JP2006295650A - Contents delivery device and its method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a contents delivery device and its method in which a network load brought about by contents download is reduced and besides contents introductions are furthered. <P>SOLUTION: A contents delivery server 20 includes a receiving section 21 for receiving contents buying notification transmitted from a second user terminal which has received contents from a first user terminal and a first meta data containing information on the first user terminal, a first producing section 24 for producing a second meta data containing information on the second user terminal from the information on the second user terminal and first meta data, a second producing section 24 for producing a decrypting key for the contents, and a transmitting section 22 for transmitting the second meta data and the decrypting key to the user terminals. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a content distribution apparatus and a content distribution method.

  Conventionally, content data such as audio and video has been downloaded via the Internet or the like. At this time, a privilege is also given to the user who introduced the content data.

For example, a technology in which an introduction source terminal device transmits introduction data (introduction mail) of content data to an introduction destination terminal device, and a server device gives a privilege to a user who introduced content data (see, for example, Patent Document 1). In addition, the content distribution device manages the user who promotes the download of content as a leading group, and gives a privilege to the users included in the leading group when the number of content downloads exceeds a predetermined number (for example, , See Patent Document 2). Etc. are disclosed.
JP 2002-31274 A JP 2002-207915 A

  However, in the above-described prior art, since content is downloaded via the Internet or the like, there is a problem that a load on the network is applied.

  SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a content distribution apparatus and a content distribution method that reduce the network load associated with content data download and promote the introduction of content data.

  In order to achieve the above object, a first feature of the present invention is a content distribution device that distributes a decryption key for decrypting content data, and (a) a second that receives content data from a first user terminal A receiving unit for receiving a purchase notification of content data and first metadata including information on the first user terminal transmitted from the user terminal; (b) information on the second user terminal; A first generation unit that generates second metadata including information on the second user terminal from one metadata, and (c) a second generation unit that generates a decryption key for the content data; (D) The gist of the present invention is that the content distribution apparatus includes a transmission unit that transmits the second metadata and the decryption key to the user terminal.

  According to the content distribution apparatus according to the first feature, the metadata including the introducer information and the content data itself are transferred between users, thereby reducing the network load associated with the download of the content data and introducing the content data. Can be promoted.

  The receiving unit of the content distribution device according to the first feature further includes an authentication unit that receives a signature from the second user terminal and authenticates the signature, and the first generation unit and the second generation unit include: When the signature is valid by the authentication unit, the second metadata and the decryption key may be generated.

  According to this content distribution apparatus, since the decryption key is generated only when the user terminal is a valid terminal, only the valid user terminal can reproduce the content data.

  The content distribution apparatus according to the first feature further includes an analysis unit that analyzes the first metadata and acquires information about the first user terminal included in the first metadata, and the analysis unit includes: You may give a privilege to a 1st user terminal.

  According to this content distribution apparatus, by analyzing the metadata, the relationship between the user terminals can be grasped, and appropriate privileges can be given to the user terminals.

  A second feature of the present invention is a content distribution method for distributing a decryption key for decrypting content data, wherein (a) the content data is transmitted from a second user terminal that has received the first user terminal. Receiving a purchase notification of content data and first metadata including information on the first user terminal; and (b) receiving information on the second user terminal and the first metadata. Generating second metadata including information on the second user terminal, (c) generating a decryption key for the content data, and (d) transmitting the second metadata and the decryption key to the user terminal. And a content distribution method including the step of performing.

  According to the content distribution method according to the second feature, the metadata including the introducer information and the content data itself are transferred between users, thereby reducing the network load associated with the download of the content data and introducing the content data. Can be promoted.

  According to the present invention, it is possible to provide a content distribution apparatus and a content distribution method that reduce the load on the network associated with the download of content data and promote the introduction of content data.

  Next, embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic.

(Content distribution server)
In the present embodiment, content data that is exchanged between user terminals in encrypted content data such as music, video, and updater files and that decrypts the encrypted content is distributed on the Internet. A system acquired from a server (content distribution device) will be described. Here, examples of the user terminal include portable devices such as a mobile phone, a notebook computer, and a PHS.

  As shown in FIG. 1, the content distribution server (content distribution device) 20 according to the present embodiment includes a reception unit 21, a transmission unit 22, an authentication unit 23, a generation unit 24, a storage unit 25, and an analysis. Part 26.

  Here, it is assumed that the user terminal 10 (second user terminal) has acquired encrypted content data from another user terminal (first user terminal).

  The receiving unit 21 includes first metadata and a user terminal that are transmitted from the user terminal 10 (second user terminal) and include content data purchase notifications and other user terminals (first user terminals). 10 signatures are received. The metadata may include billing information in addition to the content ID and distribution path information.

  The authentication unit 23 authenticates the signature of the user terminal 10 (second user terminal).

  When the authentication unit 23 determines that the signature is valid, the generation unit 24 uses the information related to the user terminal 10 (second user terminal) and the first metadata to generate another user terminal (second user terminal). Second metadata including information on the user terminal is generated. In addition, the generation unit 24 generates a decryption key for the content data when the authentication unit 23 determines that the signature is valid. Further, the generation unit 24 generates a signature for the hash value for the content data and metadata.

  The storage unit 25 holds first metadata, second metadata, a signature, and the like. The storage unit 25 may be an internal storage device such as a RAM or an external storage device such as an HD.

  The transmission unit 22 transmits the second metadata and the decryption key to the user terminal 10 (second user terminal).

  The analysis unit 26 analyzes the first metadata and obtains information related to another user terminal (first user terminal) included in the first metadata. Moreover, the analysis part 26 gives a privilege to another user terminal (1st user terminal). Here, the privilege includes, for example, giving a user terminal a point for discounting a call charge.

  The user terminal 10 that has received the decryption key can decrypt the content data and reproduce the content data.

Although not shown, the content distribution server 20 may include a program holding unit that stores an execution program for causing the central processing unit (CPU) to execute authentication processing, generation processing, analysis processing, and the like. Examples of the program holding unit include a RAM, a hard disk, a flexible disk, a compact disk, an IC chip, and a cassette tape. According to the recording medium holding such a program, the program can be easily stored, transported, sold, etc.
Next, the content distribution method according to the present embodiment will be described with reference to FIGS. Here, as shown in FIG. 3, it is assumed that the user terminal 10a possessed by the user A downloads the encrypted content data from the content distribution server 20, and transmits the content data to the user terminal 10b possessed by the user B. Furthermore, the user terminal 10b transmits content data to the user terminal 10c of the user C.

  Note that content data is downloaded from the content distribution server 20 to the user terminal 10a via a network such as broadband, a mobile communication network, or the Internet. First, it is performed via a wireless LAN, a USB cable, a memory card, or the like.

  First, the user terminal 10 a downloads content data from the content distribution server 20. At this time, the signature created using the metadata and the hash value is also downloaded. At this time, the metadata includes information indicating that the downloaded user is the user A and the introduction is also the user A. Then, a signature 'that is the signature of the user terminal 10a is generated.

  Next, the user terminal 10b receives content data from the user terminal 10a. When the user B desires to purchase content data, the user terminal 10b operates according to the flowchart shown in FIG.

  That is, first, in step S101, the user terminal 10b acquires content data. Next, in step S <b> 102, the user terminal 10 b transmits a purchase notification, metadata, and signature to the content distribution server 20.

  Next, in step S103, the content distribution server 20 authenticates the signature of the user terminal 10b. If the signature is valid, the process proceeds to step S104.

  Next, in step S104, the content distribution server 20 generates metadata and a signature. In step S105, the content distribution server 20 stores the metadata and the signature.

  Next, in step S106, the content distribution server 20 transmits metadata and a signature to the user terminal 10b. In step S107, the user terminal 10b acquires metadata and a signature. At this time, the metadata includes information indicating that the downloaded user is user A and the introduced user is user B, as shown in FIG.

  Next, in step S108, the content distribution server 20 generates a decryption key for decrypting the content data, and transmits it to the user terminal 10b. In step S109, the user terminal 10b acquires a decryption key.

  Next, in step S110, the user terminal 10b decrypts the content data encrypted using the decryption key, and reproduces the content data.

  Although the user terminal 10b has been described here, the same operation is performed in the user terminal 10c. The metadata of the user terminal 10c includes information indicating that the downloaded user is the user A and the introduced user is the user C.

(Content delivery method = Relay =)
Next, the content distribution method according to the present embodiment will be described with reference to FIGS. Here, as shown in FIG. 5, it is assumed that the user terminal 10a possessed by the user A downloads the encrypted content data from the content distribution server 20, and transmits the content data to the user terminal 10b possessed by the user B. Furthermore, the user terminal 10b transmits content data to the user terminal 10c of the user C.

  First, the user terminal 10 a downloads content data from the content distribution server 20. At this time, the signature created using the metadata and the hash value is also downloaded. At this time, the metadata includes information indicating that the downloaded user is the user A and the introduction is also the user A. Then, a signature 'that is the signature of the user terminal 10a is generated.

  Next, the user terminal 10b receives content data from the user terminal 10a. When the user B does not desire to purchase the content data and simply relays the content data, the user terminal 10b operates according to the flowchart shown in FIG.

  That is, first, in step S201, the user terminal 10b acquires content data. Next, in step S <b> 202, the user terminal 10 b transmits a relay notification, metadata, and signature to the content distribution server 20.

  Next, in step S203, the content distribution server 20 authenticates the signature of the user terminal 10b. If the signature is valid, the process proceeds to step S204.

  Next, in step S204, the content distribution server 20 generates metadata and a signature. In step S205, the content distribution server 20 stores the metadata and the signature.

  Next, in step S206, the content distribution server 20 transmits metadata and a signature to the user terminal 10b. In step S107, the user terminal 10b acquires metadata and a signature. At this time, the metadata includes information indicating that the downloaded user is user A and the introduced user is user B, as shown in FIG.

  Although the user terminal 10b has been described here, the same operation is performed in the user terminal 10c. The metadata of the user terminal 10c includes information indicating that the downloaded user is the user A and the introduced user is the user C.

(Content delivery method = privilege grant =)
Next, the content distribution method according to the present embodiment will be described with reference to FIGS. Here, as shown in FIG. 7, since the user A (user terminal 10a) has downloaded the content data from the content distribution server 20, a privilege (value) is given to the user A (user terminal 10a) (FIG. 7). 7 arrow A).

  Further, since user A (user terminal 10a) is an introducer and user B (user terminal 10b) purchases content data, a privilege (value) is given to user A (user terminal 10a) (FIG. 7). Arrow B). The operation of the content distribution server 20 when granting this privilege will be described with reference to FIG.

  First, in step S <b> 301, the content distribution server 20 receives a purchase notification, metadata, and signature from the user terminal 10.

  In step S302, the content distribution server 20 verifies whether the signature of the user terminal 10 is valid. If the signature is valid, the content distribution server 20 proceeds to step S303.

  Next, in step S303, the content distribution server 20 analyzes the metadata. For example, the identification information of the downloaded user and the identification information of the user who became the introducer included in the metadata are acquired. Here, the metadata includes information indicating that the downloaded user is user A and the introduced user is also user A.

  Next, in step S304, the content distribution server 20 returns the value to the downloaded user (or the user terminal) and the user who became the introducer (or the user terminal). Here, a privilege (value) is given to the user A (user terminal 10a) that has been downloaded and introduced (arrow B in FIG. 7).

  Further, as shown in FIG. 7, the same operation as described above is performed when the user C and the user D purchase the content. That is, when the purchase notification is received from the user terminal owned by the user C or the user D, the content distribution server 20 performs the operation shown in FIG. At this time, the metadata includes information indicating that the downloaded user is the user A and the introduced user is the user B. For this reason, privilege (value) is provided with respect to the introducer's user B (user terminal 10b) (arrow C of FIG. 7). Further, a privilege (value) is also given to the user A (user terminal 10a) who has performed the download (arrow D in FIG. 7).

(Action and effect)
According to the content distribution server 20 and the content distribution method according to the present embodiment, the metadata including the introducer information and the content itself are transferred between users, thereby reducing the load on the network associated with the content download and the content data. Can be promoted.

  The content distribution server 20 includes an authentication unit 23 that receives a signature from the user terminal and authenticates the signature. The generation unit 24 generates metadata and a decryption key when the authentication unit 23 authenticates the signature. can do. For this reason, since the decryption key is generated only when the user terminal is a legitimate terminal, only the legitimate user terminal can reproduce the content data.

  The content distribution server 20 further includes an analysis unit 26 that analyzes metadata and acquires information about the user terminal 10 included in the metadata, and the analysis unit 26 can give a privilege to the user terminal. For this reason, an appropriate privilege can be given to the user terminal 10 by analyzing metadata.

  Further, by analyzing the metadata, it is possible to grasp the relationship between the user terminals 10 and grasp the human relationship of the user having the user terminal 10.

  In addition, since transmission / reception is performed between the user terminals 10 without using broadband or the like, even user terminals that cannot access broadband can acquire content data.

(Other embodiments)
Although the present invention has been described according to the above-described embodiments, it should not be understood that the descriptions and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  For example, in the metadata held in the user terminal 10 c shown in FIG. 3, the introducer is only the user C, but the user B and the user C may be used. Further, only one of the downloader and the introducer may be held as metadata. Furthermore, the number of relayers held as metadata may be limited.

  In FIG. 2, the transmission of metadata + signature '(step S106) and the transmission of the decryption key (step S108) are transmitted at different timings, but they may be distributed simultaneously.

  Further, in the above embodiment, it has been described that the value reduction is performed by directly feeding back to the user. However, the value reduction is performed by transmitting the value information to the user management server that operates the membership system HP. May be performed.

  Further, although the content distribution server 20 according to the above embodiment has been described as generating and transmitting a decryption key, a key management server for generating and transmitting a decryption key may be separately provided.

  Further, it is possible to select not to add metadata to a user (user terminal) who does not desire download information and introducer information.

  The content distribution server 20 can also be configured to set an upper limit for value reduction (point reduction) for the same metadata and not to return points exceeding this upper limit.

  Further, an expiration date may be given to the metadata, and value reduction may not be performed when the expiration date has passed.

  In the above embodiment, the content data is the same, and the metadata + signature changes each time. However, in this case, there is a problem that the metadata + signature can be replaced. In order to prevent such replacement, different pieces of individual information may be embedded in the content data for a certain period or for each download. As described above, since there is a defect in the content data, the hash values are different and the signature cannot be changed. In addition, it is possible to verify whether or not the signature has been changed without using the content data itself to be sent to the content distribution server 20 using information (content ID or the like) for identifying the downloaded content and metadata + signature '. Become.

  As described above, the present invention naturally includes various embodiments not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

It is a block diagram of the content distribution server according to this embodiment. It is a sequence diagram which shows the content delivery method which concerns on this embodiment (the 1). It is a figure for demonstrating the introduction of the content which concerns on this embodiment. It is a sequence diagram which shows the content delivery method which concerns on this embodiment (the 2). It is a figure for demonstrating the relay of the content which concerns on this embodiment. It is a flowchart which shows the content delivery method concerning this embodiment. It is a figure for demonstrating privilege provision of the content which concerns on this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10, 10a, 10b, 10c ... User terminal 20 ... Content distribution server 21 ... Reception part 22 ... Transmission part 23 ... Authentication part 24 ... Generation part 25 ... Storage part 26 ... Analysis part

Claims (4)

A content distribution device that distributes a decryption key for decrypting content data,
Reception of receiving the purchase notification of the content data and the first metadata including information on the first user terminal transmitted from the second user terminal that has received the content data from the first user terminal And
A first generation unit that generates second metadata including information on the second user terminal from the information on the second user terminal and the first metadata;
A second generation unit for generating a decryption key for the content data;
A content distribution apparatus comprising: a transmission unit configured to transmit the second metadata and the decryption key to the user terminal. The receiving unit receives a signature from the second user terminal;
An authentication unit for authenticating the signature;
The first generation unit and the second generation unit generate the second metadata and the decryption key when the signature is valid by the authentication unit. The content distribution apparatus described. An analysis unit that analyzes the first metadata and obtains information about the first user terminal included in the first metadata;
The content distribution apparatus according to claim 1, wherein the analysis unit gives a privilege to the first user terminal. A content delivery method for delivering a decryption key for decrypting content data,
Reception of receiving the purchase notification of the content data and the first metadata including information on the first user terminal transmitted from the second user terminal that has received the content data from the first user terminal And steps to
Generating second metadata including information related to the second user terminal from the information related to the second user terminal and the first metadata;
Generating a decryption key for the content data;
Transmitting the second metadata and the decryption key to the user terminal.

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