input means using the content key decrypted by the first decryption means to obtain the content data;
Reproducing means for reproducing the content data obtained by the second decrypting means. Encrypted identification information obtained by encrypting identification information associated with a specific content user or a group of content users using a common key, and a predetermined method capable of decrypting the content key using the identification information Digital data with the first digital certificate is obtained by combining the encrypted content key that has been encrypted and the encrypted content data that has been encrypted by a predetermined method that can decrypt the content data using the content key. An input means for inputting the signed content data container;
Recording means for storing the identification information;
Signature verification means for verifying a digital signature using the second digital certificate corresponding to the first digital certificate for the content data container input by the input means;
First decryption means for decrypting the encrypted identification information extracted from the content data container that has been successfully verified by the signature verification means with the common key;
When the identification information obtained by decoding by the first decoding means has not yet been recorded in the recording means and new recording is possible, and the same information as the identification information is stored in the recording means. The encrypted content key extracted from the content data container that has been successfully verified by the signature verification means using the identification information obtained by decryption only when it is already recorded Second decryption means for decrypting and obtaining the content key;
The encrypted content data extracted from the content data container successfully verified by the signature verification means is decrypted using the content key obtained by the second decryption means, and the content data is decrypted. Third decoding means for obtaining
Reproducing means for reproducing the content data obtained by the third decrypting means. First encryption means for encrypting a content key by a predetermined method capable of decrypting the content key using identification information associated with a specific content user or a group of content users and obtaining an encrypted content key;
Second encryption means for encrypting the content data by a predetermined method capable of decrypting using the content key to obtain encrypted content data;
A content data distribution device comprising: distribution means for distributing the identification information, the encrypted content key, and the encrypted content data together as a content data container to a content data reproduction device. Identification information associated with a specific content user or a group of content users, an encrypted content key encrypted with a predetermined method that can decrypt the content key using the identification information, and the content key A recording medium, in which encrypted content data encrypted by a predetermined method that can be decrypted by using the content data is recorded and read by a content data reproducing device that reproduces the content data.

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