JP2007179556A - Information management device, information management method, recording medium, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the illegal use of a content. <P>SOLUTION: A content recorded in a CD 81 is fetched by the ripping module 91 of a client 1, and stored in a storage part 28. In the client 1, content ID (CID) for identifying a content and unique ID (Uniq ID) unique to the client 1 (ripping module 91) are generated, and those ID are added to the content fetched by the ripping module 91. Also, in the client 1, a use right in which use conditions or the like of the content are described is generated and stored. Information indicating that reproduction of the content only by the device (client) in which the same ID as the unique ID attached to the content is set is permitted is described in the use right. This information management device can be applied to an information processor such as a personal computer. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an information management apparatus, an information management method, a recording medium, and a program, and more particularly, to an information management apparatus, an information management method, a recording medium, and a program that can easily prevent unauthorized reproduction of content.

  In recent years, various broadband environments are being developed, and distribution services for various contents such as music data and video data have begun to be started in earnest.

  For example, a subscription-type music distribution service such as “PressPlay (trademark)” is provided. In this music distribution service, the user is set in advance by paying a monthly fixed fee. (For example, up to 1000 songs can be played in streaming playback, up to 100 songs can be downloaded and saved on the hard disk of a personal computer, and written (copied) to a CD (Compact Disk) -R. In any case, the music content can be used under any condition that allows copying up to 20 songs.

  By the way, as a system for managing the right information of a user who receives content provided by such a distribution service, for example, in Japanese Patent Laid-Open No. 2001-352321, nodes corresponding to a plurality of services are arranged in a tree shape. Valid including key information (DNK (Device Node Key)) set in the node that exists on the path from the node corresponding to a given service to the node (device) of each leaf belonging to that service in the system It is disclosed to use an enabling key block (EKB).

  In this system, EKB is added to the content distributed in a certain service, and by using the DNK given to each device, the updated key information included in the EKB is acquired. , Manage the devices that are allowed to use the service. In this case, a device that cannot obtain updated key information from the EKB using the DNK cannot subsequently receive a service.

  As a result, the use of content in each device can be managed without performing authentication processing or the like between the server that provides the content and the device each time.

  In a system in which content rights information is managed in this way, for example, a device that imports content from a CD (Compact Disk) manages the content using ICV (Integrity Check Value). .

  FIG. 1 is a diagram schematically illustrating a configuration in which imported content is managed by ICV.

  As shown in FIG. 1, for example, a device such as a personal computer registers content (music data) imported from a CD in a management table of a hard disk, and generates a MAC (Message Authentication) generated based on the registered content. Code) (C1, C2,..., Cn) is applied to ICV = hash (Kicv, C1, C2,..., Cn) to generate ICV. Kicv is key information for generating an ICV.

  Then, compare the ICV generated at the time of content generation and safely stored with the ICV newly generated at a predetermined timing such as playback, and if the same ICV is obtained, the content was not falsified On the other hand, if the obtained ICV is different from that at the time of content generation, it is determined that the content has been tampered with. If it is determined that the content has not been tampered with, the content reproduction process is subsequently performed. If it is determined that the content has been tampered with, the reproduction process is not performed. Therefore, the reproduction of the altered content is thereby prevented.

  However, when content is managed by ICV as described above, an ICV must be generated each time content is imported or reproduced, and there is a problem that the processing load is large.

  Therefore, a portable device such as a music playback device requires a high-performance arithmetic unit capable of performing a hash operation for generating an ICV. When such an arithmetic unit is provided, as a result, Cost will increase.

  The present invention has been made in view of such a situation, and makes it possible to easily prevent unauthorized reproduction of content.

  The information management apparatus according to the present invention includes a content acquisition unit that acquires the content, an identification information storage unit that stores identification information for identifying the information management device, and the content acquisition unit. Content storage means for storing the content obtained by adding the identification information stored in the identification information storage means to the acquired content; the identification information as information relating to the use of the content; and the content added to the content Usage right storage means for storing a usage right that includes information permitting use in a device having the same identification information as the identification information, the identification information added to the content, and the identification The identification information stored by the information storage means and the identification information added to the usage right are: When an, characterized in that it comprises a reproducing means for reproducing the content.

  The content stored in the content storage means is encrypted, and the reproduction means includes the identification information added to the content, the identification information stored by the identification information storage means, When the identification information added to the usage right is the same, the content can be decrypted and reproduced.

  The usage right stores content usage conditions and content conditions, and the reproduction means can further cause the content to be reproduced when the content conditions satisfy the content usage conditions.

  An information management method, a program recorded on a recording medium, or a program includes: a content acquisition step for acquiring content; an identification information storage step for storing identification information for identifying an information management device; and the content acquisition step A content storing step of storing the content obtained by adding the identification information stored by the processing of the identification information storing step to the content acquired by the processing of the identification; the identification information as the information regarding use of the content; and the content A right-of-use storage step for storing a right of use that includes information for permitting use in a device that has acquired the same identification information as the identification information added to the content; and the content added to the content Identification information and stored by the processing of the identification information storage step A serial identification information, and the identification information added to the usage right, when the same, characterized in that it comprises a reproduction step of reproducing the content.

  Another information management apparatus according to the present invention includes an information management apparatus that manages content, a content acquisition unit that acquires content added with identification information of the other information management apparatus from another information management apparatus, and the other Identification information acquisition means for acquiring identification information of the other information management apparatus from the information management apparatus, content storage means for storing the content acquired by the content acquisition means, and the identification information acquired by the identification information acquisition means Identification information storage means for storing identification information of other information management devices, and information relating to the use of the content, the identification information and the same identification information as the identification information added to the content are acquired A right-of-use storage means for storing a right-of-use that includes information permitting use in the device; The identification information, the identification information when the stored identification information in the storage means are the same that are characterized by comprising a reproducing means for reproducing the content.

  Another information management method of the present invention, a program recorded on a recording medium, or a program, a content acquisition step of acquiring content added with identification information of the other information management device from another information management device, An identification information acquisition step for acquiring identification information of the other information management device from the other information management device, a content storage step for storing the content acquired by the processing of the content acquisition step, and the identification information acquisition step The identification information storage step for storing the identification information of the other information management device acquired by the process of the above, and the information related to the use of the content is the same as the identification information and the identification information added to the content Describes the usage rights that contain information that permits use on devices for which identification information has been acquired. Use right storage step, and when the identification information added to the content is the same as the identification information stored by the processing of the identification information storage step, a reproduction step of reproducing the content is included. It is characterized by.

  In the information management apparatus, the information management method, the program recorded on the recording medium, or the program of the present invention, content is acquired, identification information for identifying the information management apparatus is stored, and stored in the acquired content The content to which the identification information is added is stored. In addition, as the information related to the use of the content, a usage right that includes the identification information and information that permits use in a device that has acquired the same identification information as the identification information added to the content When the identification information added to the content, the stored identification information, and the identification information added to the usage right are the same, the content is reproduced.

  In another information management apparatus, information management method, program recorded on a recording medium, or program of the present invention, content to which the identification information of the other information management apparatus is added is acquired from another information management apparatus. The identification information of the other information management device is acquired from the other information management device. Further, the acquired content is stored, the acquired identification information of the other information management device is stored, and the information related to the use of the content is the identification information and the identification information added to the content The right of use including the information that permits the use in the device from which the same identification information is acquired is stored. When the identification information added to the content is the same as the identification information stored by the processing of the identification information storing step, the content is reproduced.

  According to the present invention, content can be provided.

  In addition, according to the present invention, unauthorized use of content can be prevented.

  FIG. 2 shows a configuration of a content providing system to which the present invention is applied. Connected to the Internet 2 are clients 1-1 and 1-2 (hereinafter simply referred to as client 1 when these clients do not need to be individually distinguished). Although only two clients are shown in this example, an arbitrary number of clients are connected to the Internet 2.

  The Internet 2 includes a content server 3 that provides content to the client 1, a license server 4 that grants a usage right necessary for using the content provided by the content server 3, and the client When 1 receives a usage right, a charging server 5 is connected to perform charging processing for the client 1.

  An arbitrary number of these content servers 3, license servers 4, and billing servers 5 are also connected to the Internet 2.

  FIG. 3 shows the configuration of the client 1.

  In FIG. 3, a CPU (Central Processing Unit) 21 executes various processes according to a program stored in a ROM (Read Only Memory) 22 or a program loaded from a storage unit 28 to a RAM (Random Access Memory) 23. To do. The timer 20 performs a time measuring operation and supplies time information to the CPU 21. The RAM 23 also appropriately stores data necessary for the CPU 21 to execute various processes.

  The encryption / decryption unit 24 performs a process of encrypting the content and decrypting the already encrypted content. The codec unit 25 encodes content by, for example, ATRAC (Adaptive Transform Acoustic Coding) 3 method, and supplies the encoded content to the semiconductor memory 44 connected to the drive 30 via the input / output interface 32 for recording. Alternatively, the codec unit 25 decodes the encoded data read from the semiconductor memory 44 via the drive 30. The semiconductor memory 44 is configured by, for example, a Memory Stick (trademark).

  The CPU 21, ROM 22, RAM 23, encryption / decryption unit 24, and codec unit 25 are connected to each other via a bus 31. An input / output interface 32 is also connected to the bus 31.

  The input / output interface 32 includes an input unit 26 including a keyboard and a mouse, a display including a CRT (Cathode Ray Tube) and an LCD (Liquid Crystal Display), an output unit 27 including a speaker, a hard disk, and the like. A communication unit 29 including a storage unit 28, a modem, a terminal adapter, and the like is connected. The communication unit 29 performs communication processing via the Internet 2. The communication unit 29 also performs communication processing of analog signals or digital signals with other clients.

  A drive 30 is connected to the input / output interface 32 as necessary, and a magnetic disk 41, an optical disk 42, a magneto-optical disk 43, a semiconductor memory 44, or the like is appropriately mounted, and a computer program read from these is loaded. Installed in the storage unit 28 as necessary.

  Although illustration is omitted, the content server 3, the license server 4, and the billing server 5 are also configured by a computer having basically the same configuration as the client 1 shown in FIG. Therefore, in the following description, the configuration of FIG. 3 is also referred to as the configuration of the content server 3, the license server 4, the billing server 5, and the like.

  In the present invention, as shown in FIG. 4, devices and keys are managed based on the principle of the broadcast encryption method. The keys have a hierarchical tree structure, and the bottom leaf corresponds to a key unique to each device. Hierarchical tree structure key management used in the system of the present invention is described in Japanese Patent Laid-Open No. 2001-352321. In the case of the example in FIG. 4, keys corresponding to 16 devices from number 0 to number 15 are generated.

  Each key is defined corresponding to each node of the tree structure indicated by a circle in the figure. In this example, a root key KR (also referred to as Kroot as appropriate) is defined corresponding to the topmost root node, and keys K0 and K1 are defined corresponding to the second level node. In addition, keys K00 to K11 are defined corresponding to the third level nodes, and keys K000 to K111 are defined corresponding to the fourth level nodes. Keys K0000 to K1111 correspond to leaves (device nodes) as the lowermost nodes.

  Because of the hierarchical structure, for example, the upper key of the key K0010 and the key K0011 is K001, and the upper key of the key K000 and the key K001 is K00. Similarly, the upper key of the keys K00 and K01 is K0, and the upper key of the keys K0 and K1 is KR.

  Keys that use content are managed by keys corresponding to the nodes of one path from the lowest device node (leaf) to the highest root node. For example, in the device corresponding to the leaf of number 3, the key for using the content is managed by each key of the path including the keys K0011, K001, K00, K0, and KR.

  In the system of the present invention, as shown in FIG. 5, a key system configured based on the principle of FIG. 4 manages device keys and content keys. In the example of FIG. 5, nodes of 8 + 24 + 32 levels have a tree structure, and categories correspond to the nodes from the root node to the lower 8 levels. The category here means a category such as a category of a device that uses a semiconductor memory such as a memory stick or a category of a device that receives a digital broadcast. This system (appropriately referred to as the T system) corresponds to one of the category nodes as a system for managing the usage rights.

That is, a service provider or a service provided by a service provider is associated with a key corresponding to a node of 24 levels in a lower hierarchy than the node of the T system. Therefore, in the example of FIG. 5, 2 ²⁴ (about 16 mega) service providers or services can be defined. Further, 2 ³² (about 4 Giga) users (client 1) can be defined by the lowest 32 levels. The key corresponding to each node on the path from the lowest 32 nodes to the T system node constitutes a DNK (Device Node Key), and the ID corresponding to the lowest leaf is the leaf ID.

  The content key obtained by encrypting the content is encrypted by the updated root key KR ′, the update node key of the upper hierarchy is encrypted using the update node key of the immediately lower hierarchy, and EKB (Enabling Key Block: (Activation key block) (described later with reference to FIG. 7).

  The update node key one level above the end in the EKB is encrypted by the node key or leaf key at the end of the EKB, and placed in the EKB. The client 1 uses the DNK key described in the service data to decrypt the update node key of the latest higher hierarchy described in the EKB distributed with the content, and the node key obtained by decoding Is used to decrypt the update node key of the hierarchy further described in the EKB. By sequentially performing the same processing, the client 1 can obtain the updated root key KR ′. The service data is supplied from the license server 4 when information about the client 1 is registered, and a license for a combination of the service data and a usage right that is information that permits the use of specific content, which will be described later, is licensed. Call it.

  FIG. 6 is a diagram illustrating a specific example of classification of categories in a hierarchical tree structure.

  In FIG. 6, a root key KR2301 is set at the top level of the hierarchical tree structure, a node key 2302 is set at the intermediate level below, and a leaf key 2303 is set at the bottom level. Each device has an individual leaf key, a series of node keys from the leaf key to the root key, and a device node key (DNK) consisting of the root key.

  A predetermined node from the top to the M-th stage (M = 8 in the example of FIG. 5) is set as the category node 2304. That is, each of the M-th level nodes is a device setting node of a specific category. Nodes and leaves of the M + 1th stage and below with one node of the Mth stage as a vertex are nodes and leaves related to devices included in the category.

  For example, the category [Memory Stick (trademark)] is set in one node 2305 in the M-th stage in FIG. 6, and nodes and leaves connected to this node are dedicated to the category including various devices using the memory stick. Set as a node or leaf. That is, nodes 2305 and below are defined as a set of related nodes and leaves of devices defined in the category of the memory stick.

  A stage that is several stages lower than the M stage can be set as the subcategory node 2306. In the example of FIG. 6, a node 2306 of “reproduction-only device” is set as a subcategory node included in the category of the device using the memory stick in a node two steps below the category [memory stick] node 2305. In addition, a node 2307 of a telephone with a music playback function included in the category of the playback-only device is set below the node 2306 of the playback-only device that is a subcategory node, and further below that is included in the category of the telephone with a music playback function. [PHS] node 2308 and [mobile phone] node 2309 are set.

  Categories and subcategories are not only the types of devices, but also arbitrary units such as nodes managed uniquely by a certain manufacturer, content provider, settlement organization, etc., that is, processing units, jurisdiction units, service units provided, etc. And hereinafter referred to as an entity).

  For example, by setting one category node as a vertex node dedicated to the game device XYZ sold by the game device manufacturer, the game device XYZ sold by the manufacturer stores the lower node key and leaf key below the vertex node for sale. After that, by generating and distributing EKB composed of node keys and leaf keys below that vertex node key, encrypted content distribution processing, various key distribution processing, update processing, etc. This can be done only for other devices (game machine XYZ).

  That is, the key update or the like can be executed without affecting the devices belonging to nodes of other categories that do not belong to the vertex node.

  Further, at a certain time t, when it is discovered that the keys K0011, K001, K00, K0, KR owned by the device 3 are analyzed and exposed by an attacker (hacker), the system (devices 0, 1, In order to protect the data transmitted and received in (a few groups), it is necessary to disconnect the device 3 from the system. For this purpose, the node keys K001, K00, K0, KR are updated to new keys K (t) 001, K (t) 00, K (t) 0, K (t) R, respectively, and devices 0, 1, 2 must be notified of the update key. Here, K (t) aaa represents an update key of the generation (generation) t of the key Kaaa.

  The update key distribution process will be described. The key update is executed by, for example, storing the table configured by EKB shown in FIG. 7 via the network or storing it in a predetermined recording medium and supplying it to the devices 0, 1, and 2. The EKB is composed of an encryption key for distributing a newly updated key to devices corresponding to the leaves (bottom node) constituting the tree structure as shown in FIG.

  The EKB shown in FIG. 7 is configured as block data having a data configuration that can be updated only by a device that requires updating of the node key. The example of FIG. 7 is block data formed for the purpose of distributing generation t update node keys in the devices 0, 1, and 2 in the tree structure shown in FIG.

  As is clear from FIG. 4, it is necessary to provide K (t) 00, K (t) 0, K (t) R as update node keys for the devices 0 and 1, and for the device 2 Therefore, it is necessary to provide K (t) 001, K (t) 00, K (t) 0, K (t) R as update node keys.

  As shown in EKB in FIG. 7, the EKB includes a plurality of encryption keys. For example, the lowest encryption key in FIG. 7 is Enc (K0010, K (t) 001). This is an update node key K (t) 001 encrypted with the leaf key K0010 of the device 2, and the device 2 decrypts the encryption key with the leaf key K0010 of the device 2 and updates the update node key K (t) 001. Can be obtained.

  Further, the device 2 decrypts the encryption key Enc (K (t) 001, K (t) 00) in the second stage from the bottom of FIG. 7 using the updated node key K (t) 001 obtained by decryption. The update node key K (t) 00 can be acquired.

  Similarly, the device 2 can obtain the updated node key K (t) 0 by decrypting the encryption key Enc (K (t) 00, K (t) 0) in the second row from the top in FIG. By using this, the update root key K (t) R can be obtained by decrypting the encryption key Enc (K (t) 0, K (t) R) in the first stage from the top in FIG.

  On the other hand, the node key K000 is not included in the update target key, and the nodes 0 and 1 are required as the update node keys for K (t) 00, K (t) 0, and K (t) R.

  The nodes 0 and 1 use the device keys K0000 and K0001 to decrypt the encryption key Enc (K000, K (t) 00) in the third row from the top in FIG. 7 to obtain the updated node key K (t) 00. Similarly, the update node key K (t) 0 is acquired by sequentially decrypting the encryption key Enc (K (t) 00, K (t) 0) in the second row from the top in FIG. Further, the update root key K (t) R is obtained by decrypting the encryption key Enc (K (t) 0, K (t) R) in the first stage from the top in FIG. In this way, the devices 0, 1, and 2 can obtain the updated key K (t) R.

  7 indicates the absolute addresses of node keys and leaf keys used as decryption keys for decrypting the encryption keys shown on the right side of the diagram.

  When the update of the node keys K (t) 0 and K (t) R in the upper stage of the tree structure shown in FIG. 4 is unnecessary and only the node key K00 needs to be updated, the EKB of FIG. 8 is used. Thus, the updated node key K (t) 00 can be distributed to the devices 0, 1, and 2.

  The EKB shown in FIG. 8 can be used when, for example, a new content key shared in a specific group is distributed.

  For example, devices 0, 1, 2, and 3 in the group indicated by the one-dot chain line in FIG. 4 use a certain recording medium, and a new common content key K (t) con is set for these devices. Suppose that it is necessary to do. At this time, data Enc (K (t) in which a new common updated content key K (t) con is encrypted by K (t) 00 that updates the common node key K00 of the devices 0, 1, 2, 3 00, K (t) con) is distributed together with the EKB shown in FIG. This distribution enables distribution as data that cannot be decrypted by other groups of devices such as the device 4.

  That is, the devices 0, 1, and 2 can obtain the content key K (t) con at time point t by decrypting the encrypted data using the key K (t) 00 obtained by processing the EKB.

  FIG. 9 shows, as an example of processing for obtaining the content key K (t) con at time t, data Enc (K (t (t)) in which a new common content key K (t) con is encrypted by K (t) 00. ) 00, K (t) con) and EKB shown in FIG. 8 are diagrams schematically showing processing of the device 0 provided via a predetermined recording medium. That is, the example of FIG. 9 is an example in which the encrypted message data by EKB is the content key K (t) con.

  As shown in FIG. 9, the device 0 uses the EKB at the time of generation t stored in the recording medium and the node key K000 prepared in advance for itself as described above for the EKB processing (sequentially the keys). The node key K (t) 00 is generated by the solving process. Further, the device 0 decrypts the update content key K (t) con using the decrypted update node key K (t) 00, and uses the update content key with the leaf key K0000 that only the device 0 has in order to use it later. K (t) con is encrypted and stored.

  FIG. 10 is a diagram showing an example of the EKB format, and the EKB including such various information is included in the header of the content data.

  Version 61 is an identifier indicating the version of EKB. This version 61 has a function for identifying the latest EKB and a function for indicating a correspondence relationship with the content. The depth 62 indicates the number of hierarchies of the hierarchical tree for the device to which the EKB is distributed. The data pointer 63 is a pointer indicating the position of the data part 66 in the EKB, and the tag pointer 64 and the signature pointer 65 are pointers indicating the positions of the tag part 67 and the signature 68, respectively.

  The data unit 66 stores, for example, data obtained by encrypting the node key to be updated. For example, each encryption key related to the updated node key as shown in FIG.

  The tag unit 67 is a tag indicating the positional relationship between the encrypted node key and leaf key stored in the data unit 66. The tag assignment rule will be described with reference to FIG.

  In the example of FIG. 11, the sent data is the encryption key of FIG. 7, as shown in FIG. 11B. The top node address included in the encryption key is the top node address.

  In this example, since the root key update key K (t) R is included, the top node address is KR. At this time, for example, the uppermost data Enc (K (t) 0, K (t) R) corresponds to the position P0 shown in the hierarchical tree shown in FIG. 11A. The data of the next stage is Enc (K (t) 00, K (t) 0), and on the tree, it is at the position P00 at the lower left of the previous data Enc (K (t) 0, K (t) R). Correspond.

  That is, when there is data below the predetermined position in the tree structure, the tag is set to 0, and when there is no data, the tag is set to 1. The tags are set as {left (L) tag, right (R) tag}.

  Since there is data at the lower left position P00 of the position P0 corresponding to the uppermost data Enc (K (t) 0, K (t) R) in FIG. 11B, L tag = 0 and the lower right position of the position P0. Since there is no data, R tag = 1. Hereinafter, tags are set for all data, and a data string and a tag string shown in FIG. 11C are configured.

The tag is set to indicate where the corresponding data Enc (Kxxx, Kyyy) is located in the tree structure. The key data Enc (Kxxx, Kyyy)... Stored in the data section 66 is merely enumerated data of the encrypted key, but the encryption key tree stored as data by the tag described above. The upper position can be determined. Without using a tag, as shown in FIG. 7 or FIG. 8, using a node index corresponding to encrypted data, for example,
0: Enc (K (t) 0, K (t) R)
00: Enc (K (t) 00, K (t) 0)
000: Enc (K ((t) 000, K (t) 00)
...
However, when such an index is used, the amount of data increases, which is not preferable in distribution via a network. On the other hand, by using the tag as described above as index data indicating the key position, the key position can be determined with a smaller amount of data.

  Returning to the description of FIG. 10, the signature 68 is an electronic that is issued by the key management center (license server 4), content provider (content server 3), settlement organization (billing server 5), etc. that issued the EKB. It is a signature. The device that has received the EKB verifies the signature included in the EKB, thereby determining whether or not the acquired EKB is an EKB issued by a valid issuer.

  FIG. 12 is a diagram schematically showing processing in which the content recorded on the CD 81 is captured by the client 1 in the key management system as described above.

  The CPU 21 of the client 1 controls a ripping module 91 configured by executing a predetermined program, and takes in the content stored in the CD 81 connected to the client 1.

  The CPU 21 adds the content ID (CID) and the ID (unique ID (Uniq ID)) set as unique to the client 1 to the content fetched by the ripping module 91 and obtained. Data is stored in the storage unit 28. The unique ID is, for example, a random number having a predetermined number of digits, and the same unique ID as that added to the content is stored by the client 1.

  Further, the CPU 21 generates a right to use the content captured by the ripping module 91 as a service in the key management system described above. For example, when the ripping module 91 is a module in which the content captured by the ripping module 91 can be checked out only three times, a usage right describing a use condition indicating that the checkout can be performed only three times is described. Generated. In the usage right, a content ID and a unique ID added to the content are also described, and the content and the usage right are associated with each other.

  When playing back content that has been captured as described above, the client that plays back not only determines whether or not playback is permitted by the usage right, but also the unique ID added to the content and its It is determined whether or not the unique ID of the client that plays the content is the same. The content reproduction process is performed only when the reproduction of the content is permitted by the usage right and the unique ID added to the content is the same as the unique ID of the client that generates the content. In other words, a client that has acquired only content and usage rights by copying or the like cannot reproduce the content even if the usage rights permit reproduction.

  Hereinafter, a series of processing of the client 1 that takes in and uses content will be described with reference to flowcharts.

  First, the processing of the client 1 that takes in content will be described with reference to the flowchart of FIG.

  For example, when a predetermined recording medium such as a CD 81 (optical disk 42) on which content is recorded is loaded in the drive 30 of the client 1 and an instruction to capture the content is given, the CPU 21 of the client 1 executes a predetermined program. The ripping module 91 configured as described above is controlled, and content is captured in step S1.

  In step S2, the CPU 21 generates a content ID for identifying the content. In step S3, the CPU 21 determines whether a unique ID unique to the client 1 (the ripping module 91) is stored in, for example, the storage unit 28, and determines that it is not stored. In this case, the process proceeds to step S4, and a unique ID having a predetermined number of digits is generated. The generated unique ID is stored in the storage unit 28.

  The unique ID is not generated in the client 1. For example, when the user of the client 1 registers predetermined information in the license server 4 so that the ripping module 91 can be used, the license is not licensed. What is given from the server 4 to the client 1 may be used. When the unique ID is assigned in this way, or if it has already been generated in the past ripping, it is determined in step S3 in FIG. 13 that there is a unique ID, and the process in step S4 is skipped. The

  In step S5, the CPU 21 describes the content ID and the unique ID in “Attribute” as an area in which predetermined attribute information of the content is described. The content format will be described in detail later.

  In step S6, the CPU 21 creates a digital signature based on information described as attribute information using its own secret key. This secret key is provided from the license server 4 when information about the client 1 is registered, for example.

  In step S7, the CPU 21 creates header data to be recorded corresponding to the content. The header data includes a content ID, a usage right ID, a URL representing an access destination for acquiring the usage right, and a watermark.

  In step S8, the CPU 21 creates a digital signature based on the header data created in step S7, using its own private key. In step S9, the CPU 21 controls the encryption / decryption unit 24 to encrypt the content with the generated content key. Information such as the generated content and a header accompanying the generated content is stored in the storage unit 28 in step S10.

  FIG. 14 is a diagram illustrating an example of a content format.

  As shown in FIG. 14, the content is data (Enc (Kroot, Kc)) obtained by encrypting the header, EKB, and content key Kc with the root key Kroot, and attribute information describing the content ID and unique ID ( Attribute), certificate (Cert), digital signature generated based on the header (Sig (Header)), data obtained by encrypting the content with the content key Kc (Enc (Kc, Content)), metadata (Metal) Data) and mark (Mark).

  In the header, a content ID (CID), a usage right ID (usage right ID) for identifying a usage right corresponding to the content, a URL indicating a usage right acquisition destination (client 1), and a watermark (WM) are described. ing.

  The content attributes include a content ID, a record company ID as identification information for identifying a content provider, an artist ID as identification information for identifying an artist, a unique ID, and the like. In this embodiment, the attribute is used to specify the content that is the subject of the usage right.

  The metadata is various information related to the content. For example, for music content, data such as a jacket, a photograph, and lyrics is added to the content as metadata. Also, the mark describes a user ID (leaf ID), ownership flag, use start time, number of copies, and digital signature generated based on these information. The mark ownership flag is added, for example, when the usage right that enables the use of the content for a predetermined period is purchased as it is (when the usage period is changed to one that can be used permanently). . The mark copy count describes a history (log) such as the copy count of the content.

  In the above description, the case where the content is acquired (ripped) from the CD 81 has been described. For example, the content ID acquired from a predetermined server via the Internet 2 is also the unique ID of the client 1 together with the content ID. Is added and stored by the client 1.

  Next, processing of the client 1 that generates a usage right corresponding to the captured content will be described with reference to the flowchart of FIG.

  In step S21, the usage right set in advance as the one to be given to the content captured by the ripping module 91 is read from the storage unit 28 as the usage right corresponding to the content captured by the process of FIG. In the usage right stored in the storage unit 28, information such as a usage right ID, version, creation date and time, and expiration date is described.

  In step S22, the CPU 21 adds a unique ID to the selected usage right and can reproduce the content only in the client 1 in which the same ID as the unique ID described as the attribute information of the content is set. Add information to represent. In step S23, the CPU 21 selects a usage condition and adds it. For example, when it is set for the ripping module 91 that the content captured by the ripping module 91 can be checked out three times at the same time, a use condition indicating that the content can be checked out only three times is selected. Further, for example, when it is set for the ripping module 91 that the content captured by the ripping module 91 can be freely copied, a use condition indicating that is selected.

  In step S24, the CPU 21 creates a digital signature of the data described in the usage right selected as described above and adds it. The usage right to which the digital signature is added is stored in the storage unit 28 in step S25.

  FIG. 16 is a diagram illustrating an example of a usage right format.

  The version is information describing the version of the usage right by separating the major version and the minor version with dots. The profile is described from a decimal integer value, and is information that defines restrictions on the usage right description method. The usage right ID is identification information described by a hexadecimal constant for identifying the usage right. The creation date / time indicates the date / time when the usage right was created. The expiration date indicates the expiration date of the usage right. An expiration date of 23:59:59 of 9999 indicates that there is no limit on the expiration date. The usage conditions include an expiration date for using the content based on the usage rights, a playback expiration date for reproducing the content based on the usage rights, a maximum number of times the content can be played, and the usage rights. Based on the number of times the content can be copied (allowed number of copies), the maximum number of checkouts, and whether or not the content can be recorded on a CD-R based on its usage rights, PD (Portable Device) includes information indicating the number of times that copying can be performed, whether usage rights can be transferred, whether or not there is an obligation to take a usage log, and the like. The electronic signature of the use condition is an electronic signature corresponding to the use condition.

  The constant is a constant referred to in the use condition or use state. The unique ID is generated when content is captured. The electronic signature is an electronic signature corresponding to the entire usage right. The certificate is a certificate including the public key of the license server 4.

  The storage unit 28 of the client 1 stores a usage state (content condition) that is information indicating the state of the content and the usage right together with the usage right usage condition. The usage status includes the number of times the content has been played based on the corresponding usage rights, the number of times the content has been copied, the number of times the content has been checked out, the date and time the content was first played, the number of times the content has been recorded on the CD-R, and other content Or the information which shows the historical information etc. regarding a use right is contained. The determination of the content reproduction condition is performed based on the usage conditions included in the usage right and the usage state stored in the storage unit 28 together with the usage right. For example, when the number of times content stored in the usage state is reproduced is less than the maximum content reproduction number included in the usage condition, it is determined that the reproduction condition is satisfied.

  Next, content reproduction processing by the client 1 that has captured content by the ripping module 91 will be described with reference to the flowchart of FIG.

  In step S41, the CPU 21 of the client 1 reads the content instructed by the user operating the input unit 26 from the storage unit 28 based on the content ID, and reads the unique ID described as the attribute information of the read content. . In step S42, the CPU 21 reads the usage right corresponding to the content instructed to be played based on the usage right ID, and reads the unique ID described in the read usage right.

  In step S43, the CPU 21 reads out the stored unique ID, that is, the unique ID of the client 1 from the storage unit 28, and proceeds to step S44, where these unique IDs, that is, the unique ID described in the content, use It is determined whether the unique ID described in the right and the unique ID stored in the client 1 are all the same. Note that it may be determined whether or not the unique ID described in the content and only the unique ID stored in the client 1 are the same.

  If the CPU 21 determines in step S44 that all the unique IDs are the same, the CPU 21 proceeds to step S45 and determines whether or not use of the content is permitted by the usage right based on the described use condition. judge. For example, the CPU 21 compares the expiration date (see FIG. 16) as the description content of the usage right with the current date and time counted by the timer 20 to determine whether or not the usage right is within the expiration date. That is, it is determined whether the use of the content is permitted.

  If it is determined in step S45 that use is permitted by the usage right, the process proceeds to step S46, and the CPU 21 executes a process of decoding the content stored (read) in the RAM 23. The content decrypting process performed in step S46 will be described later with reference to the flowchart of FIG.

  In step S47, the CPU 21 supplies the content decrypted by the encryption / decryption unit 24 to the codec unit 25 to be decoded. Then, the CPU 21 supplies the data decoded by the codec unit 25 to the output unit 27 via the input / output interface 32, performs digital / analog conversion, and outputs the data from the speaker.

  If it is determined in step S44 that the unique ID described in the content is different from the unique ID stored in the client 1 (and the unique ID described in the usage right), and step S45. If it is determined that the content reproduction is not permitted by the usage right, an error process is performed in step S48, and then the process ends.

  Next, details of the client decoding process executed in step S46 of FIG. 17 will be described with reference to the flowchart of FIG.

  In step S61, the CPU 21 of the client 1 sequentially decrypts the key information included in the EKB by using the DNK included in the service data and provided from the license server 4, and obtains the root key Kroot (KR). When acquiring the root key Kroot, the CPU 21 proceeds to step S62, and decrypts the content key Kc using the root key Kroot. As shown in FIG. 14, data Enc (Kroot, Kc) obtained by encrypting the content key Kc with the root key Kroot is added to the content.

  In step S63, the CPU 21 decrypts the content using the content key Kc acquired in step S62.

  FIG. 19 schematically shows the above decoding process. In FIG. 19, the content is stored by the client 1, and only the main information is shown among the information shown in FIG.

  That is, the root key Kroot is acquired from the EKB based on the DNK provided from the license server 4 to the client 1 (step S61 in FIG. 18), and the data Enc (Kroot, Kc) is decrypted by the acquired root key Kroot. Thereby, the content key Kc is acquired (step S62 in FIG. 18). Then, the data Enc (Kc, Content) is decrypted with the content key Kc, and the content (Content) is acquired (step S63 in FIG. 18). 14 and FIG. 19 includes data Enc (DNK, Kroot) obtained by encrypting the root key Kroot with DNK, as shown in FIG.

  By controlling the reproduction of the content as described above, the content cannot be reproduced even by a client (client whose unique ID is not managed) that has illegally acquired the usage right together with the content.

  In addition, when it is determined that the content captured by the client 1 by the above processing can be checked out (when it is set as a use condition that it can be checked out), the content is checked out from the client 1 For other clients receiving the content, the content, the right to use, and the unique ID of the client 1 may be encrypted and provided by a predetermined method. In that case, the client receiving the information performs the same processing as that shown in FIGS. 17 and 18 and reproduces the content. As a result, the content is checked out / checked in under the management of the client 1 from which the content was first captured.

  In the above embodiment, the content attribute and the content condition of the usage right are used to specify the usage right necessary for using the content. However, the present invention is not limited to this. For example, the content may include a usage right ID of a usage right necessary to use the content. In this case, if the content is specified, the usage right necessary to use the content is uniquely determined. There is no need to perform a process for determining the matching between the two.

It is a schematic diagram of a conventional content management system. It is a figure which shows the structural example of the content provision system to which this invention is applied. FIG. 3 is a block diagram illustrating a configuration example of a client in FIG. 2. It is a figure which shows the structure of a key. It is a figure which shows a category node. It is a figure which shows the example of a response | compatibility of a node and a device. It is a figure which shows the structural example of an enabling key block. It is a figure which shows the other structural example of the validation key block. It is the figure which represented utilization of the enabling key block typically. It is a figure which shows the example of a format of an enabling key block. It is a figure explaining the structure of the tag of an enabling key block. It is a schematic diagram of a content management system to which the present invention is applied. It is a flowchart explaining the content acquisition process of the client of FIG. It is a figure which shows the example of the format of a content. It is a flowchart explaining the use right production | generation process of the client of FIG. It is a figure which shows the example of a format of a usage right. 2 is a flowchart for explaining content reproduction processing of the client in FIG. 1. It is a flowchart explaining the detail of the decoding process in step S46 of FIG. It is the figure which represented typically the decoding process of FIG. It is a figure which shows the example of the information contained in EKB of FIG.

Explanation of symbols

  1-1, 1-2 client, 2 internet, 3 content server, 4 license server, 5 charging server, 20 timer, 21 CPU, 24 encryption / decryption unit, 25 codec unit, 26 input unit, 27 output unit, 28 storage , 29 Communication Department

Claims (10)

In an information management device that manages content,
Content acquisition means for acquiring the content;
Identification information storage means for storing identification information for identifying the information management device;
Content storage means for storing content obtained by adding the identification information stored in the identification information storage means to the content acquired by the content acquisition means;
As the information related to the use of the content, the usage right including the identification information and the information that permits the use in the device from which the same identification information as the identification information added to the content is acquired is stored. Use right storage means to perform,
When the identification information added to the content, the identification information stored by the identification information storage means, and the identification information added to the usage right are the same, the content is reproduced. And an information management device. The content stored in the content storage means is encrypted;
The reproducing means, when the identification information added to the content, the identification information stored by the identification information storage means, and the identification information added to the usage right are the same, The information management apparatus according to claim 1, wherein the content is decrypted and reproduced. The usage right stores content usage conditions and content conditions,
The information management apparatus according to claim 1, wherein the reproduction unit further reproduces the content when the content condition satisfies the content usage condition. In the information management method of the information management apparatus that manages content,
A content acquisition step of acquiring the content;
An identification information storage step for storing identification information for identifying the information management device;
A content storage step of storing content obtained by adding the identification information stored by the processing of the identification information storage step to the content acquired by the processing of the content acquisition step;
As the information related to the use of the content, the usage right including the identification information and the information that permits the use in the device from which the same identification information as the identification information added to the content is acquired is stored. A usage right storage step,
When the identification information added to the content, the identification information stored by the processing of the identification information storage step, and the identification information added to the usage right are the same, the content is An information management method comprising: a reproduction step of reproducing. In a recording medium on which a program to be executed by a computer that controls processing of an information management apparatus that manages content is recorded,
A content acquisition step of acquiring the content;
An identification information storage step for storing identification information for identifying the information management device;
A content storage step of storing content obtained by adding the identification information stored by the processing of the identification information storage step to the content acquired by the processing of the content acquisition step;
As the information related to the use of the content, the usage right including the identification information and the information that permits the use in the device from which the same identification information as the identification information added to the content is acquired is stored. A usage right storage step,
When the identification information added to the content, the identification information stored by the processing of the identification information storage step, and the identification information added to the usage right are the same, the content is A recording medium on which a program is recorded, comprising: a reproducing step for reproducing. In a program that causes a computer to execute processing of an information management device that manages content,
A content acquisition step of acquiring the content;
An identification information storage step for storing identification information for identifying the information management device;
A content storage step of storing content obtained by adding the identification information stored by the processing of the identification information storage step to the content acquired by the processing of the content acquisition step;
As the information related to the use of the content, the usage right including the identification information and the information that permits the use in the device from which the same identification information as the identification information added to the content is acquired is stored. A usage right storage step,
When the identification information added to the content, the identification information stored by the processing of the identification information storage step, and the identification information added to the usage right are the same, the content is A program comprising: a playback step for playback. In an information management device that manages content,
Content acquisition means for acquiring content to which identification information of the other information management device is added from another information management device;
Identification information acquisition means for acquiring identification information of the other information management device from the other information management device;
Content storage means for storing the content acquired by the content acquisition means;
Identification information storage means for storing identification information of the other information management device acquired by the identification information acquisition means;
As the information related to the use of the content, the usage right including the identification information and the information that permits the use in the device from which the same identification information as the identification information added to the content is acquired is stored. Use right storage means to perform,
An information management apparatus comprising: a reproducing unit that reproduces the content when the identification information added to the content is the same as the identification information stored in the identification information storage unit. In the information management method of the information management apparatus that manages content,
A content acquisition step of acquiring content to which the identification information of the other information management device is added from another information management device;
An identification information acquisition step of acquiring identification information of the other information management device from the other information management device;
A content storage step of storing the content acquired by the processing of the content acquisition step;
An identification information storage step for storing identification information of the other information management device acquired by the processing of the identification information acquisition step;
As the information related to the use of the content, the usage right including the identification information and the information that permits the use in the device from which the same identification information as the identification information added to the content is acquired is stored. A usage right storage step,
An information management method comprising: a reproduction step of reproducing the content when the identification information added to the content is the same as the identification information stored by the processing of the identification information storage step. . In a recording medium on which a program for causing a computer to execute processing of an information management apparatus that manages content is recorded,
A content acquisition step of acquiring content to which the identification information of the other information management device is added from another information management device;
An identification information acquisition step of acquiring identification information of the other information management device from the other information management device;
A content storage step of storing the content acquired by the processing of the content acquisition step;
An identification information storage step for storing identification information of the other information management device acquired by the processing of the identification information acquisition step;
As the information related to the use of the content, the usage right including the identification information and the information that permits the use in the device from which the same identification information as the identification information added to the content is acquired is stored. A usage right storage step,
A recording program comprising: a reproduction step of reproducing the content when the identification information added to the content and the identification information stored by the processing of the identification information storage step are the same Recorded media. In a program that causes a computer to execute processing of an information management device that manages content,
A content acquisition step of acquiring content to which the identification information of the other information management device is added from another information management device;
An identification information acquisition step of acquiring identification information of the other information management device from the other information management device;
A content storage step of storing the content acquired by the processing of the content acquisition step;
An identification information storage step for storing identification information of the other information management device acquired by the processing of the identification information acquisition step;
As the information related to the use of the content, the usage right including the identification information and the information that permits the use in the device from which the same identification information as the identification information added to the content is acquired is stored. A usage right storage step,
A reproduction step of reproducing the content when the identification information added to the content is the same as the identification information stored by the processing of the identification information storage step.

Images