WO2007000805A1

WO2007000805A1 - Digital video content copyright management method

Info

Publication number: WO2007000805A1
Application number: PCT/JP2005/011782
Authority: WO
Inventors: Katsuhisa Suzuki
Original assignee: Tanimizu, Hirohiko
Priority date: 2005-06-28
Filing date: 2005-06-28
Publication date: 2007-01-04

Abstract

A digital video content copyright management method stores user information on a user, an encrypted medium file obtained by encrypting a medium file of a digital video content by a common key A, and reproduction permission file containing view limit information on a video work and the common key A in a media server. The media server transmits an encrypted medium file of the video work requested from a user terminal of a user and encryption-permitted in which a reproduction-permitted file is encrypted by a common key B generated from the user information corresponding to the user terminal, to the user terminal. The user terminal decrypts the encryption-permitted file by the common key B generated according to its user information into a reproduction-permitted file and acquires the common key A. The user terminal processes a medium file obtained by decrypting the encrypted medium file by using the key A and reproduces a video work in such a way that it can be viewed.

Description

Specification

Digital video content copyright management method

Technical field

[0001] The present invention relates to a copyright management method for digital video content encoded with a video work.

Background art

[0002] By improving the graphics processing capability of personal computers and the development of broadband Internet communication environments such as ADSL and optical fibers, high-quality digital video content can be transmitted to users' computers via an information communication network. Services that are distributed to and used for viewing are becoming widespread.

Disclosure of the invention

Problems to be solved by the invention

[0003] Digital video content can be easily duplicated by a computer, and even if duplication is repeated, there is almost no deterioration in image quality. Therefore, it is necessary to take sufficient copyright protection measures. An object of the present invention is to propose a novel copyright protection method for digital video content.

Means for solving the problem

[0004] A novel copyright management method for digital video content according to the present invention includes a media server that distributes digital video content recorded as digital data through an information communication network, and a viewer of the video product. It is implemented in a configuration that communicates with the user terminal used,

On the media server, an encrypted media file obtained by encrypting a media file corresponding to the digital video content of one video work with a common key A, and a playback permission file that includes viewing restrictions information about the common key A and the video work And a media storage step for storing for each video work,

Viewing on a user terminal to process media files and view video works In the process of installing the program, the authentication information of the viewer is stored in the user terminal, and the user information registration step of registering the individual identification information of the user terminal and the authentication information in association with each other in the media server; ,

When there is a user input for designating the video work at the user terminal, a video work requesting step for requesting the video work from the media server;

In the media server, a media file returning step for returning the corresponding encrypted media file to the user terminal that has requested the video work;

When the viewing program is activated and the user terminal gives a playback instruction for the encrypted media file returned by user input, a playback permission file corresponding to the encrypted media file is displayed. A reproduction permission file requesting step for investigating whether or not the user terminal exists, and if not, sending the authentication information to the media server and requesting the return of the reproduction permission file;

If the authentication information received from the user terminal requesting the playback permission file has already been registered in the media server, the common key B is generated using the individual identification information corresponding to the authentication information. An encrypted license file sending step for sending the encrypted license file obtained by encrypting the requested playback license file with the common key B to the user terminal; and

At the user terminal, the common key B is generated based on the individual identification information and the stored authentication information, and the encryption license file returned with the media server power is also sent to the user terminal. A license file decrypting step for decrypting into a playback license file using the common key B;

If the user terminal confirms the playback permission of the video work based on the viewing restriction information contained in the decrypted playback permission file at the user terminal, the media server power is also returned with the common key A in the playback permission file. A video work playback step of decrypting the encrypted media file into a media file, processing the media file, and playing back the video work for viewing;

Is included.

If the user terminal finishes playing the video work, the decrypted media The file is stored, the playback permission file is updated in the viewing restriction information in the playback permission file, the playback permission file is updated, and the updated playback permission file is generated in the encryption key permission file with the common key B. It is also possible to adopt a copyright management method for digital video content including a license file update step to be stored.

[0006] In the copyright management method including the license file update step, in the license file decryption step, the user terminal decrypts the encrypted license file stored in the user terminal into a reproduction license file, and the video In the work playback step, if the user terminal confirms the playback permission of the video work based on the viewing restriction information described in the playback permission file obtained by decrypting the encryption permission file, It is also possible to process the media file that is stored and play back the video work for viewing!

[0007] In the copyright management method including the permission file update step described above, the video work playback step is specified by a media file scrambling method as viewing restriction information in the playback permission file and decrypted. When playback of video works is not permitted based on the viewing restriction information contained in the playback permission file, it includes processing to encrypt the media file stored on the user terminal based on the specified scramble method. May be.

[0008] In the copyright management method including the permission file update step, the video work playback step is instructed to delete the media file as viewing restriction information in the playback permission file, and the decrypted playback permission file If playback of the video work is not permitted based on the included viewing restriction information, the media file stored in the user terminal can be deleted.

Brief Description of Drawings

FIG. 1 is a network configuration diagram in which a copyright management method according to an embodiment of the present invention is implemented.

FIG. 2 is a schematic structural diagram of viewing restriction information described in a reproduction permission file created by the above-mentioned author transfer management method.

[Figure 3] This is a flowchart of the process before viewing a video work based on the above copyright management method. [0010] *

[Fig. 4] Flow chart of processing for viewing video works based on the above copyright management method.

FIG. 5 is a flowchart of a playback prohibition process included in the above-mentioned video work viewing process flow. Explanation of symbols

[0011] 1 User terminal, 2 Media server, 3 Internet

BEST MODE FOR CARRYING OUT THE INVENTION

[0012] = = = Embodiment = = =

FIG. 1 shows a schematic configuration in an embodiment of the present invention. It is connected to a computer (user terminal) 1 used by viewers of video works, a server (media server) 2 that distributes digital video content to the user terminal, and Power Internet 3. The user terminal 1 can employ a personal computer equipped with a browser. The user terminal 1 is assumed to be installed with a program (viewing program) for processing the digital video content and reproducing the video work so that it can be viewed!

In this embodiment, digital video content is provided as a media file filed for each video work. The media server 2 stores and manages a file (encrypted media file) encrypted with the common key A in its own storage resource for a number of video works based on the common key encryption method. ing. For each video work, store / manage / manage and manage the common key A used to generate the corresponding encrypted media file and the playback permission file containing the viewing restriction information of the video work.

[0014] = = = Playback permission file = = =

FIG. 2 shows an outline of the viewing restriction information described in the reproduction permission file in this embodiment. The contents of each item of the number of reproducible times, the reproducible upper limit date, the reproducible days, the scramble method and the automatic deletion are described. The number of playable times is the maximum number of media files that can be played back to view a video work, and is specified by a numerical value. This item stipulates that playback processing exceeding the specified value is prohibited. If there is no upper limit to the number of playbacks, the content column for this item is blank. Playback is forbidden! / Turn to 0 (zero). [0015] The reproducible upper limit date is the last date on which the reproduction process can be performed, and the reproduction process is prohibited from being performed past the stated date. If no upper limit date has been set, the content field for this item will be blank. The reproducible number of days is the number of days from the first playback until the power playback is prohibited, and playback beyond that number is prohibited. If the number of days is not set, the content field will be blank as with other items. In addition, in a playback permission file corresponding to a video work that has been played back, the date of the first playback (first playback date) is described in the content field of this playable days item. Note that the playback permission file stored on the media server does not include the date of the first playback.

[0016] In the contents column of the scramble method, a method for scrambling and encrypting the media file is described. In this scramble method item, when the scramble method is specified in the content column, playback is prohibited due to any of the above items in the viewing restriction information when the media file is played back on the user terminal. In this case, it is stipulated that the media file be encrypted using the specified scramble method. In the item of automatic deletion, a flag for determining whether or not the media file can be deleted is described in the content column. It is stipulated that media files should be deleted when playback is prohibited by any of the above items at the time of playback processing of the media file and the determination flag corresponds to “delete”.

[0017] = = = Create media file Z encryption key Z storage = = =

Fig. 3 shows the flow of processing for pre-processing before viewing a video work in the copyright management method of this embodiment. The creator of the video work creates the video work in a media file of a predetermined format (si), encrypts the media file with the common key A based on the common key encryption method, and creates an encrypted media file. Generate (s2, s3). Also, a reproduction permission file is created in which viewing restriction information based on the copyright content of the video work is included. Then, the encrypted media file and the reproduction permission file are associated with each video work and stored in the storage resource of the media server 2 (s4, s5).

[0018] = = = Registration of user information = = =

On the other hand, a viewing program is installed in the user terminal. The viewing program may be supplied by a medium, etc. It may be prepared so that it can be downloaded to any server computer. When the viewing program is installed on the user terminal 1 (s6), the viewing program prompts the user to register authentication information such as a user ID and password during the installation process, and the authentication information is input by the user. Then, this is stored in the user terminal, and appropriate individual identification information for identifying the user terminal such as the MAC address of the user terminal and the identification number of the OS node disk device is acquired (s7 , s8) ₀ Then, the individual identification information and the viewer authentication information are sent to the media server as user information (s9). The media server stores the sent user information in an appropriate storage resource (slO).

[0019] = = = Download encrypted media file = = =

Next, a process for viewing a video work on the user terminal 1 based on the copyright management method in the present embodiment will be specifically described. Figure 4 shows the process flow. The viewer requests the media server 2 for the desired video work. In this example, Media Server 2 has a WWW server function and publishes a web page (work selection page) that allows the browser to select the video work stored and managed by itself! Shall. The user terminal 1 is assumed to have a browser installed. Media server 2 returns the work selection page to the browser of user terminal 2 that has been accessed by specifying the specified URL (sl l, sl2). When the viewer finds the desired video work in the work selection page ordered by the user terminal 1, the viewer requests the video work by designating the desired work (sl3, sl4). Upon receiving the request for the video work, the media server 2 returns the corresponding encrypted media file to the user terminal 1 (sl5), and the user terminal 1 stores the encrypted media file (sl6).

[0020] = = = Encryption key for playback license file = = =

In order for the viewer to view the video work, start the viewing program on user terminal 1 and specify the video work to be viewed (sl7, sl8) ₀ Here, the encrypted media file of the specified video work Is stored in user terminal 1 by sl6. Then, it is confirmed whether or not the playback permission file corresponding to the specified video work exists on the user terminal. If it does not exist, the user terminal is accessed to the media server, and the video work to be viewed is specified. Information and viewer authentication information are sent (sl9 → s20 → s21) [0021] When the video server specific information and authentication information are sent from the user terminal 1, the media server 2 confirms registration of the corresponding user information, and if the registration is confirmed, Based on the algorithm, the common key B is generated from the individual identification information in the user information, and the reproduction permission file corresponding to the video work to be viewed is encrypted with this key B to encrypt the encryption permission file. Is generated (s22 to s24). Then, the encryption permission file is sent to the user terminal 1 (s26).

[0022] = = = Watching video works = = =

When the encrypted media file is returned by the viewing program, the user terminal 1 also generates a common key B for the individual identification information power of the user terminal 1 installed by itself. The decryption permission file is decrypted into a playback permission file (s27 to s29). Then, based on the viewing restriction information included in the playback permission file, it is determined whether or not the playback process of the video work to be viewed can be executed (s30). Here, since the encrypted media file returned from the media server 2 is the processing target, the playback processing is not prohibited by any of the viewing restriction information items, and it is determined that the playback processing can be executed. Then, the user terminal uses the viewer program to decrypt the encrypted media file into a media file using the common key A in the playback permission file, process it, and play the video work to view it on the user terminal. (S30 → s31, s32).

[0023] = = = Renewal of playback permission file = = =

If the user terminal 1 receives a user input to end viewing of the video work being played back or if the video work has been completely played back, the media file is stored on the user terminal. The reproduction permission file is updated by reflecting information related to this reproduction processing opportunity in appropriate items in the viewing restriction information in the reproduction permission file of the video work (s34, s35). For example, if the reproducible number of times is initially set to “5”, it is set to “4”, or the reproduction processing date is described in the reproducible number of days column as the first reproduction date. Then, the updated reproduction permission file is encrypted again with the common key B to generate an encryption permission file and store it (s36, s37).

= = = Reproduction prohibition processing = = = When the encrypted media file is decrypted and the video work is viewed on the user terminal

Then, the encrypted media file is stored in the user terminal 1 (s34). The viewing restriction information of the playback permission file may have been updated to the content corresponding to playback prohibition after the first playback processing, such as the playback possible power S “0”. If the viewing program determines that playback of the video work subject to viewing is prohibited based on the viewing restriction information included in the playback permission file, the playback process of the video work is interrupted and playback processing prohibited processing is performed. (S30 → s40).

FIG. 5 shows the flow of the regeneration prohibiting process 40. The user terminal 1 running the viewing program encrypts the media file with the specified scramble method (s41 → s42) if the scramble method is specified by the viewing restriction information in the playback permission file. ). As a result, for example, even if the playback permission file is illegally altered and the viewing restriction information is changed to a content that does not prohibit playback processing, the scramble cannot be released and the video work cannot be viewed. If deletion is specified by the viewing restriction information, the media file itself is deleted (s41 → s43 → s44). In this case, it is possible to eliminate the possibility that the scramble information is decrypted and the scramble is illegally released. If the viewing restriction information prohibits the playback process! And there is no scramble method designation or automatic deletion instruction, the playback process for the media file is stopped (s43 → s45).

[0025] = = = Media file distribution method = = =

In the above embodiment, the entire encrypted media file has been downloaded to the user terminal. Not limited to this example, the media server 1 converts the encrypted media file into streaming data using a well-known streaming technology to the user terminal 1, and the user terminal 1 transmits the streaming data of the encrypted media file that has been transferred. The video work may be played back so as to be viewable by sequentially decoding while buffering. In this case, the encrypted media file or media file is not stored in the user terminal 2 after viewing the video work.

[0026] = = = Scope of application of the present invention = = =

The copyright management method of the present invention is not limited to the video work shown in the above embodiment, It can also be applied to still and music works.

Industrial applicability

According to the present invention, a novel digital video content copyright protection method can be realized.

Claims

The scope of the claims

Copyright management method implemented in a configuration in which a media server that distributes digital video content recorded as digital data through a communication network communicates with a user terminal used by viewers of the video product Because

In the process of installing a viewing program that enables the viewing of video works by processing media files on the user terminal, the viewer authentication information is stored in the user terminal and the individual identification of the user terminal is performed. A user information registration step of registering information and the authentication information in association with the media server;

Based on the individual identification information of the user terminal and the stored authentication information, the common key B is generated at the user terminal, and the encryption server license returned to the media server is also returned. A license file decrypting step of decrypting the file into the playback license file using the common key B;

A copyright management method for digital video content, comprising:

[2] The copyright management method according to claim 1,

When playback of the video work is completed on the user terminal, the decrypted media file is stored, and the playback permission file is updated by reflecting the playback opportunity in the viewing restriction information in the playback permission file. Including a license file update step of generating and storing a subsequent playback license file in a cryptographic key license file with the common key B, and in the license file decrypting step, the user terminal stores the cryptographic key stored in itself. Decrypt the license file into a playback license file,

In the video product playback step, if the user terminal confirms the playback permission of the video product based on the viewing restriction information described in the playback license file obtained by decrypting the encryption license file, the user terminal stores it. Processed media files that can be played and played back video images for viewing.

A copyright management method for digital video content.

[3] The copyright management method according to claim 2, wherein a scramble method of the media file is specified as the viewing restriction information in the reproduction permission file and the decoded reproduction is performed in the video work reproduction step. If playback of the video work is not permitted based on the viewing restriction information contained in the license file, includes the process of encrypting the media file stored in the user terminal based on the specified scramble method. A copyright management method for digital video content characterized by that.

[4] The copyright management method according to claim 2, wherein the video work playback step is instructed to delete a media file as viewing restriction information in the playback permission file. In addition, if playback of the video work is not permitted based on the viewing restriction information included in the decrypted playback permission file, the digital file is characterized in that the media file stored in the user terminal is deleted. Copyright management method for video content.