JP2007188429A - Content accumulator, content reproducer, content accumulation program, and content reproducing program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a content accumulator and a content reproducer, for dealing with a plurality of files different in reproduction conditions (permission conditions) of the respective files as one file group, i.e. a series of contents, in a file system for dealing with digital data as one file, while the reproduction of the digital data is not depending on an application. <P>SOLUTION: This content accumulating reproducer 1 accumulates the contents in a recording medium 13, and is provided with a content input means 3, a content encrypting means 5, an encrypted content accumulation executing means 7, a requirement extension attribute range information encrypting means 9, and an encrypted requirement extension attribute range information accumulation executing means 11. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a content storage device and content storage program for writing content to a recording medium, and a content playback device and content playback program for reading content from the recording medium.

  Conventionally, with the progress of digitalization (digitalization) of multimedia contents and documents, these digitized data, that is, digital data, are transferred and recorded via a network for the purpose of backup or reuse. Recording / playback processing that is stored and managed on a medium is routinely performed.

  In general, digital data does not deteriorate even when copied. Compared with analog data that deteriorates every time it is copied, it is easier to be used illegally and tampered with, so ensuring security on networks and recording media is important. become. Therefore, securing the security on the network is solved to some extent by using the existing encryption technology. Security on a recording medium is ensured by a file system that manages digital data as a file (see, for example, Patent Documents 1 and 2).

  In this file system, for example, there is a technique for applying security to each file. However, recent multimedia contents include a plurality of digital data (sub-contents and sub-files) attached to main digital data (main contents and main files), and are completed with one file. There is no case. In this case, in the file system, the main content and the sub-content may be combined into a single file group, and the main content and the sub-content may be handled with different security strengths to be protected.

  For example, in the case of program content in which digital data is used for broadcasting or the like, the program content generally includes sub-contents such as a license, trial listening content, still image thumbnail, and synopsis in addition to the main content program file. It is necessary to handle a plurality of files such as text (text data) as a group of files.

  In this case, the strengths of security to be protected are different in the sub-contents, and the license is permitted to be played only on the permitted devices and recording media, and can be handled by these devices and recording media. Security strength is set for the level. In addition, the sampled content is allowed to be reproduced by other devices even if it is not a licensed device, and can be freely copied to other recording media regardless of the licensed recording media.

  Furthermore, the strength of security is set so that text data describing still image thumbnails and synopses can be handled freely regardless of licensed devices and recording media.

  Incidentally, recording media (recording media) such as optical disks (CD, DVD) and magnetic disks generally have a hierarchical structure, and an “application layer”, “file system layer”, and “physical layer” are included in this hierarchical structure. is there. Conventionally, when digital data is to be recorded on the recording medium, copy protection such as CPRM (Content Protection for Recordable Media) or CSS (Content Scramble System) is performed in the application layer by an application that handles the digital data. .

In addition, various digital data are recorded on the recording medium by various applications. And various applications remove copy protection, respectively, and copy control is secured by the application.
JP 2000-122816 A Japanese Patent Laid-Open No. 10-283262

  However, if digital data recorded on a recording medium is forcibly reproduced by another application by another application, it can be reproduced if it follows a common “application layer”, otherwise it cannot be reproduced, and digital data cannot be reproduced. There is a problem that availability depends on the application.

  Further, in a file system that handles digital data as one file, there is a problem that it is difficult to handle a plurality of files having different reproduction conditions (permission conditions) of each file as one file group, that is, a series of contents. . Incidentally, for example, the function of storing a plurality of digital data (a plurality of sub files) in association with the main file is realized by Windows (registered trademark) NTFS (NT File System) or UDF (Universal Disk Format), Among them, there is a technique for encrypting one file, but there is no technique for storing (storing and reproducing) the security strength for each individual digital data.

  Therefore, in the present invention, the above-described problems are solved, and in a file system that handles the digital data as one file without depending on the application whether or not the digital data can be reproduced, the reproduction condition (permission condition) of each file is It is an object of the present invention to provide a content storage device and content playback device that can handle a plurality of different files as one file group, that is, a series of contents, and a content storage program and content playback program.

  In order to solve the above problem, the content storage device according to claim 1 is a content storage device for storing content in a recording medium, wherein the content encryption unit, the encrypted content storage execution unit, the requirement extended attribute range information encryption And an encryption requirement extended attribute range information accumulation execution unit.

  According to such a configuration, the content storage device encrypts the content based on the requirement extended attribute range information defined with respect to the strength of security referred to when the content is encrypted by the content encryption unit. The requirement extended attribute range information is one type of meta information (metadata). Subsequently, the content storage device stores the encrypted content encrypted by the content encryption unit by the encrypted content storage execution unit in the content section designated in advance of the recording medium.

  Then, the content storage device encrypts the requirement extended attribute range information based on the file system identification information defined in advance by the requirement extended attribute range information encryption means. The file system identification information is a file system ID for identifying various file systems. In the content storage apparatus, the encryption requirement extended attribute range information storage executing unit predefines the encryption requirement extended attribute range information encrypted by the requirement extended attribute range information encryption unit of the recording medium. Accumulate in the meta information section.

  That is, this content storage device focuses on the “file system layer” in the hierarchical structure of the recording medium, defines two sections (content section and meta information section) as logical volumes on the recording medium, The encrypted content obtained by encrypting the content is stored in the partition, and the requirement extended attribute range information obtained by encrypting the requirement extended attribute range information is stored in the meta information partition. Then, by using the requirement extended attribute range information when encrypting the content, and further by using the file system ID when encrypting the requirement extended attribute range information, the encryption requirement extended attribute can be used regardless of the application. The range information can be decrypted, the encrypted content can be decrypted, and the digital data recorded on the recording medium is managed. Thus, in the content storage device, the digital data can be logically managed from the viewpoint of the application by controlling the digital data at the file system layer in the file system.

  The content storage device according to claim 2 is the content storage device according to claim 1, wherein the content includes one main content and one or a plurality of sub-contents subordinate to the main content, and the element extension The attribute range information is set for each of the main content and the sub-content.

  According to such a configuration, the content storage device converts content including one main content and one or more sub-contents subordinate to the main content (in a subordinate relationship) based on the element extended attribute range information. Accumulate in the content section. Note that the sub-content includes a license, a trial listening content, a still image thumbnail, text data, and the like.

  The content reproduction apparatus according to claim 3, wherein the content reproduction apparatus reads out the content from the recording medium and reproduces the content, the encryption requirement extended attribute range information reading unit, the encryption requirement extended attribute range information decrypting unit, and the encrypted content The reading unit and the encrypted content decrypting unit are provided.

  According to such a configuration, the content reproduction device defines the strength of security to be referred to when encrypting the content from the meta information section defined in advance of the recording medium by the encryption requirement extended attribute range information reading unit. The encrypted requirement extended attribute range information obtained by encrypting the requirement extended attribute range information is read. Subsequently, the content reproduction apparatus uses the encryption requirement extended attribute range information decrypting unit to read the encryption requirement extended attribute range information read by the encryption requirement extended attribute range information reading unit, using a predetermined file system identification. Decode based on the information.

  Then, the content reproduction device reads the encrypted content obtained by encrypting the content from the predetermined content section of the recording medium by the encrypted content reading unit. In addition, the content reproduction apparatus is configured to, based on the requirement extended attribute range information decrypted by the encrypted requirement extended attribute range information decrypting unit, the encrypted content read by the encrypted content reading unit by the encrypted content decrypting unit. Decrypt.

  The content playback device according to claim 4 is the content playback device according to claim 3, wherein the content includes one main content and one or a plurality of sub-contents subordinate to the main content. The attribute range information is set for each of the main content and the sub-content.

  According to such a configuration, the content reproduction apparatus can store encrypted content obtained by encrypting content composed of one main content and one or more sub-contents subordinate to (mainly dependent on) the main content. Read from the partition and decode.

  The content storage program according to claim 5, in order to store the content in a recording medium, the computer includes a content encryption unit, an encrypted content storage execution unit, a requirement extended attribute range information encryption unit, an encryption requirement extended attribute. It is configured to function as range information accumulation execution means.

  According to such a configuration, the content storage program encrypts the content based on the requirement extended attribute range information defined with respect to the strength of security to be referred to when the content is encrypted by the content encryption unit, and stores the encrypted content. The execution unit stores the encrypted content encrypted by the content encryption unit in a predetermined content section of the recording medium.

  The content storage program encrypts the requirement extended attribute range information based on the file system identification information defined in advance by the requirement extended attribute range information encryption unit, and encrypts the requirement extended attribute range information storage execution unit. Thus, the encrypted requirement extended attribute range information encrypted by the requirement extended attribute range information encryption unit is stored in a pre-defined meta information section of the recording medium.

  The content reproduction program according to claim 6, in order to read and reproduce the content from the recording medium, the computer is operated by an encryption requirement extended attribute range information reading unit, an encryption requirement extended attribute range information decoding unit, and an encrypted content reading. And the encrypted content decrypting means.

  According to such a configuration, the content reproduction program defines the strength of security to be referred to when content is encrypted from the pre-defined meta information section of the recording medium by the encryption requirement extended attribute range information reading unit. Encryption requirement extended attribute range information encrypted by requirement extended attribute range information is read, and the encryption requirement extended attribute read by the encryption requirement extended attribute range information reading means by the encryption requirement extended attribute range information decrypting means The range information is decrypted based on the file system identification information defined in advance.

  The content reproduction program reads the encrypted content obtained by encrypting the content from the predetermined content section of the recording medium by the encrypted content reading unit, and the encrypted content reading unit by the encrypted content decrypting unit. The encrypted content read in step (b) is decrypted based on the requirement extended attribute range information decrypted by the encrypted requirement extended attribute range information decrypting means.

  The inventions according to claims 1 and 5 use the requirement extended attribute range information and the file system identification information (file system ID) to focus on the “file system layer” of the recording medium and based on the requirement extended attribute range information. The encrypted content encrypted in this manner is stored in the content section, and the encryption requirement extended attribute range information encrypted based on the file system identification information is stored in the meta information section. As a result, it is possible to eliminate the dependence of the content (digital data) on the application.

  According to the second aspect of the present invention, in a file system that handles content (digital data) composed of main content and sub-content as one file, the reproduction conditions (permission conditions) of the main content and sub-content (each file) are A plurality of different files can be stored in the content section as one file group, that is, as a series of contents.

  The inventions of claims 3 and 6 read and decrypt the encryption requirement extended range information stored in the meta information section, and read and decrypt the encrypted content stored in the content section. Since the meta information section and the content section exist in the “file system layer” of the recording medium, whether or not the content (digital data) can be reproduced does not depend on the application.

  According to the fourth aspect of the present invention, in a file system that handles content (digital data) composed of main content and sub-content as one file, the reproduction conditions (permission conditions) of the main content and sub-content (each file) are A plurality of different files can be reproduced as one file group, that is, a series of contents.

Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.
(Configuration of content storage and playback device)
FIG. 1 is a block diagram of a content storage / playback apparatus. As shown in FIG. 1, a content storage / playback apparatus 1 stores and plays back (outputs) input content, and includes content input means 3, content encryption means 5, and encrypted content storage execution means 7. , Requirement extended attribute range information encryption means 9, encryption requirement extended attribute range information storage execution means 11, recording medium 13, encryption requirement extended attribute range information reading means 15, encryption requirement extended attribute range information Decryption means 17, encrypted content reading means 19, encrypted content decryption means 21, and content output means 23 are provided.

  The content input means 3 serves as an interface that receives (receives) input content. The content input to the content input means 3 is composed of one main content and one or a plurality of sub-contents, and requirement extended attribute range information is added to the content.

  The content input means 3 generates file entry information for setting how to handle the content as physical data. This file entry information is generated for each of the main content and sub-content constituting the content. Further, a sub-content directory that is a directory indicating a relationship between the main content and the sub-content is created (defined), and the requirement extended attribute range information of the main content and the sub-content is arranged (associated) in the sub-content directory. Create a data concealment stream. That is, in the data concealment stream, the names of the main content and the sub content and the security robustness range are associated with each other.

  The main content is the main body of the content. For example, when the content is a broadcast program, video (moving image file) or audio (audio file) of the broadcast program corresponds to the main content. The sub-content is attached to the content. For example, when the content is a program broadcast over the network, the license (listed with viewing conditions), the trial-listening content (video file for trial-listening), static This includes image thumbnails.

  Requirement extended attribute range information is a type of metadata that defines how to encrypt content (main content, sub-content), and a basic range (security robustness range) that is the strength of security for each main content and sub-content. Is described. Note that the basic range (security robustness range) can be said to be security information of main content and sub-content that constitute the content.

  A data concealment stream is created in the content input means 3 in accordance with the requirement extended attribute range information. Specific examples of the data concealment stream and the security robustness range will be described later.

  Then, the content input unit 3 separates the input content and the requirement extended attribute range information added to the content, encrypts the content in the content encryption unit 5, and encrypts the requirement extended attribute range information in the content The data is output to the means 5 and the requirement extended attribute range information encryption means 9.

  The content encryption unit 5 encrypts content (main content, sub-content) based on the requirement extended attribute range information. That is, the main content and the sub content are encrypted according to the security strength described in the requirement extended attribute range information. The encryption process performed by the content encryption unit 5 is a general one. Also, the encrypted main content is the encrypted main content, and the encrypted sub content is the encrypted sub content.

  The encrypted content storage execution unit 7 stores the content (encrypted content) encrypted by the content encryption unit 5 in the recording medium 13. The encrypted content storage execution means 7 stores the encrypted content in one of the two sections (content section and meta information section) created in the logical volume of the recording medium 13.

  The requirement extended attribute range information encryption unit 9 uses the file system ID (file system information) defined in advance in the file system layer of the recording medium 13 for the requirement extended attribute range information separated by the content input unit 3. It is to be encrypted.

  When this file system ID is used, the content distribution system using the device 1 described later is restricted by a CAS (Conditional Access System) card inserted when the device 1 is used as a home server. It is configured as follows. That is, when content is stored in the home server (contents storage / playback device 1), storage (external recording device) or removable media (DVD, etc.) connected to the home server, and then played back, the CAS card inserted at the time of storage If it is not used, reproduction is not possible.

  The encryption requirement extended attribute range information storage execution unit 11 stores the encryption requirement extended attribute range information encrypted by the requirement extended attribute range information encryption unit 9 in the recording medium 13. This encryption requirement extended attribute range information storage execution means 11 includes an encryption requirement extended attribute in the other meta information section of the two sections (content section and meta information section) created in the logical volume of the recording medium 13. Accumulate range information.

  The recording medium 13 outputs the encrypted content (encrypted main content, encrypted subcontent) output from the encrypted content storage execution unit 7 to the content section, and is output from the encryption requirement extended attribute range information storage execution unit 11. The encryption requirement extended attribute range information is stored in the meta information section, and is configured by a removable medium such as a general hard disk (HDD) or an optical disk (DVD or the like).

  In this recording medium 13, the content section and the meta information section constituting the logical volume are created (formatted) at the time of installation or insertion in the apparatus 1. These content section and meta information section are defined on the recording medium 13 by section descriptors.

  The encryption requirement extended attribute range information reading unit 15 reads the encryption requirement extended attribute range information stored in the meta information section of the recording medium 13. When the encryption requirement extended attribute range information reading unit 15 fails to read the encryption requirement extended attribute range information, for example, a display device (not shown) connected to the device 1 due to an abnormality in the recording medium 13 or the like. ) Is an error response.

  The encryption requirement extended attribute range information decrypting means 17 decrypts the encryption requirement extended attribute range information read by the encryption requirement extended attribute range information reading means 15 using a file system ID (file system information). It is. Then, the requirement extended attribute range information obtained by decrypting the encrypted requirement extended attribute range information by the encrypted requirement extended attribute range information decrypting unit 17 is output to the encrypted content decrypting unit 21.

  The encrypted content reading means 19 reads the encrypted content (encrypted main content, encrypted sub-content) stored in the content section of the recording medium 13. If the encrypted content reading unit 19 fails to read the encrypted content, an error response is made to a display device (not shown) connected to the device 1 due to, for example, an abnormality in the recording medium 13.

  The encrypted content decrypting unit 21 decrypts the encrypted content read by the encrypted content reading unit 19 based on the requirement extended attribute range information. In this encrypted content decrypting means 21, for example, a license is required when decrypting the encrypted main content. When this license is encrypted as the encrypted sub content, the encrypted sub content is After decryption, the encrypted main content is decrypted.

  The content output unit 23 outputs the content decrypted by the encrypted content decryption unit 21 to a display device (not shown) connected to the device 1.

  In this way, the content storage / playback apparatus 1 can store the input content in the recording medium 13, read out from the recording medium 13, and perform playback. The definition (format) of the content section and the meta information section of the recording medium 13 is based on UDF (Universal Disk Format). However, the present invention is not limited to this UDF, and may be any as long as an equivalent partition section can be defined. Then, the content storage / playback apparatus 1 stores (stores) the content by designating such a definition (format), specifying the security strength for each of the main content and the sub-content included in the content. Yes.

  According to the content storage / playback apparatus 1, by using the requirement extended attribute range information and the file system ID (file system identification information), the content encryption unit 5 focuses on the requirement extension by focusing on the “file system layer” of the recording medium 13. The encrypted content encrypted based on the attribute range information is stored in the content section by the encrypted content storage execution means 7 and encrypted based on the file system ID by the requirement extended attribute range information encryption means 9 The extended attribute range information is stored in the meta information section by the encryption requirement extended attribute range information storage executing means 11. As a result, it is possible to eliminate the dependence of the content (digital data) on the application.

  Further, according to the content storage / playback apparatus 1, a plurality of files having different playback conditions (permission conditions) for main content and sub-content are stored in a content section of the recording medium 13 as one file group, that is, a series of contents. be able to.

  Furthermore, according to the content storage / playback apparatus 1, the encryption requirement extended attribute range information is read by the encryption requirement extended attribute range information reading means 15 to read out the encryption requirement extended range information stored in the meta information section of the recording medium 13. Decrypted by the decrypting means 17, and the encrypted content reading means 19 reads the encrypted content stored in the content section of the recording medium 13 and decrypts it by the encrypted content decrypting means 21. These meta information section and content section Exists in the “file system layer” of the recording medium 13, it is possible to eliminate the dependence of the content (digital data) on the application.

  Furthermore, according to the content storage / playback apparatus 1, a plurality of files having different playback conditions (permission conditions) for the main content and the sub-contents (each file) can be played as one file group, that is, a series of contents. it can.

(Specific examples of the logical volume of the recording medium, the data concealment stream, and the security robustness range)
Next, an outline of the logical volume of the recording medium, an outline of the data concealment stream, and a specific example of the security robustness range will be described with reference to FIGS. 2 to 4 (see FIG. 1 as appropriate). FIG. 2 is a diagram showing an outline of definitions and recording states on the recording medium. FIG. 3 is a diagram showing an outline of the data concealment stream. FIG. 4 is a diagram showing a specific example of the security robustness range.

[Logical volume of recording medium]
As shown in FIG. 2, the recording medium 13 has a logical volume on the medium 13, and a content partition and a meta information partition are defined in the logical volume by a partition descriptor in the file system layer. .

  Then, when content (main content, sub-content a, sub-content b, sub-content c) is input to the content storage / playback device 1, the content input means 3 uses file entry information based on the requirement extended attribute range information. A file entry A and a secondary content directory are created and stored in the content section of the recording medium 13 as shown in FIG. Then, the content input means 3 creates a data concealment stream based on the requirement extended attribute range information and, as shown in FIG. 2, the meta information section of the recording medium 13 associated with the sub-content directory of the content section. Accumulated in.

  The recording medium 13 stores main content (more precisely, encrypted main content) under the file entry A (in the tree structure) of the content section. In addition, on the recording medium 13, a file entry that is file entry information that is file entry information of sub-content a (license) and file entry information that is sub-content b (still image thumbnail) is located under the sub-content directory of the content section. b, file entry c which is file entry information of sub-content c (trial listening content) is created, and sub-contents (more precisely, encrypted sub-contents) a to c are respectively stored under these file entries a to c. Yes.

[Data confidential stream]
As shown in FIG. 3, the data concealment stream is one in which main content and sub-contents ac are associated with a security robustness range. In this data concealment stream, the main content and the security robustness range “3” are associated with each other, the sub-content a (license) and the security robustness range “4” are associated with each other, and the sub-content b (still image) Thumbnail) and the security robustness range “3” are associated with each other, and the sub-content c (trial listening content) and the security robustness range “0” are associated with each other.

  When these security robustness ranges “3”, “4”, and “0” are briefly described (details will be described in FIG. 4 below), the security robustness range “3” has a security strength of “3”. And stipulates that encryption is performed using a media ID for identifying the recording medium 13. Further, the security robustness range “4” indicates that the security strength is “4” (here, the maximum value), and it is defined that encryption is performed using the file system ID. Further, the security robustness range “0” indicates that the security strength is “0” (here, the minimum value), and specifies that encryption is not performed.

[Security Robustness Range]
As shown in FIG. 4, the security robustness range includes “range” indicating the security strength from “0” to “4”, as well as “protection method”, “protection content”, “threat”, and “use”. Four items are defined.

  The “protection method” is an item that defines the presence / absence of encryption and the encryption key used for encryption. “Protected content” is an item that defines the content to be protected, such as prevention of unauthorized browsing and prevention of unauthorized copying. “Threat” is an item that stipulates what kind of fraudulent actions can break security. “Use” is an item that defines how to use the main content and sub-content. In FIG. 4, “FS” is an abbreviation for file system, and “hack” is an abbreviation for hacking.

  As shown in FIGS. 2 to 4, in the content storage / playback apparatus 1, the security strength for each security robustness range is set in advance, and the content section and the meta information section are created in the logical volume of the recording medium 13. When the content with the requirement extended attribute range information added is input, a data concealment stream in which the main content and the sub content are associated with the security robustness range is created based on the requirement extended attribute range information. From, encrypted and stored.

(Operation of content storage and playback device)
Next, with reference to FIG. 5 and FIG. 6, the storage operation and the playback operation of the content storage / playback apparatus 1 will be described (see FIG. 1 as appropriate). FIG. 5 is a flowchart illustrating the storage operation of the content storage / playback apparatus, and FIG. 6 is a flowchart illustrating the playback operation (output operation) of the content storage / playback apparatus.

[Accumulation operation]
As shown in FIG. 5, first, the content storage / playback apparatus 1 receives the content (main content, sub-content) to which the requirement extended attribute range information is added by the content input means 3, and converts it into the requirement extended attribute range information. Based on this, file entry information is created, a secondary content directory is created, a data concealment stream is created (step S1), and content and requirement extended attribute range information are separated and output.

  Subsequently, the content storage / playback apparatus 1 encrypts the content (main content, sub-content) by the content encryption unit 5 based on the requirement extended attribute range information (step S2), and the encrypted content storage execution unit 7 Then, the encrypted content (encrypted main content, encrypted sub-content) is stored in the content section of the recording medium 13 (step S3).

  Then, the content storage / playback apparatus 1 encrypts the requirement extended attribute range information using the file system ID by the requirement extended attribute range information encryption unit 9 (step S4), and encrypts the requirement extended attribute range information storage execution unit. 11 stores the encryption requirement extended attribute range information in the meta information section of the recording medium 13 (step S5).

[Playback operation]
As shown in FIG. 6, first, the content storage / playback apparatus 1 reads the encryption requirement extended attribute range information stored in the meta information section of the recording medium 13 by the encryption requirement extended attribute range information reading means 15. (Step S11), the encrypted requirement extended attribute range information decrypting means 17 decrypts the encrypted requirement extended attribute range information using the file system ID (step S12), and encrypts the decrypted requirement extended attribute range information. It outputs to the content decryption means 21.

  Then, the content storage / playback apparatus 1 reads the encrypted content stored in the content section of the recording medium by the encrypted content reading means 19 (step S13), and the encrypted content decrypting means 21 reads the encrypted content. The content is decoded based on the requirement extended attribute range information (step S14) and output from the content output means 23.

(Content distribution system using content storage and playback device)
Next, a content distribution system in which the content storage / playback apparatus 1 is used as a home server will be described with reference to FIG. 7 (see FIG. 1 as appropriate). FIG. 7 is a schematic diagram of the content distribution system.

  As shown in FIG. 7, the content distribution system S distributes content (hereinafter also referred to as program content) to each home (here, only home A and home B are described) using a network. The distribution side (broadcast station) and the reception side (home) can be broadly classified. On the distribution side, a broadcast station server 2 that distributes content on the network and a content DB 4 that stores a large number of contents connected to the broadcast station server 2 are provided. On the receiving side, home server 1 (1A, 1B), viewing device 6 (6A, 6B), CAS card 8 (8A, 8B), storage 10 (10A, 10B), and removable media 12 (12A, 12B) ) And are provided.

  In this content distribution system S, the content storage / playback apparatus 1 is used as a home server 1 (1A, 1B) for inserting a CAS card. Further, instead of the recording medium 13, a fixed storage 10 (10A, 10B) that is an external recording device and a portable removable medium 12 (12A, 12B) are used.

  In this content distribution system S, content is distributed from the broadcast station server 2 on the distribution side according to a distribution schedule that is organized in advance, or content is distributed individually according to requests from the homes A and B on the reception side. Then, the homes A and B receive the distributed content and store the content in the storage 10 (10A and 10B) or the removable medium 12 (12A and 12B) via the home server 1 (1A and 1B).

  The requests from the homes A and B on the receiving side include a program guide request for requesting delivery of a list of distributable contents (program guide), and trial viewing requesting delivery of test viewing content that is content that can be auditioned. Examples thereof include a content request, a program content request for requesting distribution of desired content, and a viewing license request for requesting distribution of a license.

  Thereafter, in the homes A and B, the stored content is viewed by the viewing device 6 (6A and 6B) via the home server 1 (1A and 1B). If the content stored in the removable media 12A (12A, 12B) is inserted into the viewing device connected to another home server and the CAS card 8 (8A, 8B) that was inserted at the time of storage is inserted, It can be viewed on a viewing device connected to another home server. That is, the home server 1 (1A, 1B) uses the CAS card 8 (8A, 8B) inserted at the time of storage to use the file system ID used when decrypting the encryption requirement extended attribute range information. Is configured to be available.

  In order to view the content distributed by the content distribution system S, it is necessary to obtain in advance a content viewing right, so-called license, from the distribution side (broadcast station) or purchase the content. Further, when the content is composed of main content and sub-content, and the sub-content includes still image thumbnails (also simply referred to as thumbnails) or preview content, for example, the security robustness range is set to “ By setting it to “0” (no encryption), it is possible to purchase after referencing.

  Here, the file structure of the content distributed by the content distribution system S is shown in FIG. As shown in FIG. 8, the content has a file structure organized by the “Program Information File” that is the main file, among which “MAIN TS” that is the main content and “Sample” that is the sub-content. “TS”, “Thumbnail”, “Text”, “License”, and “Data Privacy” are stored.

  “MAIN TS” is the main body of content, “Sample TS” is preview content (hereinafter also referred to as test viewing content), and “Thumbnail” is a still image thumbnail (hereinafter referred to as “still image thumbnail”). , Also simply called thumbnails). “Text” is accompanying text data, “License” is a viewing right (license), and “Data Privacy” is requirement extended attribute range information added to each content.

  In the content distribution system S, data concealment is created based on the requirement extended attribute range information depending on the storage location of the content, whether the viewing right of the content is acquired, or whether the content is purchased. The security robustness range of the stream is set to be different. FIG. 9 shows the data concealment stream created here (referred to here as range information of each content). Each numerical value in the range information of each content is the same as that shown in FIG.

  In FIG. 9, the license status and the security robustness of each content when the storage location is the storage 10 (10A, 10B) connected to the home server 1 (1A, 1B) and the removable medium 12 (12A, 12B). The relationship with the range is shown.

  When “trial viewing” is performed on the home server 1 (1A, 1B), the security robustness range of “Program Information File” and “MAIN TS” is “0”, and the security robustness range of “Sample TS” and “Thumbail” is The security robustness range of “1” and “Text” is “2”, and the security robustness range is not set in “License”.

  Further, when “viewing license acquisition” is performed in the home server 1 (1A, 1B), the security robustness ranges of “Program Information File” and “MAIN TS” are “0”, “Sample TS”, and “Thumbnail” security. The robustness range is “1”, and the security robustness range of “Text” and “License” is “2”.

  Furthermore, when “content purchase” is performed in the home server 1 (1A, 1B), the security robustness range of “Program Information File” is “0”, “MAIN TS”, “Sample TS”, and “Security Thumbnail”. The security robustness range of the range “1” and “Text” is “2”, and the security robustness range is not set in “License”.

  When “trial viewing” is performed on the removable media 12 (12A, 12B), the security robustness range of “Program Information File” and “MAIN TS” is “0”, and the security robustness range of “Sample TS” and “Thumbnail” is The security robustness range of “1” and “Text” is “4”, and the security robustness range is not set in “License”.

  Further, when “viewing license acquisition” is performed on the removable media 12 (12A, 12B), the security robustness ranges of “Program Information File” and “MAIN TS” are “0”, “Sample TS”, and “Thumbnail” security. The robustness range of “1”, “Text”, and “License” is “4”.

  Further, when “content purchase” is performed in the removable media 12 (12A, 12B), the security robustness range of the “Program Information File” is “0”, “MAIN TS”, “Sample TS”, “Thumbail”, and “Text”. The security robustness range of “3” is “3”, and the security robustness range is not set in “License”.

(Example of overall operation of content distribution system)
Next, an example of the overall operation of the content distribution system S will be described using the sequential chart shown in FIG. 10 (see FIGS. 7 and 8 as appropriate).
First, the home server 1A makes a program guide request to the broadcast station server 2, and the broadcast station server 2 distributes the program guide to the home server 1A. Here, the user of the home server 1A selects the program content to be viewed.

  Then, the home server 1A makes a trial viewing content request to the broadcast station server 2, and the broadcast station server 2 delivers the trial viewing content to the home server 1A. At this time, what is distributed from the broadcast station server 2 to the home server 1A is “Sample TS”, “Thumbnail”, and “Text” in the “Program Information File”. Then, the home server 1A accumulates these in the storage 10A, and at this time, creates “Data Privacy”.

  Then, the home server 1A can view the trial viewing content and the still image thumbnail (the trial viewing OK of the home server 1A and the thumbnail OK of the home server 1A). Here, the user of the home server 1A decides to obtain the program content by viewing the trial viewing content and the still image thumbnail.

  Subsequently, the home server 1A makes a program content request to the broadcast station server 2, and the broadcast station server 2 distributes the program content. At this time, what is distributed from the broadcast station server 2 to the home server 1A is “MAIN TS” in the “Program Information File”. Then, the home server 1A accumulates the received program content in the storage 10A.

  However, since the home server 1A has not acquired a license for the received program content, the program content cannot be viewed (viewing NG of the home server 1A). Therefore, the home server 1A makes a viewing license request to the broadcasting station server 2, and the broadcasting station server 2 distributes the viewing license to the home server 1A. At this time, what is distributed from the broadcast station server 2 to the home server 1A is “License” in “Program Information File”. The home server 1A accumulates the received viewing license in the storage 10A.

  Thereby, the home server 1A can view the program content (viewing OK of the home server 1A). Thereafter, the home server 1A can be viewed even if the program content is moved (accumulated) to the removable medium 12A in accordance with the description of “Program Information File” (viewing OK of the removable medium 12A).

  Further, when the removable media 12A is inserted into the home server 1B, the home server 1B can view the trial viewing content and the still image thumbnail, but when the program content is stored in the removable media 12A, the home server 1A Since the inserted CAS card 8A is not inserted in the home server 1B, the content of the program cannot be viewed under the restriction of the CAS card (trial viewing of the home server 1B, thumbnail of the home server 1B, home server 1B). NG).

  Therefore, when the CAS card 1A is inserted into the home server 1B, the home server 1B can view the program content (viewing of the home server 1B is OK).

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment. For example, in the present embodiment, the content storage / playback apparatus 1 has been described. However, the content storage program and the content playback program are written in a general or special computer language so that the processing of each component of the apparatus 1 can be realized. Is possible.

1 is a block diagram of a content storage / playback apparatus (including a content storage apparatus and a content playback apparatus) according to an embodiment of the present invention. It is the figure which showed the outline of the logical volume of a recording medium. It is the figure which showed the outline of the data concealment stream. It is a figure explaining the specific example of the security robustness range. 3 is a flowchart for explaining a storage operation of the content storage / playback apparatus shown in FIG. 1. 3 is a flowchart for explaining a reproduction operation of the content storage / reproduction apparatus shown in FIG. 1. It is the figure which showed the outline of the content delivery system which used the content storage / reproduction apparatus as a home server. It is the figure which showed the file structure of the program (content) delivered with the content delivery system shown in FIG. It is the figure which showed the range information (data confidential stream) of each content used with the content delivery system shown in FIG. 8 is a sequence chart showing an example of the overall operation of the content distribution system shown in FIG. 7.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Content storage reproduction apparatus 3 Content input means 5 Content encryption means 7 Encrypted content storage execution means 9 Requirement extended attribute range information encryption means 11 Encryption requirement extended attribute range information accumulation execution means 13 Recording medium 15 Encryption requirement extended attribute Range information reading means 17 Encrypted requirement extended attribute range information decrypting means 19 Encrypted content reading means 21 Encrypted content decrypting means 23 Content output means

Claims (6)

In a content storage device that stores content in a recording medium,
Content encryption means for encrypting the content based on requirement extended attribute range information that defines the security strength to be referred to when encrypting the content;
Encrypted content storage executing means for storing the encrypted content encrypted by the content encryption means in a pre-designated content section of the recording medium;
Requirement extended attribute range information encryption means for encrypting the requirement extended attribute range information based on pre-defined file system identification information;
Encryption requirement extended attribute range information storage execution means for storing the encryption requirement extended attribute range information encrypted by the requirement extended attribute range information encryption means in a pre-defined meta information section of the recording medium;
A content storage device comprising:   The content is composed of one main content and one or a plurality of sub-contents subordinate to the main content, and the requirement extended attribute range information is set for each of the main content and the sub-content. The content storage device according to claim 1. In a content playback device that reads content from a recording medium and plays it back,
Cryptography that reads encrypted requirement extended attribute range information in which requirement extended attribute range information that is defined with regard to the strength of security to be referred to when encrypting the content is encrypted from a predetermined meta information section of the recording medium Requirements extended attribute range information reading means,
Encryption requirement extended attribute range information decrypting means for decrypting the encryption requirement extended attribute range information read by the encryption requirement extended attribute range information reading means, based on pre-defined file system identification information;
Encrypted content reading means for reading out encrypted content obtained by encrypting the content from a predetermined content section of the recording medium;
Encrypted content decrypting means for decrypting the encrypted content read by the encrypted content reading means based on the requirement extended attribute range information decrypted by the encrypted requirement extended attribute range information decrypting means;
A content playback apparatus comprising:   The content is composed of one main content and one or a plurality of sub-contents subordinate to the main content, and the requirement extended attribute range information is set for each of the main content and the sub-content. The content reproduction apparatus according to claim 3. In order to store content on a recording medium,
Content encryption means for encrypting the content based on requirement extended attribute range information that defines the security strength to be referred to when encrypting the content;
Encrypted content accumulation executing means for accumulating the encrypted content encrypted by the content encryption means in a pre-designated content section of the recording medium;
Requirement extended attribute range information encryption means for encrypting the requirement extended attribute range information based on pre-defined file system identification information;
Encryption requirement extended attribute range information storage execution means for storing the encryption requirement extended attribute range information encrypted by the requirement extended attribute range information encryption means in a pre-defined meta information section of the recording medium,
Content storage program characterized by functioning as In order to read and play content from a recording medium,
Cryptography that reads encrypted requirement extended attribute range information in which requirement extended attribute range information that is defined with regard to the strength of security to be referred to when encrypting the content is encrypted from a predetermined meta information section of the recording medium Requirements extended attribute range information reading means,
Encryption requirement extended attribute range information decrypting means for decrypting the encryption requirement extended attribute range information read by the encryption requirement extended attribute range information reading means, based on file system identification information defined in advance,
Encrypted content reading means for reading out encrypted content obtained by encrypting the content from a predetermined content section of the recording medium;
Encrypted content decrypting means for decrypting the encrypted content read by the encrypted content reading means based on the requirement extended attribute range information decrypted by the encrypted requirement extended attribute range information decrypting means;
A content reproduction program characterized by being made to function as:

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