JP2002314525A - Content distribution method and content distribution device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] In a content distribution system for freely distributing encrypted content and distributing a content key for decrypting the content for a fee, a distribution cooperator cooperating with the distribution of the encrypted content is provided. There is no mechanism to be rewarded according to the degree of contribution. A distribution cooperator further encrypts encrypted content distributed by a distribution company with a unique cooperator key to create double-encrypted content, and provides the content to a user using various distribution means. The distribution company distributes the cooperator key to the user, and the user obtains the cooperator key and the content key from the distribution company. The content holder evaluates how much the distribution cooperator has cooperated based on the contents of the distribution log of the distribution company, and pays the distribution cooperator a reward according to the degree of contribution.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic distribution method for distributing digital contents using a storage medium or a network, and more particularly, to a bypass distribution method in which a third party supplies contents to a user on behalf of a distribution company, and Regarding the system.

[0002]

2. Description of the Related Art A distributor has content provided from a content holder having digital content such as music, video, images, etc., and distributes the content electronically to a user having a terminal such as a mobile phone or a computer via a network. Content distribution service for distribution to the public.

[0003] The billing method in this service includes a billing method according to the amount of content distributed to the user,
The method is broadly divided into two methods of charging according to the amount (frequency) of use of the content by the user. As a content distribution model for realizing the latter method, a model in which encrypted content is distributed to the user free of charge, and a key for decrypting the content is distributed for a fee is conceivable.

In the latter model, the encrypted content cannot be used by the user as it is, but can be used only by the user who purchased the key for decrypting the encrypted content. Therefore, even if one user makes an electronic copy of the encrypted content and gives it to another user, the problem arises that the other user does not have the key to decrypt it, and that it is used illegally. Absent.

[0005] The latter model has a feature that all users do not need to directly obtain the encrypted content from the distributor, and can obtain the encrypted content from various distribution channels other than the distributor. . Thereby, there is an advantage that the traffic amount of the communication network occupied by the distribution of the encrypted content can be reduced.

[0006]

Since digital content generally has a large data amount, in the conventional distribution model, it takes a long communication time for a user to obtain encrypted content through a communication network prepared by a distribution company. And communication fees are expensive. Therefore, it is conceivable to provide a service in which a third party, a distribution cooperator, can obtain an encrypted content for a user at a shorter time and at a lower cost than a distribution provider, instead of the distribution provider.

[0007] The content providing service provided by the distribution cooperator can be regarded as a part of cooperation for promoting sales of the content from the viewpoint of the content holder. However, since it is performed independently of the distribution service of the distribution company, no matter how much the distribution co-operator contributes to the content distribution, the mechanism that the reward according to the contribution is given from the content holder is based on the conventional technology. Is not considered at all.

An object of the present invention is to provide a system necessary for giving a reward to a distribution cooperator from a content holder according to the contribution degree of the distribution cooperator.

[0009]

[Means for Solving the Problems] The distribution cooperator creates his own cooperator key, and further encrypts the encrypted content distributed by the distributor with the cooperator key to create a double encrypted content. It is provided to the user using various distribution means. The delivery company distributes the cooperator key to the user.

The user can use the content only after decrypting the double-encrypted content into the encrypted content and then decrypting the original content. That is, the user must obtain the cooperator key from the distributor. When the user obtains the cooperator key and the content key from the distributor, a distribution log remains on the distribution server of the distributor. Since it is possible to confirm from the distribution log how much the cooperator key has been distributed, the content holder can accurately evaluate how much the distribution cooperator has contributed to the content distribution business. Then, the distribution cooperator can receive a legitimate reward according to his / her contribution from the content holder.

[0011]

FIG. 1 is a diagram showing the configuration of a system to which the present invention is applied.

The content holder 101 stores music, video,
A person who owns digital contents such as images, and more specifically, a person corresponding to a record company in the case of music contents. The delivery company 102 is the content holder 1
01 is provided by the distribution server 112 to a communication network 107 such as a mobile phone line or the Internet.
Is a person who distributes it electronically to the user 103 through. The user 103 pays a usage fee to the distribution company 102 using the distributed content. The distribution company 102
A payout is paid to the content holder 101 according to the content usage amount of the user 103.

In this system, the content is encrypted in advance by the content holder 101 and distributed in the form of encrypted content 105. For the encrypted content 105, a content key 106 for restoring the encrypted content 105 to the original content is prepared. The encrypted content 105 and the content key 106 are distributed to the user 103 independently of the encrypted content 105.

When the user 103 obtains the encrypted content 105, no content usage fee is charged. The user 103 pays the content usage fee to the distribution company 102 when obtaining the content key 106. In the present system, the user 103 sets the content key 10
6, the encrypted content 105 cannot be used. Therefore, the encrypted content 105 may be delivered to the user 103 through any distribution channel, or the user 103 may freely create a copy and transfer it to another person.

[0015] The distribution cooperator 104 determines that the encrypted content 1 is
05 is a person who conducts a business of distributing the encrypted content 105 to the user 103 on behalf of the distributor 102 by utilizing the feature of being freely distributable.

The digital content has a large data size, and the user 103 needs a long communication time to obtain the digital content through the communication network 107, and the communication fee is high. Therefore, a service is provided in which the distribution cooperator 104 can obtain the encrypted content 105 at a shorter time and at a lower cost for the user 103 than the distribution company 102. In this case, the user 103 selects to obtain the encrypted content 105 via the distribution cooperator 104.

The content holder 101 pays the distribution cooperator 104 who has contributed to the distribution a reward 111 according to the contribution level. What is important here is that since the user 103 purchases the content key 106 from the distribution company 102 and uses the content for the first time, the distribution cooperator 104 only distributes the encrypted content 105 to the user 103, It does not mean that it has completely contributed to content distribution.

In the present system, the content holder 101
Is an appropriate means to evaluate the degree of contribution of the distribution cooperator 104 according to the amount of the content key 106 distributed. Therefore, it is necessary to introduce the following method that can identify the distribution cooperator 104 who has distributed the encrypted content 105 possessed by the user 103 who has purchased the content key 106.

The distribution cooperator 104 is the content holder 1
The encrypted content 105 provided from 01 is further encrypted to create a double encrypted content 108. The double encrypted content 108 can be restored to the encrypted content 105 only by the cooperator key 109 generated uniquely for the distribution cooperator 104.

The distribution cooperator 104 distributes the double encrypted content 108 to the user 103. On the other hand, the cooperator key 109 is distributed by the distributor 102 to the user 103 in the same manner as the content key 106.

Thus, in order for the user 103 who has obtained the double encrypted content 108 to use the content,
Cooperator key 10 corresponding to double encrypted content 108
9 and the content key 106 must be obtained from the distributor 102.

Cooperator key 109 and content key 10
6, the distribution server 11 of the distribution business 102
From the communication log 110 remaining in 2, it is possible to obtain information indicating what content has been distributed from which distribution cooperator 104 and how much content has been used by the user 103.

The content holder 101 is a distributor 1
It is only necessary to evaluate the amount of the reward 111 according to the degree of cooperation of the distribution cooperator 104 using the information of the distribution log 110 disclosed from 02 and pay the reward to the distribution cooperator 104.

In the present embodiment, the user restores the double encrypted content 108 to the encrypted content 105, but the distribution cooperator 104 who has received the cooperator key 109 from the user 103 substitutes for this. Alternatively, a distribution method of passing the restored encrypted content 105 to the user 103 may be adopted.

FIG. 2 is a diagram showing a registration procedure of the distribution cooperator 104 in the distribution company 102.

The content holder 101 generates a content encryption key and a content decryption key, and encrypts the content with the content encryption key to create an encrypted content 105. The content decryption key corresponds to the content key 106 described above (201, 202). Step 20
1, 202 may be performed by the distribution company 102 or another person in place of the content holder 101.

The content holder 101 is a distributor 1
02 is requested to register the content key 106 with the distribution server 112. When the symmetric key algorithm is used for the encryption process, the content key 106 becomes the same as the content encryption key (203).

[0028] The distribution company 102 sets the content key 10
6 is added to the identification number and registered in the distribution server 112.
Thus, the user can access the content key 1 via the communication network.
06 can be purchased (204). The content holder 101 starts to supply the encrypted content 105 (205), but only by having the distribution server 112 of the distributor 102 register the encrypted content 105 like the content key 106 (206). Instead, the encrypted content 105 is also provided to the distribution cooperator 104.

The distribution cooperator 104 obtains the encrypted content 105 cooperating with the distribution from the content holder 101 (207). Further, the distribution cooperator 104 generates a cooperator encryption key for further encrypting the encrypted content 105 and a cooperator decryption key for restoring the encrypted encrypted content 105 (208). Then, the distribution cooperator 104 uses the cooperator encryption key to encrypt the encrypted content 10.
5 to create double encrypted content (20
9). The cooperator decryption key corresponds to the cooperator key 109 described above.

Distribution cooperator 104 requests distribution company 102 to register cooperator key 109 in distribution server 112 (210). When a symmetric key algorithm is used for encryption, the cooperator key 109 is the same as the cooperator encryption key.

The distribution company 102 adds an identification number to the cooperator key 109 and registers it in the distribution server (211).
Thus, the user can enter the cooperator key 109 through the communication network.
Will be available. Here, steps 208 and 209
Means that the distribution company 102 or another person
It may be performed instead of.

FIG. 3 is a flowchart showing an example of a procedure for using the content of the user 103.

The user 103 obtains the double encrypted content 108 through the distribution cooperator 104 (301).
Then, the user 103 sets the double encrypted content 108
The coordinator key 109 used to restore the encrypted content 105 to the encrypted content 105 and the content key 106 used to restore the encrypted content 105 to the content are identified by the identification numbers respectively corresponding to the content provider 106. A request is made for distribution of the cooperator key 109 and the content key 106 (302).

[0034] The distribution company 104 includes a cooperator key 105 and a content key 106 corresponding to the specified identification number.
Is distributed from the distribution server 112 to the user 103 (30
3) Record the fact of distribution in the distribution log (304).
Based on the information of the distribution log, the user 103 is charged a content usage fee (305).

The user 103 obtains the cooperator key 109 and the content key 106 (306), and obtains the cooperator key 10
In step 9, the encrypted content 105 is restored from the double encrypted content 108 (307), and the content is restored from the encrypted content 105 using the content key 106 and used (308).

FIG. 4 is a diagram showing a different example of the content use procedure of the user 103.

[0037] The user 103 has the double encrypted content 1
Cooperator key 1 for restoring 08 to encrypted content 105
The distribution company 102 is requested to distribute the cooperator key 109 using the identification number corresponding to 09 (401). The distribution company 102 distributes the cooperator key 109 corresponding to the specified identification number from the distribution server 112 to the user 103 (402), and records the fact of the distribution in the distribution log (40).
3).

The user 103 enters the acquired cooperator key 10
The cooperator key 109 is presented to the distribution cooperator 104 corresponding to No. 9 (404). The distribution cooperator 104 restores the encrypted content 105 from the double encrypted content 108 with the provided cooperator key 109 (405), and provides the encrypted content 105 to the user 103 (406).

The user 103 obtains the encrypted content (407). Thereafter, the user 103 issues a content key 1 for restoring the content from the encrypted content 105.
The distribution key 102 is requested to distribute the content key 106 using the identification number corresponding to 06 (408).

The distribution company 102 distributes the content key 106 corresponding to the specified identification number from the distribution server 112 to the user 103 (409), and records the fact of the distribution in the distribution log (410). Based on the information of the distribution log, the user 103 is charged a content usage fee (411).

The user 103 obtains the content key 106 (412), and restores and uses the content from the encrypted content 105 using the content key 106 (41).
3). Steps 408 and 409 are the same as steps 401 and 402
May be performed at the time of the exchange between the distribution company and the user in the above.

FIG. 5 is a flowchart showing a procedure in which the content holder 101 pays a reward to the distribution cooperator 104.

The distribution company 102 discloses the contents of the distribution log recorded on the distribution server 112 to the content holder 101 and the distribution cooperator 104 (501). Then, a payout is paid to the content holder 101 of the content corresponding to the content key 106 according to the distribution amount of the content key 106 recorded in the distribution log (502).

The content holder 101 is the distributor 1
A payout is received from 02 (503). Further, the content holder 101 stores the cooperator key 1 recorded in the distribution log.
The distribution amount of 09 is checked (504), the contribution degree of the distribution cooperator 104 corresponding to the cooperator key 109 is evaluated, and a reward corresponding to the contribution degree is paid to the distribution cooperator 104 (505).
The distribution cooperator 104 receives the reward (506).

FIG. 6 is a diagram showing a specific system necessary for the user 103 shown in FIG. 3 to use the content.

The distribution storage medium 601 is a CD-ROM or DVD-RO storing the double encrypted content 108.
M and other storage media. The distribution cooperator 104 sells the distribution storage medium 601, and the user 103 purchases the distribution storage medium 601.

The user 103 is an information processing device 603 such as a personal computer equipped with a distribution storage medium reading device 602 such as a CD-ROM drive or a DVD-ROM drive. The encrypted content 108 can be read. Note that the information processing device 603 has a storage device such as a hard disk, and can store software and various data.

The user content management device 604 includes a key management unit 605 for storing the content key 106 and the cooperator key 109 obtained by the user 103 from the distributor 102, and a content storage unit 606 for storing the encrypted content 105. It is a device to do. It is preferable that the key management unit 605 has a structure with high tamper resistance so that the content of the stored data is not duplicated or falsified. Also,
The content storage means 606 is not necessarily the key management means 6
The information processing device 603 may not be in the same device as the information processing device 603, for example, may be in the storage device in the information processing device 603 described above, or may be in a storage device external to the information processing device 603. The user content management device 604 is connected to the information processing device 603 via the data input / output device 607, and can be accessed from the information processing device 603.

The content use device 612 is used by the user 10
3 encrypts the encrypted content 105, which can be obtained by decrypting the double encrypted content 108, into the content key 106.
It is a device used for decrypting and using. The content use device 612 is used in connection with the user content management device 604.

As a specific example of the content use device 612, a portable content player can be considered. As a specific example of the user content management device 604, a readable / writable memory card using a non-volatile memory such as a flash memory as a storage medium is conceivable. Note that the content use device 612 and the information processing device 603 may be the same device.

The double-encrypted content decrypting means 608 comprises:
In the information processing device 603, the double encrypted content 10
8 with the helper key 109 and the encrypted content 105
Is a means for obtaining The double encrypted content compounding means 608 is installed in the information processing device 603 as software, and is executed as needed.

The double-encrypted content decryption means 608
Is stored in the distribution storage medium 601 together with the double-encrypted content 108 and can be installed from the distribution storage medium reading device 602 to the information processing device 603, which is convenient for the user 103.

[0053] The user 103 sets the double encrypted content 1
To obtain 08, a communication network 610 such as the Internet, broadcasting equipment such as satellite broadcasting, and cable television equipment may be used in addition to the storage medium 601 for distribution. At this time, the user 103 uses the network connection means 609 of the information processing device 603 to connect to the distribution cooperator server 611 via these communication networks 610, and transmits the double encrypted content 108 to be used to the distribution cooperator server 611. Download from Here, the distribution cooperator 104 determines that the double encrypted content decrypting means 608 is also the double encrypted content 1.
It is more convenient for the user 103 if a service that can be downloaded together with the service 08 is provided.

FIG. 7 is a flowchart showing a procedure in which the user 103 uses the content via the distribution storage medium 601.

The distribution cooperator 104 records the double encrypted content 108 and the double encrypted content decrypting means 608 in the storage medium 601 for distribution (701), and the user 103
The distribution storage medium 601 is sold to the company (702). The user 103 purchases the distribution storage medium 601 (703), reads out the double encrypted content decryption means 608 from the distribution storage medium 601 and installs it in the information processing device 603 (704).

The user 103 reads out the double encrypted content 108 desired to be used from the double encrypted content 108 stored in the distribution storage medium 601 (70).
5). Further, the user 103 reads out the read double encrypted content 10 from the cooperator key 109 stored in the key management unit 605 in the user content management device 604.
The cooperator key 109 corresponding to No. 8 is read (706).

The user 103 decrypts the double encrypted content 108 using the read double encrypted content decrypting means 608 and the cooperator key 109 to restore the encrypted content 105 (707). After that, the user 103
Stores the encrypted content 105 in the content storage means 606 in the user content management device 604 (7
08).

When using the contents, the user 10
3 connects the user content management device 604 to the content use device 612 and reads out the content key 106 corresponding to the content to be used from the key management means 605 (709). Thereafter, the user 103 reads out the encrypted content 105 from the content storage means 606 (710).

The user 103 can use the content by decrypting the encrypted content 105 with the content key 106 (711).

The double-encrypted content decryption means 608
Is not recorded in the distribution storage medium 601 and the distribution cooperator 1
04 or communication network 6 sold separately by distribution company 102 or the like.
10 may be distributed.

FIG. 8 is a flowchart showing a procedure in which the user 103 uses the content via the distribution cooperator server 611.

The distribution cooperator 104 registers the double encrypted content 108 and the double encrypted content decryption means 608 in the distribution cooperator server 611 (801).

The user 103 uses the information processing device 603 or the like to connect to the distribution cooperator server 611 via the communication network 610 (802). The distribution cooperator 104 uses the distribution cooperator server 611 to transmit a list of contents that can be distributed via the communication network 610 to the user 10 who has connected to the server.
3 At this time, the distribution cooperator 104 may also provide a service for distributing the double encrypted content decryption means 608 registered in the distribution cooperator server 611 (803).

The user 103 specifies the content to be used in the list, and transmits the content to the distribution cooperating server 611.
(804). Upon receiving the transmission, the distribution cooperator server 611 transmits the double-encrypted content 108 corresponding to the designated content to the user 103 (80
5).

The user 103 receives the transmitted double encrypted content 108 by the information processing device 603 or the like (8
06). On the other hand, the user 103 downloads the double-encrypted content decryption means 608 from the distribution cooperator server 611.
(807), the distribution cooperator server 611
The double encrypted content decrypting means 608 is transmitted to the user 103 who has requested the download (808). User 1
03, the information processing device 603 receives the double encrypted content decryption means 608 (809),
(810).

Thereafter, the user 103 reads the cooperator key 109 corresponding to the downloaded double-encrypted content 108 from the key management means 605 in the user content management device 604 (811).

The user 103 decrypts the double encrypted content 108 using the double encrypted content decrypting means 608 and the cooperator key 109 to restore the encrypted content 105 (812). The encrypted content 105 is stored in the content storage
Is stored (813).

When the user 103 uses the content, the user 103 connects the user content management device 604 to the content usage device 612 and reads out the corresponding content key 106 from the key management means 605 (814). The user 103 reads the encrypted content 105 from the content storage unit 606 (81
5), encrypted content 105 with content key 106
Is used by decrypting (81)
6).

In step 805, the distribution cooperating server 611 can also broadcast-transmit a plurality of double-encrypted contents 108 in time series. At this time, the double-encrypted content 108 corresponding to the content requested by the plurality of users 103 may be transmitted by broadcast, or the double-encrypted content to be distributed by the distribution cooperating server 611 to the user 103. After the information of 108 is notified in advance, the double-encrypted content 108 corresponding to the content of the notification may be broadcast transmitted.

In the latter case, in step 806, the user 103 determines from the data of the plurality of double-encrypted contents 108 broadcast-transmitted,
11 or the double encrypted content 108 reserved by the information processing device 603 may be selected and received.

Further, it is more convenient for the user 103 if the double-encrypted content decryption means 608 is included in the data broadcast-transmitted from the distribution cooperator server 611.

FIG. 9 is a diagram showing a specific system for realizing the procedure for the user 103 to use the content.

The content distribution device 901 is a device for providing the encrypted content 105 to the user 103, and includes a double encrypted content storage unit 902, a double encrypted content decryption unit 608, a data input / output unit 904, and a user interface. 905.

The double encrypted content storage means 902 stores the double encrypted content 108 distributed by the content distribution device 901. Double encrypted content 1 stored in double encrypted content storage means 902
08 is decrypted by the double encrypted content decryption means 608 and provided to the user 103.

The data input / output unit 904 is connected to the user content management device 906. Content distribution device 9
01 can access the key management unit 605 and the content storage unit 606 via the data input / output unit 904.

The user interface 905 is for the user 1
An input device for receiving designation of the content 03 and a display for displaying content information to the user 103 are provided.

Since the content using device 612 has already been described, the description is omitted.

The content distribution device 901 is provided for the user 10
3 to easily obtain the encrypted content 105,
Installed in public places such as stations and shops. It is also conceivable that the information terminal is installed at a station integrally with another information terminal, for example, a ticket service terminal.

FIG. 10 is a flowchart showing a procedure for distributing the encrypted content 105 in the content distribution device 901.

[0107] The user 103
The user content management device 604 storing the cooperator key 109 corresponding to No. 1 is connected to the data input / output unit 904 (1001). The content distribution device 901 displays a list of the contents registered in the double encrypted content storage means 902 on the user interface 905 of the content distribution device 901 itself (1002).

The user 103 selects a desired content from the content list displayed on the user interface 905. As a method of selection, the user 103 can select the target content from the touch panel, input a number assigned to the target content from the keyboard, or the like (1003).

The content distribution device 901 is connected to the user content management device 604 via the data input / output unit 904.
The coordinator key 109 is read from the server (1004). Also,
The content distribution device 901 transmits the double encrypted content 10 designated by the double encrypted content storage unit 902.
8 is read (1005). Content distribution device 901
Decrypts the read double encrypted content 108 by using the read cooperator key 109 and the double encrypted content decrypting means 608 (1006), and restores the restored encrypted content 105 to the user content management device 604.
(1007).

When the user 103 uses the content, the corresponding content key 106 is stored in the distribution company 102
And store it in the key management means 605 (100
8). Thereafter, the user 103 reads out the purchased content key 106 from the key management unit 605 in the user content management device 604 (1009), reads out the encrypted content 105 from the content storage unit 606 (1010), and encrypts it with the content key 106. The content is used by decrypting the content 105 (1011).

FIG. 11 is a diagram for explaining how the content holder or the like creates the encrypted content 105 and the double-encrypted content 108.

Consider a case in which digital content such as music, video, images, etc., to be distributed can sufficiently lose its utility value by only partially encrypting the content.

First, the person who encrypts the content, for example, the content holder 101 divides the content data into a plurality of data blocks (1101). When creating the encrypted content 105, some of the divided blocks are encrypted with the content encryption key (1102).

When creating the double-encrypted content 108, the person who creates the double-encrypted content 108, for example, the distribution cooperator 104, encrypts a part of the divided block with the cooperator encryption key. I do. At this time, a block header 1110 is added to each block.

In the block header 1110, encryption information indicating how the block is encrypted is set. For example, 00 = unencrypted, 01 = encrypted only with content encryption key, 02 = encrypted only with collaborator encryption key, 03 = encrypted with content encryption key and collaborator encryption key, etc. Numerical values expressing the four states in two bits are used as the encryption information in the block header 111.
Set to 0. Here, if the encryption information is 03 throughout the entire content, that is, if no block is created with the content encryption key and the cooperator encryption key, the user 103 will be able to use the content key 106 and the cooperation key. Any one of the user keys 109 can be used first to decrypt the double encrypted content 108 (1
103).

It should be noted that even if the encrypted content 105 and the double-encrypted content 108 are added with content information 1105 such as a content identification number, copyright information, reproduction time, image resolution, compression method, distribution cooperator information, etc. Good.
Before using the content, the user 103 can use the content information 1105 to check the content and usage of the content, which is convenient.

The cooperator key 109 is a decryption key for specifying the distribution cooperator 104. The cooperator key 109 need not always be one prepared for one distribution cooperator 104. For example, one delivery contributor 1
A different cooperator key 109 may be prepared for each of the plurality of encrypted contents 105 distributed by the server 04.

Alternatively, a plurality of encrypted contents 105
May be stored, and a cooperator key 109 may be prepared for one distribution storage medium 601 issued by one distribution cooperator 104. However, it is better to prepare different cooperator keys 19 for a plurality of encrypted contents 105 distributed by one distribution cooperator 104, respectively.
When 1 checks the delivery log of cooperator key 109,
This is convenient because the distribution cooperator 104 can immediately know what the content has been distributed.

[0092]

According to the present invention, a mechanism is realized in which a reward is given from a content holder for a distribution cooperator contributing to content distribution. Further, according to the present invention, since the user cannot use the content without obtaining the cooperator key unique to the distribution cooperator, the content holder can reliably determine whether or not the content is actually used with the cooperation of the distribution cooperator. It can be determined, and the reward amount paid to the distribution cooperator can be properly evaluated.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a system to which the present invention is applied.

FIG. 2 is a diagram showing a registration procedure of a distribution cooperator in a distribution company.

FIG. 3 is a flowchart illustrating an example of a user's content use procedure.

FIG. 4 is a flowchart showing a different example of a user's content use procedure.

FIG. 5 is a flowchart showing a procedure in which a content holder pays a reward to a distribution cooperator.

FIG. 6 is a diagram showing a system for realizing the use of content by a user.

FIG. 7 is a flowchart showing a procedure in which a user uses a content via a distribution storage medium.

FIG. 8 is a flowchart showing a procedure in which a user uses a content via a distribution cooperator server.

FIG. 9 is a diagram showing a system for realizing a user's use of contents in FIG. 4;

FIG. 10 is a flowchart showing a procedure for distributing encrypted content in the content distribution device.

FIG. 11 is a diagram showing an example of a method for creating encrypted content and double-encrypted content.

[Explanation of symbols]

101: content holder, 102: distributor, 10
3 ... User, 104 ... Distributor, 105 ... Encrypted content, 106 ... Content key, 108 ... Double encrypted content, 109 ... Cooperator key, 110 ... Distribution log,
111: reward, 112: distribution server, 601: distribution storage medium, 603: information processing device, 604: user content management device, 605: key management means, 606: content storage means, 608: double encrypted content decryption means , 612... Content utilization device, 901.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 7/167 H04L 9/00 601D 7/173 610 H04N 7/167 Z 640 H04L 9/00 641 (72) Inventor Shinya Iguchi 1099 Ozenji Temple, Aso-ku, Kawasaki City, Kanagawa Prefecture Inside Hitachi, Ltd.System Development Laboratory Co., Ltd. (72) Inventor Akira Kanehira 5-2-1, Josuihonmachi, Kodaira-shi, Tokyo Within Hitachi Semiconductor Company, Ltd. (72) Inventor Motoyasu Kakuda 1099 Ozenji Temple, Aso-ku, Kawasaki City, Kanagawa Prefecture Inside Hitachi, Ltd.System Development Laboratory (72) Inventor Junichi Maruyama 1099, Ozenji Temple, Aso-ku, Kawasaki-shi, Kanagawa Hitachi, Ltd. Office F-term (reference) 5C064 BA01 BA07 BB02 BB07 BC07 BC17 BC18 BC22 BC23 BD0 2 BD08 BD09 CA14 CB01 CC04 5J104 AA16 EA01 EA04 EA16 EA26 MA06 NA02 PA11

Claims (10)

[Claims] 1. A content distribution method performed by a person who receives encrypted content, wherein the encrypted content is double-encrypted using an encryption key, and the double-encrypted content is encrypted. And distributing the decryption key corresponding to the encryption key to a person who uses the content via a person other than a person who has received the encrypted content. 2. The method according to claim 1, wherein the step of distributing stores the double-encrypted content in a storage medium and distributes the storage medium to a person who uses the content. Content delivery method. 3. The content distribution method according to claim 1, wherein, in the distributing step, the doubly encrypted content is distributed to a person who uses the content via a network. 4. In the step of distributing the doubly encrypted content to a person who uses the content, software for decrypting the doubly encrypted content is also distributed. 3. The method according to claim 2, wherein
Or the content distribution method according to claim 3. 5. A content distribution method performed by a person having content, wherein the content is encrypted with a specific encryption key, and a decryption key for decrypting the encrypted content is distributed to a distributor. Distributes the encrypted content to a distribution cooperator, collects information indicating the degree of contribution of the distribution cooperator to the distribution of the encrypted content from the distribution company, and performs the distribution cooperation in accordance with the information. Content distribution method characterized by paying a reward to a user. 6. The method according to claim 1, wherein the person having the content receives information indicating the number of times the decryption key has been distributed from the distribution business, and pays the distribution business in accordance with the number of times. 5. The content distribution method according to item 5. 7. The information indicating the degree of contribution includes: a key for the distribution cooperator to decrypt a double-encrypted content obtained by doubly encrypting the encrypted content; 6. The content distribution method according to claim 5, wherein the number of distributions is a number of distributions to a user of the content. 8. A content distribution method performed by a distribution company, comprising: receiving a decryption key for decrypting encrypted content from a person having the content; Receiving the information indicating the content, and distributing the decryption key and the information indicating the cooperating person to a person who uses the content. 9. Recording that the decryption key and the information indicating the cooperating person are distributed to a person who uses the content, and distributing the recording to a person having the content. Content distribution method described. 10. A user interface for input / output to / from the outside, double encrypted content storage means for storing double encrypted content, and double encryption for decrypting the double encrypted content. And a data input / output unit, read out a specific decryption key from a device connected to the data input / output unit, and encrypt the double-encrypted content with the double encryption. A content distribution device for decrypting encrypted content using content decryption means.