JP2008187421A - Digital content distribution system, copyright protection method, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a digital content distribution system, a copyright protection method and a program for flexibly changing a different copyright protection policy for every content to be provided to a service. <P>SOLUTION: This distribution device distributes encrypted digital content including a copyright protection program, and performs mutual authentication between the copyright protection program received by the reception device and a cooperated media player. Then, the reception device decodes the received encrypted digital content by using the copyright program, and reproduces the decoded digital content by a media player. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a digital content distribution system, a copyright protection method, and a program provided for a digital content distribution service.

  In recent years, with the rapid spread of network technology, general users can easily obtain data related to various copyrighted works such as image data, audio information data, and character data via the network. . In addition, the author of a copyrighted work can easily publish his own copyrighted work without going through a publisher or broadcast media, for example, by publishing his / her copyrighted work on a network. In this way, by distributing a copyrighted work using a network as a medium, a user can obtain a desired copyrighted work without any geographical or temporal handicap. The work can be announced without the need for funds.

On the other hand, considering the current state of the content distribution service as described above, it is necessary to encrypt and distribute the content in order to prevent unauthorized distribution of content that is performed regardless of the intention of the copyright holder. Therefore, a copyright management program is incorporated in many media players in existing receiving terminals for such purposes (see, for example, Patent Document 1).
JP 2002-359616 A

  However, the above-described conventional technique has a problem that the media player needs to be modified when the copyright protection policy is changed in the method of incorporating the copyright management program into the media player. For this reason, the change in the copyright protection policy imposes a burden on the user not only on the service provider who modifies the media player but also on the user, such as updating the program. In general, since the copyright protection policy is different for each service, there is a problem that it is necessary to use a plurality of media players depending on the service.

  Accordingly, the present invention has been made in view of the above-described problems, and provides a digital content distribution system, a copyright protection method, and a program capable of flexibly changing different copyright protection policies for each content provided for a service. The purpose is to do.

The present invention proposes the following items in order to solve the above-described problems.
(1) The present invention provides a distribution device for distributing encrypted digital content (for example, equivalent to the broadcasting station 100 in FIG. 1) and a reception device for receiving and reproducing the distributed digital content (for example, FIG. Digital content distribution system comprising: a digital content distribution system, wherein the distribution device distributes the encrypted digital content including a copyright protection program. Has proposed.

According to the present invention, the distribution device distributes the encrypted digital content including the copyright protection program. Therefore, unlike a method of incorporating a copyright management program into a conventional media player, a different copyright protection policy can be flexibly changed for each content provided for a service.

  (2) The present invention relates to the digital content distribution system of (1), wherein the receiving device decrypts the received digital content (for example, corresponding to the content combining unit 203 in FIG. 3), A media player (for example, equivalent to the media player 210 of FIG. 3) for reproducing the decrypted digital content is provided, and interface means (for example, FIG. 3) for the media player to perform mutual authentication with the copyright protection program. 3 is equivalent to the interface unit 211 of the third embodiment).

  According to the present invention, the receiving device includes the decrypting means for decrypting the received digital content and the media player for playing back the decrypted digital content, and the media player performs mutual authentication with the copyright protection program. Interface means for performing are provided. Therefore, by performing mutual authentication between the media player and the copyright protection program, unauthorized use or impersonation of the copyright protection program can be accurately prevented.

  (3) In the digital content distribution system according to (1) or (2), the digital content is terrestrial digital broadcast content, and the receiving device is a mobile communication terminal. A distribution system is proposed.

  According to this invention, the digital content is terrestrial digital broadcast content, and the receiving device is a mobile communication terminal. Therefore, the technology of the present invention can be applied to mobile terminal digital broadcasts, which are so-called one-segment broadcasts, which are currently being spread by terrestrial digital broadcasts.

  (4) The present invention proposes a digital content distribution system according to (1) to (3), wherein the copyright protection program is configured in plain text and has tamper resistance. is doing.

  According to this invention, the copyright protection program is composed of plaintext and has tamper resistance. Accordingly, since the copyright protection program is distributed in plain text, the processing load such as decryption processing is reduced. In addition, since the copyright protection program is distributed in plain text, the program is made tamper-resistant by obfuscation of the program and anti-debugger.

  (5) The present invention is a copyright protection method in a digital content distribution system comprising a distribution device that distributes encrypted digital content and a reception device that receives and reproduces the distributed digital content, The distribution apparatus performs mutual authentication between the first step of distributing the encrypted digital content including a copyright protection program, and the copyright protection program received by the reception apparatus and the built-in media player. A second step of performing, a third step of decrypting the encrypted digital content received by the receiving device using a copyright protection program, and reproducing the decrypted digital content by the media player A copyright protection method characterized by comprising a fourth step is proposed.

  According to the present invention, the distribution device distributes the encrypted digital content including the copyright protection program, and performs mutual authentication between the copyright protection program received by the reception device and the built-in media player. Then, the receiving device decrypts the received encrypted digital content using the copyright protection program, and reproduces the decrypted digital content by the media player. Therefore, since the distribution device distributes the encrypted digital content including the copyright protection program, different copyright protection policies can be flexibly changed for each content provided for the service. Further, since mutual authentication is performed between the copyright protection program and the built-in media player, unauthorized use of the copyright protection program and impersonation can be prevented accurately.

(6) The present invention executes on a computer a copyright protection method in a digital content distribution system that includes a distribution device that distributes encrypted digital content and a reception device that receives and reproduces the distributed digital content. A program for
The distribution apparatus performs mutual authentication between the first step of distributing the encrypted digital content including a copyright protection program, and the copyright protection program received by the reception apparatus and the built-in media player. A second step of performing, a third step of decrypting the encrypted digital content received by the receiving device using a copyright protection program, and reproducing the decrypted digital content by the media player A program for causing a computer to execute the fourth step is proposed.

  According to the present invention, the distribution device distributes the encrypted digital content including the copyright protection program, and performs mutual authentication between the copyright protection program received by the reception device and the built-in media player. Then, the receiving device decrypts the received encrypted digital content using the copyright protection program, and reproduces the decrypted digital content by the media player. Therefore, since the distribution device distributes the encrypted digital content including the copyright protection program, different copyright protection policies can be flexibly changed for each content provided for the service. Further, since mutual authentication is performed between the copyright protection program and the built-in media player, unauthorized use of the copyright protection program and impersonation can be prevented accurately.

  According to the present invention, the service provider can design and implement the media player and the copyright protection program independently, and the copyright protection system can be flexibly changed for each content. In addition, there is also an effect that the user does not need to update the media player in accordance with the change of the copyright protection policy, or to properly use the player according to the service.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
Note that the constituent elements in the present embodiment can be appropriately replaced with existing constituent elements and the like, and various variations including combinations with other existing constituent elements are possible. Therefore, the description of the present embodiment does not limit the contents of the invention described in the claims.

<Configuration of digital content distribution system>
A digital content distribution system according to this embodiment will be described with reference to FIG.
In the present embodiment, an explanation will be given by taking an example of so-called one-segment broadcasting in which the distribution side is a broadcasting station, the reception side is a mobile terminal, and the distributed digital content is terrestrial digital broadcast content.

  As shown in FIG. 1, the digital content distribution system according to the present embodiment includes a broadcasting station 100, a portable terminal 200, a management server 300, and a network 400. The broadcast station 100 distributes broadcast waves including a copyright protection program to encrypted digital content for terrestrial digital broadcasting to the mobile terminal 200.

  The portable terminal 200 is a portable terminal having a communication function and a broadcast wave receiving function, and reproduces received digital content. The management server 300 manages the content key, and delivers the content key via the network 400 in response to a request from the mobile terminal 200. Further, billing processing is executed as necessary.

<Broadcasting station configuration>
Next, the configuration of the broadcasting station will be described with reference to FIG.
As shown in FIG. 2, the broadcasting station according to the present embodiment includes a key management unit 101, a content database 102, a content encryption unit 103, a synthesis unit 104, a copyright protection program management unit 105, and content transmission. Part 106.

  The key management unit 101 manages a key for encrypting terrestrial digital broadcast digital content. The content database 102 is a database that stores and stores digital content for terrestrial digital broadcasting distributed to the mobile terminal 200.

  The content encryption unit 103 encrypts the digital content for terrestrial digital broadcasting stored in the content database 102 and distributed to the mobile terminal 200 with the encryption key managed by the key management unit 101.

  The combining unit 104 generates data to be distributed by combining the digital content for digital terrestrial broadcasting encrypted by the content encryption unit 103 and a copyright protection program described later. The copyright protection program management unit 105 manages different copyright protection programs for each content. In addition, the content transmission unit 106 distributes the distribution data generated by the combining unit 104 to the mobile terminal 200. Although the copyright protection program is composed of plain text, it has tamper resistance through techniques such as obfuscation of the program and anti-debugger.

<Configuration of mobile terminal>
Next, the configuration of the mobile terminal will be described with reference to FIG.
As shown in FIG. 3, the portable terminal according to the present embodiment includes a content receiving unit 201, a copyright protection program storage unit 202, a content storage unit 203, a content decryption unit 204, and a media player 210. In addition, the media player 210 includes an interface unit 211 and a content playback unit 212.

  The content receiving unit 201 receives encrypted digital content for digital terrestrial broadcasting including a copyright protection program distributed from the broadcasting station 100. The copyright protection program storage unit 202 extracts the copyright protection program from the data received by the content reception unit 201 and temporarily stores it.

  The content storage unit 203 extracts digital content for terrestrial digital broadcasting from the data received by the content reception unit 201 and temporarily stores it. The content decryption unit 204 obtains a content key via a copyright protection program and decrypts the encrypted digital content for digital terrestrial broadcasting.

  The media player 210 has a content reproduction unit 212, and thereby reproduces the decrypted digital content for digital terrestrial broadcasting. In addition, an interface unit 211 is provided to perform mutual authentication with the copyright protection program. That is, the media player 210 in this embodiment does not have a copyright protection function, and uses the interface unit 211 as described above in order to prevent unauthorized use or impersonation of the copyright protection program. Mutual authentication between the media player 210 and the copyright protection program is executed.

<Processing of digital content distribution system>
Next, processing of the digital content distribution system according to the present embodiment will be described with reference to FIG.
First, the broadcasting station 100 extracts digital content for terrestrial digital broadcasting to be distributed from the content database 102, and performs encryption processing by the content encryption unit 103 using the key from the key management unit 101. The encrypted digital content for terrestrial digital broadcasting is synthesized with a copyright protection program corresponding to the content managed by the copyright protection program management unit 105 in the synthesis unit 104 and distributed from the content transmission unit 106 to the portable terminal 200. (Step S101).

  On the other hand, the content receiving unit 200 of the portable terminal 200 receives the encrypted digital content for digital terrestrial broadcasting including the copyright protection program from the broadcasting station, and the copyright protection program is written out of the received digital content. Temporarily stored in the right protection program storage unit 202 and encrypted digital content for digital terrestrial broadcasting is temporarily stored in the content storage unit 203. The copyright protection program temporarily stored in the copyright protection program storage unit 202 performs mutual authentication via the media player 210 and the interface unit 211 (step S102). As a result, unauthorized use or impersonation of the copyright protection program can be prevented.

  Next, the copyright protection program downloads the content key from the management server 300, and the content decrypting unit 204 decrypts the encrypted digital content for digital terrestrial broadcasting using the acquired content key (step S103). ). Then, the decrypted digital content for terrestrial digital broadcasting is input to the content reproduction unit in the media player 210, and the digital content for terrestrial digital broadcast is reproduced (step S104).

  Therefore, according to the present embodiment, since the broadcasting station 100 distributes the encrypted digital content including the copyright protection program, a different copyright protection policy can be flexibly applied to each content provided for the service. Can change.

  Each process of the digital content distribution system is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read into the digital content distribution system and executed, thereby executing the digital content distribution system of the present invention. Can be realized. The computer system here includes an OS and hardware such as peripheral devices.

  Further, the “computer system” includes a homepage providing environment (or display environment) if a WWW (World Wide Web) system is used. The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line.

  The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes a design and the like within a scope not departing from the gist of the present invention. For example, in the present embodiment, one-segment broadcasting has been described as an example. However, the present invention is not limited to this, and can be applied to a digital content distribution system that is distributed from a server via a network.

It is a block diagram of the digital content delivery system which concerns on this embodiment. It is a block diagram of the broadcasting station which concerns on this embodiment. It is a block diagram of the portable terminal which concerns on this embodiment. It is a processing flow of the digital content delivery system which concerns on this embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 100 ... Broadcast station, 101 ... Key management part, 102 ... Content database, 103 ... Content encryption part, 104 ... Composition part, 105 ... Copyright protection program management part, 106・ ・ ・ Content transmission unit, 200... Portable terminal, 201... Content reception unit, 202... Copyright protection program storage unit, 203... Content storage unit, 204. 210 ... Media player 211 ... Interface unit 212 ... Content playback unit 300 ... Management server 400 ... Network

Claims (6)

A digital content distribution system comprising a distribution device that distributes encrypted digital content and a reception device that receives and reproduces the distributed digital content,
The digital content distribution system, wherein the distribution device distributes the encrypted digital content including a copyright protection program. The receiving device is
Decryption means for decrypting the received digital content;
A media player for playing back the decrypted digital content;
2. The digital content distribution system according to claim 1, further comprising an interface unit for the media player to perform mutual authentication with the copyright protection program.   The digital content distribution system according to claim 1 or 2, wherein the digital content is terrestrial digital broadcast content, and the receiving device is a mobile communication terminal.   The digital content distribution system according to any one of claims 1 to 3, wherein the copyright protection program is configured in plain text and has tamper resistance. A copyright protection method in a digital content distribution system comprising a distribution device that distributes encrypted digital content and a reception device that receives and reproduces the distributed digital content,
A first step in which the distribution device distributes the encrypted digital content including a copyright protection program;
A second step of performing mutual authentication between the copyright protection program received by the receiving device and the built-in media player;
A third step in which the receiving device decrypts the received encrypted digital content using a copyright protection program;
A fourth step of reproducing the decrypted digital content by the media player;
A copyright protection method characterized by comprising: A program for causing a computer to execute a copyright protection method in a digital content distribution system including a distribution device that distributes encrypted digital content and a reception device that receives and reproduces the distributed digital content. ,
A first step in which the distribution device distributes the encrypted digital content including a copyright protection program;
A second step of performing mutual authentication between the copyright protection program received by the receiving device and the built-in media player;
A third step in which the receiving device decrypts the received encrypted digital content using a copyright protection program;
A fourth step of reproducing the decrypted digital content by the media player;
A program that causes a computer to execute.

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