JP2009048330A - Content protection system, content protection method, and content protection program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a content protection system, a content protection method and a content protection program for tracing a leak history when content is illegally leaked to the outside of a network, and for suppressing the illegal leak of the content. <P>SOLUTION: This content protection system is provided with a content sharing server 1; an authentication server 2; and a proxy server 3. This content protection system is provided with a transfer user ID confirmation means 14 for confirming a user ID when a user transfers content; a transfer user ID recording means 16 for recording the user ID in the content when the content is stored; a user ID confirmation means 15 for confirming the user ID when the user uses the content; a user ID recording means 17 for recording the user ID in the content when the content is distributed to the computer of the user; and a distribution means 5 for distributing the content to the computer of the user. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a content protection system, a content protection method, and a content protection program.

  By using a computer connected to a network such as the Internet, a plurality of users can use contents such as still images, moving images, sounds, and documents (Patent Document 1). As shown in FIG. 6, the network system includes computers 103A, 103B, and 103C used by a user and a server 104 connected via a network line. In this network system, for example, a method in which the user B uses the content stored in the content sharing server 102 from the computer 103A on the computer 103B and a method in which the user C uses the computer 103C will be described.

First, when the user A inputs a user ID or the like from the computer 103A (arrow l), the authentication server 101 authenticates the user A (arrow m), and the user A is permitted to use the network system. (Login). Then, the user A can transfer and save the content to the content sharing server 102 (arrow n: upload). On the other hand, the user B who requests distribution of contents first logs in to the system (arrow o, arrow p) as with the user A. Then, when the user B requests content distribution (arrow q), the content sharing server 102 distributes the content to the computer 103B (arrow r: download). Thereby, the user B can use the content stored in the content sharing server 102. User C can also use content created by user A in the same manner as user B. In addition, the content saved by the user B or the user C can be used by other users.

  By the way, the content shared by the content sharing server 102 as described above is basically used inside the network. However, the user B who downloaded the content may easily leak or leak out of the network by copying the content consciously or unconsciously. In particular, when it is assumed that content is used only by a limited number of users, such as an in-house network or a membership network, information leakage to the outside of the network becomes a serious problem.

As means for preventing information leakage to the outside of the network, a method has been proposed in which a content transferer records his / her user ID in the content and also records the user ID of the content user in the content. That is, the content transferer (user A) records the user ID of user A in the content using dedicated software, and the content users (user B, user C) also use this software to B's user ID is recorded in the content. Thereby, when content flows out of the network, it is possible to identify the user who used the content by detecting the user ID recorded in the content, so that the outflow of content is suppressed. .
JP 2004-13635 A

  However, as described above, the method using the software for recording the user ID of the transferor and the user ID of the user in the content is very difficult to apply. That is, when a large number of users become both transferers and users as in the in-house network, user A may become a content user, or user B may become a content transferer. In this case, if dedicated software is used each time, the system becomes complicated and difficult to apply.

  In view of the above-described problems, the present invention provides a content protection system and content that can enable the tracking of outflow history when content is illegally leaked outside the network and can prevent the illegal leak of content. A protection method and a content protection program are provided.

  A content protection system according to the present invention includes a computer used by a user and a server connected via a network line. The server includes a content sharing server for storing content transferred by the user, and a content sharing server. A content protection system comprising: an authentication server that permits use; and a proxy server that distributes content stored in the content sharing server to the computer or another computer with permission from the authentication server, the proxy server When the user transfers the content to the content sharing server via the computer, the transfer user ID confirmation means for confirming the user ID recorded in the authentication server, and when the content is stored in the content sharing server, the transfer Confirm with user ID confirmation means Transfer user ID recording means for recording the user ID in the content and user ID confirmation for confirming the user ID recorded in the authentication server when the user uses the content stored in the content sharing server on the computer Means, a use user ID recording means for recording the user ID confirmed by the use user ID confirmation means in the content when distributing the content stored in the content sharing server to the user's computer, and a computer from the user Distribution means for distributing the content recorded with the user ID by the transfer user ID recording means and the use user ID recording means to the user's computer. Here, “transfer” refers to an operation of transmitting content stored in a computer used by a user to a content sharing server. “Save” refers to an operation of storing created or edited data in the hard disk of the content sharing server.

  The content protection system of the present invention includes a proxy server, and the proxy server includes a transfer user ID confirmation unit, a transfer user ID recording unit, a use user ID confirmation unit, a use user ID recording unit, and a distribution unit. ing. Thus, when the user who transfers the content authenticates and transfers the content, the transfer user ID confirmation unit can confirm the user ID of the user recorded in the authentication server, and the transfer is performed based on this confirmation. User ID recording means records this user ID in the content. Then, the content in which the user ID of the user transferring the content is recorded can be stored in the content sharing server. Further, when a user who requests content distribution authenticates and requests content distribution, the user ID confirmation unit can confirm the user ID of the user recorded in the authentication server, and based on this confirmation. The user ID recording means records this user ID in the content. The distribution unit distributes the content in which the user ID of the user who transfers the content and the user ID of the user who uses the content are recorded to the user's computer. Thereby, since the user ID of the user who finally used the content is recorded in the content, it becomes possible to specify the final user of the content.

  Another content protection system of the present invention includes a computer used by a user and a server connected via a network line, and the server shares a content sharing server for storing content transferred by the user, and content sharing A content protection system comprising: an authentication server that permits use of a server; and a proxy server that distributes content stored in a content sharing server to the computer or another computer with permission from the authentication server, the proxy When the user transfers the content to the content sharing server via the computer, the transfer user ID confirmation means for confirming the user ID recorded in the authentication server, and when the content is stored in the content sharing server, Confirm with the transfer user ID confirmation means. A transfer user ID recording means for recording the user ID recorded in the content, a user restriction ID recording means for recording in the content the user ID of the user allowed to distribute the content as a user restriction ID, and the user in the content sharing server A user ID confirmation unit for confirming a user ID recorded in the authentication server when the stored content is used by a computer, and a user restriction ID recorded by the user restriction ID recording unit; The comparison unit that compares the user ID of the user who requests content distribution, and the user restriction ID and the user ID of the user who requests content distribution match based on the comparison of the comparison unit In this case, content distribution is permitted to the user's computer, and the user restriction ID and content When the user ID of the user who requests the distribution does not match, the determination means for determining that the distribution of the content is restricted to the user's computer, and the content stored in the content sharing server is distributed to the user's computer The user ID recording means for recording the user ID confirmed by the use user ID confirmation means in the content, and the transfer user ID recording means if distribution of the content is permitted by the determination by the determination means And a distribution unit that distributes the content recorded by the user ID recording unit to the user's computer.

  According to another content protection system of the present invention, a proxy server is provided, a transfer user ID confirmation unit, a transfer user ID recording unit, a use user ID confirmation unit, a use user ID recording unit, a user, Restriction ID recording means, comparison means, determination means, and distribution means are provided. Thereby, the transfer user ID recording unit records the user ID of the user who transfers the content in the content, and the user restriction ID recording unit can record the user ID of the user permitted to distribute the content. When the user requests content distribution, the comparison unit compares the user restriction ID and the user ID of the user, and if they match, the content distribution is permitted to the user's computer. If not, the determination means makes a determination to restrict the distribution of the content. This makes it possible to distribute content only to a specific user's computer.

  The transfer user ID recording unit and the use user ID recording unit can embed a user ID in the content with a digital watermark. Thereby, the user ID can be embedded in the content in an invisible state. It can also be embedded in a visible state.

  The transfer user ID recording unit and the use user ID recording unit include a determination unit that determines the type of content, and can embed an electronic watermark corresponding to the type of content. That is, the discriminating unit automatically discriminates the type of the content as a still image, a moving image, sound, or a document, and embeds a different digital watermark for each type.

  The content protection method of the present invention is a content protection method in which a user transfers content to a content sharing server and stores it, and the content stored in the content sharing server is distributed to this computer or another computer. The server confirms the user ID of the user recorded in the authentication server based on the authentication of the user who transfers the content, and the user who transfers the content when the proxy server stores the content in the content sharing server Embedded in the content as a digital watermark, the proxy server confirming the user ID of the user recorded in the authentication server based on the authentication of the user requesting distribution of the content, and the proxy server Request content delivery when delivering content The user ID of the over THE those comprising burying the content as an electronic watermark.

  Another content protection method of the present invention is a content protection method in which a user transfers content to a content sharing server and stores it, and the content stored in the content sharing server is distributed to this computer or another computer. The proxy server confirms the user ID of the user recorded in the authentication server based on the authentication of the user who transfers the content, and transfers the content when the proxy server stores the content in the content sharing server. Embedding the user ID of the user to be used as a digital watermark, the step of embedding the user ID of the user whose distribution of content is permitted as a user restriction ID, and the authentication of the user from whom the proxy server requests content distribution Based on the user's user information recorded on the authentication server. A step of confirming the ID, a step of determining whether or not the user restriction ID recorded in the content by the proxy server matches the user ID of the user requesting distribution of the content, and the proxy server When the user ID of the user who distributes the content is recorded in the content as a digital watermark.

  The content protection program of the present invention stores content transferred by a user in a content sharing server and authenticates the user who transfers the content to a computer used as a proxy server that distributes the content to this computer or another computer. A step of confirming the user ID of the user recorded in the authentication server, a step of embedding the user ID of the user transferring the content in the content as a digital watermark when the content is stored in the content sharing server, The step of confirming the user ID of the user recorded in the authentication server based on the authentication of the user who requests the distribution of the user, and the user ID of the user who requests the distribution of the content as the digital watermark when distributing the content Content It is intended to execute the order writing step.

  Another content protection program of the present invention stores content transferred by a user in a content sharing server and transfers the content to a computer used as a proxy server that distributes the content to this computer or another computer. A step of confirming the user ID of the user recorded in the authentication server based on the authentication; a step of embedding the user ID of the user who transfers the content as a digital watermark when the content is stored in the content sharing server; Recording a user ID of a user permitted to be distributed as a user restriction ID, and confirming a user ID of a user recorded in the authentication server based on authentication of a user who requests content distribution; , Embedded in content Determining whether or not the user restriction ID and the user ID of the user requesting distribution of content match, and when distributing the content, the user ID of the user distributing the content is digitally watermarked Are embedded in the content.

  Since the content protection system, the content protection method, and the content protection program of the present invention can identify the user who finally used the content, when the content is illegally leaked outside the network, the leakage history is recorded. It can be tracked, and illegal leakage of content can be effectively prevented. Here, fraudulent leakage means not only the content itself stored in the content sharing server but also illegally taking out a copy of the content or a content stored in a medium outside the network. Furthermore, since the proxy server automatically records the user ID in the content, no dedicated software or the like is required for recording the user ID, and the user ID is recorded by a simple method without any operation on the user side. can do. Further, since all users can be content transferers and users, it is possible to transfer and use content from all computers. For this reason, it is not necessary to provide a dedicated device for transferring content. In addition, since the proxy server only needs to be connected to the authentication server and to the content sharing server, the existing system can be used and the cost can be reduced.

  Further, since the distribution of the content can be permitted only to a specific user, the user can be specified more clearly when the content is illegally leaked outside the network.

  When the user ID is embedded in the content by the digital watermark, the content in which the user ID is embedded in an invisible state can be distributed to the user, and the possibility that the user ID embedded in the content is removed is reduced. In addition, it is possible to distribute to the user content in which the user ID is embedded in a visible state. In this case, since the content user recognizes that his / her ID remains as a history, the outflow of the content to the outside can be further prevented. Furthermore, two types of user IDs, a visible state and an invisible state, may be embedded in one content.

  Since the transfer user ID recording means and the use user ID recording means can embed an electronic watermark according to the type of content, it is possible to deal with various contents in one network, and the application range is wide. can do.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  As shown in FIG. 1, the content protection system according to the first embodiment of the present invention includes computers 11A, 11B, and 11C used by a user and a server 12 connected through a network line. The content sharing server 1 that stores the content transferred by the user, the authentication server 2 that permits the use of the content sharing server 1, and the content stored in the content sharing server under the permission of the authentication server 2 are stored in the computer 11A. , 11B, and 11C. Here, the content is information such as a still image, a moving image, sound, and a document. “Transfer” refers to an operation of transmitting content stored in a computer used by a user to the content sharing server 1. “Save” refers to an operation of storing created or edited data in the hard disk of the content sharing server 1.

  The content sharing server 1 is a server that stores content transferred by a user via a computer.

  The authentication server 2 performs authentication (login) when a user uses the network system (content sharing server 1). When the user uses the network system for the first time, the authentication server 2 authenticates the user ID and password of the user, issues a cookie that records the user access information, and gives the user the authority to use the network system. give. Thereafter, when the user uses the network system, when the user inputs a user ID or the like, the authentication server 2 allows the user to access the content sharing server 1 and the user starts using the network system. be able to.

  As shown in FIG. 2, the proxy server 3 includes a transfer user ID confirmation unit 14 for confirming a user ID recorded in the authentication server 2 when a user transfers content to the content sharing server 1 via a computer. When the content is stored in the content sharing server 1, the transfer user ID recording unit 16 that records the user ID confirmed by the transfer user ID confirmation unit 14 in the content and the user are stored in the content sharing server 1. When the content is used on the computer, the user ID confirmation means 15 for confirming the user ID recorded in the authentication server 2 and the content stored in the content sharing server 1 are distributed to the user's computer. The user ID confirmed by the use user ID confirmation means 15 is recorded in the content. The user ID recording means 17 and the distribution that distributes the user ID recorded by the transfer user ID recording means 16 and the user ID recording means 17 to the user's computer in response to a distribution request from the user via the computer. Means 5 are provided. Here, recording the user ID means embedding the user ID in the content with a digital watermark.

  The transfer user ID confirmation means 14 identifies a user by confirming the cookie of the authentication server 2 when a user having the authority to use the network system transfers the content to the content sharing server 1.

  The transfer user ID recording means 16 embeds the user ID in the content as a digital watermark based on the user ID confirmed by the transfer user ID confirmation means 14. The transfer user ID recording unit 16 includes a determination unit 7. The determination unit 7 automatically determines whether the content is a still image, a moving image, a sound, or a document, and for each type. Embed different watermarks. For example, if the content is a still image and is a black and white binary image (FAX image or the like), the rule is determined to be 0 if the number of black pixels per line is an even number and 1 if it is an odd number. Add a pixel. In the case of black and white multi-valued images (black-and-white photographs, etc.), one pixel is expressed by multi-values with a plurality of bits. Embed black and white binary images. In the case of a compressed color image (JPEG format), a rule is set such that the coefficient at the time of discrete cosine transform is 0 if the coefficient is even and 1 if the coefficient is odd, and the bit information corresponding to the number of compressed blocks is embedded so as not to affect the compression. If the content is a moving image and is a moving image (MPEG) by differential compression, a watermark is embedded using a recording method for a still image for each reference still image from which still image information of the entire screen can be extracted. If it is an uncompressed moving image (Motion JPEG), a watermark is embedded in the still image. If the content is audio and is uncompressed audio (such as a CD), a bit string corresponding to the number of times of sampling is embedded by a method of 0 if the amplitude value of the waveform is an even number and 1 if it is an odd number. For compressed audio (such as MP3), the bit information to be embedded is converted to the frequency domain and added to the original sound. Furthermore, if the content is a document, the number of meaningless blanks is embedded in the original document data in association with the bit string.

  The use user ID confirmation means 15 identifies a user by confirming a cookie of the authentication server 2 when a user having the authority to use the network system requests the content sharing server 1 to distribute the content. It is.

  The use user ID recording means 17 embeds the user ID in the content as a digital watermark based on the user ID confirmed by the use user ID confirmation means 15. Similarly to the transfer user ID recording unit, the use user ID recording unit 17 also includes a determination unit 7. The type of content is determined by the same method as the determination unit 7 of the transfer user ID recording unit, Embed different digital watermarks in the content.

  The distribution means 5 distributes the content stored in the content sharing server 1 to the computers 11A, 11B, and 11C of users who request content distribution.

  Next, a content protection method using this content protection system will be described with reference to FIGS. FIG. 3 is a flowchart showing the procedure of the content protection method. In the present embodiment, for example, a case will be described in which one of two users is a content transferer and the other user is a content user. First, when a user (user A) who transfers content inputs a user ID or the like on the computer 11A (arrow a), the authentication server 2 authenticates the user A (arrow b). Use of the network system is permitted (login) (step S1). When the user A transfers the content stored in the computer 11A to the content sharing server 1 (step S2, arrow c), the transfer user ID confirmation unit 14 of the proxy server 3 confirms the cookie of the authentication server 2. (Arrow d), it is confirmed that the content transfer person is the user A (step S3, arrow e).

  In this case, the determination unit 7 determines the content type as one of a still image, a moving image, audio, and a document, and the transfer user ID recording unit 16 makes the user ID of the user A invisible according to the content type. The content is embedded as a digital watermark (step S4). Then, the content with the digital watermark embedded is stored in the content sharing server (step S5, arrow f).

  On the other hand, a user (user B) who requests distribution of this content inputs a user ID and logs in to the system (step S6, arrow g, arrow h). When the user B requests content distribution (step S7, arrow i), the proxy server 3 receives the content from the content sharing server 1 (arrow j). Then, the user ID confirmation means 15 of the proxy server 3 confirms that the user who requests the distribution of the content is the user B by confirming the cookie of the authentication server 2 (arrow d) (step S8). , Arrow e). Also in this case, the determination unit 7 determines the type of content, and the use user ID recording unit 17 embeds the user ID of the user B as an invisible digital watermark in the content (step S9). Then, the distribution means 5 of the proxy server 3 distributes the content in which the user ID of the user A and the user ID of the user B are embedded to the computer 11B of the user B (step S10, arrow k), and the system is completed. .

  As described above, according to the content protection system, the content protection method, and the content protection program of the first embodiment of the present invention, it is possible to identify the user who finally used the content. When illegally leaking outside, it is possible to track the leaked history and effectively prevent illegal leakage of content. Here, fraudulent leakage means not only the content itself stored in the content sharing server but also illegally taking out a copy of the content or a content stored in a medium outside the network. Furthermore, since the proxy server 3 automatically embeds the user ID in the content, dedicated software or the like for embedding the user ID becomes unnecessary, and the user ID can be embedded by a simple method without any operation on the user side. Can do. Further, since all users can be content transferers and users, it is possible to transfer and use content from all computers. For this reason, it is not necessary to provide a dedicated device for transferring content. In addition, since the proxy server 3 only needs to be connected to the authentication server 2 and to the content sharing server 1, an existing system can be used and cost reduction can be achieved.

  Since the user ID is embedded in the content by the digital watermark, the content in which the user ID is embedded in an invisible state can be distributed to the user, and the possibility that the user ID embedded in the content is removed is reduced.

  The transfer user ID recording unit 16 and the use user ID recording unit 17 include a determination unit 7 that determines the type of content, and can embed an electronic watermark according to the type of content. Can be applied, and can be applied in a wide range.

  Next, a second embodiment of the content protection system of the present invention will be described. As shown in FIG. 4, the content protection system includes a transfer user ID confirmation unit 14, a use user ID confirmation unit 15, a transfer user ID recording unit 16, and a use user ID recording unit 17 similar to those shown in FIG. , The distribution means 5, the user restriction ID recording means 8 for embedding the user ID of the user who is allowed to distribute the content in the content as the user restriction ID, and the user restriction ID embedded in the user restriction ID recording means 8 The comparison means 9 for comparing the ID with the user ID of the user who requests the content distribution, and the user restriction ID and the user ID of the user who requests the content distribution match based on the comparison means 9. The user is allowed to distribute the content, and the user restriction ID and the content distribution are requested. In the case where the user ID of the user does not match and a determination means 10 to regulate the distribution of content to a computer used by a user.

  The user restriction ID recording unit 8 embeds a user ID of a user who can distribute the content in the content as a user restriction ID. That is, the user A who transfers the content can limit the users who distribute the content, and the user restriction ID recording unit 8 can embed the ID of the user who can distribute the content in the content.

  The comparison means 9 compares the user restriction ID embedded in the user restriction ID recording means 8 with the user ID of the user who requests content distribution.

  The determination unit 10 allows the user to distribute the content when the user ID of the user who requests the content distribution matches, and determines the user restriction ID and the user ID of the user who requests the content distribution. If they do not match, it is determined that content distribution is restricted to a computer used by the user.

  Next, a content protection method using the previous system will be described. In FIG. 5, the processes up to step S24 are performed by the same method as in the first embodiment. That is, the transfer user ID recording unit 16 embeds the user ID of the user A who is the content transferer in the content as an invisible digital watermark (step S24). At the same time, the user restriction ID recording means 8 embeds the user ID of the user who can distribute the content in the content as the user restriction ID (step S25). In this way, the content in which the user ID of the user A and the user ID of the user who can distribute the content are embedded is stored in the content sharing server 1 (step S26).

  On the other hand, when the user B requests distribution of the content, the process up to step S29 is performed by the same method as in the first embodiment. That is, the user ID confirmation unit 15 of the proxy server 3 confirms that the user who requests the content distribution is the user B by confirming the cookie of the authentication server 2 (step S29). When the comparison unit 9 compares the user restriction ID embedded in the content with the user B user ID (step S30), the user restriction ID and the user B user ID match. The determination unit 10 allows the user B to distribute the content. That is, the use user ID recording unit 16 embeds the user ID of the user B in the content as an invisible digital watermark (step S31). Then, the distribution means 5 of the proxy server 3 distributes the content in which the user ID of the user A and the user ID of the user B are embedded to the computer 11B of the user B (step S32), and the system is completed.

  In step S <b> 30, when the user restriction ID and the user ID of the user B do not match, the determination unit 10 restricts the content distribution to the user B. That is, the content is returned to the content sharing server 1 (step S33), and the system is completed.

  As described above, according to the content protection system, the content protection method, and the content protection program of the second embodiment of the present invention, content distribution can be permitted only to a specific user. The user can be identified more clearly when illegally leaked.

  Since the user restriction ID recording unit 8 includes the determination unit 7 for determining the type of content, the user restriction ID recording unit 8 can cope with various types of content in one network and can be applied in a wide range.

  As described above, the embodiment of the present invention has been described. However, the present invention is not limited to the above-described embodiment, and various modifications can be made. For example, content in which a user ID is recorded in a visible state is distributed to a user. You can also In this case, since the content user recognizes that his / her ID remains as a history, the outflow of the content to the outside can be further prevented. Furthermore, two types of user IDs, a visible state and an invisible state, may be embedded in one content. The recording of the user restriction ID may not be performed simultaneously with the recording of the user ID of the user who transfers the content, and can be recorded after the content is stored in the content sharing server 1. Although the number of users has been described as two in the embodiment, the number of users can be arbitrarily set. Furthermore, the content transferer and the content user may be the same user.

It is a block diagram which shows the content protection system of this invention. It is a block diagram of the proxy server used for the content protection system of 1st Embodiment of this invention. It is a flowchart which shows the content protection method of 1st Embodiment of this invention. It is a block diagram of the proxy server used for the content protection system of 2nd Embodiment of this invention. It is a flowchart which shows the content protection method of 2nd Embodiment of this invention. It is a block diagram which shows the conventional content protection system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Content sharing server 2 Authentication server 3 Proxy server 5 Distribution means 7 Determination means 8 User restriction ID recording means 9 Comparison means 10 Determination means 14 Transfer user ID confirmation means 15 Use user ID confirmation means 16 Transfer user ID recording means 17 Use user ID recording means

Claims (8)

A computer used by a user; and a server connected via a network line, the server sharing a content shared by the user, an authentication server allowing the use of the content sharing server, A content protection system comprising: a proxy server that distributes content stored in a content sharing server to the computer or another computer with permission of an authentication server,
In the proxy server,
Transfer user ID confirmation means for confirming the user ID recorded in the authentication server when the user transfers the content to the content sharing server via the computer;
A transfer user ID recording unit that records the user ID confirmed by the transfer user ID confirmation unit in the content when storing the content in the content sharing server;
A user ID confirmation means for confirming a user ID recorded in the authentication server when the user uses the content stored in the content sharing server on the computer;
Use user ID recording means for recording the user ID confirmed by the use user ID confirmation means when the content stored in the content sharing server is distributed to the user's computer;
Content comprising: distribution means for distributing content recorded with a user ID by the transfer user ID recording means and use user ID recording means to a user's computer in response to a distribution request from the user via a computer Protection system. A computer used by a user; and a server connected via a network line, the server sharing a content shared by the user, an authentication server allowing the use of the content sharing server, A content protection system comprising: a proxy server that distributes content stored in a content sharing server to the computer or another computer with permission of an authentication server,
In the proxy server,
Transfer user ID confirmation means for confirming the user ID recorded in the authentication server when the user transfers the content to the content sharing server via the computer;
A transfer user ID recording unit that records the user ID confirmed by the transfer user ID confirmation unit in the content when storing the content in the content sharing server;
User restriction ID recording means for recording in the content the user ID of the user permitted to deliver the content as the user restriction ID;
A user ID confirmation means for confirming a user ID recorded in the authentication server when the user uses the content stored in the content sharing server on the computer;
Comparison means for comparing the user restriction ID recorded by the user restriction ID recording means with the user ID of the user requesting distribution of content;
Based on the comparison by the comparison means, if the user restriction ID and the user ID of the user requesting distribution of content match, the user's computer is allowed to distribute the content, and the user restriction ID Determining means for determining that content distribution is restricted to the user's computer when the user ID of the user requesting content distribution does not match;
Use user ID recording means for recording the user ID confirmed by the use user ID confirmation means when the content stored in the content sharing server is distributed to the user's computer;
A distribution unit that distributes the content recorded with the user ID by the transfer user ID recording unit and the use user ID recording unit to a user's computer when content distribution is permitted by the determination by the determination unit; A content protection system characterized by   3. The content protection system according to claim 1, wherein the transfer user ID recording unit and the use user ID recording unit embed a user ID in the content by digital watermark.   5. The content protection according to claim 3, wherein the transfer user ID recording unit and the use user ID recording unit include a determination unit that determines a type of content, and embeds an electronic watermark according to the type of content. system. A content protection method in which a user transfers content to a content sharing server, stores the content, and distributes the content stored in the content sharing server to this computer or another computer,
The proxy server confirms the user ID of the user recorded in the authentication server based on the authentication of the user transferring the content; and
When the proxy server stores the content in the content sharing server, the step of embedding the user ID of the user transferring the content in the content as a digital watermark;
A step in which the proxy server confirms the user ID of the user recorded in the authentication server based on the authentication of the user who requests distribution of the content;
A content protection method comprising: embedding a user ID of a user who requests content distribution in the content as a digital watermark when the proxy server distributes the content. A content protection method in which a user transfers content to a content sharing server, stores the content, and distributes the content stored in the content sharing server to this computer or another computer,
The proxy server confirms the user ID of the user recorded in the authentication server based on the authentication of the user transferring the content; and
Embedding the user ID of the user who transfers the content as a digital watermark when the proxy server stores the content in the content sharing server;
A process in which the proxy server embeds a user ID of a user whose content distribution is permitted as a user restriction ID;
A step in which the proxy server confirms the user ID of the user recorded in the authentication server based on the authentication of the user who requests distribution of the content;
A step in which the proxy server determines whether or not the user restriction ID recorded in the content matches the user ID of the user requesting distribution of the content;
And a step of recording the content of the user ID of the user who distributes the content as a digital watermark when the proxy server distributes the content. In a computer used as a proxy server that stores content transferred by a user in a content sharing server and distributes the content to this computer or another computer,
Confirming the user ID of the user recorded in the authentication server based on the authentication of the user transferring the content;
Embedding a user ID of a user who transfers content in the content as a digital watermark when storing the content in the content sharing server;
Checking the user ID of the user recorded in the authentication server based on the authentication of the user requesting distribution of the content;
A content protection program that, when distributing content, causes a user ID of a user who requests distribution of content to be embedded in the content as a digital watermark. In a computer used as a proxy server that stores content transferred by a user in a content sharing server and distributes the content to this computer or another computer,
Confirming the user ID of the user recorded in the authentication server based on the authentication of the user transferring the content;
Embedding a user ID of a user who transfers content as a digital watermark when storing the content in the content sharing server;
Recording a user ID of a user allowed to deliver content as a user restriction ID;
Checking the user ID of the user recorded in the authentication server based on the authentication of the user requesting distribution of the content;
Determining whether the user restriction ID embedded in the content matches the user ID of the user requesting the content distribution;
A content protection program that, when distributing content, causes a user ID of a user who distributes the content to be embedded in the content as a digital watermark.

Images