JP2010263453A - Information processing apparatus, content distribution system, information processing method, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a configuration that provides confidential information to a server and carrying out safe data processing in the server without leaking the confidential information. <P>SOLUTION: A server receives encryption data of confidential information, and carries out data processing using the received encryption data and a device key stored in a memory to acquire the confidential information. Further, an application process of the confidential information is carried out. For example, a unit key file storing a content encryption key is decoded to carry out content encryption using a unit key acquired from the unit key file. Alternatively, bind information or the like is added to the unit key file to provide the information to a user apparatus. The confidential information is provided to the server and data are processed in the server safely without leaking the confidential information. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an information processing device, a content distribution system, an information processing method, and a program. More specifically, the present invention relates to an information processing apparatus, a content distribution system, an information processing method, and a program that realize secure transfer without leaking confidential information such as an encryption key and execute data processing to which the confidential information is applied.

  The present invention provides confidential information such as a content encryption key to a server that provides content to a user device, such as sub-content corresponding to content stored in an information recording medium such as Blu-ray Disc (registered trademark) or DVD. Information processing apparatus, content distribution system, and information that realizes secure provision processing of highly confidential information and that can safely execute data processing to which confidential information is applied in a server without leaking confidential information The present invention relates to a processing method and a program.

  Various software data such as audio data such as music, image data such as movies, game programs, and various application programs (hereinafter referred to as “contents”) are stored on recording media such as Blu-ray Disc (registered). Trademark) or an information recording medium (recording medium) such as a DVD (Digital Versatile Disc). In particular, Blu-ray Disc (registered trademark) using a blue laser is widely used as a recording medium for high-quality video content, for example.

  These discs can be mounted on a playback device such as a user-owned PC (Personal Computer) or a disc player, for example, to enable content playback.

  However, a lot of contents such as music data and image data generally have a distribution right or the like in the creator or seller. Therefore, when such content is provided to the user, it is often provided with a certain usage restriction set. For example, settings are made so that only authorized users who have purchased content in accordance with regular procedures are allowed to use the content, or unauthorized copying is not performed. Specifically, content encryption processing or the like is performed.

  As a specific standard for realizing content usage control, for example, there is a Blu-ray Disc (registered trademark) standard. This classifies content stored on a disc into content management units (CPS units: Content Protection System Units) defined as usage management units, and performs management by associating usage control information (Usage Rules) with each unit. It is a standard. Content belonging to one CPS unit is permitted to be used within a range defined in the usage control information (Usage Rule) corresponding to the CPS unit to which the content belongs.

  Usage control information (Usage Rule) is recorded on the disc together with the content. The playback device reads usage control information corresponding to the CPS unit to which the playback content belongs at the time of content playback from the disc and uses the content according to the usage control information. The usage control information (Usage Rule) is permitted, for example, content copy / playback control information (CCI), specifically, whether the content is permitted to be copied or not allowed to be copied. It holds information such as usage modes and unacceptable usage modes.

  When the content belonging to the CPS unit is an encrypted content, a CPS unit key that is an encryption key corresponding to the unit is associated with each unit constituting the content. When reproducing the encrypted content, decryption processing using the CPS unit key is performed in units. A CPS unit key file storing the CPS unit key is also recorded on the disc. The content stored in the Blu-ray Disc (registered trademark) is subjected to usage control under such strict usage management.

  In the Blu-ray Disc (registered trademark) standard, attached data corresponding to content recorded on a disc, for example, caption data and dubbing data corresponding to movie content, other content-compatible service data, moving images, still images, etc. It also stipulates usage control when content is downloaded from a server and used as subsequent data.

  For example, Patent Document 1 (Japanese Patent No. 3959735) or a content utilization system that acquires subsequent data from a server or the like, records it in a local storage unit such as a hard disk of a user device, and reproduces it together with the recorded content of the disk. It is disclosed in Patent Document 2 (Japanese Patent Laid-Open No. 2003-140662).

  In this way, not only the content recorded on the disc but also the subsequent data acquired from the server and stored in the local storage unit such as a hard disk is set as a usage control target, thereby realizing strict content usage management. Such use management of subsequent data is specified in, for example, AACS (Advanced Access Content System).

  For example, in AACS, the server requests the user device to provide the subsequent data encrypted. The server applies the same CPS unit key as the CPS unit key, which is the encryption key of the stored content of the disc mounted on the user device, and provides the subsequent data encrypted.

  With this setting, the user apparatus can also reproduce the content acquired from the server by performing a decryption process using the CPS unit key stored on the disc.

  However, in the case of the above setting, a server that provides content as subsequent data needs to perform encryption processing using the same CPS unit key as the CPS unit key stored in the disk used by the user. . Therefore, the server must obtain this CPS unit key.

  The CPS unit key is created by the disc factory. Content encryption using the CPS unit key is executed at the disc factory, and a disc on which the encrypted content and the CPS unit key file are recorded is manufactured and provided to the user. A disc factory is a limited number of disc factories with a specific license, and the CPS unit key generation process in the disc factory is executed under strict management.

  On the other hand, servers that provide content as subsequent data are scattered all over the world, and there are many servers. Therefore, it is difficult to perform under strict management like the generation of a CPS unit key in a disk factory, and it is required to perform provision processing via a network. However, there is a possibility that the transfer data via the network is obtained illegally. For example, if the CPS unit key leaks, the encrypted content stored on the disk can be illegally used, and content protection is impaired.

  Once the CPS unit key is leaked, it becomes possible to use the encrypted content randomly. Therefore, it is necessary to transfer the CPS unit key safely without leaking.

Japanese Patent No. 3959735 JP 2003-140662 A

  The present invention has been made in view of the above-described situation, for example, and is an information processing apparatus, content distribution system, information processing method, and program for safely transferring confidential information such as a CPS unit key. The purpose is to provide.

The first aspect of the present invention is:
A communication unit that performs data communication;
A data processing unit that executes data processing using received data via the communication unit;
It has a memory that stores a device key that is key data for the device,
The communication unit receives encrypted data of confidential information,
The data processing unit executes encrypted data received by the communication unit and data processing using the device key to acquire confidential information, performs data processing using the confidential information, and obtains a data processing result. An information processing apparatus that performs a process of outputting via the communication unit.

  Furthermore, in one embodiment of the information processing apparatus of the present invention, the communication unit is necessary for generating a CPS unit key file storing a content-corresponding encryption key as encrypted data and a key for decrypting the CPS unit key file. The media key block (MKB) in which the media key to be stored as encrypted data is received, and the data processing unit receives the media key by data processing using the device key for the media key block (MKB). Obtaining and decrypting the CPS unit key file by data processing using a media key, and generating and outputting encrypted content by encrypting the content to which the CPS unit key obtained from the decrypted CPS unit key file is applied.

  Furthermore, in one embodiment of the information processing apparatus of the present invention, the communication unit is necessary for generating a CPS unit key file storing a content-corresponding encryption key as encrypted data and a key for decrypting the CPS unit key file. The media key block (MKB) in which the media key to be stored as encrypted data is received, and the data processing unit receives the media key by data processing using the device key for the media key block (MKB). The obtained CPS unit key file is decrypted by data processing using a media key, and content usage permission information corresponding to the decrypted CPS unit key is generated and output.

  Furthermore, in one embodiment of the information processing apparatus of the present invention, the content use condition is media binding information that allows content use only when a specific disc is loaded in the playback device, or content use is allowed only in a specific playback device. Including at least one of the device binding information to be generated, and when the data processing unit generates the media binding information, the operation value applied with the media ID received from the playback device via the communication unit is used for verification. When generating as device data and generating device binding information, an operation value to which the device ID received from the playback device via the communication unit is applied is generated as verification data, and the generated verification data is used as the CPS unit key. It is included in a file and provided to the playback device.

  Furthermore, in an embodiment of the information processing apparatus of the present invention, the content use permission information is content use permission information that limits a use frequency or a use period of the content in the playback device. Including a verification value for confirming validity, and the data processing unit includes a CPS unit key file that stores, as encrypted data, an encryption key corresponding to the content received from the playback device via the communication unit, and the CPS unit. An operation value based on a media key block (MKB) in which a media key necessary for generating a key for decrypting a key file is stored as encrypted data is generated as verification data and provided to the playback device.

  Furthermore, in one embodiment of the information processing apparatus of the present invention, the communication unit is necessary for generating a CPS unit key file storing a content-corresponding encryption key as encrypted data and a key for decrypting the CPS unit key file. A media key block (MKB) that stores the media key as encrypted data and a volume ID that is identification information corresponding to a set of discs on which content is recorded, and the data processing unit receives the media key block ( MKB), a media key is obtained by data processing using the device key, a volume unique key is obtained by data processing applying the media key and the volume ID, and decryption using the volume unique key is applied. By processing, the CPS unit key file Perform the decoding.

Furthermore, the second aspect of the present invention provides
A content distribution system having a server that executes content providing processing and a playback device that executes content acquisition processing from the server,
The playback device transmits a CPS unit key file storing a content encryption key as encrypted data to the server,
The server decrypts the CPS unit key file by data processing using a device key that is key data unique to the server device, performs content encryption processing using the CPS unit key included in the decrypted CPS unit key file, The content distribution system transmits the generated encrypted content to the playback device.

  Further, in one embodiment of the content distribution system of the present invention, the server further executes a CPS unit key file update process by adding verification data corresponding to the content usage conditions for the decrypted CPS unit key file, and updates CPS. A unit key file is generated and transmitted to the playback device.

  Furthermore, in one embodiment of the content distribution system of the present invention, the server further executes a process of generating content usage permission information corresponding to usage control information (Usage Rule) for the decryption CPS unit key file, and the playback device Send to.

Furthermore, the third aspect of the present invention provides
An information processing method executed in an information processing apparatus,
A communication unit receiving encrypted data of confidential information;
The data processing unit acquires the confidential information by executing the data processing using the encrypted data received by the communication unit and the device key that is the device-specific key data stored in the memory, and applies the confidential information. A data processing step of performing data processing and outputting a data processing result via the communication unit;
The data processing step includes
Executing a decryption process of the CPS unit key file storing the encryption key corresponding to the content as encrypted data;
Content encryption processing using a CPS unit key included in the CPS unit key file, CPS unit key file update processing for additionally adding verification data corresponding to content usage conditions for the CPS unit key file, or the CPS unit key The information processing method includes a step of executing at least one of generation processing of content usage permission information corresponding to usage control information (Usage Rule) for a file.

Furthermore, the fourth aspect of the present invention provides
A program for executing information processing in an information processing apparatus;
Receiving the encrypted data of the confidential information in the communication unit;
The data processing unit executes the data processing using the encrypted data received by the communication unit and the device key that is the device-specific key data stored in the memory to obtain the confidential information, and applied the confidential information. A data processing step for performing data processing and outputting a data processing result via the communication unit;
The data processing step includes
A decryption step of the CPS unit key file storing the encryption key corresponding to the content as encrypted data;
Content encryption processing using a CPS unit key included in the CPS unit key file, CPS unit key file update processing for additionally adding verification data corresponding to content usage conditions for the CPS unit key file, or the CPS unit key The program includes a step of executing at least one process of generating content usage permission information corresponding to usage control information (Usage Rule) for the file.

  The program of the present invention is a program that can be provided by, for example, a storage medium or a communication medium provided in a computer-readable format to an image processing apparatus or a computer system that can execute various program codes. By providing such a program in a computer-readable format, processing corresponding to the program is realized on the image processing apparatus or the computer system.

  Other objects, features, and advantages of the present invention will become apparent from a more detailed description based on embodiments of the present invention described later and the accompanying drawings. In this specification, the system is a logical set configuration of a plurality of devices, and is not limited to one in which the devices of each configuration are in the same casing.

  According to the configuration of one embodiment of the present invention, the server receives the encrypted data of the confidential information, performs data processing using the received encrypted data and the device key stored in the memory, and acquires the confidential information. Furthermore, confidential information is applied. For example, the decryption process of the CPS unit key file storing the content encryption key is executed, and the content encryption process using the CPS unit key acquired from the CPS unit key file is performed. Alternatively, additional processing such as binding information for the CPS unit key file is executed, and these are provided to the user device. With this configuration, it is possible to safely perform processing for providing confidential information to the server and data processing in the server without leaking confidential information.

It is a figure explaining the storage data and reproduction | regeneration sequence of a disc. It is a figure explaining the example of a utilization structure of a disk storage content and a server provision content. It is a figure explaining the utilization structural example of subsequent data in a reproducing | regenerating apparatus. It is a figure explaining the utilization structural example of subsequent data in a reproducing | regenerating apparatus. It is a figure explaining the example of subsequent data encryption processing of the server according to one Example of this invention. It is an example of the data transfer process between a server and another apparatus, and is a figure explaining the transfer process example of the confidential information using a disk. It is a figure explaining the data processing sequence performed in a server. It is an example of data transfer processing between a server and another device, and is a diagram for explaining an example of transfer processing of confidential information without using a disk. It is a figure explaining the structural example of the usage control information file recorded about bind conditions. It is an example of the data transfer process between a server and another apparatus, and is a figure explaining the process example which produces | generates bind information (Binding) in a server, and provides to a reproducing | regenerating apparatus (user apparatus). It is a figure explaining the data processing sequence performed in a server. It is a figure explaining bind information (Binding). It is a figure which shows the flowchart explaining the content utilization control sequence to which bind information (Binding) is applied. It is a data transfer process example between a server and another apparatus, and is a figure explaining the process example which produces | generates content use permission information (permission: Permission) in a server, and provides to a reproducing | regenerating apparatus (user apparatus). It is a figure explaining the data processing sequence performed in a server. It is a figure explaining content utilization permission information (permission: Permission). It is a figure which shows the flowchart explaining the content use control sequence to which content use permission information (permission: Permission) is applied. It is a figure explaining the hardware structural example of a server. FIG. 25 is a diagram for explaining an example hardware configuration of a playback device.

Hereinafter, details of an information processing apparatus, an information recording medium, an information processing method, and a computer program of the present invention will be described with reference to the drawings. The description will be made according to the following items.
1. 1. Reproduction processing example of content stored in disc storage data and reproduction device 2. Usage configuration of disk storage content and server-provided content Outline of processing in server 4. 4. Specific examples of data provision processing to server and data processing in server 4.1. Example of confidential information transfer process using disk 4.2. Example of transfer processing of confidential information without using a disk 4.3. Processing example in which bind information (Binding) is generated in the server and provided to the playback device (user device) 4.4. 4. Processing example in which content usage permission information (permission) is generated in the server and provided to the playback device (user device) Server and playback device configuration example

[1. Example of playback processing of content stored in disc storage data and playback device]
First, an example of content playback processing in the disc storage data and the playback device will be described with reference to FIG. FIG. 1 shows a disc 100 in which the encrypted content 105 is recorded, and a playback device (user device) 120 that loads the disc 100 and executes decryption and playback of the encrypted content 105. The disc 100 stores an MKB (media key block) 101, a volume ID 102, a CPS unit key file 103, a usage control information file (Usage File) 104, and encrypted content 105.

  The MKB (media key block) 101 is a key block that stores a media key necessary for generating a key applied to the decryption process of the encrypted content 105 as encrypted data. The media key can be extracted by MKB processing using the device key 121 stored in the playback device 120. However, the MKB is appropriately updated. In other words, update processing is performed as needed so that the media key cannot be acquired with the device key stored in the disabled playback device.

  The volume ID 102 is identification information (ID) set corresponding to various content sets such as a set of content of a certain title or a set of provided content for a certain period. The volume ID 102 is data necessary for generating a key to be applied to the decryption process of the encrypted content 105.

  The CPS unit key file 103 is a file that stores a CPS unit key applied to the decryption process of the encrypted content 105. Each CPS unit is set corresponding to the title of the content, for example, and a different CPS unit key is assigned to each title. The CPS unit key file 103 is an encrypted file, and stores an encrypted CPS unit key. In order to obtain the CPS unit key from the CPS unit key file 103, a decryption process according to a predetermined sequence is required.

  The usage control information file (Usage File) 104 is a file in which usage control information of the encrypted content 105 is recorded. For example, information regarding whether or not content copying is permitted is recorded. Further, conditions for using the subsequent data acquired from the server are recorded. The playback device 120 uses the content recorded on the disc and the content acquired from the server in accordance with the information recorded in the usage control information file 104.

  Note that the usage conditions of the content (such as subsequent data) recorded in the usage control information file 104 include media binding information that allows the use of subsequent data only when a specific disc is mounted, or a specific playback device (device). ) Only includes device binding information that allows the use of subsequent data. Details of the binding information will be described later.

  The encrypted content 105 is encrypted data of content such as a movie. The playback device 120 executes the sequence described below, executes the decryption process of the encrypted content 105, and uses (plays back) the content.

  Processing of the playback device 120 will be described. First, in step S11, the playback device 120 executes the process (decryption processing) of the MKB 101 by applying the device key 121, which is a key unique to the playback device (device) held in the memory in the playback device 120 in advance. To obtain the media key 122.

  Next, in step S12, a key generation process using the media key 122 acquired from the MKB 101 and the volume ID 102 read from the disk 100 is executed to generate the volume unique key 123.

  Further, in step S13, the generated volume unique key 123 is applied to execute the decryption process of the CPS unit key file 104 read from the disk 100, and the CPS unit key 124 is obtained from the decrypted CPS unit key file.

  Finally, in step S14, the decryption process of the encrypted content 105 read from the disc 100 is executed by applying the CPS unit key 124, and the content 125 is acquired and reproduced.

[2. Usage of disk storage contents and server-provided contents]
Next, a usage configuration example of the disk storage content and the server-provided content will be described with reference to FIG.

  A playback device (user device) 120 that executes playback processing of content stored on the disc 100 is subsequent data corresponding to the content stored on the disc, for example, caption data, trailer, or bonus data when the disc is movie content. Various subsequent data such as service content such as a game or a CPS unit key file can be acquired from a server via a network such as the Internet. The subsequent data acquired from the server is stored in a local storage unit such as a hard disk of the user device, and can be reproduced together with the content stored in the disk. Alternatively, when the subsequent data is a CPS unit key, the stored content can be decrypted by applying the key.

  FIG. 2 shows a content editing unit 150 that performs content creation and editing processing, a disc factory 170 that receives content from the content editing unit 150 and creates a disc 100 storing the content, and stores the disc by mounting the disc 100. 1 shows a playback device (user device) 120 that performs content playback processing. Furthermore, a server 190 that provides subsequent data (caption, service data, advertisement data, movie trailer, application program, CPS unit key, etc.) corresponding to the content stored on the disc 100 to the playback device (user device) 120 is shown. ing.

  The reproduction apparatus (user apparatus) 120 transmits identification information (ID) 191 such as identification information (media ID) of the disc 100 and identification apparatus (device ID) of the reproduction apparatus 150 to the server 190, for example. Various subsequent data 192 can be acquired.

  A configuration example of use of subsequent data in the playback device 120 will be described with reference to FIGS. 3 and 4. The playback device 120 shown in FIG. 3 acquires the subsequent data 251 from the server 190 and stores it in the local storage unit 250 such as a hard disk. An encrypted content 201 such as a movie is recorded on the disc 100 set in the playback device 120. The disc 100 further records a CPS unit key file 202 which is a CPS unit key storage file applied to the decryption process of the encrypted content 201. In addition to the above, various data described with reference to FIG. 1 are recorded on the disc 100, but are omitted in FIG.

  When the playback device 120 plays back the encrypted content 201, the CPS unit key is extracted from the CPS unit key file 202 and the decryption process of the encrypted content 201 is executed. As described with reference to FIG. 1, this decryption process is performed as a process to which various data other than the CPS unit key, such as a device key stored in the memory of the playback device 120, is applied.

  In the example illustrated in FIG. 3, the subsequent data 251 acquired by the playback device 120 from the server 190 and stored in the local storage unit 250 is also encrypted data. The subsequent data 251 is subsequent data encrypted with the same CPS unit key as the encrypted content 201 stored on the disc 100, that is, with the CPS unit key included in the CPS unit key file 202 recorded on the disc 100. . Accordingly, the playback device 120 can play back the subsequent data 251 by applying the CPS unit key acquired from the CPS unit key file 202 recorded on the disc 100 to perform the decryption process of the subsequent data 251.

  The example shown in FIG. 3 is a setting applied when, for example, the encrypted content 201 stored on the disc 100 is movie content and the subsequent data 251 is caption data corresponding to a movie.

  Subsequent data provided to the playback device 120 by the server 190 may be a CPS unit key file in addition to various data such as content such as caption data, service data, advertisement data, or applications. This setting will be described with reference to FIG.

  The example illustrated in FIG. 4 is an example in which the playback device 120 acquires the subsequent data acquired from the server 190 and stored in the local storage unit 250 as the CPS unit key file 252.

  The disc 100 includes a CPS unit key file 205 that stores encrypted content (title 1) 203, encrypted content (title 2) 204, and a CPS unit key applied to decrypt the encrypted content (title 1) 203. Is stored.

  However, the disc 100 does not store a CPS unit key file storing a CPS unit key applied to decrypting the encrypted content (title 2) 204. Therefore, the playback device 120 cannot decrypt and play back the encrypted content (title 2) 204 even if the recorded data on the disc 100 is used.

  The playback device 120 acquires a CPS unit key file storing a CPS unit key applied to decrypting the encrypted content (title 2) 204 from the server 190, and stores the acquired CPS unit key file 252 in the local storage unit 250. .

  The playback device 120 can play back the encrypted content (title 2) 204 stored on the disc 100 by decryption processing using the CPS unit key file 252 acquired from the server 190.

  Thus, the server provides various data as subsequent data to the user's playback device, and the user can perform playback of the subsequent data received from the server and data processing using the subsequent data.

[3. Overview of server processing]
As described above, the server (see FIG. 3) that performs the process of providing the subsequent data to the playback device (user device) 120 is recorded in the CPS unit key file stored in the disc 100 attached to the playback device 120 of the user. By applying the same key as the CPS unit key, the subsequent data is encrypted and provided to the playback device 120 of the user.

  Therefore, the server must execute an encryption process using the CPS unit key. The CPS unit key is confidential information generated by the disc factory. When the CPS unit key leaks, there is a problem that the encrypted content stored on the disc can be decrypted and the content cannot be protected. Therefore, it is dangerous to transfer the CPS unit key via the network, which is not preferable from the viewpoint of content protection.

  Therefore, in one configuration according to the present invention, a server that performs processing for providing subsequent data also executes processing according to the same process as that of the playback device (user device) to execute decryption of the CPS unit key file. And Processing of the server according to one embodiment of the present invention will be described with reference to FIG.

  The server 190 is configured to hold the device key 301 shown in FIG. 5 in the memory in the server 190 in advance. This device key 301 is a key unique to the server (device) device, and is a key applied to obtain a media key from the MKB. This device key 301 is provided in advance from the key management center.

  The server 190 further includes an MKB (media key block) 302 storing the media key as encrypted data, a volume ID 303 set as identification information corresponding to a set of contents recorded on the disc, and a CPS unit key as encrypted data. The CPS unit key file 304 that is an encrypted file stored as is acquired from the outside.

The MKB (media key block) 302 stores the media key in an encrypted state, and a valid device key is required to extract the media key from the MKB. Even if the MKB itself leaks, confidential information is stored. There is little possibility that the media key is leaked.
The volume ID 303 is not confidential information, and it does not matter if data leaks.

  The CPS unit key file 304 stores a CPS unit key that is confidential information. However, the CPS unit key file is an encrypted file, and the CPS unit key is stored as encrypted data in the CPS unit key file. Yes. The encrypted CPS unit key file can be decrypted only by the volume unique key acquired by the sequence described above with reference to FIG. Therefore, even if the CPS unit key file itself leaks, there is little possibility that the CPS unit key that is encrypted data in the file is illegally acquired.

  In the configuration of the present invention, the device key 301 is provided to the server 190 in advance, and the MKB (media key block) 302, the volume ID 303, and the CPS unit key file 304, which is an encrypted file, are provided as necessary. For example, it is provided via a network. The provider of these data is, for example, a disc factory or a playback device (user device) holding a disc. The disc factory holds these data in order to encrypt the content recorded on the disc to be manufactured.

  For example, when MKB (media key block) 302, volume ID 303, and CPS unit key file 304 are transferred from a disk factory or playback device (user device) to a server via a network such as the Internet, these network transfer data are There is a possibility of leakage.

  However, as described above, a highly confidential media key or CPS unit key is stored in an MKB or CPS unit key file in an encrypted state, and an MKB (media key block) 302 or a CPS unit key file 304 is stored. Is illegally acquired in the transfer path, it is extremely unlikely that a highly confidential media key or CPS unit key stored as encrypted data will be illegally acquired. Therefore, the possibility of leakage of highly confidential data is significantly reduced.

  The server uses these acquired data to encrypt subsequent data. A processing sequence executed by the server will be described with reference to FIG. First, in step S101, the server 190 applies the device key 301, which is a key unique to the server (device) held in the memory in the server 190 in advance, and performs processing (decryption processing) of the MKB 302 acquired from the outside. Execute to obtain the media key 311.

  Next, in step S102, a volume generation key 312 is generated by executing a key generation process using the media key 311 acquired from the MKB 302 and the volume ID 303 acquired from the outside.

  In step S103, the generated volume unique key 312 is applied to execute decryption processing of the CPS unit key file 304 acquired from the outside to acquire the decrypted CPS unit key file 313.

  Finally, in step S104, processing using the decrypted CPS unit key file 313 is performed. For example, subsequent data encryption processing using a CPS unit key extracted from the decrypted CPS unit key file 313, or binding information (Binding) or content usage permission information (Permission) for the decrypted CPS unit key file 313 CPS unit key file update processing such as additional recording). These processes will be described in detail later.

  Thus, in this processing example, the server holds the device key as the device unique key in the memory, and each piece of data in which confidential information is stored as encrypted data, that is, MKB (media key block) 302, volume ID 303, The CPS unit key file 304 is received. The media key and the CPS unit key as confidential information are received as encrypted data, and processing that significantly reduces the possibility of leakage of the confidential information becomes possible.

[4. Specific examples of data provision processing to the server and data processing in the server]
Next, specific examples of data provision processing such as a CPS unit key file for the server and a plurality of examples of data processing in the server and data provision processing from the server will be described with reference to FIG.

The following four processing examples will be described sequentially.
4.1. Example of confidential information transfer process using disk (Fig. 6)
4.2. Example of transferring confidential information without using a disk (Fig. 8)
4.3. Processing example in which binding information (Binding) is generated in the server and provided to the playback device (user device) (FIG. 10)
4.4. Processing example in which content use permission information (permission: permission) is generated in the server and provided to the playback device (user device) (FIG. 14)

(4.1. Example of confidential information transfer process using disk)
First, an example of confidential information transfer processing using a disk will be described with reference to FIG.
In this processing example, as shown in FIG. 6, the volume ID, the CPS unit key file, and the MKB are transferred from the disk factory 170 to the server 190 via the content editing unit 150.

  In step S201, the content editing unit 150 provides the master data 401 including the content to be recorded on the disc to the disc factory 170. The disc factory uses this master data 401 to generate encrypted content for recording on the disc and manufacture the disc. The disc manufacturing process is the same as that described above with reference to FIG. The disc manufactured in the disc factory 170 is provided to a playback device (user device) (not shown). As described with reference to FIG. 1, the disc stores various data such as MKB in addition to the encrypted content.

  As shown in FIG. 6, the disk factory 170 provides the manufactured disk 411 and volume ID (file) 412 to the content editing unit 150 in step S202. As described with reference to FIG. 1, the disk 411 stores MKB (media key block) storing the media key as encrypted data, volume ID, and CPS unit key as encrypted data in addition to the encrypted content. CPS unit key file. However, the volume ID recorded on the disc may be written by a recording method different from general data, and a special reproduction process may be required for reading.

  Although the content editing unit 150 can read the volume ID from the disc by a special data reproduction process, in the example shown in FIG. 6, the content editing unit 150 has a setting that does not require the special data reproduction process. . That is, the disc factory 170 provides the disc 411 and the volume ID file 412 to the content editing unit 150. As described above, since the volume ID itself is not confidential, it does not matter if it is leaked.

  The CPS unit key file recorded on the disk 411 stores the CPS unit key as confidential information. However, the CPS unit key file is an encrypted file, and it is unlikely that the CPS unit key as confidential information will leak. . Similarly, the MKB recorded on the disk 411 stores a media key as confidential information. However, since the media key in the MKB is stored in the MKB as encrypted data, the media key as confidential information is stored. Is unlikely to leak.

  The content editing unit 150 reads the MKB and CPS unit key file from the disk 411 received from the disk factory 170, and in step S203, the volume ID received from the disk factory, and the MKB and CPS unit key file (encrypted from the disk 411). File) is provided to the server 190 that performs encryption processing of subsequent data.

  The CPS unit key file includes many CPS unit keys. In step S203, the content editing unit 150 notifies the server 190 of a CPS unit number as information for specifying a CPS unit key to be applied to encryption of subsequent data.

The server 190 receives the following data from the content editing unit 150. That is,
Volume ID,
MKB,
CPS unit key file (encrypted file),
CPS unit number,
Receive these data.

  The server 190 applies these received data and executes the same processing as the sequence described above with reference to FIG. 5 to generate encrypted subsequent data. In step S <b> 204, the server 190 provides the generated encrypted subsequent data to the content editing unit 150. Note that the CPS unit key file is also returned to the content editing unit 150 when there is no subsequent use plan.

  Note that the processing example shown in FIG. 6 is a setting in which the server 190 performs generation processing of encrypted subsequent data and provides the generated encrypted subsequent data to the content editing unit 150. This is an example in which encrypted subsequent data is provided to the content providing server and the encrypted subsequent data is provided from the content providing server to the playback device (user device). The server 190 shown in FIG. 6 may be set to function as a content providing server. In this case, the server 190 performs a process for generating the subsequent data for encryption, and also provides a process for providing the subsequent data for encryption generated for the playback apparatus (user apparatus) via the network.

  A detailed sequence of processing executed by the server 190 in the setting shown in FIG. 6 will be described with reference to FIG. As shown in FIG. 7, the server 190 receives the MKB 302, the volume ID 303, and the CPS unit key file 304 from the disc factory 170 via the content editing unit 150.

  In the MKB 302, a media key that is confidential information is stored as encrypted data. The CPS unit key file 304 stores a CPS unit key, which is confidential information, as encrypted data.

  The processing in steps S101 to S103 is similar to the processing described above with reference to FIG. In step S103, the decrypted CPS unit key file 313 is acquired.

  Next, in step S121, the server 190 extracts the CPS unit key to be applied to the encryption process of the subsequent data 305 from the decrypted CPS unit key file 313, and performs the encryption process of the subsequent data 305.

  Although many CPS unit keys are stored in the CPS unit key file, the server 190 selects the CPS unit key according to the CPS unit number received from the content editing unit 150 and encrypts the subsequent data 305. I do. The encrypted subsequent data 314 generated in this way is transmitted to the playback device (user device) 120 or the content editing unit 150.

(4.2. Example of transferring confidential information without using a disk)
Next, an example of confidential information transfer processing without using a disk will be described with reference to FIG.
As shown in FIG. 8, this processing example is a processing example of transferring the volume ID, CPS unit key file, and MKB from the disk factory 170 to the server 190 via the content editing unit 150, as in FIG. .

  In step S211, the content editing unit 150 provides master data 401 including content to be recorded on the disc to the disc factory 170. The disc factory uses this master data 401 to generate encrypted content for recording on the disc and manufacture the disc. The disc manufacturing process is the same as that described above with reference to FIG.

  In the example shown in FIG. 8, the disc factory 170 provides the content editing unit 150 with the volume ID (file), CPS unit key file, and MKB in step S212. For example, it is provided via a network. That is, in the example shown in FIG. 8, such data can be provided via a network, for example, without using a disk as in the processing example described with reference to FIG.

  Although the CPS unit key file stores the CPS unit key as confidential information, the CPS unit key file is an encrypted file, and the possibility of leakage of the CPS unit key as confidential information is low. Similarly, the MKB stores a media key as confidential information. However, since the media key in the MKB is stored in the MKB as encrypted data, the possibility that the media key as confidential information is leaked is low. .

  In step S213, the content editing unit 150 provides the server 190 with the MKB, the CPS unit key file (encrypted file), the volume ID, and the CPS unit number received from the disk factory 170. The server applies these received data, and executes the process according to the sequence described above with reference to FIG. 5 to generate the subsequent encrypted data. In step S214, the server 190 provides the generated encrypted subsequent data to the content editing unit 150. Note that the CPS unit key file is also returned to the content editing unit 150 when there is no subsequent use plan.

  Similarly to the server 190 shown in FIG. 6, when the server 190 functions as a content providing server, the server 190 performs processing for generating encrypted subsequent data and a playback device ( The user device is provided with the encrypted subsequent data generated via the network.

  In the setting shown in FIG. 8, the detailed sequence of processing executed by the server 190 is the same sequence as described above with reference to FIG.

(4.3. Processing example in which bind information (Binding) is generated in the server and provided to the playback device (user device))
Next, with reference to FIG. 9 and FIG. 10, an example of processing for generating binding information (Binding) in the server and providing it to the playback device (user device) will be described.

First, the binding information (Binding) will be described with reference to FIG. Bind information (Binding) is setting information for content usage conditions corresponding to subsequent data provided from a server to a playback device (user device) or content stored on a disc. In particular,
(1) Media Binding
(2) Device binding
(3) Device / Media Binding (Device / Media Binding)
There are these three types.
As shown in FIG. 9, a content usage condition 351 corresponding to any of the above binding conditions is recorded in a usage control information file 350 that defines usage conditions for various contents.

Media binding is content usage condition information that is set to permit the use of content such as subsequent data only when a specific medium (disc) is attached to the playback device.
For example, when the use condition of the subsequent data provided by the server is set as the media binding, the playback device reads out the subsequent data from the local storage unit and uses (plays back) the specific media (disc) in the playback device. A process of confirming whether or not it is attached is performed. Only when it is confirmed that a specific medium (disc) is attached to the reproducing apparatus, the subsequent data can be reproduced.

Device binding is content usage condition information that is set to permit the use of content such as subsequently generated data that is set to permit the use only in a specific playback device (device).
When the use condition of the subsequent data provided by the server is set as device binding, the playback apparatus reads out the subsequent data from the local storage unit and uses (plays back) the playback apparatus that is permitted to use the subsequent data ( To check whether the device is a device). Only when it is confirmed that the reproduction device (device) is permitted to use the subsequent data, the subsequent data can be reproduced.

  Device / Media Binding (Device / Media Binding) is a combination of the above-mentioned media binding (Media Binding) and device binding (Device Binding), and can be used only when the combination is a specific medium and a specific playback device. This is the usage condition information of the content to be played.

  For example, when such various use restrictions are set for the subsequent data, a specific process is performed between the server that provides the subsequent data and the playback device (user device) that uses the subsequent data when the subsequent data is provided. . This process is the process of steps S222 to S223 shown in FIG.

  The process shown in FIG. 10 will be described. The processing in step S221 is processing similar to that described above with reference to FIGS. 6 and 8, and is processing for providing master data 401 including content from the content editing unit 150 to the disc factory 170. The disc factory uses this master data 401 to generate encrypted content for recording on the disc and manufacture the disc. The disc manufacturing process is the same as that described above with reference to FIG. The manufactured disc is provided to the playback device (user device) 120.

  After the disc is loaded in the playback device (user device) 120, the processing in steps S222 to S223 is executed between the server 190 and the playback device (user device) 120.

  Prior to the start of the processing in step S222, communication is performed between the server 190 and the playback device (user device) 120, and the type of subsequent data that can be provided from the server 190 to the playback device 120, and each subsequent data It is assumed that usage conditions have been notified. The use condition is information indicating whether the data is one of the above-described media binding, device binding, device / media binding, or data not corresponding to any of them.

  The process of step S222 is a subsequent data acquisition request process from the playback device 120 to the server 190. The playback device 120 reads the volume ID, the CPS unit key file (encrypted file), and the MKB from the disk attached to the playback device in the server 190 and transmits them to the server 190. Further, a CPS unit key number, which is identification information of a CPS unit key applied to decryption of the content to be reproduced, is acquired from the usage control information file recorded on the disc and transmitted to the server 190. For example, it is transmitted via a network such as the Internet.

  Although the CPS unit key file stores the CPS unit key as confidential information, the CPS unit key file is an encrypted file, and the possibility of leakage of the CPS unit key as confidential information is low. Similarly, the MKB stores a media key as confidential information. However, since the media key in the MKB is stored in the MKB as encrypted data, the possibility that the media key as confidential information is leaked is low. .

  Furthermore, in addition to these pieces of information, the playback device 120 provides the server 190 with data for creating binding information (Binding). The data to be provided differs depending on the usage conditions of the acquired subsequent data.

  When the subsequent data to be acquired is media binding, a media ID that is media (disc) identification information is transmitted to the server. The media ID is read from a disc mounted on the playback device 120. Specifically, for example, a serial number (PMSN) recorded as disc-specific identification information is read from the disc and transmitted to the server.

  On the other hand, when the subsequent data to be acquired is device binding, a device ID that is identification information of the playback apparatus (device) is transmitted to the server. The device ID may be read from the memory in the playback device 120, or the playback device 120 may generate a random number (Nonce) and use this as the device ID. When transmitting the generated random number (Nonce) to the server as a device ID, the playback device 120 stores the random number (Nonce) in a memory in the playback device, for example, a local storage unit.

  Further, when the subsequent data to be acquired is device / media binding, the above-mentioned media ID and device ID are transmitted to the server.

  The server 190 generates binding information according to the binding mode of the subsequent data provided to the playback device 120. The bind information is set as usage condition information for subsequent data provided by the server 190 to the playback device 120.

  For example, when the subsequent data to be provided is media binding, a message authentication code (MAC: Message Authentication Code) of a media ID (for example, PMSN) that is media (disc) identification information is generated as bind information, and the playback device 120 Send to.

  Also, when the subsequent data to be provided is device binding, a message authentication code (MAC: Message Authentication Code) that is identification information of the playback device (device) is generated as binding information and transmitted to the playback device 120. .

  If the subsequent data to be provided is a device / media binding, the above-mentioned media ID MAC and device ID MAC, or a MAC based on the total data of the two IDs is generated as binding information, and the playback device 120 Send.

  In step S223 shown in FIG. 10, the server 190 provides any of the above-described binding information, encrypted content (encrypted data), and CPS unit key file. Note that the bind information is provided in the playback device 120 by being recorded in, for example, a CPS unit key file.

  That is, when the subsequent data to be provided to the playback device 120 is usage control content based on any of the above-described binding information, the server 190 stores the CPS unit key file received from the playback device 120 in step S222 shown in FIG. Update processing of the CPS unit key file to which the MAC value is added is performed. In step S223, the server 120 transmits the updated CPS unit key file to which the binding information has been added, together with the encrypted content (subsequent data), to the playback device 120.

  The playback device 120 receives the updated CPS unit key file from the server 190 and uses the content according to the bind condition.

  In the example illustrated in FIG. 10, a CPS unit key file including a CPS unit key as encrypted data and an MKB (media key block) including a media key as encrypted data are transmitted from the playback device 120 to the server 190. The transmission process is performed via a network such as the Internet. Also in this case, as described with reference to FIGS. 6 and 8, the CPS unit key or media key as confidential data is stored as encrypted data in the CPS unit key file and the MKB, respectively. Therefore, even if the CPS unit key file or MKB leaks via the network, the possibility of leakage of the CPS unit key or media key, which is confidential information, is reduced, and secure confidential information can be transferred. .

  A specific example of the process of the server 190, the update process of the CPS unit key file, and the process of the playback device in the setting shown in FIG. 10 will be described with reference to FIGS.

  FIG. 11 is a diagram illustrating a detailed sequence of processing executed by the server 190 in the setting shown in FIG. The server 190 receives the MKB 302, the volume ID 303, and the CPS unit key file 304 from the playback device (user device) 120 as shown in FIG.

  In the MKB 302, a media key that is confidential information is stored as encrypted data. The CPS unit key file 304 stores a CPS unit key, which is confidential information, as encrypted data.

  The processing in steps S101 to S103 is similar to the processing described above with reference to FIG. In step S103, the decrypted CPS unit key file 313 is acquired.

  Next, in step S121, the server 190 extracts the CPS unit key to be applied to the encryption process of the subsequent data 305 from the decrypted CPS unit key file 313, and performs the encryption process of the subsequent data 305.

  A number of CPS unit keys are stored in the CPS unit key file, but the server 190 selects the CPS unit key according to the CPS unit number received from the playback device (user device) 120 and stores the subsequent data 305. Perform encryption processing.

  Further, in step S131, the server 190 performs a CPS unit key file update process. Specifically, a process of adding bind information is executed.

  With reference to FIG. 12, an example of additional processing for binding information will be described. FIG. 12 shows the CPS unit key file 520 in which the bind information 521 is written and the content use condition information 351 related to the bind information recorded in the use control information file 350 recorded in advance on the disc.

  As shown in the CPS unit key file 520 of FIG. 12, the CPS unit key file stores a number of CPS unit keys from CPS unit keys 1 to nnn. As described above, these are recorded as encrypted data. The bind information [MAC of (media ID)] 521 shown at the bottom of the CPS unit key file 520 shown in FIG. 12 is the bind information 521 generated and added by the server 190.

  As described above, the bind information includes media bind, device bind, device / media bind, etc., and the server calculates the bind information according to the bind mode of the provided content, writes it in the CPS unit key file, and plays it. Provide to the device. The example shown in FIG. 12 shows an example of writing bind information corresponding to media bound content.

  A usage control information file 350 shown in FIG. 12 is a usage control information file 350 recorded on a disc mounted on the playback device 120. As shown in FIG. 12, the usage control information file 350 includes a description of the binding conditions for the application target content of each CPS unit key recorded in the CPS unit key file. Although not shown in the figure, the usage control information file also records information on the CPS unit key number corresponding to each content, and information on usage conditions (such as the allowable number of reproductions and the allowable number of copies) of each content. ing.

The following binding condition information is recorded in the usage control information file 350 shown in FIG.
CPS unit keys aa to bb = no content binding key CPS unit keys cc to dd = media binding key CPS unit keys ee to ff = device binding key CPS unit keys gg to hh = device / media binding key It is a setting.

For example, when the content that the server 190 provides to the playback device is media-bound content, the CPS unit key that is applied to the decryption of subsequent data is:
It is set as one key in the range of CPS unit keys cc to dd.
When applying this key, first, a verification process using the bind information (MAC value) recorded in the CPS unit key file is performed. That is, the media ID is read from the disc loaded in the playback device, the MAC value is calculated, and the calculated MAC value is compared with the MAC value recorded in the binding information 521 of the CPS unit key file 520. When the MAC values match, it is allowed to acquire the designated CPS unit key and decrypt the content. If they do not match, it is determined that the correct disc is not loaded, and the use of the content is stopped.

  The update process of the CPS unit key file in step S131 shown in FIG. 11 is a process of adding the bind information 521 shown in FIG. 12 to the CPS unit key file, for example. The server 190 executes such an update of the CPS unit key file. In step S132 shown in FIG. 11, the server 190 further applies the volume unique key 312 to execute the encryption process of the CPS unit key file to update the CPS unit key file. A key file (encrypted file) 315 is generated.

  The updated CPS unit key file (encrypted file) 315 and the encrypted subsequent data 314 generated in this way are transmitted to the playback device (user device) 120. This transmission process corresponds to the process of step S223 shown in FIG.

  The playback device 120 uses the content (subsequent data) according to the binding information by applying the CPS unit key file to which the binding information is added, and uses the content using the specific binding information executed by the playback device 120 The sequence will be described with reference to the flowchart shown in FIG.

  In step S301, the playback device refers to the usage control information file and acquires a CPS unit key number corresponding to the playback target content. Further, based on the acquired key number, it is confirmed whether the key is set with the bind condition of the CPS unit key. This can be confirmed based on the record of the usage control information file 350 described with reference to FIG.

First, in step S302, it is determined whether the CPS unit key corresponding to the key number is a key for which media binding is set as a binding condition. If media binding is set, the process proceeds to step S303. If not set, the process proceeds to step S306.
If the media binding is set, the process proceeds to step S303, where the media ID (for example, PMSN) is read from the disc mounted on the playback device, and the MAC value is calculated.
In step S304, the verification MAC value included in the bind information recorded in the CPS unit key file is compared with the calculated MAC value.

  If it is determined in step S305 that the calculated MAC value matches the verification MAC value, the process proceeds to step S306. If it is determined that they do not match, it is determined that the correct disc is not loaded, and the process proceeds to step S310 where the decryption and use of the content to which the CPS unit key is applied are stopped.

  If it is determined in step S302 that media binding is not set as the binding condition, or if it is determined in step S305 that the calculated MAC value matches the verification MAC value, the process proceeds to step S306. In step S306, it is determined whether or not device binding is set as the binding condition for the content-compatible CPS unit key. The determination is made according to the description of the usage control information file 350 shown in FIG.

If device binding is set, the process proceeds to step S307. If not set, the process proceeds to step S311.
If the device binding is not set, the process proceeds to step S311, where a CPS unit key corresponding to the content is acquired from the CPS unit key file, and decryption and playback processing of the content to which the CPS unit key is applied is performed. This decoding and reproduction process is executed according to the sequence described above with reference to FIG.

If it is determined in step S306 that device binding is set, the process proceeds to step S307, where a device ID (for example, a random number) is read from the memory in the playback apparatus, and a MAC value is calculated.
In step S308, the verification MAC value included in the bind information recorded in the CPS unit key file is compared with the calculated MAC value.

  If it is determined in step S309 that the calculated MAC value matches the verification MAC value, the process advances to step S311 to acquire a CPS unit key corresponding to the content from the CPS unit key file, and the content of the content to which the CPS unit key is applied. Perform decryption and playback processing. This decoding and reproduction process is executed according to the sequence described above with reference to FIG.

  If it is determined in step S309 that the calculated MAC value does not match the verification MAC value, it is determined that the content is not recorded in the correct playback device, and the process proceeds to step S310, where the decryption of the content using the CPS unit key is performed. Use will be suspended.

(4.4. Processing example in which content usage permission information (permission) is generated in the server and provided to the playback device (user device))
Next, with reference to FIG. 14, an example of processing in which content usage permission information (permission) is generated and provided to the playback device (user device) in the server will be described.

First, content usage permission information (permission) will be described. The content use permission information (permission) is setting information for content use conditions corresponding to subsequent data provided from the server to the playback device (user device) or disc storage content. In particular,
(1) Content usage permission information (permission) that permits one-time use of content (reproduction, etc.)
(2) Content usage permission information (permission) permitting content usage (playback, etc.) for multiple times (n times)
(3) Content usage permission information (permission) that permits content usage (playback, etc.) within the set period
For example, there are these types.

  The playback device stores content use permission information (permission) provided by the server 190 in the local storage unit. For example, when content usage permission information (permission) is associated with subsequent data provided by the server, the playback device refers to the content usage permission information (permission) before using the subsequent data and within the usage permission range. Verify whether it exists. Only when it is within the use permission range, decoding and use of the subsequent data is executed, and when it is outside the use permission range, decoding and use of the subsequent data is stopped.

  For example, when content use permission information (permission) permitting one-time use of content (such as playback) is received and the content is used, the content use permission information is deleted, and then This setting is not available for content. However, if new content use permission information (permission) is received from the server, it can be used.

  In addition, when using content associated with content use permission information (permission) that permits content use (playback, etc.) only multiple times (n times), the playback device records the content use permission information (permission). An update process is performed to decrement (decrement) the permitted use frequency.

  In addition, when using content associated with content usage permission information (permissions) that permits content usage (playback, etc.) within the set period, date and time confirmation is performed using the clock in the playback device or the clock on the network. To do. That is, a determination process is executed to determine whether or not the current date and time when the content is to be used is within the set period set in the content use permission information (permission). The use of content is permitted only when the current date and time is within the set period set in the content use permission information (permission).

  Note that the content use permission information (permission) generated by the server 190 includes a title ID as an identifier corresponding to content to be used, a volume ID as a disc-compatible identifier, and a playback device as identification information of the playback device. The calculation data (content use permission information (permission) verification value) to which the random number (Nonce) generated by is applied is included.

The server 190 calculates the content use permission information (permission) verification value, for example, using the following arithmetic expression.
Content use permission information (permission) verification value = AES-128E (Kvu, Kt (XOR) Nonce (XOR) AES_H (volume ID‖title ID))
Each data in the above formula has the following meaning.
Kvu: Volume unique key (XOR): Exclusive OR operation Kt: CPS unit key (= title key)
Nonce: a random number generated by the playback device and transmitted to the server (see step S232 in FIG. 14)
AES_H (volume ID‖title ID) is a hash value for the concatenated data of the volume ID recorded on the disc and the title ID corresponding to the content,
AES-128E (Kvu, Kt˜): AES encryption processing applying a volume unique key (Kvu) to the calculation result of Kt or less,
The content use permission information (permission) verification value is, for example, 16-byte data. The 16-byte data is used as verification data for content usage permission information. Whether or not the content requires usage permission based on the content usage permission information (Permission) is described in the usage control information file (CPS Unit Usage File).

  The server 190 applies the received data from the playback device 120 in step S232 shown in FIG. 14, and generates the content use permission information (permission) verification value by the above calculation. This is content use permission information corresponding to the decrypted CPS unit key. The content usage permission information (permission) may further include a description of usage conditions. For example, the content usage conditions such as the above-described one time, a plurality of times, or a time limit. The server 190 generates such content use permission information (permission) and transmits it to the playback device 120.

  When using content such as subsequent data associated with content usage permission information (permission), the playback device 120 executes the same calculation process as the above calculation, and calculates the value received from the server (verification) Value). If the calculated value matches the verification value, the content is used according to the content usage conditions. If they do not match, the content usage is stopped.

  For example, when such various use restrictions are set for the subsequent data, a specific process is performed between the server that provides the subsequent data and the playback device (user device) that uses the subsequent data when the subsequent data is provided. . This process is the process of steps S232 to S233 shown in FIG.

  The process shown in FIG. 14 will be described. The processing in step S231 is processing similar to that described above with reference to FIGS. 6 and 8, and is processing for providing master data 401 including content from the content editing unit 150 to the disc factory 170. The disc factory uses this master data 401 to generate encrypted content for recording on the disc and manufacture the disc. The disc manufacturing process is the same as that described above with reference to FIG. The manufactured disc is provided to the playback device (user device) 120.

  After the disc is loaded in the playback device (user device) 120, the processing in steps S232 to S233 is executed between the server 190 and the playback device (user device) 120.

  Prior to the start of the process of step S232, communication is performed between the server 190 and the playback device (user device) 120, and the type of subsequent data that can be provided from the server 190 to the playback device 120, and each subsequent data It is assumed that usage conditions have been notified.

  The process in step S232 is a subsequent data acquisition request process from the playback device 120 to the server 190. The playback device 120 reads the volume ID, the CPS unit key file (encrypted file), and the MKB from the disk attached to the playback device in the server 190 and transmits them to the server 190. Further, a CPS unit key number, which is identification information of a CPS unit key applied to decryption of the content to be reproduced, is acquired from the usage control information file recorded on the disc and transmitted to the server 190.

  Although the CPS unit key file stores the CPS unit key as confidential information, the CPS unit key file is an encrypted file, and the possibility of leakage of the CPS unit key as confidential information is low. Similarly, the MKB stores a media key as confidential information. However, since the media key in the MKB is stored in the MKB as encrypted data, the possibility that the media key as confidential information is leaked is low. .

  Further, in addition to these pieces of information, the playback device 120 provides the server 190 with data for creating content usage permission information (permissions). The provided data is, for example, a random number (Nonce) generated by the playback device 120. The playback device 120 transmits the generated random number (Nonce) to the server and stores it in a memory in the playback device, for example, a local storage unit.

The server 190, based on the data received from the playback device 120, the arithmetic expression described above, that is,
Content usage permission information (permissions)
= AES-128E (Kvu, Kt (XOR) Nonce (XOR) AES_H (volume ID‖title ID))
A content usage permission information (permission) verification value is calculated according to the above formula, and further content usage permission information (permission) including a description of usage conditions is generated.

  In step S233 shown in FIG. 14, the server 190 performs content use permission information (permission) including the above-described content use permission information (permission) verification value and description of use conditions, encrypted content (encrypted data), CPS. The unit key file is provided to the playback device 120.

  The playback device 120 receives the content usage permission information (permission), the encrypted content (encrypted data), and the CPS unit key file from the server 190, and uses the content according to the content usage permission information (permission). Do.

  Also in the example illustrated in FIG. 14, as in the example illustrated in FIG. 10, the CPS unit key file including the CPS unit key as encrypted data and the MKB (media key block) including the media key as encrypted data are included in the playback device 120. To the server 190. The transmission process is performed via a network such as the Internet. Also in this case, as described with reference to FIGS. 6 and 8, the CPS unit key or media key as confidential data is stored as encrypted data in the CPS unit key file and the MKB, respectively. Therefore, even if the CPS unit key file or MKB leaks via the network, the possibility of leakage of the CPS unit key or media key, which is confidential information, is reduced, and secure confidential information can be transferred. .

  A specific example of the process of the server 190, the update process of the CPS unit key file, and the process of the playback device in the setting shown in FIG. 14 will be described with reference to FIGS.

  FIG. 15 is a diagram for explaining a detailed sequence of processing executed by the server 190 in the setting shown in FIG. As shown in FIG. 15, the server 190 receives the MKB 302, the volume ID 303, and the CPS unit key file 304 from the playback device (user device) 120.

  In the MKB 302, a media key that is confidential information is stored as encrypted data. The CPS unit key file 304 stores a CPS unit key, which is confidential information, as encrypted data.

  The processing in steps S101 to S103 is similar to the processing described above with reference to FIG. In step S103, the decrypted CPS unit key file 313 is acquired.

  Next, in step S121, the server 190 extracts the CPS unit key to be applied to the encryption process of the subsequent data 305 from the decrypted CPS unit key file 313, and performs the encryption process of the subsequent data 305.

  A number of CPS unit keys are stored in the CPS unit key file, but the server 190 selects the CPS unit key according to the CPS unit number received from the playback device (user device) 120 and stores the subsequent data 305. Perform encryption processing.

  Further, in step S141, the server 190 executes processing for generating content use permission information (permission) corresponding to the selected CPS unit key.

  An example of content usage permission information (permission) generation processing will be described with reference to FIG. FIG. 16 shows content usage permission information (permission) 541, a CPS unit key file 540, and part of the usage control information file 530 recorded in advance on the disc.

  As shown in the CPS unit key file 540 of FIG. 16, the CPS unit key file stores a large number of CPS unit keys from CPS unit keys 1 to nnn. One CPS unit key nn is selected from the CPS unit key file 540 shown in FIG. 16 according to the CPS unit number received from the playback device (user device) 120. The selected CPS unit key is a key applied to encryption of subsequent data. The server 190 generates content use permission information (permission) 541 corresponding to the selected CPS unit key nn.

  As described above, the content use permission information (permission) includes a content use permission information verification value obtained by calculation using data read from the disc or data such as a random number generated by the playback device.

  A usage control information file 530 shown in FIG. 16 shows a part of the data of the usage control information file 530 recorded on the disc mounted on the playback device 120. As shown in FIG. 16, in the usage control information file 530, each CPS unit key recorded in the CPS unit key file is a key corresponding to content usage permission information (permission) unnecessary content or content usage permission. Information indicating whether the corresponding key of the application content of information (permission) is included.

In the usage control information file 530 of FIG. 16, the following content usage permission information (permission) is recorded.
CPS unit key pp to qq = content usage permission information (permission) unnecessary content correspondence key CPS unit key rr to ss = content usage permission information (permission) request content correspondence key.

For example, when the content (subsequent data) provided to the playback device by the server 190 is the application content of the content use permission information (permission), the CPS unit key applied to decrypt the subsequent data is:
It is set as one key in the range of CPS unit keys rr to ss.
When applying this key, first, verification processing using the content usage permission information (permission) verification value recorded in the CPS unit key file is performed.

  That is, the media ID and the like are read from the disc loaded in the playback device, and the device ID (Nonce) is read from the memory of the playback device, and the same operation as the calculation of the content use permission information (permission) verification value is executed. The calculated value and the verification value recorded in the content use permission information 541 are collated. If they match, it is permitted to acquire the designated CPS unit key and decrypt the content. If they do not match, the use of the content is stopped.

  The process of step S141 shown in FIG. 15 is a process for generating the content use permission information 541 shown in FIG. The server 190 executes the generation processing of the content use permission information 541, and further executes the encryption processing of the CPS unit key file by applying the volume unique key 312 in step S142 shown in FIG.

  The content usage permission information, the CPS unit key file (encrypted file) 316, and the encrypted subsequent data 314 generated in this way are transmitted to the playback device (user device) 120. This transmission processing corresponds to the processing in step S233 shown in FIG.

  A specific processing sequence executed by the playback device that uses the content (subsequent data) in accordance with the content use permission information (permission) will be described with reference to the flowchart shown in FIG.

  In step S351, the playback device refers to the usage control information file and acquires the CPS unit key number corresponding to the playback target content. Further, referring to the content usage permission information (permission) of the usage control information file 530 shown in FIG. 16 based on the acquired key number, the key corresponding to the scheduled usage content is the application target key of the content usage permission information (permission). Check if it is.

  If the key corresponding to the content to be used is not the application target key of the content usage permission information (permission), the process proceeds to step S361, where the CPS unit key corresponding to the content is obtained from the CPS unit key file and the CPS unit key is applied. Performs content decryption and playback processing. This decoding and reproduction process is executed according to the sequence described above with reference to FIG.

  If it is determined in step S352 that the key corresponding to the content scheduled to be used is the application target key of the content use permission information (permission), the process proceeds to step S353. In step S353, content usage permission information (permission) correspondence value calculation data is acquired from the disc loaded in the playback device and the memory in the playback device, and the content usage permission information (permission) correspondence value is calculated.

As described above, this value is calculated according to, for example, the following equation.
Content usage permission information (permission) correspondence value = AES-128E (Kvu, Kt (XOR) Nonce (XOR) AES_H (volume ID‖title ID))

Next, in step S354, the calculated value calculated by the above calculation is compared with the verification value included in the content use permission information (permission) recorded in the CPS unit key file.
If it is determined in step S355 that the calculated value matches the verification value, the process proceeds to step S361. In step S361, the CPS unit key corresponding to the content is acquired from the CPS unit key file, and the decryption and reproduction processing of the content to which the CPS unit key is applied is performed.

  On the other hand, if it is determined in step S355 that the calculated value and the verification value do not match, it is determined that the correct disc as a content use permission condition is not loaded or the playback device is not correct, and the process proceeds to step S362. Decryption and use of the content to which the unit key is applied is stopped.

[5. Example of server and playback device configuration]
Next, a hardware configuration example of a server that performs processing for providing subsequent data and a playback device that performs processing for acquiring and using subsequent data will be described with reference to FIGS. 18 and 19.

  FIG. 18 is a diagram illustrating a hardware configuration example of a server that performs processing for providing subsequent data. As illustrated in FIG. 18, the server includes a data processing unit 711, a communication unit 712, a memory 713, and a media IF (interface) 714.

  The data processing unit 711 executes, for example, encryption processing of subsequent data described above with reference to FIG. Furthermore, the processing described with reference to FIGS. 6 to 14, for example, processing for generating binding information and content use permission information (permission) is executed.

The communication unit 712 executes communication with the user's playback device, content editing unit, or disc factory, for example, communication via a network such as the Internet.
The memory 713 is used as a storage unit for data processing programs executed by the data processing unit 711, parameters, or data received from other devices. The memory 713 stores a device key applied to the processing described above with reference to FIG.
The media interface 714 is applied to reading data such as data such as MKB and CPS unit key file from a disk 720 constituted by, for example, DVD, Blu-ray Disc (registered trademark).

  FIG. 19 shows an example of the hardware configuration of a playback apparatus that performs acquisition and use processing of subsequent data. As shown in FIG. 19, the playback apparatus includes an input unit 721, a data processing unit 722, a communication unit 723, a memory 724, an output unit 725, a local storage unit 726, and a media IF 727. The media IF (interface) 727 is applied to data recording on or reproducing data from the medium 730 constituted by, for example, a DVD, Blu-ray Disc (registered trademark), or the like.

The input unit 721 inputs user operation information, for example.
The data processing unit 722 executes, for example, processing such as the content reproduction processing described above with reference to FIG. 1 and the subsequent data acquisition processing described with reference to FIGS.
The communication unit 723 performs communication processing with a server that provides subsequent data, for example.
The memory 724 is used as a storage area for data processing programs and parameters executed by the data processing unit 722.
The output unit 725 is an output unit that executes playback content display, audio output, and the like.

  The local storage unit 726 is, for example, a hard disk, and is used as a storage area for subsequent data acquired from the server, and further as a storage area for programs executed in the data processing unit 722.

  The present invention has been described in detail above with reference to specific embodiments. However, it is obvious that those skilled in the art can make modifications and substitutions of the embodiments without departing from the gist of the present invention. In other words, the present invention has been disclosed in the form of exemplification, and should not be interpreted in a limited manner. In order to determine the gist of the present invention, the claims should be taken into consideration.

  The series of processing described in the specification can be executed by hardware, software, or a combined configuration of both. When executing processing by software, the program recording the processing sequence is installed in a memory in a computer incorporated in dedicated hardware and executed, or the program is executed on a general-purpose computer capable of executing various processing. It can be installed and run. For example, the program can be recorded in advance on a recording medium. In addition to being installed on a computer from a recording medium, the program can be received via a network such as a LAN (Local Area Network) or the Internet and can be installed on a recording medium such as a built-in hard disk.

  Note that the various processes described in the specification are not only executed in time series according to the description, but may be executed in parallel or individually according to the processing capability of the apparatus that executes the processes or as necessary. Further, in this specification, the system is a logical set configuration of a plurality of devices, and the devices of each configuration are not limited to being in the same casing.

  As described above, according to the configuration of the embodiment of the present invention, the server receives the encrypted data of the confidential information and performs the data processing using the received encrypted data and the device key stored in the memory. Obtain confidential information. Furthermore, confidential information is applied. For example, the decryption process of the CPS unit key file storing the content encryption key is executed, and the content encryption process using the CPS unit key acquired from the CPS unit key file is performed. Alternatively, additional processing such as binding information for the CPS unit key file is executed, and these are provided to the user device. With this configuration, it is possible to safely perform processing for providing confidential information to the server and data processing in the server without leaking confidential information.

100 discs 101 MKB (media key block)
102 Volume ID
103 CPS unit key file 104 Usage control information file 105 Encrypted content 120 Playback device (user device)
121 device key 122 media key 123 volume unique key 124 CPS unit key 125 content 150 content editing unit 151 master data 170 disk factory 171 encryption processing unit 172 master generation unit 173 disk generation unit 190 server 191 identification information 192 subsequent data 201 encrypted content 202 CPS unit key file 203, 204 Encrypted content 205 CPS unit key file 250 Local storage unit 251 Subsequent data 252 CPS unit key file 301 Device key 302 MKB (media key block)
303 Volume ID
304 CPS unit key file 311 Media key 312 Volume unique key 313 CPS unit key 314 Encrypted data 315, 316 Update CPS unit key file 350 Usage control information file 351 Content usage conditions 401 Master data 411 Disc 412 Volume ID
520 CPS unit key file 521 Binding information 530 Usage control information file 540 CPS unit key file 541 Content usage permission information (permission)
711 Data processing unit 712 Communication unit 713 Memory 714 Media interface 720 Disk 721 Input unit 722 Data processing unit 723 Communication unit 724 Memory 725 Output unit 726 Local storage unit 727 Media interface 730 Disk

Claims (11)

A communication unit that performs data communication;
A data processing unit that executes data processing using received data via the communication unit;
It has a memory that stores a device key that is key data for the device,
The communication unit receives encrypted data of confidential information,
The data processing unit executes encrypted data received by the communication unit and data processing using the device key to acquire confidential information, performs data processing using the confidential information, and obtains a data processing result. An information processing apparatus that performs a process of outputting via the communication unit. The communication unit is
A CPS unit key file storing an encryption key corresponding to content as encrypted data, and a media key block (MKB) storing a media key necessary for generating a key to be decrypted by the CPS unit key file as encrypted data And
The data processing unit
For the media key block (MKB), a media key is obtained by data processing applying the device key, and the CPS unit key file is decrypted by data processing applying the media key;
The information processing apparatus according to claim 1, wherein the encrypted content is generated and output by encrypting the content to which the CPS unit key acquired from the decrypted CPS unit key file is applied. The communication unit is
A CPS unit key file storing an encryption key corresponding to content as encrypted data, and a media key block (MKB) storing a media key necessary for generating a key to be decrypted by the CPS unit key file as encrypted data And
The data processing unit
For the media key block (MKB), a media key is obtained by data processing applying the device key, and the CPS unit key file is decrypted by data processing applying the media key;
The information processing apparatus according to claim 1, wherein content usage permission information corresponding to the decryption CPS unit key is generated and output. The content usage conditions are:
Including at least one of bind information of media bind information that allows content use only when a specific disc is mounted in a playback device, or device bind information that allows content use only in a specific play device,
The data processing unit
When generating media binding information, generate a calculation value to which the media ID received from the playback device via the communication unit is applied as verification data,
When generating device binding information, generate a calculation value to which the device ID received from the playback device via the communication unit is applied as verification data,
The information processing apparatus according to claim 3, wherein the generated verification data is included in the CPS unit key file and provided to the playback apparatus. The content use permission information is:
Content usage permission information for limiting the number of times or the period of use of content in the playback device, including a verification value for confirming the validity of the content usage permission information in the playback device,
The data processing unit
A CPS unit key file that stores an encryption key corresponding to the content received from the playback device via the communication unit as encrypted data, and a media key necessary for generating a key to be decrypted by the CPS unit key file. The information processing apparatus according to claim 3, wherein an operation value based on the media key block (MKB) stored as is generated as verification data and provided to the playback apparatus. The communication unit is
A CPS unit key file that stores an encryption key corresponding to content as encrypted data, and a media key block (MKB) that stores a media key necessary for generating a key to be decrypted by the CPS unit key file as encrypted data; Receiving a volume ID which is identification information corresponding to a set of discs for recording content;
The data processing unit
For the media key block (MKB), a media key is obtained by data processing to which the device key is applied, a volume unique key is obtained by data processing to which the media key and the volume ID are applied, and the volume unique key is further obtained. The information processing apparatus according to claim 1, wherein the CPS unit key file is decrypted by decryption processing using a key. A content distribution system having a server that executes content providing processing and a playback device that executes content acquisition processing from the server,
The playback device transmits a CPS unit key file storing a content encryption key as encrypted data to the server,
The server decrypts the CPS unit key file by data processing using a device key that is key data unique to the server device, performs content encryption processing using the CPS unit key included in the decrypted CPS unit key file, A content distribution system for transmitting generated encrypted content to the playback device.   The server further executes a CPS unit key file update process by adding verification data corresponding to a content usage condition for a decrypted CPS unit key file, generates an updated CPS unit key file, and transmits the updated CPS unit key file to the playback device. Item 8. The content distribution system according to Item 7.   8. The content distribution system according to claim 7, wherein the server further executes processing for generating content usage permission information corresponding to usage control information (Usage Rule) for the decryption CPS unit key file, and transmits the content usage permission information to the playback device. An information processing method executed in an information processing apparatus,
A communication unit receiving encrypted data of confidential information;
The data processing unit acquires the confidential information by executing the data processing using the encrypted data received by the communication unit and the device key that is the device-specific key data stored in the memory, and applies the confidential information. A data processing step of performing data processing and outputting a data processing result via the communication unit;
The data processing step includes
Executing a decryption process of the CPS unit key file storing the encryption key corresponding to the content as encrypted data;
Content encryption processing using a CPS unit key included in the CPS unit key file, CPS unit key file update processing for additionally adding verification data corresponding to content usage conditions for the CPS unit key file, or the CPS unit key An information processing method including a step of executing at least one of generation processing of content usage permission information corresponding to usage control information (Usage Rule) for a file. A program for executing information processing in an information processing apparatus;
Receiving the encrypted data of the confidential information in the communication unit;
The data processing unit executes the data processing using the encrypted data received by the communication unit and the device key that is the device-specific key data stored in the memory to obtain the confidential information, and applied the confidential information. A data processing step for performing data processing and outputting a data processing result via the communication unit;
The data processing step includes
A decryption step of the CPS unit key file storing the encryption key corresponding to the content as encrypted data;
Content encryption processing using a CPS unit key included in the CPS unit key file, CPS unit key file update processing for additionally adding verification data corresponding to content usage conditions for the CPS unit key file, or the CPS unit key A program including a step of executing at least one of content usage permission information generation processing corresponding to usage control information (Usage Rule) for a file.

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