JP2005157688A - Content receiving terminal, history retrieving device, history data generating method, history retrieving method, history data generating program and history retrieval program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a content receiving terminal for specifying an illegal user who has illegally circulated contents distributed from a provider or performed any illegal operation to the contents. <P>SOLUTION: A content receiving terminal 50 is provided with a content receiving means 54 which receives contents with trace information including contents ID to identify contents and distribution destination information showing the distribution destination of contents, a trace information updating means 56 which updates the distribution destination information to redistribution destination for distributing the contents to the other terminal, a content distributing means 58c for distributing the contents whose trace information are updated to the other terminal and a history data generating means 59 for generating history data including distribution origin history information showing the distribution origin of redistribution and distribution destination history information showing the distribution destination of redistribution, and for transmitting the history data to a history data storage device for storing the history data. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a technology for detecting unauthorized use of content, and more particularly to a technology for detecting an unauthorized user by notifying a content provider of an operation performed on distributed content.

  In recent years, multimedia contents such as video and audio (hereinafter referred to as contents) have been distributed on networks (such as the Internet). In such an environment, a purchaser (hereinafter referred to as a user) who purchases content from a content provider (hereinafter referred to as a provider) or a third party who illegally obtained content from this user or the like receives the content via a network. There is a problem of illegal acts such as illegal distribution or recording on a recording medium and illegal distribution.

  In order to prevent such illegal acts, conventionally, the provider encrypts the content and distributes it to the user so that only the authorized user can decrypt and view it. (Rights Management) is used (see Patent Document 1). In this system, the user is authenticated on the provider side, and the encrypted content and the key for decrypting the content are distributed to the users for whom the sales contract is established, so that only authorized users can decrypt the content. I have to.

In addition, as a technology for identifying a user who has performed an illegal act as described above with respect to the content, when the content is illegally distributed by embedding the information of the user who purchased the content in the content using a digital watermark and distributing it. The method of reading the information of the user who purchased from the illegally distributed content and identifying the user who performed the illegal act is performed (see Patent Document 2).
JP 2002-281477 (paragraphs 0031 to 0040) JP 2001-305957 A (paragraphs 0014 to 0018)

  However, the system of Patent Document 1 has a problem that the decrypted content is illegally distributed because a key for decrypting the encrypted content is leaked to a third party. Further, in the method of Patent Document 2, a user who purchases this content and distributes it illegally can be identified from the illegally distributed content. However, a third party illegally distributes the content from the user who purchased the content. When it was obtained and distributed, there was a problem that this third party could not be specified.

  Furthermore, in the method of Patent Document 2, when a provider finds illegally distributed content, the user who has illegally distributed can be identified, and a user or a third party who has illegally obtained the content can connect each terminal. When an illegal operation was performed with, the illegal operation could not be detected. For example, if a user performs an operation that exceeds the range where the content can be used, such as the expiration date of the content and the limit on the number of playbacks, as stipulated in the sales contract between the user and the provider, When an operation such as obtaining and viewing this content is performed, these unauthorized operations cannot be detected.

  The present invention has been made to solve the above-described problems of the prior art, and a user or a third party who illegally obtained content from a user illegally distributes content distributed from a provider, Content receiving terminal, history search device, history data generation method, history search method, history data generation program, and the like, which can identify an unauthorized user who has performed these fraudulent actions An object is to provide a history search program.

  In order to solve the problem, the content receiving terminal according to claim 1 receives the content to which tracking information including at least a content ID for identifying the content and distribution destination information indicating a distribution destination of the content is added. A content receiving terminal that generates history data indicating a redistribution history for distributing the content to another terminal and transmits the history data to a history data storage device that stores the history data, the content receiving unit, and a tracking The information updating unit, the content distribution unit, and the history data generation unit are provided.

  According to such a configuration, the content receiving terminal receives the content by the content receiving unit, and the distribution information indicating the distribution destination of the content included in the tracking information added to the content by the tracking information update unit. The content is updated to a redistribution destination that is a redistribution destination for distributing the content to other terminals. Then, the content distribution unit distributes the content to which the tracking information updated to the redistribution destination by the tracking information update unit is added to another terminal.

  Further, history data including at least content ID included in the tracking information, distribution source history information indicating a redistribution source that is a distribution source of redistribution, and distribution destination history information indicating a redistribution destination by the history data generation unit. Is transmitted to a history data storage device that stores history data.

  As a result, when the content receiving terminal distributes the received content to other terminals, the content receiving terminal updates the distribution destination information included in the tracking information added to the content to a redistribution destination that is a new distribution destination. The content to which the tracking information is added can be distributed to other terminals. Therefore, the content to which distribution destination information indicating this terminal is added is distributed to other terminals. In addition, history data including a content ID for identifying the content to be distributed, distribution destination history information indicating a redistribution destination, and distribution source history information indicating the content receiving terminal that distributed the content is stored in the history data storage device. Can be sent.

  Here, the distribution destination information indicates information for specifying a content receiving terminal that receives content. The distribution source history information indicates information for identifying the content receiving terminal that has distributed the content, and the distribution destination history information specifies the content receiving terminal (another terminal) that has received the content. Information is shown. The distribution destination information, distribution source history information, and distribution destination history information include, for example, an identifier for identifying each content receiving terminal, a device ID of the content receiving terminal, an IP address fixedly assigned to the content receiving terminal, and the like. By using this, it is possible to specify the content receiving terminal of the distribution destination or the distribution source.

  Also, the tracking information is distributed to the content receiving terminal by being added to the beginning or end of the content, for example. The tracking information is preferably encrypted and added to the content so that it cannot be rewritten by the user or a third party who illegally obtained the content.

  A history search device according to claim 2 is a history search for searching history data of content to be searched from a history data storage device storing history data generated by the content receiving terminal according to claim 1. The apparatus includes a final history data search unit, a history data search unit, and a history data output unit.

  According to such a configuration, the history search device uses the final history data search means to determine the final history data that is the history data when the content was last distributed based on the tracking information added to the search target content. Is retrieved from the history data storage device. Then, the history data search means uses the final history data as the search source based on the content ID of the history data of the content and the distribution destination history information, and the history of distribution performed before the distribution of the content indicated by the history data Retrieve data sequentially. The history data searched by the history data search means is output by the history data output means.

  Thereby, the history search apparatus can search the final history data based on the content ID and the distribution destination information added to the content to be searched. In other words, since both the distribution destination information of the content tracking information and the distribution destination history information of the history data indicate the distribution destination of the content, the distribution destination information and the final history data of the content to be searched are added. The distribution destination history information matches, and the content ID added to the content matches the content ID of the final history data. Therefore, the history search device can search the final history data by searching the history data based on the content ID of the tracking information of the content to be searched and the distribution destination information.

  Further, the distribution source history information of the retrieved history data matches the distribution destination history information of the history data indicating the history of distributing the content to the distribution source indicated by the distribution source history information. Therefore, the history search device uses the final history data as a search source, and sequentially searches the history data based on the content ID of the searched history data and the distribution source history information. History data from the history data at the time of distribution to the history data at the time of first distribution from the content receiving device can be searched.

  Furthermore, the content receiving terminal according to claim 3 receives the content to which tracking information including at least a content ID for identifying the content is added, generates history data indicating a history of operations on the content, and A content receiving terminal that transmits to a history data storage device that stores history data, comprising a content receiving means, a content operating means, and a history data generating means.

  According to such a configuration, the content receiving terminal receives the content by the content receiving unit, and performs an operation on the content by the content operating unit. The history data generation means includes at least a content ID included in the tracking information added to the content, operation information indicating an operation at the content operation means, and operation terminal history information indicating a terminal that has performed the operation. History data is generated and transmitted to the history data storage device.

  Thus, when the content receiving terminal performs an operation on the received content, the content ID indicating the content, the operation information indicating the operation performed on the content, and the content reception on which the operation is performed History data including operation terminal history information indicating a terminal can be generated and transmitted to a history data storage device that stores history data.

  Here, the operation on the content is, for example, reproduction or copying, and the operation information indicates these operations. The operation terminal history information indicates information for identifying the terminal that has performed these operations. For example, an identifier for identifying each content receiving terminal, a device ID of the content receiving terminal, and a fixed to the content receiving terminal. The content receiving terminal that has performed the operation can be specified using the IP address or the like assigned automatically.

  According to a fourth aspect of the present invention, there is provided a history data generation method using a content receiving terminal that generates history data indicating a history of distributing content to another terminal and transmits the history data to a history data storage device that stores the history data. The history data generating method for generating the history data includes a content receiving step and a content distribution / history data generating step.

  According to this method, the content receiving step receives the content to which the tracking information including at least the content ID for identifying the content and the distribution destination information indicating the distribution destination of the content is added. In the history data generation step, the distribution destination information included in the tracking information added to this content is updated to the redistribution destination that is the distribution destination of the redistribution that distributes this content to other terminals. The added content is distributed to other terminals that are redistribution destinations, and the content ID included in the tracking information, the distribution source history information indicating the redistribution source that is the redistribution distribution source, and the redistribution destination History data including at least the distribution destination history information shown is generated and transmitted to the history data storage device.

  As a result, when the received content is distributed to other terminals, the distribution destination information included in the tracking information added to the content is updated to the redistribution destination which is a new distribution destination, and this tracking information is added. The distributed content can be distributed to other terminals. Further, history data including a content ID for identifying the content, distribution destination history information indicating the redistribution destination, and distribution source history information indicating the content receiving terminal that distributed the content is transmitted to the history data storage device. be able to.

  Furthermore, the history search method according to claim 5 is a history search for searching history data of content to be searched from a history data storage device storing history data generated by the content receiving terminal according to claim 1. A history search method for searching history data of content using an apparatus, comprising a final history data search step, a history data search step, and a history data output step.

  According to this method, the last history data search step searches the history data storage device for the last history data, which is the history data when the content was last distributed, based on the tracking information added to the content. Subsequently, in the history data search step, based on the content ID of the history data of the content and the distribution destination history information, the final history data is used as a search source, and the distribution performed before the distribution of the content indicated by the history data is performed. Search historical data sequentially. Further, the history data searched in the history data search step is output by the history data output step.

  Thereby, the final history data can be searched based on the content ID added to the content to be searched and the distribution destination information. In addition, by sequentially searching the history data of the content using the final history data as a search source, the content that is the search target is the first when the content is first delivered from the content receiving device. History data up to history data can be searched.

  According to a sixth aspect of the present invention, there is provided the history data generation method, wherein the history data is generated using a content receiving terminal that generates history data indicating a history of operations on the content and transmits the history data to a history data storage device that stores the history data. Is a history data generation method including a content reception step, a content operation step, and a history data generation step.

  According to this method, the content to which the tracking information including at least the content ID for identifying the content is added is received in the content receiving step. Subsequently, the content operation step performs an operation on the content. Further, history data including at least the content ID included in the tracking information added to the content by the history data generation step, the operation information indicating the operation in the content operation step, and the operation terminal history information indicating the terminal that performed the operation Is generated and transmitted to the history data storage device.

  Thus, when an operation is performed on the received content, the content ID indicating the operated content, the operation information indicating the operation performed on the content, and the content receiving terminal that performed the operation are displayed. The history data including the operation terminal history information shown can be generated and transmitted to the history data storage device that stores the history data.

  The history data generation program according to claim 7 receives the content to which tracking information including at least a content ID for identifying the content and distribution destination information indicating a distribution destination of the content is added, and the content In order to generate history data indicating a history of redistribution that is distributed to other terminals and to transmit the history data to a history data storage device that stores the history data, a content receiving unit, a tracking information updating unit, a content distribution And function as history data generation means.

  According to this configuration, the history data generation program receives the content by the content receiving unit, and the distribution destination information indicating the distribution destination of the content included in the tracking information added to the content by the tracking information update unit. Is updated to a redistribution destination which is a distribution destination of the redistribution for distributing this content to other terminals. Then, the content distribution unit distributes the content to which the tracking information updated to the redistribution destination by the tracking information update unit is added to another terminal.

  Further, history data including at least content ID included in the tracking information, distribution source history information indicating a redistribution source that is a distribution source of redistribution, and distribution destination history information indicating a redistribution destination by the history data generation unit. Is transmitted to a history data storage device that stores history data.

  As a result, when the received content is distributed to other terminals, the history data generation program updates the distribution destination information included in the tracking information added to the content to a redistribution destination that is a new distribution destination. The content to which the tracking information is added can be distributed to other terminals. Further, history data including a content ID for identifying the content, distribution destination history information indicating the redistribution destination, and distribution source history information indicating the content receiving terminal that has distributed the content is transmitted to the history data storage device. be able to.

  A history search program according to claim 8 is for searching history data of content to be searched from a history data storage device storing history data generated by a content receiving terminal according to claim 1. , Based on the tracking information added to the content, the computer records final history data that is history data when the content was last delivered, final history data search means, history data search means, history data output It was decided to function as a means.

  According to this configuration, the history search program uses the final history data search means to store the last history data that is history data when this content was last distributed based on the tracking information added to the content to be searched. From the history data storage device, and by the history data search means, based on the content ID of the history data of this content and the distribution destination history information, the final history data is used as a search source to distribute the content indicated by the history data. The history data of previous distributions are sequentially searched. The history data searched by the history data search means is output by the history data output means.

  Thereby, the history search program can search the final history data based on the content ID added to the content to be searched and the distribution destination information. Further, by sequentially searching the history data of the content using the final history data as a search source, the content that is the search target is the first when the content is first delivered from the content receiving device. History data up to history data can be searched.

  Furthermore, the history data generation program according to claim 9 receives the content to which tracking information including at least a content ID for identifying the content is added, generates history data indicating a history of operations on the content, In order to transmit the history data to the history data storage device, the computer is caused to function as a content reception unit, a content operation unit, and a history data generation unit.

  According to this configuration, the history data generation program receives the content by the content receiving unit, and performs an operation on the content by the content operating unit. The history data generation means includes at least a content ID included in the tracking information added to the content, operation information indicating an operation at the content operation means, and operation terminal history information indicating a terminal that has performed the operation. History data is generated and transmitted to the history data storage device.

  Accordingly, when an operation is performed on the received content, the history data generation program performs a content ID indicating the operated content, operation information indicating the operation performed on the content, and this operation. History data including operation terminal history information indicating the performed content receiving terminal can be generated and transmitted to a history data storage device that stores the history data.

  The content receiving terminal, history search device, history data generation method, history search method, history data generation program, and history search program according to the present invention have the following excellent effects.

  According to the invention described in claim 1, claim 4 or claim 7, for example, the content is recorded on the recording medium by a legitimate user who purchased the content or a third party who illegally obtained the content from this user. When recorded and illegally distributed, tracking information that can identify an unauthorized user who has been illegally distributed can be added to the content. In other words, when the content is recorded on the recording medium, the recorded user or a third party content receiving terminal is the last distribution destination of the content, and therefore this terminal is shown in the content recorded on the recording medium. Tracking information including distribution destination information is added. Therefore, when this content is illegally distributed, it is possible to identify an unauthorized user who is illegally using the content from this distribution destination information.

  Also, for example, if the content is illegally distributed over the network by a legitimate user who purchased the content or a third party who illegally obtained this content from this user, the content is illegally distributed. It is possible to generate tracking information and history data that can identify an unauthorized user. In other words, since the history data at the time of unauthorized distribution is transmitted to the history data storage device, an unauthorized user can be specified by searching the history data based on the tracking information of the content distributed illegally. it can.

  According to the invention described in claim 2, claim 5 or claim 8, by searching the history data in which the illegally used content is distributed, the user who distributed the content to the unauthorized user or the unauthorized user Can be specified.

  According to the invention described in claim 3, claim 6, or claim 9, for example, a legitimate user can use the content defined in the content sales contract such as the content expiration date and the number of times of reproduction. When an operation exceeding the scope is performed, or when a third party who has not entered into a sales contract illegally obtains content and performs operations such as viewing this content, the history data indicating the operation is used. Unauthorized users can be identified.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Content distribution system configuration]
First, with reference to FIG. 1, the structure of the content delivery system 1 which is embodiment of this invention is demonstrated. FIG. 1 is a block diagram showing a configuration of a content distribution system according to the present invention. The content distribution system 1 includes a content server 10, a license server 30, a history management server 70, and a gateway (GW) 5 connected to the content provider (distributor) side via an intranet 3, via the Internet 7. Thus, the content is distributed to the content receiving terminal 50 which is a terminal on the user (purchaser) side of the content.

  The content server 10 holds a plurality of contents in a storage means (not shown), and distributes the contents to the content receiving terminal 50 when a content request is received from the content receiving terminal 50 described later. In addition, the content server 10 adds tracking information including a content ID for identifying the content and distribution destination information indicating the distribution destination to the content, and a tracking information key that is an encryption key (common key) of the tracking information In addition, the tracking information is encrypted with the content key, and the content is encrypted with a content key that is a content encryption key (common key) input from the license server 30 to be described later, and distributed to the content receiving terminal 50.

  The license server 30 manages the license of content held in the content server 10. That is, the license server 30 performs user authentication in response to a license request from the content receiving terminal 50, which will be described later, and issues a license including the user's content usage conditions and content key.

  The content receiving terminal 50 acquires the content desired by the user from the content server 10, acquires a license from the license server 30, operates and distributes the content, and generates history data indicating these histories. The data is transmitted to the history management server 70 described later.

  The history management server 70 accumulates history data transmitted from the content server 10 and the content receiving terminal 50, searches for history data of content to be searched, and presents it. Further, the history management server 70 determines from the history data received from the content receiving terminal 50 whether or not the operation on the content at the content receiving terminal 50 conforms to the usage conditions specified by the license, and shows the history indicating unauthorized use. It also presents data.

  The gateway (GW) 5 is a device for connecting each network of the intranet 3 and the Internet 7. The gateway 5 is, for example, an IP router (IP: Internet Protocol), and has a firewall function that prevents unauthorized access to the intranet 3.

  Hereinafter, in the content distribution system 1, the content server 10 that distributes content, the content receiving terminal 50 that receives content from the provider side, and the history management server 70 that manages history data will be described in detail.

(Content server configuration)
First, the configuration of the content server 10 will be described with reference to FIG. 2 (refer to FIG. 1 as appropriate). FIG. 2 is a block diagram showing the configuration of the content server in the present invention. The content server 10 includes a communication transmitting / receiving unit 11, a tracking information adding unit 12, a history data generating unit 13, a content key acquiring unit 14, an encrypted additional content generating unit 15, an encrypted additional content transmitting unit 16, Storage means 17.

  The communication transmission / reception means 11 transmits / receives communication data via a network (such as the intranet 3). For example, the communication transmission / reception means 11 transmits / receives communication data using a TCP / IP (Transmission Control Protocol / Internet Protocol) communication protocol.

  The tracking information adding unit 12 is a content request including a content ID for identifying the content and an identifier for identifying the content receiving terminal 50 that has requested the content, notified from the content receiving terminal 50 via the communication transmitting / receiving unit 11. The content M corresponding to the content ID is read from the storage unit 17 and tracking information including the content ID and the distribution destination information that is the identifier of the content receiving terminal 50 is added to the content M. The additional content to which the tracking information is added is input to the encrypted additional content generation unit 15. Further, the history data generating unit 13 is notified of the content ID and the identifier of the content receiving terminal 50.

  Here, the method of adding the tracking information to the content M is, for example, when the content M is data encoded by MPEG-2 (Moving Picture Experts Group 2), user data in the sequence header of the bit stream. Tracking information may be described in the area, and when the content M is encoded by WMV (Windows (R) Media Video), the tracking information can be described in the header area. Here, it is assumed that the tracking information is described in the header portion of the content M.

  The content ID is an identifier that can uniquely identify the content. Further, instead of the identifier for identifying the content receiving terminal 50, for example, the device ID of the content receiving terminal 50, an IP address fixedly given to the content receiving terminal 50, or the like may be used as the distribution destination information. .

  The history data generating unit 13 generates history data based on the content ID notified from the tracking information adding unit 12 and the identifier of the content receiving terminal 50. The history data generated here is transmitted to the history management server 70.

  Here, the history data generated by the history data generation means 13 will be described with reference to FIG. FIG. 5 is an explanatory diagram for explaining an example of history data generated by the history data generation unit of the content server when the content server distributes the content to the content receiving terminal.

  Here, the history data includes a content ID, distribution source history information indicating a content distribution source, distribution destination history information indicating a distribution destination, operation information indicating an operation on the content, and date information indicating the date and time when the operation was performed. Has been. This history data can be described in a language such as XML (extensible Markup Language), for example. In FIG. 5, for convenience of explanation, a line number is attached to the left side of the history data.

  The history data specifies the content by the content ID (CID in the figure). For example, in FIG. 5, the content with the content ID “10001” is specified by the <CID> tag in the (1) line. Also, the distribution history information that is the distribution source of this content is described by the <from> tag on the (2) line. Here, “NHK” indicating a provider that distributes content is described. Furthermore, distribution destination history information indicating the distribution destination of the content is described by a <to> tag on the (3) line. Here, “userA” is described as the identifier of the destination content receiving terminal 50 (FIG. 1). Then, operation information indicating an operation performed on the content is described by an <action> tag on the (4) line. Here, “distribution” indicating that delivery from the provider to the user is described. Further, date information (here, “2003/06/27 19:20:00”) indicating the date and time when the above operation is performed is described by a <Date> tag on the (5) line.

  In this way, the history data can describe information indicating the history of operations on the content, or information indicating the distribution history when the content is distributed.

Returning to FIG. 2, the description will be continued. The content key acquisition unit 14, the content key request including the notified content ID from the encrypted additional content generation means 15 to be described later, and transmitted via the communications transceiver means 11, acquires the content key K _M from the license server 30 Is. The content key acquisition unit 14 includes a content key request transmission unit 14a and a content key reception unit 14b.

  The content key request transmission unit 14 a transmits a content key request including the content ID notified from the encrypted additional content generation unit 15 to the license server 30 via the communication transmission / reception unit 11.

Content key receiving unit 14b, to the content key request content key request transmitting unit 14a transmits the content key K _M to be returned from the license server 30, and receives via the communication transmitting and receiving means 11. Here the content key K _M received in is output to the encrypted additional content generation means 15.

Encrypted additional content generation means 15 encrypts the header portion and the content M containing tracking information of the input added contents from the tracking information adding means 12, and generates the encrypted additional content C _M. The encrypted additional content generation unit 15 includes a tracking information encryption unit 15a and a content encryption unit 15b.

The tracking information encryption unit 15a stores the header portion including the tracking information of the additional content input from the tracking information adding unit 12 and stored in advance in the storage unit 17 as a tracking information key that is a common key in the common key cryptosystem. encrypted with K _a, the tracking information is intended to be encrypted encrypted log information.

The content encryption unit 15b notifies the content key request transmission unit 14a of the content ID of the additional content input from the tracking information adding unit 12, and acquires the content key K _M that is a common key in the common key encryption method. Obtained from the means 14, the content M is encrypted with the content key K _M to obtain encrypted content. Encrypted encryption added contents C _M in tracking information encrypting unit 15a and the content encryption unit 15b is output to the encrypted added contents transmitting means 16.

Encrypted additional content transmission unit 16, and transmits the encrypted additional content C _M input from the encrypted additional content generation means 15, to the content receiving terminal 50 that requested the content M through the communication transmitting and receiving means 11 .

Storage means 17, and the content M, intended for storing in advance and tracking information key K _A is an encryption key for encrypting (common key) a header portion containing tracking information, a semiconductor memory, general recording such as a hard disk It is a medium. Here, the storage unit 17 stores the content M in association with the content ID.

  By configuring the content server 10 in this way, the content server 10 adds the tracking information to the content M requested from the content receiving terminal 50, and encrypts the content M and the header portion including the tracking information. Delivered to the content receiving terminal 50. Further, history data indicating the distribution history is generated and transmitted to the history management server 70. The content server 10 encrypts the tracking information and cannot be rewritten by the user who has received the content.

(Content receiving terminal configuration)
Next, the configuration of the content receiving terminal 50 will be described with reference to FIG. 3 (refer to FIG. 1 as appropriate). FIG. 3 is a block diagram showing the configuration of the content receiving terminal according to the present invention. The content receiving terminal 50 includes a communication transmitting / receiving unit 51, a license receiving unit 52, a license analyzing unit 53, an encrypted additional content receiving unit 54, an encrypted additional content decrypting unit 55, a tracking information updating unit 56, a tracking Information encryption means 57, content operation means 58, history data generation means 59, and storage means 60 are provided. Further, here, the content receiving terminal 50 is connected to a display device 9a for displaying characters, images, and the like.

  The communication transmission / reception means 51 transmits / receives communication data via a network (Internet 7 or the like). For example, the communication transmission / reception means 51 transmits / receives communication data using a TCP / IP communication protocol.

License receiving unit 52 is for acquiring the license L _M user corresponding to the desired content M from the license server 30. The license receiving means 52 includes a license request transmitting unit 52a and a license receiving unit 52b.

  The license request transmission unit 52a transmits a license request including a content ID and data necessary for registration as a regular user to the license server 30 such as a user ID to the license server 30 via the communication transmitting / receiving means 51. It is.

License receiving unit 52b, to the license request to the license request transmission section 52a transmits the license L _M returned from the license server 30, and receives via the communication transmitting and receiving means 51. The license L _M, and a content key for decrypting the encrypted contents of the encrypted additional content C _M received by the encrypted added contents receiving means 54 to be described later, and the rights information indicating the range available this content M include. The license L _M received here is stored in the storage means 60.

License analyzing means 53 analyzes the license L _M stored in the storage unit 60, and extracts the content key and rights information. The content key extracted here is output to the encrypted additional content decrypting means 55, and the right information is output to the encrypted additional content decrypting means 55 and the content operating means 58.

  The encrypted additional content receiving means 54 acquires the content M desired by the user from the content server 10. The encrypted additional content receiving unit 54 includes a content request transmitting unit 54a and a content receiving unit 54b.

  The content request transmitting unit 54a receives the content ID and the identifier of the content receiving terminal 50 from an input unit (not shown), and sends the content request including the content ID and the identifier of the content receiving terminal 50 to the communication transmitting / receiving unit 51. To the content server 10.

Content receiving unit 54b is for the content request content request transmission unit 54a transmits the encrypted additional content C _M delivered from the content server 10 receives, via the communication transmitting and receiving means 51. The encrypted additional content C _M received here is stored in the storage unit 60.

Encrypting additional content decrypting unit 55, the encrypted additional content C _M stored in the storage unit 60, it is to decode the header portion and an encrypted content including encrypted tracking information. The encrypted additional content decrypting means 55 includes a tracking information decrypting unit 55a and a content decrypting unit 55b.

Tracking information decoding unit 55a is a pre-stored tracking information key K _A in the storage unit 60, is to decode the header portion including the encrypted log information encrypted additional content C _M. The content ID read here is notified to the content operation means 58.

Content decryption unit 55b, based on the content key and rights information input from the license analysis means 53, and decrypts the encrypted content of the encrypted additional content C _M stored in the storage unit 60. Here, the content decrypting unit 55b decrypts the encrypted content within the range defined in the right information, using the content key. The additional content decoded by the tracking information decoding unit 55a and the content decoding unit 55b is output to the tracking information update unit 56 and the content operation unit 58.

  The tracking information update unit 56 receives the distribution destination information added to the additional content input from the encrypted additional content decryption unit 55 as an input unit (not shown) as a distribution destination (redistribution destination) of the content M. It is updated (rewritten) to an identifier for identifying another content receiving terminal 50. The additional content to which the updated tracking information is added is output to the tracking information encryption unit 57.

Tracking information encrypting means 57, a header portion containing tracking information of the input added contents from the tracking information update unit 56, encrypts it with pre-stored tracking information key K _A in the storage unit 60 encrypted additional content C _M is generated. Here encrypted additional content C _M to be generated is output to the content distribution unit 58c of the content operation unit 58.

  The content operation means 58 operates the content M received by the encrypted additional content reception means 54 based on the right information input from the license analysis means 53. Further, when operating the content M, the content operating unit 58 outputs the operation information indicating this operation and the content ID notified from the encrypted additional content decrypting unit 55 to the history data generating unit 59. Is. The content operation unit 58 includes a content reproduction unit 58a, a content copy unit 58b, and a content distribution unit 58c.

  The content reproduction unit 58a converts the additional content input from the encrypted additional content decrypting means 55 into data that can be viewed by the user and outputs the data to the display device 9a. For example, when the content is data encoded by MPEG-2, the content reproduction unit 58a functions as a decoder that decodes the content into a moving image. Further, when reproducing the content M, the content reproduction unit 58 a outputs operation information indicating content reproduction and a content ID to the history data generation unit 59.

  In addition, when the content playback unit 58a applies a playback method that cannot be played back unless the content is in a predetermined format, the header portion of the encrypted additional content is illegally removed or altered by an unauthorized user. This content can not be reproduced. For example, if content in the WMV format is played back on Windows (R) Media Player, since the Windows (R) Media Player can only play back content in a predetermined format, the content from which the header portion (tracking information) has been removed You can prevent playback. Also, even when the encrypted header part is deliberately falsified, it cannot be reproduced because the header part does not have a predetermined format at the time of decryption. This prevents content that cannot be tracked by unauthorized users by falsifying the tracking information contained in the header part, and prevents unauthorized distribution of content that cannot be tracked by unauthorized users. it can.

Content copy unit 58b is for recording on a recording medium or the like by copying the encrypted additional content C _M stored in the storage unit 60. The content copy unit 58b, when copying the encrypted additional content C _M, and outputs the operation information and the content ID indicating a copy of the encrypted additional content C _M in the history data generating unit 59.

Content distributor (content delivery means) 58c is encrypted additional content C _M input from the tracking information encrypting unit 57 via the communication transmitting and receiving means 51, the delivery destination of the encrypted additional content C _M (redistribution destination ) Is distributed (redistributed) to the content receiving terminal 50 corresponding to the identifier of the other content receiving terminal 50 input from an input means (not shown). In addition, when distributing the encrypted additional content C _M , the content distribution unit 58 c outputs operation information indicating the distribution of the encrypted additional content C _M and the content ID to the history data generation unit 59.

  The history data generation unit 59 generates history data based on the content ID notified from the encrypted additional content decryption unit 55 and the operation information input from the content operation unit 58. The history data generated here is transmitted to the history management server 70.

  Here, the history data generated by the history data generating means 59 will be described with reference to FIGS. FIG. 6A is an explanatory diagram for explaining an example of history data generated by the history data generating means of the content receiving terminal when the content is played back by the content receiving terminal, and FIG. FIG. 6C is an explanatory diagram for explaining an example of history data generated by the history data generating means of the content receiving terminal when the content is copied by the content receiving terminal. FIG. It is explanatory drawing for demonstrating the example of the historical data which the historical data production | generation means of a content receiving terminal produces | generates when delivering content.

  Here, the history data includes the content ID, the operation terminal history information (distribution source history information) indicating the terminal that performed the operation on the content or the content distribution source terminal, the distribution destination history information indicating the distribution destination terminal, and the content. It consists of operation information indicating the operation and date information indicating the date and time when the operation was performed. In FIG. 6, for convenience of explanation, a line number is assigned to the left side of the history data.

  First, an example of history data generated by the history data generating unit 59 of the content receiving terminal 50 when the content receiving terminal 50 reproduces the content will be described. As shown in FIG. 6A, the history data specifies the content that has been reproduced by the content ID. That is, the content with the content ID “10001” is specified by the <CID> tag in the (1) line. In addition, operation terminal history information (distribution source history information) indicating a content receiving terminal that has played back this content is described by a <from> tag on the (2) line. Here, “userA” is described as an identifier for identifying a content receiving terminal that reproduces content. Furthermore, distribution destination history information indicating the distribution destination of the content is described by a <to> tag on the (3) line. Here, since content is not distributed, the same “userA” as the operation terminal history information is described. Then, operation information indicating an operation performed on the content is described by an <action> tag on the (4) line. Here, “play” indicating that the content has been reproduced is described. Furthermore, date information (here, “2003/06/27 19:25:00”) indicating the date and time of reproduction is described by the <Date> tag on the (5) line.

  Similarly, when content is copied by the content receiving terminal 50, as shown in FIG. 6B, the history data identifies the content that was copied by the content ID (“10001” in the figure). doing. In addition, operation terminal history information (distribution source history information) (“userA” in the figure) indicating the content receiving terminal that has copied this content is described by the <from> tag on the (2) line. Furthermore, distribution destination history information (operation terminal history information) (“userA” in the figure) is described by a <to> tag on the (3) line. Then, operation information (“copy” in the figure) indicating a copy that is an operation performed on the content is described by an <action> tag on the (4) line. Furthermore, date information (here, “2003/06/27 20:05:00”) indicating the date and time of copying is described by the <Date> tag on the (5) line.

  Further, when the content is distributed to the other content receiving terminals 50 by the content receiving terminal 50, the history data is distributed by the content ID (“10001” in the figure) as shown in FIG. 6C. The content that has been performed is identified. In addition, the <from> tag in the (2) line describes distribution source history information (operation terminal history information) (“userA” in the figure) indicating the content receiving terminal that has distributed this content. . Furthermore, distribution destination history information indicating the distribution destination of the content is described by a <to> tag on the (3) line. Here, it is assumed that an identifier for identifying a content receiving terminal of a distribution destination for distributing content is userB, and “userB” is described as distribution destination history information. Then, operation information (“distribution” in the figure) indicating delivery, which is an operation performed on the content, is described by the <action> tag on the (4) line. Further, date information (here, “2003/06/28 09:28:00”) indicating the date and time of delivery is described by the <Date> tag on the (5) line.

  In this way, the history data can describe information indicating the history of operations on the content, or information indicating the distribution history when the content is distributed.

Storage means 60 stores the encrypted added contents C _M received by the encrypted additional content receiving unit 54, and a license L _M received by the license receiving unit 52, also intended for previously storing tracking information key K _A Thus, it is a general recording medium such as a semiconductor memory or a hard disk. The license L _M includes a content key that is a common key for decrypting or encrypting the encrypted content of the encrypted additional content C _M , and right information indicating a range in which the content M can be used.

The storage unit 60 stores the encrypted additional content C _M and the license L _M in association with each other. Also, tracking information key K _A so as not to leak outside, which is preferably stored in an area having a tamper-resistant in the storage unit 60. Thereby, it is possible to prevent the tracking information from being illegally decoded and falsified by an unauthorized user.

  By configuring the content receiving terminal 50 as described above, the content receiving terminal 50 receives the content M from the content server 10 and performs operations such as reproduction, copying, and distribution on the content M. History data indicating an operation history is generated and transmitted to the history management server 70. Further, when the content M is distributed by the content receiving terminal 50, the content receiving terminal 50 may update the distribution destination information added to the content M to a new distribution destination and distribute the content M. it can. When the content is recorded on the recording medium by the content receiving terminal 50 and illegally distributed, the content receiving terminal 50 that has performed the illegal act can be identified from the distribution destination information added to the content. .

  Further, the content receiving terminal 50 can also realize each means as each function program in a computer, and can also operate the history data generation program by combining each function program.

(Configuration of history management server)
Next, the configuration of the history management server 70 will be described with reference to FIG. 4 (refer to FIG. 1 as appropriate). FIG. 4 is a block diagram showing the configuration of the history management server in the present invention. The history management server 70 includes a communication transmitting / receiving unit 71, a history data receiving unit 72, a history DB (database) 73, an input unit 74, a history search unit 75, a storage unit 76, and a license issuance information receiving unit 77. License issue information DB (database) 78, history determination means 79, and determination result output means 80. Further, here, the history management server 70 is connected to the outside a display device 9b for displaying characters and images.

  The communication transmitting / receiving unit 71 transmits / receives communication data via a network (such as the intranet 3). For example, the communication transmission / reception means 71 transmits / receives communication data using a TCP / IP communication protocol.

  The history data receiving unit 72 receives history data from the content server 10 and the content receiving terminal 50 via the communication transmitting / receiving unit 71. The history data received here is stored in the history DB 73 and output to the history determination means 79.

  The history DB (history data storage device) 73 has an appropriate search for the history of the content to be searched by the distribution history data search means 752 to be described later and the operation described in the history data by the history determination means 79 to be described later. It is a general recording medium such as a semiconductor memory or a hard disk, which stores history data necessary for determining whether or not it is a memory. The history DB 73 stores history data generated by the content server 10 or the content receiving terminal 50.

The input means 74 is for inputting content to be searched (encrypted additional content C _M ) from the outside. Input encrypted added contents C _M is output to the tracking information decoding unit 751 of the history search means 75.

  The history search means (history search apparatus) 75 searches the history DB 73 for the history data of the content to be searched, which is input from the input means 74, and displays it on the display device 9b. The history search means 75 includes tracking information decoding means 751, distribution history data search means 752, and history data output means 753.

Tracking information decoding unit 751, a header portion including the encrypted log information encrypted additional content C _M input from the input unit 74 is for decoding the stored tracking information key K _A in the storage means 76. The tracking information decoded here is output to the distribution history data search means 752.

  The distribution history data search means 752 searches the history DB 73 for the history data of the content to be searched, which is input from the input means 74. The distribution history data search means 752 includes a final history data search means 752a and a history data search means 752b.

  The final history data search means 752a searches the history DB 73 for the history data in which the content to be searched was last distributed based on the tracking information input from the tracking information decoding means 751. The last history data, which is the history data for which the content has been distributed last time searched here, is output to the history data search means 752b and the history data output means 753.

  The history data search means 752b, based on the content ID of the history data of the content to be searched and the distribution source history information, history data until the content to be searched is distributed from the provider based on the final history data. Are sequentially searched from the history DB 73. The history data searched here is output to the history data output means 753.

  Here, with reference to FIGS. 7 and 8 (refer to FIGS. 1 and 4 as appropriate), an example in which the distribution history data search means 752 searches the history DB 73 for history data of content to be searched will be described. FIG. 7 schematically illustrates an example of a flow of content distribution, history data input to the history management server, and tracking information added to the content when content is distributed by the content server and the content receiving terminal. It is explanatory drawing shown. FIG. 8 is an explanatory diagram showing history data searched for by the distribution history data search means 752 for the content described in FIG. 7.

For example, as shown in FIG. 7, the encrypted additional content C _M (C _MA ) obtained by encrypting the content M is distributed from the content server 10 to the content receiving terminal 50A based on an appropriate sales contract, and the content receiving terminal 50A. Is copied illegally from the content receiving terminal 50A to the content receiving terminal 50B, and after being copied by the content receiving terminal 50B, the content receiving terminal 50B is illegally distributed to the content receiving terminal 50C. History data input to the history management server 70 will be described.

First, the content ID is "10001" in which the content M is added tracking information encrypted encryption added contents C _MA is, the content receiving terminal from the content server 10, the content receiving terminal identifier is "userA" Suppose that 50A is distributed based on an appropriate sales contract. Then, “10001” as the content ID, “NHK” indicating the provider as the distribution source history information, “userA” as the distribution destination history information, “distribution” as the operation information, and “2003/06 / History data R ₀ including “27 19:20:00” is generated by the content server 10 and input to the history management server 70.

Next, the encrypted added contents C _MA distributed from the content server 10, after being copied by the content receiving terminal 50A, from the content receiving terminal 50A is the identifier of the content receiving terminal unauthorized to the content receiving terminal 50B is "userB" Suppose that it was delivered to. Then, the content receiving terminal 50A first sets “10001” as the content ID, “userA” as the operation terminal history information (distribution source history information), “userA” as the distribution destination history information, and “copy” as the operation information. The history data R _A1 indicating the copy of the encrypted additional content C _MA including the date information “2003/06/27 20:05:00”, for example, is generated and input to the history management server 70. Further, by the content receiving terminal 50A, the content ID is “10001”, the distribution source history information is “userA”, the distribution destination history information is “userB”, the operation information is “distribute”, and the date information is “2003”, for example. The history data R _A2 indicating the distribution of the encrypted additional content C _MB including “/ 06/28 09:28:00” is generated and input to the history management server 70.

Then, after the encrypted additional content C _MB distributed from the content receiving terminal 50A is copied by the content receiving terminal 50B, the content receiving terminal 50B illegally sends the content receiving terminal 50C whose identifier is “userC”. Suppose that it was delivered to. Then, by the content receiving terminal 50B, “10001” as the content ID, “userB” as the operation terminal history information (distribution source history information), “userB” as the distribution destination history information, “copy” as the operation information, History data R _B1 indicating a copy of the encrypted additional content C _MB including, for example, “2003/06/28 15:00:00” as date information is generated and input to the history management server 70. Further, the content receiving terminal 50B sets “10001” as the content ID, “userB” as the distribution source history information, “userC” as the distribution destination history information, “distribute” as the operation information, and “2003” as the date information, for example. / 07/01 18:38:00 "and a historical data R _B2 indicating the distribution of the encrypted additional content C _MC is generated, it is input to the history management server 70.

At this time, the content server 10 sends the encrypted content added to the content receiving terminal 50A by encrypting the content M to which the tracking information including “10001” as the content ID and “userA” as the distribution destination information is added. Content _CMA is distributed. Then, the encrypted additional content C _MB whose distribution destination information is updated to “userB” by the content receiving terminal 50A is distributed from the content receiving terminal 50A to the content receiving terminal 50B. Furthermore, the content receiving terminal 50C from the content receiving terminal 50B, the distribution destination information by the content receiving terminal 50B is "userC" updated on encrypted added contents C _MC is served.

Next, the distribution history data retrieval means 752 historical data of the illegal distribution encrypted added contents C _MC will be described an example of searching. Here, the history DB 73 of the history management server 70 includes contents data R ₀ , R _A1 , R _A2 , R _B1 , R _B2 , content from the content server 10 or the content receiving terminals 50, 50,... (FIG. 1). receiving terminal 50, 50, delivered to ..., conducted and historical data of various encryption additional content including encrypted additional content C _M, the content receiving terminal 50, 50, ... are for various encrypted additional content It is assumed that history data indicating the history of operations performed is stored.

The distribution history data retrieval means 752, the tracking information decoding unit 751, tracking information of the decoded encrypted added contents C _MC is inputted. Then, the final history data retrieval means 752a of distribution history data retrieval means 752, based on the tracking information, searches the history data R _B2 encrypted additional content C _MC is delivered to the end from the history DB 73.

Here, since illustrates the distribution destination information of the tracking information of the encrypted additional content C _MC, both destination history information of the history data indicating the distribution of the encrypted additional content C _MC is a distribution destination of the distribution, The final history data search means 752a associates the distribution destination information of the tracking information of the content to be searched with the distribution destination history information, further associates the tracking information with the content ID of the history data, and searches for the history data that matches each other. By doing so, it is possible to search the history data R _B2 to which the encrypted additional content _CMC was distributed last. Therefore, the final history data retrieval means 752a, based on the content ID "10001" included in tracking information of the input from the tracking information decoding unit 751 encrypts the additional content C _MC and destination information "userC" Content ID Is searched from the history DB 73 for history data R _B2 with “10001” and distribution destination history information “userC”. Then, the history data R _B2 (final history data) (5) shown in FIG. 8 is acquired.

Subsequently, the historical data searching means 752b is based on historical data R _B2 (final history data), the history data to the encrypted added contents C _M is distributed from being delivered from the provider to the content receiving terminal 50C sequentially Search from the history DB 73. Here, the distribution source history information of the retrieved history data indicates the distribution source that distributed the content to the distribution destination indicated by the distribution destination history information of the history data. Since the distribution destination history information of the history data when the content is distributed to the distribution source describes the distribution source terminal described in the distribution source history information of the retrieved history data, Among the history data, search is made for history data in which the distribution source history information and the distribution destination history information of the history data indicating the distribution history match, and the content ID also matches, and the distribution history among the searched history data is indicated. By sequentially performing the same search operation based on the history data, it is possible to search the distribution history of the content to be searched retroactively from the final history data.

Therefore, historical data searching means 752b is based on the final historical data retrieval means content ID "10001" in the history data R _B2 input from 752a deliver the original history information "userB" content ID "10001", the distribution History data whose destination history information is “userB” is searched from the history DB 73. Then, the history data R _B1 (4) and the history data R _A2 (3) shown in FIG. 8 are acquired.

Furthermore, the history data search means 752b has a content ID “10001” of the history data R _A2 whose operation information is “distribution” among the history data R _B1 and R _A2 input from the final history data search means 752a. And history data with the content ID “10001” and the distribution destination history information “userA” are retrieved from the history DB 73 based on the distribution source history information “userA”. Then, the history data R _A1 (2) and the history data R ₀ (1) shown in FIG. 8 are acquired.

Here, since the distribution source history information of the history data R ₀ is “NHK” and indicates the provider, the history data R ₀ indicates the history distributed from the content server 10. Therefore, the history data search means 752b confirms that the distribution source history information “NHK” of the history data R ₀ whose operation information is “distribution” indicating distribution among the searched history data R _A1 and R ₀ matches. Recognize and end the search, and output the history data searched here to the history data output means 753.

  In this way, the distribution history data search unit 752 can search the history DB 73 for history data of content to be searched. Then, it is possible to search for an unauthorized user who obtains and distributes content illegally (here, the content receiving terminal 50B) or an authorized user who distributes content to this unauthorized user (here, the content receiving terminal 50A). it can. Further, here, the history data indicating the history of operations other than the distribution is also searched at the same time, but only the history data indicating the distribution history is sequentially searched to search the history data of the content to be searched. Anyway. In this case, the history data search means 752b searches for history data in which the distribution source history information of the searched history data matches the distribution destination history information, the content IDs match, and the operation information indicates distribution. By doing so, it is possible to sequentially search only the history data indicating the distribution history from the history DB 73.

  Returning to FIG. 4, the description will be continued. The history data output means 753 converts the search result input from the distribution history data search means 752 into a displayable output format and outputs it to the display device 9b.

Storage means 76 is for previously storing the tracking information key K _A, a semiconductor memory, a general recording medium such as a hard disk.

  The license issuance information receiving unit 77 receives license issuance information from the license server 30 via the communication transmitting / receiving unit 71. The license issue information received here is stored in the license issue information DB 78.

  The license issuance information DB 78 stores license issuance information necessary for determining whether or not the operation described in the history data is appropriate by the history determination means 79 described later. Is a typical recording medium. The license issuance information DB 78 stores license issuance information that is generated each time a license is issued by the license server 30 and input to the license issuance information receiving unit 77.

  Here, the license issuance information indicates the contents of the license issued by the license server 30 based on the license request transmitted from the content receiving terminal 50 to the license server 30. Here, the license issuance information includes the content ID of the content for which the license has been issued, the license distribution destination information indicating the license distribution destination, and the right information indicating the range in which the content can be used included in the license. ing. This right information includes, for example, the content of the operation on the content, the time limit of the operation, the number of operations, etc., which are granted to the user (content receiving terminal 50).

  The history determination unit 79 determines whether the operation on the content described in the history data input from the history data receiving unit 72 is an appropriate operation. Here, the history determination unit 79 determines whether or not this operation is appropriate by comparing the operation described in the history data with the usage range permitted by the license corresponding to the content for which the operation has been performed. To do. The history determination unit 79 includes a license issuance information search unit 79a, an operation history data search unit 79b, and an operation history collation unit 79c.

  The license issuance information search unit 79a searches the license issuance information DB 78 for license issuance information corresponding to the content for which the operation described in the history data input from the history data receiving means 72 has been performed. Here, the license issuance information search unit 79a extracts the content ID of the history data and the operation terminal history information (distribution source history information) indicating the content receiving terminal 50 that has performed an operation on the content, A search is performed in association with the content ID of the license issuance information and the license distribution destination information. The license issuance information retrieved here is output to the operation history matching unit 79c.

  The operation history data search unit 79b searches the history DB 73 for history data of operations performed by the content receiving terminal 50 on the content described in the history data input from the history data receiving means 72. Here, the operation history data search unit 79b is based on the content ID of the history data, the operation terminal history information (distribution source history information) indicating the content receiving terminal that performed the operation on the content, and the operation information. The history data on the operation described in the history information for the content is searched. The history data searched here is output to the operation history matching unit 79c.

  The operation history collating unit 79c collates the operation indicated by the history data input from the history data receiving unit 72 with the right information described in the license issuance information input from the license issuance information searching unit 79a. Further, the operation history collation unit 79c inputs history data stored in the history DB 73 from the operation history data search unit 79b based on the license issuance information, and the operation indicated by the history data input from the history data receiving unit 72. Are compared with the rights information. The determination result which is the result of collation here is output to the determination result output means 80.

  The determination result output means 80 converts the determination result input from the operation history collating unit 79c into a displayable output format and outputs it to the display device 9b.

  By configuring the history management server 70 as described above, the history management server 70 receives the history data from the content server 10 and the content receiving terminal 50, stores the history data in the history DB 73, and stores the history data of the content to be searched. It can search from history DB73. Then, by searching the history data of content that has been illegally used, it is possible to output history data indicating an unauthorized user who has illegally used this content. Also, the operation indicated by the received history data can be checked against the license right information to determine whether this operation is appropriate.

  Further, the history management server 70 can also realize each means as each function program in a computer. For example, the history search means 75 can be operated as a history search program. It is also possible to combine the function programs and operate as a history management program.

[Operation of content distribution system]
Next, the operation of the content distribution system 1 in the present invention will be described with reference to FIGS. Here, first, the content distribution operation of the content server will be described with reference to FIG. Next, the content reception operation of the content reception terminal will be described with reference to FIG. In addition, the content operation / history data generation operation of the content receiving terminal will be described with reference to FIG. Furthermore, the history search operation of the history data management server will be described with reference to FIG. Further, the history determination operation of the history data management server will be described with reference to FIG.

[Content distribution operation of content server]
First, referring to FIG. 9 (see FIGS. 1 and 2 as appropriate), the content server 10 distributes content to the content receiving terminal 50, generates history data, and transmits it to the history management server 70 (content distribution operation). ). FIG. 9 is a flowchart illustrating an operation in which the content server according to the present invention distributes content to the content receiving terminal, generates history data, and transmits the history data to the history management server.

  The content server 10 receives the content request including the content ID for identifying the content and the identifier for identifying the content receiving terminal 50 to which the content is distributed, via the communication transmitting / receiving means 11 (step S10). Then, the content server 10 reads the content corresponding to the content ID included in the content request from the storage unit 17 by the tracking information adding unit 12, and the content receiving terminal 50 serving as a content distribution destination as the content ID and distribution destination information. The tracking information including the identifier is added to the header portion to generate additional content (step S11).

  Further, the content key request transmission unit 14a of the content key acquisition unit 14 transmits a content key request including the content ID to the license server 30 (step S12), and the content key reception unit 14b receives the content key from the license server 30. Receive (step S13). Then, the tracking information encryption unit 15a of the encrypted additional content generation unit 15 encrypts the header part including the tracking information with the tracking information key stored in advance in the storage unit 17, and the content encryption unit 15b performs step S13. The content is encrypted with the content key received at step S14 to generate encrypted additional content (step S14).

  Then, the encrypted additional content transmitting unit 16 distributes the encrypted additional content encrypted in step S14 to the content receiving terminal 50 that has transmitted the content request received in step S10 via the communication transmitting / receiving unit 11 ( Step S15).

  Further, the history data generating unit 13 includes the content ID included in the content request received in step S10, the distribution source history information indicating the provider, the identifier of the content receiving terminal 50 as the distribution destination history information, and the operation on the content (here Then, history data including operation information indicating distribution and date information indicating the date and time when the operation was performed is generated (step S16) and transmitted to the history management server 70 via the communication transmitting / receiving means 11 (step S17). ).

  Through the above operation, the content server 10 adds the tracking information to the content requested from the content receiving terminal 50, encrypts the content and the header portion including the tracking information, and distributes the encrypted content to the content receiving terminal 50. Further, history data indicating the distribution history is generated and transmitted to the history management server 70.

[Content receiving operation of content receiving terminal]
Next, with reference to FIG. 10 (refer to FIGS. 1 and 3 as appropriate), an operation (content receiving operation) in which the content receiving terminal 50 receives the encrypted additional content desired by the user and this license will be described. FIG. 10 is a flowchart showing an operation in which the content receiving terminal according to the present invention receives content from the content server.

  The content receiving terminal 50 registers the content ID and the license server 30 as a legitimate user by the license request transmitting unit 52a via the communication transmitting / receiving means 51 based on the content distribution request command from the user. A license request including data necessary for the license is transmitted to the license server 30. In addition, the content request transmitting unit 54a transmits a content request including the content ID and the identifier of the content receiving terminal 50 to the content server 10 (step S20).

The license receiving unit 52b receives the license returned from the license server 30 via the communication transmitting / receiving means 51 (step S21). The content receiving unit 54b are the encrypted additional content C _M delivered from the content server 10 receives, via the communication transmitting and receiving means 51 (step S22; content receiving step).

  Then, the content receiving terminal 50 stores the encrypted additional content and the license of this content in association with each other in the storage unit 60 (step S23).

  Through the above operation, the content receiving terminal 50 receives the encrypted additional content desired by the user and the license based on the content distribution request command from the user.

[Content operation / history data generation operation of content receiving terminal]
Subsequently, referring to FIG. 11 (refer to FIGS. 1 and 3 as appropriate), the content receiving terminal 50 performs an operation on the content stored in the storage unit 60 based on an operation command for the content from the user. An operation (content operation / history data generation operation) for generating history data indicating the history of the operation will be described. Here, a case will be described in which the content receiving terminal 50 performs any one of reproduction, copying, and distribution operations on content. FIG. 11 is a flowchart showing an operation in which the content receiving terminal according to the present invention performs operations on content and generates history data.

  The content receiving terminal 50 reads out a license corresponding to the content from the storage unit 60 by the license analysis unit 53 based on a user operation instruction on the content, analyzes the license, and obtains a content key and rights information. Extract (step S30).

Subsequently, the content receiving terminal 50 determines whether or not a command for reproducing the content is input from the user (step S31). When the content receiving terminal 50 receives an instruction to reproduce the content from the user (Yes in step S31), the tracking information decrypting unit 55a of the encrypted additional content decrypting unit 55 receives the instruction from the user. The encrypted additional content C _M is read from the storage unit 60, and the header portion including the encrypted tracking information of the encrypted additional content C _M is decrypted with the tracking information key stored in advance in the storage unit 60. Further, the content decrypting unit 55b decrypts the encrypted content within the range defined in the right information based on the content key and the right information extracted in step S30 (step S32). Then, the content reproducing unit 58a of the content operating unit 58 converts (reproduces) the additional content decrypted in step S32 into data that can be viewed by the user, and outputs the data to the display device 9a (step S33), and proceeds to step S42. . Further, when the content receiving terminal 50 does not receive an instruction to reproduce the content from the user (No in step S31), the process directly proceeds to step S34.

Subsequently, the content receiving terminal 50 determines whether an instruction to copy content is input from the user (step S34). When the content receiving terminal 50 receives an instruction to copy the content from the user (Yes in step S34), the tracking information decrypting unit 55a of the encrypted additional content decrypting means 55 receives the instruction from the user. The encrypted additional content C _M is read from the storage unit 60, and the header portion including the encrypted tracking information of the encrypted additional content C _M is decrypted with the tracking information key stored in advance in the storage unit 60 (step S35). . Then, the content copy unit 58b of the content operation unit 58 copies the encrypted additional content stored in the storage unit 60 (step S36), and proceeds to step S42. If the content receiving terminal 50 does not receive an instruction to copy content from the user (No in step S34), the process directly proceeds to step S37.

Subsequently, the content receiving terminal 50 determines whether or not a command for distributing content is input from the user (step S37). When the content receiving terminal 50 inputs an instruction to distribute (redistribute) content from the user (Yes in step S37), the tracking information decrypting unit 55a of the encrypted additional content decrypting unit 55 receives the command from the user. reads a encrypted added contents C _M of instruction from the memory means 60, in a pre-stored tracking information key in the storage unit 60 decodes the header portion including the encrypted tracking information of the encrypted additional content C _M ( Step S38).

  Then, the tracking information update unit 56 updates the distribution destination information included in the tracking information decoded in step S38 to an identifier for identifying another content receiving terminal 50 that is a distribution destination (redistribution destination) of this content. (Step S39). Further, the tracking information encryption unit 57 encrypts the header portion including the tracking information with the tracking information key stored in advance in the storage unit 60 for the additional content to which the tracking information updated in step S39 is added (step S39). S40). Then, the content distribution unit 58c distributes the encrypted additional content generated in step S40 (step S41), and proceeds to step S42. In addition, when a command for distributing content is not input from the user (No in step S37), the content receiving terminal 50 ends the operation as it is.

Further, the history data generating unit 59 generates history data indicating the history of operations performed in steps S31 to S41 (step S42). That is, when the encrypted additional content _CM is reproduced, the content ID included in the tracking information decrypted in step S32, the identifier of the content receiving terminal 50 as the operating terminal information (distribution source history information), the distribution History data including the identifier of the content receiving terminal as the previous history information (operation terminal information), operation information indicating the operation (playback) for the content performed in step S33, and date information indicating the date and time when the operation was performed is generated. . When the encrypted additional content _CM is copied, the content ID included in the tracking information decrypted in step S35, the identifier of the content receiving terminal as operation terminal information (distribution source history information), the distribution destination History data including the identifier of the content receiving terminal as the history information (operation terminal information), the operation information indicating the operation (copy) for the content performed in step S36, and the date information indicating the date and time when the operation was performed is generated. Furthermore, when performing the distribution of the encrypted additional content C _M includes a content ID included in the decoded tracking information at step S38, the identifier of the content receiving terminal as a distribution source history information (operation terminal information), the delivery destination History data including an identifier of another content receiving terminal that distributes content as history information, operation information indicating an operation (distribution) on the content performed in step S41, and date information indicating the date and time when the operation was performed is generated. .

  Then, the history data generating unit 59 transmits the history data to the history management server 70 via the communication transmitting / receiving unit 51 (Step S43).

  With the above operation, the content receiving terminal 50 plays the content when a playback command is input based on the operation command for the content from the user, and the content when the copy command is input. Copy and distribute the content when a distribution command is input. Then, the history data of this operation is generated and transmitted to the history management server 70.

  The content distribution / history data generation step described in the claims corresponds to steps S39 to S43. The content operation step corresponds to one of steps S33, S36, and S41, and the history data generation step corresponds to steps S42 and S43.

[History search operation of history management server]
With reference to FIG. 12 (refer to FIGS. 1 and 4 as appropriate), the history management server 70 stores the history of the content to be searched from the history DB 73 storing the history data transmitted from the content server 10 and the content receiving terminal 50. An operation for retrieving data (history retrieval operation) will be described. FIG. 12 is a flowchart showing an operation in which the history management server in the present invention searches the history data of the content to be searched from the history DB storing the history data.

  The history management server 70 inputs the encrypted additional content to be searched from the outside by the input means 74 (step S50). Then, the tracking information decrypting means 751 of the history searching means 75 decrypts the header portion including the tracking information of the encrypted additional content input in step S50 with the tracking information key stored in the storage means 76 (step S51). . Further, the final history data search means 752a of the distribution history data search means 752 finally distributes the content to be searched based on the content ID and the delivery destination information included in the tracking information decoded in step S51. History data is retrieved from the history DB 73 (step S52; final history data retrieval step).

(History data search step)
Subsequently, the history data search unit 752b searches the history DB 73 for history data based on the content ID of the history data searched in step S52 and the distribution source history information (step S53). Then, the history data search means 752b determines whether or not history data corresponding to the search condition for the search performed in step S53 has been searched (step S54). If there is no history data corresponding to the search condition in the history DB 73 (No in step S54), the process directly proceeds to step S56.
When history data corresponding to the search condition is searched (Yes in step S54), the history data search means 752b determines whether the distribution source history data of the searched history data indicates a provider. If the distribution source history data does not indicate the provider (No in step S55), the process returns to step S53 and is based on the content ID and the distribution source history information of the history data searched last. Then, the operation after the operation of searching the history data from the history DB 73 is performed.

  If the distribution source history data indicates the provider (Yes in step S55), it is determined that all the history data of the content to be searched has been searched, and the process proceeds to step S56.

  Then, the history data output means 753 converts the history data searched in steps S52 to S55 into a displayable output format and outputs it (step S56; history data output step).

  Through the above operation, the history management server 70 searches the history DB 73 for history data of content to be searched, and outputs history data indicating the content receiving terminal 50 that has distributed this content.

[History judgment operation of history management server]
Referring to FIG. 13 (refer to FIGS. 1 and 4 as appropriate), the history management server 70 issues a license input from the license server 30 based on the history data transmitted from the content server 10 and the content receiving terminal 50. An operation (history determination operation) for comparing the license issuance information retrieved from the license issuance information DB 78 storing information and determining whether the operation indicated by the history data is appropriate will be described. Here, the right information included in the license issued by the license server 30 defines the type of operation permitted in the content receiving terminal 50, the time limit for performing the operation, and the limit on the number of operations. The case will be described. FIG. 13 is a flowchart showing an operation in which the history management server according to the present invention determines whether the operation indicated in the history data is appropriate based on the license right information.

  The history management server 70 receives history data from the content server 10 or the content receiving terminal 50 via the communication transmitting / receiving means 71 by the history data receiving means 72 (step S70). Then, the license issuance information search unit 79a of the history determination unit 79 determines the content ID of the history data received in step S70 and the operation terminal history information (distribution source) indicating the content receiving terminal 50 that has operated this content. (History information) is extracted (step S71), and the license issuance information DB 78 that stores the license issuance information input from the license server 30 is associated with the content ID of the license issuance information and the license distribution destination information. The issue information is searched (step S72).

  Subsequently, the license issuance information search unit 79a determines whether there is license issuance information corresponding to the search condition (step S73). If the license issuance information corresponding to the search condition is not found in the license issuance information DB 78 (No in step S73), the operation history collating unit 79c determines that the user (content receiving terminal 50) who has performed this operation is the license. It is determined that the user is an unauthorized user, and the process directly proceeds to step S80.

  When the license issuance information corresponding to the search condition is searched (Yes in step S73), the operation history matching unit 79c describes the type of operation permitted in the content receiving terminal 50 described in the right information. In addition, the time limit for performing the operation is compared with the operation information and date information described in the history data (step S74), and it is determined whether the operation described in the history data is an illegal operation (step S75). . At this time, the operation described in the operation information of the history data is not described in the operation permitted in the right information, or the date and time described in the date information of the history data is the operation permitted in the right information. If it is out of date, the operation history collation unit 79c determines that the operation indicated in the history data is illegal (Yes in step S75), and proceeds to step S80.

  When the operation described in the operation information of the history data is within the range of the operation permitted by the right information and the time limit (No in step S75), the operation history collating unit 79c adds this operation to the right information. It is determined whether the number of times limit is described (step S76). If the number of operations is not limited in the right information (No in step S76), the operation history matching unit 79c determines that the operation indicated in the history data is appropriate, and performs the operation. finish.

  When the restriction on the number of operations is described in the right information (Yes in step S76), the operation history data search unit 79b includes the content ID, operation terminal history information (distribution source history information), operation information, Based on the above, the history DB 73 is searched for history data indicating a history in which the content receiving terminal 50 has previously performed an operation described in the history data for the content (step S77). Then, the operation history collation unit 79c collates the number of times this operation has been performed with the number of operations described in the right information based on the retrieved history data (step S78), and the number of times this operation has been performed is appropriate. That is, it is determined whether the number of times this operation has been performed is within the limit of the number of operations described in the right information (step S79). If the number of times this operation is performed is less than the number of operations described in the right information, that is, if the number of history data indicating the history of performing this operation is less than the number of operations described in the right information. The operation history matching unit 79c determines that the operation indicated in the history data is appropriate (Yes in step S79), and ends the operation.

  In addition, when the number of times of performing this operation is greater than the number of operations described in the right information, that is, when the number of history data indicating the history of performing this operation is greater than the number of operations described in the right information. Then, it is determined that the operation indicated in the history data is illegal (No in step S79), and the process proceeds to step S80. Then, the determination result output means 80 outputs the history data indicating the history of the operation determined to be an unauthorized operation by the operation history matching unit 79c to the display device 9b as the determination result (Step S80), and ends the operation.

  Through the above operation, the history management server 70 determines whether the operation indicated by the history data transmitted from the content server 10 and the content receiving terminal 50 is appropriate, and outputs the history data determined to be an unauthorized operation. To do.

It is the block diagram which showed the structure of the content delivery system in this invention. It is the block diagram which showed the structure of the content server in this invention. It is the block diagram which showed the structure of the content receiving terminal in this invention. It is the block diagram which showed the structure of the log | history management server in this invention. It is explanatory drawing for demonstrating the example of the historical data which the historical data production | generation means of a content server produces | generates. It is explanatory drawing for demonstrating the example of the historical data which the historical data production | generation means of a content receiving terminal produces | generates. Explanatory drawing which showed typically an example of the flow of content distribution at the time of content distribution by a content server and a content receiving terminal, history data input to the history management server, and tracking information added to the content It is. FIG. 8 is an explanatory diagram showing history data searched for by the distribution history data search means for the content explained in FIG. 7. It is the flowchart which showed the operation | movement which the content server in this invention distributes a content to a content receiving terminal, produces | generates historical data, and transmits to a historical management server. It is the flowchart which showed the operation | movement which the content receiving terminal in this invention receives a content from a content server. It is the flowchart which showed the operation | movement which the content receiving terminal in this invention operates with respect to a content, and produces | generates historical data. It is the flowchart which showed the operation | movement in which the log | history management server in this invention searches the log | history data of the content made into search object from log | history DB which memorize | stored log | history data. It is the flowchart which showed the operation | movement which the log | history management server in this invention determines whether operation shown to log | history data is appropriate based on the rights information of a license.

Explanation of symbols

1 Content distribution system 50 Content receiving terminal 54 Encrypted additional content receiving means (content receiving means)
56 tracking information update means 58 content operation means 58c content distribution unit (content distribution means)
59 History data generating means 73 History DB (history data storage device)
75 History search means (history search device)
752a Final history data search means 752b History data tracking means 753 History data output means

Claims (9)

History indicating redistribution history of receiving the content to which tracking information including at least content ID for identifying content and distribution destination information indicating the distribution destination of the content is added, and distributing the content to other terminals A content receiving terminal that generates data and transmits it to a history data storage device that stores the history data,
Content receiving means for receiving the content;
Tracking information update means for updating the distribution destination information included in the tracking information added to the content to a redistribution destination that is a distribution destination of the redistribution;
Content distribution means for distributing the content to which the tracking information updated by the tracking information update means is added to the other terminal;
Generating the history data including at least the content ID included in the tracking information, distribution source history information indicating a redistribution source that is the distribution source of the redistribution, and distribution destination history information indicating the redistribution destination And a history data generating means for transmitting to the history data storage device. A history search device that searches history data of content to be searched from a history data storage device that stores history data generated by the content receiving terminal according to claim 1,
Based on the tracking information added to the content, a final history data search unit that searches the history data storage device for final history data that is history data when the content was last distributed;
History data search means for sequentially searching the history data of the content using the final history data as a search source based on the content ID of the history data of the content and the distribution source history information;
A history search apparatus comprising: history data output means for outputting history data searched by the history data search means. Content that receives the content to which tracking information including at least a content ID for identifying content is added, generates history data indicating a history of operations on the content, and transmits the history data to a history data storage device that stores the history data A receiving terminal,
Content receiving means for receiving the content;
Content operating means for operating the content;
History data including at least the content ID included in the tracking information added to the content, operation information indicating the operation by the content operation unit, and operation terminal history information indicating a terminal that performed the operation is generated. And a history data generating means for transmitting to the history data storage device. A history data generation method for generating history data using a content receiving terminal that generates history data indicating a history of distributing contents to other terminals and transmits the history data to a history data storage device that stores the history data. ,
A content receiving step of receiving the content to which tracking information including at least a content ID for identifying the content and distribution destination information indicating a distribution destination of the content is added;
The distribution destination information included in the tracking information added to the content is updated to a redistribution destination that is a distribution destination of the redistribution that distributes the content to the other terminal, and the tracking information is added to the distribution destination information. While distributing content to the other terminal, the content ID included in the tracking information, distribution source history information indicating a redistribution source that is a distribution source of the redistribution, and a distribution destination history indicating the redistribution destination A history data generation method comprising: a content distribution / history data generation step of generating the history data including at least information and transmitting the history data to the history data storage device. The history data of the content is searched using a history search device that searches history data of the content to be searched from a history data storage device that stores history data generated by the content receiving terminal according to claim 1. A history search method,
Based on the tracking information added to the content, a final history data search step of searching the history data storage device for final history data that is history data when the content was last distributed;
A history data search step for sequentially searching the history data of the content using the final history data as a search source based on the content ID of the history data of the content and the distribution source history information;
A history data output step of outputting history data searched by the history data search step. A history data generation method for generating history data using a content receiving terminal that generates history data indicating a history of operations on content and transmits the history data to a history data storage device that stores the history data,
A content receiving step of receiving the content to which tracking information including at least a content ID for identifying the content is added;
A content operation step of performing an operation on the content;
History data including at least the content ID included in the tracking information added to the content, operation information indicating the operation in the content operation step, and operation terminal history information indicating a terminal that performed the operation is generated. And a history data generation step for transmitting the history data to the history data storage device. History indicating redistribution history of receiving the content to which tracking information including at least content ID for identifying content and distribution destination information indicating the distribution destination of the content is added, and distributing the content to other terminals A computer for generating data and sending it to a history data storage device storing the history data;
Content receiving means for receiving the content;
Tracking information update means for updating the distribution destination information included in the tracking information added to the content to a redistribution destination that is a distribution destination of the redistribution;
Content delivery means for delivering the content to which the tracking information updated by the tracking information update means is added to the other terminal;
Generating the history data including at least the content ID included in the tracking information, distribution source history information indicating a redistribution source that is the distribution source of the redistribution, and distribution destination history information indicating the redistribution destination And a history data generation program that functions as history data generation means for transmitting to the history data storage device. A computer for searching history data of content to be searched from a history data storage device that stores history data generated by the content receiving terminal according to claim 1,
Based on the tracking information added to the content, a final history data search unit that searches the history data storage device for final history data that is history data when the content was last distributed;
History data search means for sequentially searching the history data of the content using the final history data as a search source based on the content ID of the history data of the content and the distribution source history information;
A history search program that functions as history data output means for outputting history data searched by the history data search means. To receive the content to which tracking information including at least a content ID for identifying the content is added, generate history data indicating a history of operations on the content, and send the history data to a history data storage device that stores the history data Computer
Content receiving means for receiving the content;
Content operating means for operating the content;
History data including at least the content ID included in the tracking information added to the content, operation information indicating the operation by the content operation unit, and operation terminal history information indicating a terminal that performed the operation is generated. And a history data generation program that functions as history data generation means for transmitting to the history data storage device.

Images