JP2003223569A - Content distribution method, content distribution system, program therefor, and recording medium - Google Patents

Abstract

(57) [Summary] [Problem] Freely copy and redistribute content.
Eliminate the problem of illegal copying, and distribute the legitimate reward to creators. SOLUTION: A management server 100 collects and manages a flat fee from each user 10 in the form of a monthly fee, regardless of the amount of used content, and sends playback software to the user in response to a request from the user. . Also, the management server 1
00 encapsulates the content from the creator 20 and distributes it to the user via the distribution server 200 or the like.
The user installs the playback software 310 in the playback device 300, plays back the content using the playback software, encrypts and retains the playback record, and transmits it to the management server at a predetermined timing or the like. The management server tallies the playback records from each user, creates a rating for each content, and distributes rewards to creators in accordance with the usage amount.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the field of content distribution technology in any format such as Peer-to-Peer, client / server type, electronic mail, package, etc. A content distribution method and system that can be freely redistributed and that does not require a charge process for each distribution of content, its program,
Recording medium

[0002]

2. Description of the Related Art Conventionally, the following two types of methods are mainly known as non-package distribution methods for contents. (1) Copy protection type This is a method in which contents are encrypted by using a unique ID of a reproducing apparatus or a recording medium, and then reproduced only on the reproducing apparatus or the recording medium before being distributed.
In this method, the content distribution device requires copy protection processing and billing processing functions. (2) Super-distribution type This is a system in which super-distribution content that can be played only on a super-distribution machine is created and the super-distribution content can be freely copied. However, the usage record including the personal identification information is periodically transmitted to the management device, and the user is charged for this usage record.

[0003]

The above-mentioned conventional methods have the following problems, respectively. (1) Copy protection type 1. Because of the copy protection function, it is difficult to replace the playback device or transfer it to a portable player to play the music content, which is low in convenience. 2. Since the distribution device requires copy protection and billing functions, Peer-
Distribution on to-peer is difficult. 3. For each content distribution, it is necessary to transmit to each distribution device a credit number and privacy information such as what content to purchase.

(2) Super distribution type 4. The usage fee will determine the amount charged by the user.
There is a need for a technology for safely and periodically communicating with a management device while protecting a usage record from being tampered with by a user. 5. Since the usage record of the user serves as the billing information, the usage record always needs information for identifying an individual, and there is a possibility of leaking information about who used which content, which is a privacy problem.

As described above, in the conventional non-package distribution of contents, the contents are copy-protected to protect the copyright, and backup or private copying cannot be performed. In addition, there is a problem in terms of convenience and privacy because a billing process is required for each download. There is also a problem in distributing content by Peer-to-Peer.

An object of the present invention is that contents can be freely copied and redistributed, that charging processing is not required for each distribution of contents, and that they can coexist with Peer-to-Peer, which is convenient and convenient.
It is to provide a content distribution method, system, etc. that can improve leakage of personal information and can distribute a fair reward to creators who provide content.

[0007]

According to the present invention, contents provided by creators are regarded as shared property, and all contents are unlimited and copy-free. Instead, the user pays a monthly fee regardless of the usage amount of contents. Pay a flat rate with. This improves convenience,
Unauthorized copying is also eliminated. Further, it is possible to save the trouble of inputting a credit card number or the like for each download and alleviate the problem of leakage of personal information due to wiretapping.

[0008] The management server collects and manages a fixed fee from the user and sends the playback software to the user side in response to the user's request. Further, the management server distributes and distributes the content provided by the creator to the user side free of charge. Since the billing process is unnecessary, P
eer-to-Peer, client / server type, e-mail,
Content can be distributed in any format or route, such as a package. The user can also redistribute the distributed content to other users.

On the user side, playback software is installed in the playback device, the content is played back using the playback software, and a content usage record is created for each playback, encrypted and retained. When the accumulated reproduction time becomes equal to or more than the specified value, the content use record is transmitted to the management server at every predetermined time or at the request of the management server, and the content use record up to that point is initialized. By thus encrypting and retaining the content usage record, it is possible to prevent the user from tampering with the usage record. Also, use a disposable key as the encryption key for recording content usage,
If the content usage record is updated every time it is transmitted to the management server, the security of the content usage record can be further enhanced.

The management server totals the content use records sent from each user side and calculates the audience rating for each content. Then, the reward amount for each creator is calculated based on the audience rating for each content and the total deposit amount collected from the user, and distributed to each creator. This allows
Creators can get a fair reward. Further, the management server invalidates suspicious content usage record data such as that the content usage recording data is filtered and the usage frequency of the particular content is abnormally large or the reproduction interval is abnormally short. As a result, it is possible to improve the accuracy of the content usage record aggregation.

In one embodiment, the management server uses the common key K
_The content ID and the content are encrypted with _s , the content is signed with the secret key KR _s of the management server, and the content capsule including the encrypted content and the signature information is distributed. In the distribution of the reproduction software, the common key K _s and the reproduction software ID are shared with the reproduction software by the user's public key KU _a.
(SID) and disposable public key KU ⁿ (n = 0, 1,
2, ...) is sent to the user side.

On the user side, the reproduction software is installed in the reproduction device and used. The reproduction software decrypts the additional encryption information with the user's private key KR _s to obtain K _s , SI
D, KU ⁿ , and the disposable common key K from the KU ⁿ
Generate and hold _D. Then, for the distributed content capsule, the signature of the content capsule is checked using the public key KU _s of the management server, the encrypted content is decrypted with K _s to obtain the content ID and content, and the content is reproduced. , it encrypts the content using the recording to find the appropriate SID using the K _D.

Further, the reproducing software decrypts the content use record encrypted by using the K _s, and the KU
^{The n} is used to encrypt the SID and the content usage record, which is sent to the management server, and the playback function is temporarily locked. Thereafter, the management server receives the public key KU n ^{+ 1} of the next disposable, generates a new K _D from the KU n ^{+ 1,} to resume playback unlock, subsequent content usage by using the K _D Keep records encrypted. The management server is
The disposable private key KR ⁿ is used to decrypt the encrypted SID and content usage record sent from the user side, the SID owner's deposit is checked, and the next disposable public key KU ^{n + 1} , the secret The key KR ^{n + 1} is generated and the KU ^{n + 1} is transmitted to the user side. As a result, the playback service can be prohibited for users who have not paid the fixed amount.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the overall configuration of an embodiment of a content distribution system according to the present invention. In FIG. 1, each user 10 has one or more playback devices 300.
Owns. Here, it is assumed that the users a, b, and c own the playback devices A, B, and C, respectively. Each user 1
0 means membership fee (monthly, etc.) regardless of the amount of content used
Make sure to pay a flat rate. The definition of the user is all people who can view the content. On the other hand, each creator 20 who is a content provider sends the content to the management server 100 and receives a reward from the management server 100.

The management server 100 is the creator list 1
10, member list 120, content usage record 130,
The key storage unit 140 and the like are provided. The management server 100 is
In response to a request from the user 10, a content reproduction program (hereinafter, reproduction software) is transmitted to the reproduction device 300 together with a necessary key and installed. Further, the management server 100 encapsulates the content sent from the creator 20 and sends it to the distribution server 200, and the distribution server 200 receives the content (content capsule).
Is distributed to users. The content can be distributed by any method such as peer-to-peer, client / server type, electronic mail, and package. Also, the user may redistribute the distributed content to other users.

The reproducing apparatus 300 has reproducing software 31 installed (downloaded) from the management server 100.
0, a content usage record 320 in the device, a key storage unit 330 that stores a necessary key, and the like. The playback device 3
At 00, the content is played back using the playback software 310, and the usage record (content usage amount) is transmitted to the management server 100. Playback software 310 of the playback device 300
Encrypts the usage record using a disposable key and holds it, and transmits it to the management server 100 when the reproduction time becomes equal to or longer than a specified value or at regular intervals.

The management server 100 totals the usage records transmitted from the respective reproduction devices 300, calculates the audience rating for each content, and distributes the reward to the creator 20.
Here, the management server 100 filters the usage record transmitted from each reproduction device 300, and uses only the usage record data that has passed through the usage record for aggregation. The details of this will be described later.

FIG. 2 shows an example of the creator list 110 held by the management server 100. The creator list 110 manages a creator ID, a reward amount to be distributed, a content ID, and other necessary information for each creator.

FIG. 3 shows an example of the member list 120 held by the management server 100. The member list 120 is, for each member (user), an ID such as a user ID, a member's last deposit date, and a serial number for identifying downloaded playback software.
(SID) and other necessary information are managed.

FIG. 4 shows an example of the content usage record 130 held by the management server 100. The content usage record 130 in the management server 100 is
It records the cumulative playback time of all members of the content. The content of the content use record 130 is read out at regular intervals, and is initialized every time the audience rating and the reward amount are calculated.

FIG. 5 shows an example of the content usage record 320 held by the playback device 300. The content use record 320 in the playback device 300 records, for each content ID, the cumulative playback time of the content in the playback device (playback software). In addition, the content use record 320 also records the total accumulated reproduction time obtained by summing the accumulated reproduction times of the respective contents in the reproduction apparatus (reproduction software). The content usage record 320 in the playback device 300 is encrypted so that the member cannot tamper with it. The data of the content usage record 320 is initialized each time it is transmitted to the management server 100, such as when the total accumulated reproduction time becomes equal to or longer than a fixed value, or at fixed intervals.

Next, the flow of processing in this content distribution system will be described in detail. The processing is roughly divided into content encapsulation, reproduction software installation, content delivery, content reproduction, audience rating calculation / reward distribution. Hereinafter, these will be described in detail. In this system, the common key method and the public key method are used together, and keys and other symbols are defined as follows. K _s : Common key for content encryption / decryption in common key system _KD : Common key system for use recording encryption / decryption common key KU _s : Public key of public key system management server KR _s : Public key Method management server secret key KU _a : Public key method user (a) public key KR _a : Public key method user (a) secret key KU ⁿ , KR ⁿ : Disposable public key / secret key (n = 0,
1, 2, ...) //: Combination of bit strings Content: Content CID: Content ID SID: ID of playback software IDa: ID of user (a) DATA: Content usage record EP [Key, M]: Key by public key method Encryption of plaintext M by Key DP [Key, M]: Decryption of ciphertext M by key Key by public key method EC [Key, M]: Encryption DC [Key, M] of plaintext M by key Key by common key method M]: Decryption of ciphertext M with key Key by common key method

Here, the disposable public key / private key K
U ⁿ and KR ⁿ are KU ⁰ and KR ⁰ at ^first , and KU ¹ , KR ¹ , KU ² , and K each time a usage record is transmitted and received.
It is a key that is updated as R ² , ... In the key storage unit 140 of the management server 100, for each installed playback software,
Each KR ⁿ is saved. The key storing unit 330 of the playback device 300 has been sent from the management server 100 KU ⁿ
Is saved. As described later, in the present embodiment, the reproduction apparatus 300 generates a common key K _D for use recording encryption / decryption from the KU ^n.

[Encapsulation of Content] FIG.
Processing flow of content encapsulation in the server 100
-An example of a chart is shown. In the management server 100,
When content is received from Eta 20 (step 10
01) to generate an ID (CID) of the content (step
1002), the key K stored in the key storage unit 140
_sContent ID (CID), content (C
encryption) (step 1003). Dark
Encoded content fEC (K_s, CID // Content
Represented by t). Next, it is held in the key storage unit 140.
Key KR_sTo sign (step 1004). Signature is EP
[KR _s, EC [K_s, CID // Content]]
Represented. It is illegal to sign the management server 100
Proved that the content ID has not been rewritten to
This is because

Next, the management server 100 creates a content capsule by combining the encrypted content and the signature (step 1005), and sends the content capsule to the distribution server 200 (step 1006). Then, the corresponding content ID is added to the creator in the creator list 110 (FIG. 2) (step 100).
7).

[Distribution of Content] Distribution Server 200
Distributes / delivers the content capsule received from the management server 100 to the user side. As described above, content distribution / distribution can be performed by any method such as peer-to-peer, client / server type, or electronic server.
Also, the user may redistribute it to other users. In addition,
The management server 100 may also have the function of the distribution server 200.

[Installation of Playback Software] When viewing the content, the user (member) 10 needs to download and install the playback software from the management server 100 for each playback device 300 in advance. this is,
The process is started by the user side (referred to as a reproduction device) transmitting a reproduction software delivery request to the management server 100. here,
The user ID and the user public key KU are included in the playback software sending request.
It is assumed that _a is included. The user ID and KU _a may be separately notified to the management server 100.

FIG. 7 shows an example of a processing flowchart of the management server 100 when the reproduction software is installed. In the management server 100, when the reproduction software sending request is received from the reproduction device 300 (the device of the user a) (step 2).
001), after confirming the members, an ID (SID) such as a serial number for identifying the playback software is generated (step 2).
002), and further disposable public / private keys KU ⁰ , KR
⁰ is generated (step 2003). Next, using KU _a included in the playback software delivery request, K _s , SID,
KU ⁰ is encrypted (step 2004). Where K
_s , SID, and KU ⁰ are referred to as additional information. The encryption additional information is represented by EP [KU _a , K _s // SID // KU ⁰ ].

The management server 100 reproduces the reproduction software, the encryption additional information, and the public key KU _s of the management server.
00 (step 2005). Where K _s ,
The reason why the SID and KU ⁰ are encrypted and transmitted is that if any one of them is eavesdropped, it is possible to illegally decrypt the content capsule, falsify the usage record, and impersonate. In addition, transmitting the SID assumes that the user owns a plurality of playback devices / playback software.

In the management server 100, thereafter, the SID is added to the member (user) in the member list 120 (FIG. 3) (step 2006), and the key storage unit 140 is further stored with K.
Register U _a , KU ⁰ , and KR ⁰ (step 200)
7).

FIG. 8 is an example of a processing flowchart on the reproducing apparatus 300 side when the reproducing software is installed. The playback device 300 sends a playback software delivery request to the management server 100 (step 2011), and waits for the playback software to be delivered from the management server 100. And the management server 1
When the reproduction software, the encryption additional information, and the management server public key KU _s are received from 00 (step 2012), first, the encryption additional information is decrypted using the user secret key KR _a held in the key storage unit 330, that is, , DP [KR _a ,
Perform EP [KU _a , K _s // SID // KU ⁰ ]],
Obtain K _s , SID, and KU ⁰ (step 201)
3). Next, the used record encryption / decryption common key K _D is generated from KU ⁰ (step 2014). In particular,
The upper bit of KU ⁰ is designated as K _D. For example, KU ⁰ to 5
If 12 bits (for RSA), the upper 64
Bits (for DES) and _{K D.} This is K
The same applies when updated to U ¹ , KU ² ,.

The reproducing device 300 has KU _s , K _s , K
U ⁰ and K _D are stored in the key storage unit 330 (step 201
5) Install playback software (step 201)
6). The initial format of the content usage record to find SID (content ID of FIG. 5, the cumulative play time, both total accumulated playback time NULL) creates a (step 2017), the content usage records with _{K D} Is encrypted (step 2018) and is used as a content usage record 320.

[Content Reproduction] FIGS. 9 to 11 show processing flowcharts when the reproduction apparatus 300 reproduces content. The content usage record 320 in the playback device 300 has the format shown in FIG. The content usage record 320
Data (DATA) is stored encrypted with _{K D.} This is represented by EC [K _D , DATA]. Also,
KU ⁰ in the key storage unit 330 is updated to KU ⁿ , and K _D
Is generated from KU ⁿ .

When reproducing the content, the user (a) activates the reproduction software 310 (reproduction software ID = SID) (step 3001). The processing after step 3002 is processing of the reproduction software 310.

The reproduction software 310 reads the already distributed content capsule (step 300).
2). The content capsule is the encrypted content EC [K
_s , CID // Content] and signature EP [KR _s , E
C [K _s , CID // Content]]. The reproduction software 310 uses DPs [KU _s , EP [KR _s , EC by using KUs stored in the key storage unit 330.
[K _s , CID // Content]]] is used to decrypt the signature part to extract EC [K _s , CID // Content], and compare this with the encrypted content part to check the signature of the content capsule (step 300
3,3004). If they do not match as a result of the comparison, a reproduction impossible message or the like is output (step 3005) and the process ends at this stage. If they match (signature is OK), DC is stored using Ks stored in the key storage unit 330.
[K _s , EC [K _s , CID // Content]] decrypts the encrypted content portion,
(CID) and content (Content) are taken out (step 3006). Then play the content,
The reproduction time is acquired (step 3007).

After the reproduction of the content is completed, the reproduction software 31
0 reads the content usage record 320 is encrypted the SID to the key (step 3008), DC _[K D with _{K D} stored in the key storing unit 330,
By using EC [K _D , DATA]], the encrypted content use record 320 is decrypted, and the use record data (D
ATA) is acquired (step 3009). Then, the corresponding content ID (CI in the usage record data (FIG. 5) is
The current playback time is added to the cumulative playback time and the total cumulative playback time of D) (step 3010), and it is determined whether the total cumulative playback time is equal to or more than a specified value (for example, 10 hours or more) (step 3011). .

In the case of total accumulated playback time <specified value, the reproduction software 310 encrypts the usage record data after update (DATA) using the _{K D} again, i.e., EC _[K D, D
ATA] is executed, and this is rewritten as the content use record 320 (step 3012). This completes one content reproduction process.

On the other hand, if the total accumulated reproduction time ≧ the specified value, the reproduction software 310 first locks the reproduction function of the reproduction apparatus 300 (step 3013). Then, the SID, encrypts the updated usage record data by using the KU ⁿ the current stored in the key storing unit 330, generates an encryption using the recording information (step 3014), to the management server 100 (Step 3015). The cipher use record information is represented by EP [KU ⁿ , SID // DATA]. Here, in DATA, the accumulated reproduction time for each content ID and the total accumulated reproduction time are recorded. After that, the reproduction software 310 initializes the use record data of the corresponding SID up to that point (step 3016) and waits for the next disposable public key (KU ^{n + 1} ) to be sent from the management server 100.

[0039] to the management server 100 in the playback device 300, EP ^{[KR n, KU} n ^{+ 1]} as, come and send the following disposable public key ^{KU n + 1} encrypted with ^{KR n.}

When the reproduction software 310 receives EP [KR ⁿ , KU ^{n + 1} ] from the management server 100 (step 3017), the KU still stored in the key storage unit 330.
ⁿ , DP [KU ⁿ , EP [KR ⁿ , K
U ^{n + 1} ] is decoded and KU ^{n + 1} is extracted (step 3018). Then, the ^{KU n + 1,} and generates a common key _{K D} for renewed use recording encryption / decryption (step ^{3019) and} stores the ^{KU n} + 1, _{K D} (step 3020). Also, using this new K _D , the corresponding S
The initialized use record data of the ID is encrypted (step 3021). After that, the reproduction function is unlocked and the content can be reproduced again (step 3022).

[0041] Each Thus, the total accumulated playback time reaches the above predetermined time, and transmits the management server forest usage record data, updating the KU ^n, by changing the K _D each time, content usage The security of the record 320 can be increased.

FIG. 12 is a processing flow chart on the management server side when the content use record is received from the reproducing apparatus side. When the management server 100 receives the encrypted usage record information from the playback device 300 (step 400).
1) Decrypt using KR ⁿ stored in the key storage unit 140, that is, DP [KR ⁿ , EP [KU ⁿ , SI
D // DATA]] is executed to take out the SID and the used recording data (DATA) (step 4002).

First, the management server 100 determines the member list 1
20 (FIG. 3), the owner (member) of the SID
Check the final deposit date of (step 4003). Here, if the owner of the SID has not paid the membership fee by the predetermined date, the received usage record data is discarded and the process ends. After that, for example, the user (member) is urged to pay the membership fee, a reproduction software sending request is received from the user, and the reproduction software is installed again.

Next, the management server 100 carries out filtering of the received use record data (step 40).
04). The filtering is performed to invalidate suspicious usage record data such as an abnormally large number of times of use of a specific content or an abnormally short reproduction interval prior to the aggregation of the usage record data. Here, (i) the same S
If it is sent from the ID within the specified time (for example, within 10 hours), the usage record data is discarded. (ii) When the reproduction time of a specific CID is abnormally long, the used record data is discarded. (iii) The used record data received from each reproducing apparatus side is randomly selected at a rate of 1/1000, for example, and the rest is discarded.

The management server 100 is filtered.
Content in the management server using the usage record data
Update data in usage record 130 (FIG. 4) (step
4005). Then, for the corresponding SID, K
U^{n + 1}, KR^{n + 1}Is generated (step 4006),
KRⁿUsing KU^{n + 1}Encrypted, ie EP
[KR ⁿ, KU^{n + 1}] And send to the playback device 300
(Step 4007). Also, KRⁿ, KUⁿNika
Well, KR^{n + 1}, KU^{n + 1}Is stored in the key storage unit 140
(Step 4008).

As described above, in the embodiment, the reproducing apparatus 300 transmits the use record data to the management server 100 when the total accumulated reproduction time in the content use record 320 is equal to or more than the specified value. It may be sent every one day or every week).
You may receive a transmission request from 0 and may transmit.

[Audit Rating / Reward Amount Calculation] FIG. 13 shows a processing flowchart of the audience rating / reward amount calculation in the management server 100. The management server 100, for example, at regular intervals (for example,
(Eg, every month), the content usage record 130 (FIG. 4) in the management server 100 is read (steps 5001 and 50).
02), an audience rating for each content and a reward amount for each creator are calculated (steps 5003 and 5004).

The audience rating for each content is calculated, for example, by the following equation (1). Formula 1 shows a formula for calculating the audience rating with the content ID being CID.

[0049]

[Equation 1] However, CID is content ID N is total content number T is cumulative reproduction time X of each content is a correction value

Here, the correction value X is determined as follows. For example, in the case of text contents and video contents, if the creator's reward is determined by a simple audience rating,
It is expected that only vulgar content will earn viewership, and content with high social value such as cultural programs and papers will suffer disadvantages even if viewership is not high. Therefore, it is desirable to correct and adjust the content type. In this way, contents that have been difficult to distribute in the market, such as papers, can be distributed by this method, and researchers can directly earn income from papers. This enables the commercialization of conventionally desired papers. However, the correction value is not determined for each content but for each type of content. As a result, normal free competition works within the same type of content. 14A and 14B show an example of the correction value X, a correction value list for each content ID, and an example of calculating the audience rating. This information is stored in the management server 100 and is shown in FIG.
The correction value X of each content is determined based on 4 (a) and (b).

The reward amount for each creator is calculated by referring to the creator list 110 (FIG. 2) and multiplying the audience rating of each content corresponding to the creator by the total deposit amount from the user (member).

The management server 100 records the amount of reward for each creator in the creator list 110 and distributes it to each creator (step 5005). The method of distribution may be any method. After that, the management server 100 initializes the content use record 130 (step 5006) and returns to step 5001.

It should be noted that some or all of the processing functions of each part in the system shown in FIG. 1 can be configured by a computer program, and the program can be executed by the computer to implement the present invention, or It goes without saying that the processing procedure shown in FIGS. 6 to 13 can be configured by a computer program and the computer can execute the program. A computer-readable recording medium, such as an FD, MO, or R, stores a program for realizing the processing function of the computer, reproduction software, or a program for causing the computer to execute the processing procedure.
The program can be recorded in an OM, a memory card, a CD, a DVD, a removable disk, etc., and saved or provided, and the program can be distributed through a network such as the Internet.

[0054]

As described above, according to the present invention, it is possible to freely copy and back up between the members and the reproducing apparatus owned by the person, so that it can coexist with the Peer-to-Peer file sharing software. Further, since the purchase operation for each download is unnecessary, convenience is improved and leakage of personal information is improved. Furthermore, the creator can be given a proper reward according to the usage amount.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of a content distribution system according to the present invention.

FIG. 2 is an example of a creator list in the management server.

FIG. 3 is an example of a member list in a management server.

FIG. 4 is an example of content recording in the management server.

FIG. 5 is an example of a content usage record in the playback device.

FIG. 6 is a flowchart of processing of content encapsulation in the management server.

FIG. 7 is an example of a reproduction software installation process flowchart in the management server.

FIG. 8 is a processing flowchart of playback software installation in the playback device.

FIG. 9 is an example of a processing flowchart of content reproduction in the reproduction device.

FIG. 10 is a processing flowchart subsequent to FIG. 9;

FIG. 11 is a processing flowchart continued from FIG. 10;

FIG. 12 is a processing flowchart when the management server receives a usage record.

FIG. 13 is a processing flowchart of a content audience rating / creator reward amount calculation in the management server.

FIG. 14: Content classification, correction value, and content ID
It is a figure which shows the corresponding example of a classification.

[Explanation of symbols]

10 users 20 Creator 100 management server 110 Creator List 120 member list 130 Content usage record 140 Key storage 200 distribution server 300 playback device 310 Playback software 320 Content Usage Record 330 Key storage

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) G06F 13/00 540 H04L 9/00 601F H04L 9/08 G06F 9/06 660C F term (reference) 5B076 FA01 FC10 5J104 AA16 EA01 EA04 EA15 PA07 PA10 PA11

Claims (15)

[Claims] 1. A content distribution method in which content from a creator is distributed to a user side via a management server, the user side uses a playback device, and the content can be played back by playback software sent from the management server. The management server collects and manages a fixed fee from the user.
Reproducing software is sent to the user side in response to a request from the user side, and the reproducing device on the user side reproduces the content by the reproducing software, encrypts and retains the content use record,
The stored content usage record is transmitted to the management server, and the management server totals the content usage records sent from each user side for each content, calculates the audience rating for each content, and views each content. A content distribution method characterized in that a reward amount for each creator is calculated based on a rate and a total amount of money collected from a user and distributed to each creator. 2. The content distribution method according to claim 1, wherein the content usage record is made up of a cumulative playback time for each content and a total cumulative playback time thereof, and when the total cumulative playback time exceeds a specified value, A content distribution method characterized by transmitting a content use record to the management server at predetermined time intervals or in response to a request from the management server, and initializing the content use record. 3. The content distribution method according to claim 2, wherein each time the content usage record is transmitted to the management server, a key for encrypting the subsequent content usage record is updated. . 4. The content distribution method according to claim 3, wherein the management server issues a disposable public key each time the playback software is sent or each time the content usage record is received, and the playback software is the disposable Generates a common key for encrypting the content usage record from the public key, encrypts the content usage record using the common key, and uses the public key when transmitting the content usage record to the management server. A content distribution method characterized by encrypting a content usage record and transmitting it to a management server. 5. The content distribution method according to claim 4, wherein the reproduction software locks the reproduction function when transmitting the content usage record to the management server, and receives the next disposable public key from the management server. And releasing the lock of the playback function. 6. The content distribution method according to claim 5, wherein the management server, upon receiving the content usage record, checks the deposit of the corresponding user and determines whether or not to issue the next disposable public key. Content distribution method characterized by. 7. The content distribution method according to claim 6, wherein the management server adds information for identifying the reproduction software (hereinafter, reproduction software ID) to the reproduction software and distributes the reproduction software to the user side. , The reproduction software ID is added to the content usage record and transmitted to the management server. Based on the reproduction software ID added to the received content usage record, the management server identifies the user who owns the reproduction software. A content distribution method characterized by checking deposit. 8. The content distribution method according to claim 1, wherein the management server filters the content usage record sent from each user side, and records the content usage record selected by the filtering. A content distribution method characterized by being used for counting by content. 9. The content distribution method according to claim 8, wherein the management server discards the content usage record sent from the same playback software within a specified time, and the playback time by the specific playback software is abnormally long. A content distribution method characterized by performing any one or all of discarding content use records, randomly selecting sent content use records, and discarding the rest. 10. The content distribution method according to claim 1, wherein the management server corrects the audience rating for each content according to the type of the content. . 11. The content distribution method according to claim 1, wherein the management server encrypts the content ID and the content with the common key K _s , and signs the content ID and the content with the secret key KR _s of the management server. Then, the process of distributing the content capsule including the encrypted content and the signature information, the common key K _s and the reproduction software ID by the reproduction software and the user's public key KU _a
(SID) and disposable public key KU ⁿ (n = 0, 1,
2, ...) is sent to the user side, and the reproduction software decrypts the encrypted additional information with the user's private key KR _s to obtain K _s , SID, get the KU ^n, a processing process of generating a disposable common key K _D from the KU ^n, checks the signature of the content capsules using the public key KU _s of the management server decrypts the encrypted content in the K _s content ID Te, acquires the content, and plays back the content, and a processing process of encrypting the content using the recording to find the appropriate SID using the K _D, content distribution method, characterized in that. 12. The content distribution method according to claim 11, wherein the reproduction software decrypts the content use record encrypted using the K _s , and the SID using the KU ⁿ .
A process of encrypting the content usage record and transmitting it to the management server, and receiving the next disposable public key KU ^{n + 1} from the management server, generating a new K _D from the KU ^{n + 1} , and using the K _D The management server decrypts the encrypted SID and the content usage record sent from the user side by using the disposable secret key KR ^n. And the following disposable public key KU ^{n + 1} and secret key KR ^{n + 1} are generated, and the KU
and a processing process for transmitting ^{n + 1} to the user side,
A content distribution method characterized by the above. 13. A content distribution system, characterized in that a management server, a distribution server, and a playback device are connected by a network, and the content distribution method according to claim 1 is implemented. 14. Playback software used in the content distribution method according to claim 1. 15. A recording medium on which reproduction software used in the content distribution method according to claim 1 is recorded.