JP2001195369A - Digital contents utilization control method, system therefor and machine readable recording medium recording program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To change the definition of a constituting element set to be a control object even after contents distribution for digital contents for which respective constituting element data in contents such as images and texts are ciphered by mutually different keys. SOLUTION: Property information for defining the set of element data for constituting the contents is added to encapsulated digital contents beforehand and a utilization condition description describing a utilization permission code for each constituting element set is registered in a utilization permission server 1. From the utilization permission server 1 to a reproducing device 2 to utilize the contents, the property information is updated first and a utilization permit including the utilization permission code is distributed. Thereafter, the reproducing device 2 acquires the deciphering key of the constituting element data included in the constituting element set from the utilization permission server 1 in exchange with the utilization permission code.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technology for controlling the use of digital contents, and more particularly to a technology for controlling the use of digital contents that can change the use unit of digital contents and prevent unauthorized distribution of a decryption key for encrypted content data. About.

[0002]

2. Description of the Related Art Conventionally, a digital content use control system of this type distributes content data after encrypting it, and gives a decryption key in exchange for proof that a user has paid a certain amount of money. It was demanded that the conditions of use such as were surely satisfied. An example of a conventional digital content use control system is disclosed in
-274729.

[0003] The system described in this publication includes an antenna for receiving content data delivered via a satellite, a satellite line I / F section, an ID card reading device on which information for identifying a user is recorded, A communication I / F unit for transmitting billing information to the collection center and receiving a decryption key for the encrypted content data via a telephone line, and a decryption key obtained from the communication I / F unit for the encrypted content data; It comprises a decryption circuit for decrypting, and an operation device and a display device necessary for a dialog with the user.

When the user uses the content data received through the antenna and the satellite line I / F, the display device requests the user to approve the charge in accordance with the charge information recorded in the content data. When the user accepts the billing using the operation device, the system connects to the money collection center via the telephone line by the communication I / F unit, and transmits the billing information together with the personal information recorded in the ID card. Upon receiving the billing information and the personal information, the payment collection center transmits the decryption key of the content data in exchange for the billing information and the personal information. The system that has received the decryption key decrypts the encrypted data with a decryption circuit and displays the decrypted data on a display device.

There is also known a system that regards contents as a set of component data and controls the availability of each subset of the component data. One example of such a system is described in Japanese Patent Application Laid-Open No. 8-8852.

The system described in this publication includes an information providing server and an information terminal device. The information providing server encrypts the information to be distributed and a receiver and a transmitter for communicating with the information terminal device. And a distribution information database that stores various information.

[0007] Each piece of information stored in the distribution information database is composed of primary information and some differences with respect to the primary information. The partial information is divided into several groups according to a use request issued from the information terminal device. Can be delivered. At the time of distribution, the information providing server encrypts the grouped information using a different encryption key for each group and transmits the information to the information terminal device. When the user uses the grouped information using the information terminal device, the information providing server sequentially gives a decryption key for the group, thereby charging for partial information.

Further, there is also known a system in which an arbitrary data set is defined in advance and encryption and decryption are performed on each set with a different key, irrespective of difference information as in the system described in the above publication. ing. One example of such a system is described in JP-A-8-212198.

In the system described in this publication, use control of fonts is performed. The font has one-to-one correspondence with a predetermined set of character codes, and each character code set is encrypted with a different key, and the encrypted font information is distributed. This system includes a font database and a font reading module for storing encrypted font information, a font decoding module for decoding the encrypted font information, and a font display module for displaying the decoded font. When a user attempts to display a font, the font reading module reads encrypted font information from the font database, and the font decoding module calculates a decoding key based on a character code set to which the font belongs, and obtains font information. And the font is displayed by the font display module.

[0010]

The first problem is that it is difficult to change the group configuration of the partial data of the content after the distribution of the content.

The reason is that, at the time of content distribution, a set of an encryption key and a decryption key is uniquely determined for each group, and it is impossible in principle to change the set of the encryption key and the decryption key.

[0012] The second problem is that it is easy for the user to illegally transfer the right to use the content.

The reason is that the request for the decryption key or the decryption key itself has no relation to the user-specific information, or is information in a format that can be easily forged even if there is a relation. This is because, when the decryption key is distributed to the three parties, there is no means to confirm that the decryption key has been obtained by an unauthorized method.

[0014] The third problem is that it is difficult to reliably limit the number of times the same content is used when there is a person who intends to commit fraud.

The reason is that, when the same content is used, the request for the decryption key is always constant or can be easily forged regardless of the number of uses.

Therefore, an object of the present invention is to make it possible to change the configuration of a set of constituent elements of a content after distribution of the content.

Another object of the present invention is to prevent a user from illegally transferring the right to use contents.

Still another object of the present invention is to make it possible to reliably limit the number of times the same content is used, even when there is a person trying to commit fraud.

[0019]

According to the digital content use control method of the present invention, a reproducing apparatus and a use permission server are connected via a network so that the composition of a set of constituent elements of a content can be changed after the content is distributed. A digital content use control method for controlling use of digital content in a connected system, wherein the digital content includes a plurality of component data encrypted with different encryption keys, and the use permission server includes the digital Each component data of the content is managed by being divided into a plurality of component sets, and a use permission code for each of the component sets and a decryption key for each of the component data are managed, and are set as playback targets from the playback device. When a license request specifying a set of components is sent, the specified component Sends a license including usage authorization code corresponding to the set to the reproduction apparatus, the reproduction apparatus,
When the license is sent from the license server, a decryption key sequence request including the license code in the license is sent to the license server, and the license server decrypts the decryption request from the playback device. When the key sequence request is sent, after performing authentication based on the use permission code in the decryption key sequence request and the use permission code managed by the own server, the component corresponding to the use permission code is performed. The decryption key of each component data included in the set is sent to the playback device.

As a system suitable for carrying out this method, the digital content use control system of the present invention comprises a playback device and a use permission server connected via a network, and is encrypted with different encryption keys. A digital content use control system for controlling use of digital content including a plurality of component data, wherein the use permission server manages each component data of the digital content by dividing the component data into a plurality of component sets. Manages the use permission code for each of the component sets and the decryption key for each of the component data, and when a license request specifying a component set to be played back is sent from the playback device, A license containing a license code corresponding to the specified set of constituent elements is sent to the playback device, and When a decryption key sequence request is sent from the device, after performing authentication based on the use permission code in the decryption key sequence request and the use permission code managed by the own server, the device responds to the use permission code. The decryption key of each component data included in the set of constituent elements to be transmitted to the playback device, wherein the playback device specifies the component set to be played back when the component set is played back. Sending a license request to the license server, and, when the license is sent from the license server, transmitting a decryption key sequence request including the license code in the license to the license server. Have.

Further, the digital content use control method of the present invention uses digital content in a system in which a playback apparatus and a use permission server are connected via a network in order to prevent a user from illegally transferring a content use right. A method for controlling use of digital content, wherein the digital content includes a plurality of component data encrypted with different encryption keys, and the use permission server includes a plurality of component data of the digital content in a plurality of configuration data. A license request that manages a license code for each of the component sets and a decryption key for each of the component data and manages the component sets to be played back from the playback device. Is sent, the license code corresponding to the specified component set is included. Feed the license to the playback device,
When the license is sent from the license server, the playback device generates a modified license code based on the license code in the license and the user information managed by the device. And transmitting the decryption key sequence request including the modified use permission code and the user information to the use permission server. The use permission server transmits the decryption key sequence request when the reproduction key sequence request is transmitted from the playback device. After performing authentication based on the modified use permission code in the series request, the user information sent from the playback device, and the use permission code managed by the own server, a configuration corresponding to the use permission code The decryption key of each component data included in the element set is sent to the playback device.

As a system suitable for carrying out this method, the digital content use control system of the present invention comprises a playback device and a use permission server connected via a network, and is encrypted with different encryption keys. A digital content use control system for controlling use of digital content including a plurality of component data, wherein the use permission server manages each component data of the digital content by dividing the component data into a plurality of component sets. Manages the use permission code for each of the component sets and the decryption key for each of the component data, and when a license request specifying a component set to be played back is sent from the playback device, A license containing a license code corresponding to the specified set of constituent elements is sent to the playback device, and When a decryption key sequence request is sent from the device, the modified use permission code in the decryption key sequence request, the user information sent from the playback device, and the use permission code managed by the own server. After performing the authentication based on, based on the configuration, the decryption key of each component data included in the component set corresponding to the use permission code is sent to the playback device, and the playback device At the time of reproduction, a license request specifying a set of components to be played is sent to the license server, and when the license is sent from the license server, the license code in the license is A modified use permission code is generated based on the user information managed by the own device, and a decryption key sequence request including the corrected use permission code and the user information are transmitted to the use permission server. .

According to the digital content use control method of the present invention, a reproducing apparatus and a use permission server are used to ensure that the number of uses of the same content can be reliably restricted even when a person tries to commit fraud. Is a digital content use control method for controlling the use of digital content in a system connected via a network, wherein the digital content includes a plurality of component data encrypted with different encryption keys, The server manages the component data of the digital content by dividing the component data into a plurality of component sets, and also includes a use permission code for each component set, an upper limit on the number of times of use for each component set, and each component. A decryption key is managed for each element data, and a license request specifying a set of constituent elements is sent from the playback apparatus. When the time has come, a license containing the upper limit of the number of uses of the specified component set and a seed are transmitted to the playback device, and the upper limit of the number of uses is determined based on the upper limit of the number of uses and the type. A temporary key sequence including the same number of temporary keys as the upper limit of the number of uses corresponding to the different number of uses up to the value is generated and stored, and the playback device, when playing back a set of components, If the license for the set has not been received, a license request specifying the component set to be reproduced is sent to the license server, and thereafter,
The use corresponding to different use counts up to the use count upper limit, respectively, based on the use count upper limit and the seed in the use license sent from the use permit server in response to the use permit request. A temporary key sequence including the same number of temporary keys as the upper limit of the number of times is generated and stored, and a decryption key sequence request for the reproduction target component set including the temporary key corresponding to the current number of uses in the temporary key sequence is generated. If the license is sent to the license server and a license for the set of constituent elements to be reproduced is received, a temporary key corresponding to the current number of times of use in the temporary key sequence stored when the license is received is included. Sending a decryption key sequence request for the set of components to be played back to the use permission server, and the use permission server sends a decryption key sequence for the set of components to be played back from the playback device. Request is sent, after performing authentication based on the temporary key in the decryption key sequence request and the temporary key corresponding to the number of times of use this time in the temporary key sequence stored in the server itself, A decryption key of each component data included in the component set to be reproduced is sent to the reproducing device.

As a system suitable for carrying out this method, the digital content use control system of the present invention comprises:
A digital content use control system comprising a playback device and a use permission server connected via a network, and controlling use of digital content including a plurality of component data encrypted with different encryption keys,
The use permission server manages the component data of the digital content by dividing the component data into a plurality of component sets, and uses a use permission code for each of the component sets, an upper limit on the number of times of use for each of the component sets, and Manages the decryption key for each of the component data, and when a license request specifying the component set is sent from the playback device, the upper limit value and seed of the number of times of use of the specified component set are determined. Including the use license including the same number of temporary use times as the use number upper limit value corresponding to different use numbers up to the use number upper limit value based on the use number upper limit value and the type, respectively. A temporary key sequence including a key is generated and stored, and when a decryption key sequence request for a set of components to be reproduced is sent from the playback device, the temporary key in the decryption key sequence request and the After performing authentication based on the temporary key corresponding to the number of uses this time in the temporary key series stored in the server, the decryption key of each component data included in the set of components to be reproduced is obtained. The playback device has a configuration for sending to the playback device. When the playback device does not receive a license for the component set to be played back at the time of playback of the component set, the playback device A license request specifying a set of constituent elements to be sent is sent, and then, based on the upper limit and the number of times of use in the license sent from the license server in response to the license request, A temporary key sequence including the same number of temporary keys as the use count upper limit corresponding to the different use counts up to the use count upper limit is generated and stored, and also corresponds to the current use count in the temporary key sequence. Sends a decryption key sequence request for the set of components to be reproduced including the temporary key to the license server, and stores a license for the set of components to be reproduced when the license is received. And transmitting a decryption key sequence request for the reproduction target component set including a temporary key corresponding to the current number of uses in the temporary key sequence to the use permission server.

[0025]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a block diagram of a first embodiment of the present invention. Referring to FIG. 1, in a first embodiment of the present invention, a use permission server 1 that distributes a use certificate and a decryption key sequence, and a reproduction that reproduces digital contents (sometimes simply referred to as contents). It includes a device 2 and a network 0 connecting the two.

The use permission server 1 is composed of, for example, a computer.
The usage condition description management unit 12, the condition determination unit 13, the usage certificate generation unit 14, the decryption key sequence generation unit 15, the usage permission code authentication unit 16, the latest property acquisition unit 17, and the recording medium K1 Prepare.

The communication control unit 11 receives the license request transmitted from the playback device 2 via the network 0 and transmits the usage license input from the condition determination unit 13 to the playback device 2. Further, it receives a decryption key sequence request including the use permission code sent from the playback device 2 and transmits the decryption key sequence input from the condition determination unit 13 to the network 0.
To the playback device 2 via the.

The use condition description management unit 12 manages the following information (use condition description) for each content whose use permission is managed by the server 1 itself. Note that each content includes a plurality of component data items (sometimes simply referred to as component components) encrypted with different encryption keys. The contents of the use condition description management unit 12 can be changed by an administrator of the use permission server 1 using an input device such as a keyboard (not shown).

The component set ID of each component set when the component data included in the content is divided into a plurality of component sets (for example, if the content is an electronic book, paragraphs, figures, photographs, etc.) Is the component data, and the pages, chapters, etc. are the component set) ・ Usage permission code for each component set ・ Component ID of component data included in the component set ・ Usage condition of component set ( (For example, usage methods such as allowing display only, restrictions on display resolution, billing methods, etc.) ・ Decryption keys for each component data ・ Property information

The condition determination unit 13 compares the request condition in the license request input from the communication control unit 11 with the usage condition description (ACL) managed by the usage condition description management unit 12 and thereafter. , The information necessary for generating a usage certificate (a usage permission code of a set of components for which the playback device 2 is to receive a usage license) is passed to the usage license generation unit 14 and used based on this information. Permit generation unit 14
Is output to the communication control unit 11. Furthermore, after the validity of the decryption key sequence request input from the communication control unit 11 is determined by using the use permission code authentication unit 16, the decryption key sequence generation unit 15 needs to generate a decryption key sequence. Information (such as the decryption key of each component data included in the component set for which the playback device 2 is about to receive the use permission) is passed, and the decryption key sequence generated by the decryption key sequence generation unit 15 is transmitted to the communication control unit 11. Output.

The license generating unit 14 includes the condition determining unit 13
Use the information from to generate an appropriately formatted license.

The decryption key sequence generation unit 15
, A decryption key sequence of an appropriate format is generated.

The use permission code authentication section 16 checks the use permission code in the decryption key sequence request passed from the condition determination section 13 against the use permission code in the use condition description.
It determines whether the decryption key sequence request is valid or not, and outputs the result to the condition determination unit 13.

The latest property acquisition unit 17 is provided for the playback device 2
When a request to acquire property information designating the content is issued from, the property information of the designated content is acquired from the use condition description management unit 12 and returned to the playback device 2.

The recording medium K1 is a disk, a semiconductor memory, or another recording medium, in which a program for causing a computer to function as the use permission server 1 is recorded. This program is read by a computer, and by controlling the operation of the computer, a communication control unit 11, a use condition description management unit 12,
A condition determination unit 13, a license generation unit 14, a decryption key sequence generation unit 15, a license code authentication unit 16, and a latest property acquisition unit 17 are realized.

The playback device 2 is constituted by, for example, a computer, and has an input unit 21 such as a keyboard.
And an output unit 22 such as a display device or a printing device,
Content management unit 23, license management unit 24, usage control unit 25, license request generation unit 26, decryption key sequence request generation unit 27, decryption unit 28, communication control unit 29
And a recording medium K2.

The input unit 21 outputs a reproduction request including information such as digital contents to be reproduced and a reproduction mode to the use control unit 25 in accordance with a user operation.

The output unit 22 presents the user with the decrypted data from the use control unit 25 and other dialog boxes.

The content management section 23 stores digital contents obtained by the user.

The license management section 24 stores the licenses transmitted from the license server 1.

The use control unit 25 receives a reproduction request from the user obtained through the input unit 21, checks whether or not there is a use license using the use license management unit 24, and transmits the request via the communication control unit 29. Communication processing for obtaining the usage certificate and the decryption key sequence, generating the usage certificate request using the usage certificate request generation unit 26, and generating the decryption key sequence request using the decryption key sequence request generation unit 27 The decryption unit 28 decrypts the encrypted data in the digital content using the decryption unit 28 and outputs the decrypted data to the output unit 22.

The license request generator 26 generates a license request in an appropriate format according to the input from the usage controller 25.

The decryption key sequence request generation unit 27 generates a decryption key sequence request in an appropriate format according to the input from the use control unit 25.

The decryption unit 28 uses the decryption key sequence input from the use control unit 25 and the corresponding encrypted data to
Restore the original data.

The communication control unit 29 transmits a license request, receives a license, and
Communication with the transmission of the decryption key sequence request and the reception of the decryption key sequence are performed.

The recording medium K2 is a disk, a semiconductor memory, or another recording medium, in which a program for causing a computer to function as the reproducing apparatus 2 is recorded. This program is read by a computer, and by controlling the operation of the computer, a use control unit 25, a license request generation unit 26, a decryption key sequence request generation unit 27, a decryption unit 28, and a communication control unit 29 are provided on the computer.
To achieve.

Next, the operation of the first embodiment of the present invention will be described in detail with reference to the drawings. FIG. 2 is a processing sequence diagram showing information exchanged between the use permission server 1 and the playback device 2 in chronological order. FIG. 3 is a flowchart showing a processing example of the playback device 2, and FIG. 5 is a flowchart illustrating a processing example of a server 1;

First, the user sends digital content (encapsulated content, C) encapsulated via the network 0 from an appropriate distribution server (not shown) in advance.
AP) (FIG. 3, step 201).
The downloaded encapsulated content is stored in the content management unit 23 (Step 202).

The encapsulated content includes a plurality of component data, each of which is encrypted with a different encryption key, a server name of a usage-permitted server used to obtain a usage certificate and a decryption key, and a component set definition. And described property information.

FIG. 5 is a diagram showing an example of the property information. The content name, the author name, the production date, the component list, the use permitted server name, the component set definition, and the display are shown. Includes order definition. The example in FIG.
If the content name of the encapsulated content is "Mich
i ", and the author name is" Masayuki Nakae "
The production date is “February 23, 1999”, and the ID of each component data included in the encapsulated content is “g”.
k01, gk02, gk03,... ”, and the name of the use permission server used to obtain the use permit or the decryption key is“ ts ”.
1. nec. co. jp ". Further, the component set “C1, C2,...” Includes component data “{gk01, gk02}, {gk02, g
k03 @,..., and the display order of the component set is "C
1, C2,... ".

When reproducing the content stored in the content management section 23, the user inputs a request for reproducing the encapsulated content from the input section 21.

When a request to reproduce the encapsulated content is input from the user (YES in step 203), the use control unit 25 performs the processing in step 204. Step 2
In 04, a list of each encapsulated content stored in the content management unit 23 is displayed on the output unit 22 to allow the user to select the encapsulated content to be reproduced,
Further, the user is caused to designate a reproduction portion. After that, based on the component set definition in the property information included in the selected encapsulated content, the component set C to be requested for reproduction is determined. For example, if the user requests reproduction of a certain page P of a certain encapsulated content CAP, a set of components including the components E1, E2,. A search is made from the component set definition in the information, and the searched component set is set as a component set C to be requested for reproduction. At this time, when a plurality of constituent element sets are searched as candidates, a method of displaying the candidates in the form of a dialog box on the output unit 22 and prompting the user to select an appropriate one may be used. Also, the license management unit 2
4, the latest license or the license with the lowest billing amount among the usage conditions is selected from the licenses corresponding to the candidates, and the license corresponding to the license is selected. A method of selecting a component set may be used.

Here, when determining the component set C to be played back, the playback device 2 requests the use permission server 1 for the latest property information of the encapsulated content to be played back as appropriate, and responds to this request. Alternatively, the component set C may be determined using the latest property information transmitted from the use permission server 1. By doing so, it is possible to change the structure of the content or change the billing amount of a certain set of components after distributing the encapsulated content. In this case, the property information in the encapsulated content stored in the content management unit 23 is rewritten with the property information acquired from the use permission server 1 so that the relevant component set definition can be referred to in subsequent use. In the use permission server 1, when the latest property information of a certain encapsulated content is requested, the latest property acquisition unit 17 acquires the latest property information of the encapsulated content from the use description management unit 12, and The data is transmitted to the playback device 1 via the communication control unit 11.

Next, the usage control unit 25 sets the component set C
It is confirmed whether or not the usage license for has already been stored in the usage license management unit 24 (step 205). If it is stored, the process immediately proceeds to the decryption key sequence acquisition process (step 212).
The license server 1 sends the license to the component set C
In order to make a request, a license request is generated using the license request generation unit 26, and the generated license request is transmitted to the license server 1 via the communication control unit 29 (step 206). ). The license request includes, for example, “content name”, “author name”,
It has fields such as “component set ID” and “requirement condition”. The “required condition” includes, for example, a usage method such as display and printing, a display resolution restriction, and the like. Thereafter, the use control unit 25 in the playback device 2 waits for the use permit to be sent from the use permit server 1 (step 20).
7).

The communication control unit 11 in the use permission server 1
When there is an access from the playback device 2 (FIG. 4, step 30)
1), and pass the received message to the condition determination unit 13.

When the message is passed, the condition determining unit 13 determines whether the message is a license request or a decryption key sequence request (steps 302 and 308). In this example, since the message is a license request (YES in step 302), the condition determination unit 13 calculates and calculates the usage condition description ID based on the information included in the license request. Based on the use condition description ID, the use condition description of the plurality of digital contents is used as the use condition description ID.
Is extracted from the usage condition description management unit 12 stored in association with the usage condition description of the digital content including the component set requested to be reproduced (step 30).
3). When the usage certificate request has the fields shown in FIG. 6, the usage condition description ID can be, for example, a character string obtained by concatenating the content name and the author name.

Subsequently, by referring to the component set ID in the license request, a use condition corresponding to the component set ID in the use condition description extracted in step 303 is extracted. Are compared with the extracted use conditions (step 304). At this time, if the collation fails, the license request is rejected (step 307).

Here, the use condition description includes, in association with the component set ID, the ID of the component included in the component set, the use permission code of the component set, the use condition of the component set, And the billing conditions of the component set are described. Further, the use condition description describes a decryption key of the component in association with the component ID. The description format of the use condition description can take any description format as long as the predicate logic can be expressed in a machine-readable format such as a Boolean expression, and has a format shown in FIG. 7, for example. In this case, the use condition and the required condition are collated, for example, as follows.

An arbitrary number of variables and their values are specified in the request condition. Terms and conditions include variables and constants,
A set of comparison expressions composed of comparison operators such as equal signs and inequality signs is described. For variables included in common to both, the variable value specified in the request condition is embedded in an appropriate comparison expression described in the usage condition, and it is determined whether the comparison expression is satisfied. If the logical product of all the truth values of such a comparison expression is true, it is determined that the required condition conforms to the use condition, and if false, it is not conformed. However, if there is a variable that is included in the requirement but not in the usage condition, the variable is simply ignored,
Conversely, if there is a variable that is included in the use condition but not included in the request condition, it is immediately determined that the request condition does not conform to the use condition.

In particular, when the use condition description includes information on the expiration date of the license, the validity information is compared with the reception time of the license request.
Since the use period of the encapsulated content can be restricted using the clock on the use permission server 1 side, it is more secure.

When the license request is received (YES in step 304), the condition determining unit 13 determines whether the components included in the license request in the license description extracted in step 303 are included. The usage condition and the usage permission code corresponding to the set ID, the content name, the author name, the component set ID, and the requesting user name included in the above-mentioned usage certificate request are input to the usage certificate generation unit 14. The license generating unit 14 generates a license including the information passed from the condition determining unit 13 (step 305).
The license is transmitted to the playback device 2 via the communication control unit 11.
(Step 306). FIG. 8 is a diagram showing an example of the structure of a usage certificate. The “serial number”, “content name”, “author name”, “requesting user name”, “component set ID”, “usage condition”, "Usage permission code",
It has fields of “expiration date”, “validity flag”, and “signature”.

When a license for the license request is sent from the license server 1 (YES in step 207 in FIG. 3), the communication control unit 29 in the playback device 2 uses the license to use the license. Pass to 25.

As a result, the use control unit 25 first checks the signature part in the license, and confirms that there is a signature from the license server 1 (step 208). If the signature verification fails, it is determined that the license may have been tampered with, and the subsequent processing is interrupted. For example, a dialog box as shown in FIG. This is notified to the user (step 209).

Next, the use control unit 25 checks the validity flag of the license, and confirms whether or not the license request is actually accepted (step 210). The validity flag holds a state such as "valid" / "error" / "expired". For example, if the flag is "error", the license is regarded as an error notification and the subsequent processing is performed. Is interrupted and, for example, a dialog box as shown in FIG. 10 is displayed on the output unit 22 to notify the user of this (step 211).

If the license is valid, the usage control unit 25 stores the license in the license management unit 24. Then, the access permission server 1 is accessed again via the communication control unit 29, and the decryption key sequence request generation unit 27 is accessed.
And transmits the decryption key sequence request generated by using (step 212). The decryption key sequence request includes the usage permission code described in the usage certificate. In addition, for example,
"Content name", "author name", "user ID",
It has fields such as “component set ID”. Thereafter, the use control unit 25 waits for reception of the decryption key sequence from the use permission server 1 (Step 213).

The communication control unit 11 in the use permission server 1
When a decryption key sequence request is sent from the playback device 2, it is passed to the condition determination unit 13 (FIG. 4, step 301: YE
S).

When the decryption key sequence request is passed (YES in step 308), condition determination unit 13 calculates the usage condition description ID in the same manner as in the case of the license request, and further includes the usage condition description ID in the decryption key sequence request. Extracted component set ID and use permission code. Then, a use condition description having the use condition description ID is extracted from the use condition description management unit 12, and is input to the use permission code authentication unit 16 together with the use permission code in the decryption key sequence request.

The use permission code authenticating section 16 extracts a use permission code described corresponding to the above-mentioned component set ID from the use condition description (step 30).
9). Then, the use permission code is collated with the use permission code included in the decryption key sequence request (step 310). If they match, it is determined that the request is "valid" and the control is shifted to the subsequent stage. If they do not match, it is determined that the request is "illegal", and an error message notifying the request is transmitted to the playback device 2 (step 314).

When it is determined that the request is a legitimate decryption key sequence request up to the previous stage, the condition determination unit 13 compares the component set ID extracted from the decryption key sequence request with the use condition description extracted from the use condition description management unit 12. Is input to the decryption key sequence generation unit 15.

The decryption key sequence generation unit 15 extracts a corresponding component set definition from the use condition description based on the component set ID. In the component set definition, component IDs of components included in the component set are described. After that, the decryption key sequence generation unit 15 extracts the decryption key described corresponding to the component ID from the usage condition description, and generates a pair of the component ID and the decryption key (element = key pair). (Step 311).

Next, the element = key pair is grouped in a format as shown in FIG. 11 (step 312). A decryption key sequence is generated, including information such as a use permission code and a serial number, in addition to the set of element = key pairs that have been grouped in this way, and output to the condition determination unit 13. Condition determination unit 13
Transmits the decryption key sequence to the playback device 2 via the communication control unit 11 (step 313).

When the decryption key sequence is sent from the use permission server 1 (YES in step 213 in FIG. 3), the communication control unit 29 in the playback device 2 passes it to the use control unit 25.

As a result, the use control unit 25 sets the decryption unit 2
Then, the server sends the encrypted constituent data belonging to the constituent element set C and the decryption key sequence to 8 and requests to decrypt the constituent data into the original data (step 214). Thereby, the decryption unit 28 decrypts each component data into the original data using the corresponding decryption key in the decryption key sequence, and returns the decryption result to the use control unit 25. The use control unit 25 outputs the returned original data of each component data to the output unit 22 (Step 215).

Thereafter, while referring to the reproduced encapsulated content, the user may follow a link, for example, and continue to use another component set. In this case, after the completion of step 215, the reproducing device 2 proceeds to step 203.

Further, as shown in FIG. 12, for example, as shown in FIG. 12, a device selecting device 221, a display device 222, a printing device 223, and a secondary storage device 224 And the like, a plurality of output device devices may be provided so that the output destination device of the reproduction data can be designated. In this case, when a device selection signal is received from the use control unit 25, the device selection device 221 refers to a correspondence table (not shown) indicating a correspondence relationship between the device selection signal and the output device device, and determines an output destination device. After that, the reproduction data input from the use control unit 25 is output to the selected device. If the reproduction data is input to the device selection device 221 without outputting the device selection signal, the display device 222 is selected. By doing so, "only display display is possible"
And "print prohibition" can be controlled.

Next, a second embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 13 is a block diagram showing a configuration example of the second embodiment of the present invention. In place of the use permission server 1 and the reproduction apparatus 2 in the first embodiment shown in FIG. A server 4 and a playback device 3 are provided.

The difference between the reproducing apparatus 3 of the present embodiment and the reproducing apparatus 2 of the first embodiment is that a second decryption key sequence request generation unit 31 is used instead of the decryption key sequence request generation unit 27. That the recording medium K3 is provided instead of the recording medium K2, and that the usage control unit 33 is used instead of the usage control unit 25.
And that a terminal-side user information management unit 32 is added.

The terminal-side user information management section 32 stores user information in association with a user name.

The second decryption key sequence request generation unit 31 converts the use permission code described in the use license sent from the use permission server 4 and the user information extracted from the terminal-side user information management unit 32. It has a function of calculating a first modified use permission code based on the first modified use permission code and generating a decryption key sequence request including the first modified use permission code.

The recording medium K3 is a disk, a semiconductor memory, or another recording medium, in which a program for causing a computer to function as the reproducing device 3 is recorded. This program is read by a computer, and controls the operation of the computer, thereby realizing a use control unit 33, a use license request generation unit 26, and a second decryption key sequence request generation unit 31 on the computer.

The difference between the use permission server 4 of the present embodiment and the use permission server 1 of the first embodiment is that a second use permission code authentication unit 41 is used instead of the use permission code authentication unit 16. , A recording medium K4 instead of the recording medium K1, a condition determining unit 43 instead of the condition determining unit 13, and a server-side user information management unit 42 are added. It is a point.

The server-side user information management section 42 stores the user information sent from the playback device 3.

The second use permission code authenticating section 41 receives the first modified use permission code included in the decryption key sequence request from the reproducing apparatus 3 and the use permission stored in the use condition description management section 12. Code and server-side user information management unit 4
2 has a function of determining the validity of the decryption key sequence request based on the user information stored in the storage device 2.

The recording medium K4 is a disk, a semiconductor memory, or another recording medium, and stores a program for causing a computer to function as the use permission server 4. This program is read by a computer, and by controlling the operation of the computer, a communication control unit 11, a use condition description management unit 12,
The condition determining unit 43, the license generating unit 14, the decryption key sequence generating unit 15, the latest property acquiring unit 17, and the second license code authenticating unit 41 are realized.

Next, the operation of the second embodiment of the present invention will be described in detail with reference to the drawings. FIG. 14 is a processing sequence diagram showing information exchanged between the playback device 3 and the use permission server 4 in chronological order, FIG. 15 is a flowchart showing a processing example of the playback device 3, and FIG. 6 is a flowchart illustrating a processing example of No. 4;

When the user inputs a digital content playback request, the playback device 3 performs steps 203 to 20 in FIG. 3 performed by the playback device 2 in the first embodiment.
6, the component set C to be reproduced is determined, and a license request for the component set C is transmitted to the license server 4.

When the use permit server 4 receives the use permit request from the playback device 3, the use permit server 4 performs steps 301 to 30 in FIG. 4 performed by the use permit server 1 in the first embodiment.
By performing the same processing as in step No. 6, a license for the component set C is generated and transmitted to the playback device 3.

When the license for the component set C is received from the license server 4, the reproducing device 3 performs the steps 207 to 211 of FIG. 3 performed by the reproducing device 2 of the first embodiment.
After performing the same processing as in step 150, step 150 shown in FIG.
1 is performed.

In step 1501, the usage control unit 33
Searches the terminal-side user information management unit 32 using the requesting user name described in the license as a key, and user information that should be kept secret from third parties other than the user and the license server operator. Is extracted. Thereafter, the pair of the user information and the user name is transmitted to the use permission server 4 (Step 1502). Such a process corresponds to, for example, a settlement process for a license, and the user information may be, for example, credit card information of the user.

The condition judging section 43 in the use permission server 4
When a pair of the user information U and the user name is sent from the playback device 3, the pair is registered in the server-side user information management unit 42 (FIG. 16, step 1601).

When transmitting the pair of the user information U and the user name, the use control unit 33 in the reproducing apparatus 3 extracts the use permission code UPC and the user name described in the use certificate and transmits them to the second (Step 1503 in FIG. 15).

Thus, the second decryption key sequence request generation section 31 acquires the user information U corresponding to the user name from the terminal side user information management section 32 and uses the function F shown in the following equation (1). Then, the first modified use permission code MUPC is calculated (step 1504).

F (UPC, U) = H [U] (MUPC) (1)

Here, the function H [x] (y) may be any function that calculates different values with high probability for different sets (x, y). For example, an encryption function using x as a key or a hash function with a key such as HMAC described in RFC-2104 can be used. In particular, when a one-way function such as a keyed hash function is used, an effect is obtained that it is more difficult for a third party to steal an unauthorized use permission code.

Then, the second decryption key sequence request generation unit 31
, A decryption key sequence request including the first modified use permission code is generated instead of the use permission code in the first embodiment, and transmitted to the use permission server 4 (step 1505).

The condition determining unit 43 in the use permission server 4
When a decryption key sequence request is sent from the playback device 3, the first modified use permission code M included in the decryption key sequence request
The UPC sends the use permission code of the logical component set C to be reproduced stored in the use condition description management unit 12 and the user who transmitted the decryption key sequence request extracted from the server side user information management unit 42 to the user. It is verified that the relationship with the corresponding user information U satisfies the following expression (2) (steps 1602 and 1603).

MUPC = F (UPC, U) (2)

When the relationship as in equation (2) holds, the second use permission code authenticating unit 41 determines that the decryption key sequence request is “valid” (YES in step 1603). Is determined to be “illegal” (step 160
3 is NO).

Then, by performing the same processing as steps 311 to 314 in FIG. 4 performed by the use permission server 1 in the first embodiment, when the decryption key sequence is “valid”, the decryption key sequence is generated. Is transmitted to the playback device 3 and, if "illegal", an error message notifying that the decryption key sequence request is unauthorized is sent to the playback device 3 (steps 311 to 314).

Upon receiving the decryption key sequence request, the reproducing device 3 performs the same processing as in steps 213 to 215 of FIG. 3 to decrypt the encrypted component data, and outputs the content data to the output unit 22. Output

Next, a third embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 17 is a block diagram showing a configuration example of the third embodiment of the present invention. In place of the use permission server 1 and the reproduction apparatus 2 of the first embodiment shown in FIG. A server 6 and a playback device 5 are provided.

The difference between the reproducing apparatus 5 of the present embodiment and the reproducing apparatus 2 of the first embodiment is that the license management unit 24
In that a second license management unit 53 is provided in place of the above, a third decryption key sequence request generation unit 51 is provided in place of the decryption key sequence request generation unit 27, and in place of the use control unit 25. That the recording medium K2
In that a recording medium K5 is provided instead of the above, and a terminal-side key scheduling unit 52 is added.

The second license management unit 53 stores the second license transmitted from the license server 6. Further, the second license management unit 53 associates the license serial number included in the license with the second license and grants the license with the license. The ID of the component set in question, a temporary key sequence generated based on the contents of the license, and the number of times the component set permitted to be used by the license are used so far are stored.

The terminal-side key scheduling unit 52 differs from the use number upper limit value and the type used in the second use certificate, extracted by the use control unit 54, to the above use number upper limit value. A temporary key sequence including the same number of temporary keys as the use count upper limit corresponding to the use count is generated.

The third decryption key sequence request generation unit 51
A temporary key corresponding to the number of uses of the logical component to be reproduced is obtained from the temporary key sequence corresponding to the logical component to be reproduced this time, which is stored in the license management unit 53 of
A decryption key sequence request including the temporary key is generated.

A recording medium K5 is a disk, a semiconductor memory,
It is another recording medium in which a program for causing a computer to function as the reproducing device 5 is recorded. This program is read by the computer, and by controlling the operation of the computer,
A use license request generation unit 26, a communication control unit 29, a third decryption key sequence request generation unit 51, a terminal-side key scheduling unit 52, and a use control unit 54 are realized.

The difference between the use permission server 6 of the present embodiment and the use permission server 1 of the first embodiment is that a use condition description management unit 63 is provided instead of the use condition description management unit 12. That the condition determining unit 13 is provided instead of the condition determining unit 13;
6, a third permission code authentication unit 61 is provided, a recording medium K6 is provided instead of the recording medium K1, a server-side key scheduling unit 62 is added, and a schedule table. The point is that the management unit 621 is added.

The use condition description management unit 63 stores, in addition to the information stored in the use condition description management unit 12 in the first embodiment, an upper limit value of the number of uses for each component set. .

The server-side key scheduling unit 62, when a license request designating a component set is sent from the playback device 5, sends an upper limit on the number of times of use of the specified component set from the use condition description management unit 63. A value is generated together with a seed, and a temporary key including the same number of temporary keys as the use frequency upper limit corresponding to different use times up to the use frequency upper limit based on the use frequency upper limit and the seed, respectively. A key sequence is generated and stored in the schedule table management unit 621.

When a request for a decryption key sequence for a set of components to be played back is sent from the playback device 5, the third use permission code authentication unit 61 sends the temporary key in the decryption key sequence to the schedule table management unit 621. Performs authentication based on the stored temporary key.

[0114] The recording medium K6 is a disk, a semiconductor memory, or another recording medium, and stores a program for causing a computer to function as the use permission server 6. This program is read by the computer, and by controlling the operation of the computer, the communication control unit 11, the use condition description management unit 63,
The condition determining unit 64, the usage certificate generation unit 14, the decryption key sequence generation unit 15, the server-side key scheduling unit 62, and the third usage permission code authentication unit 61 are realized.

Next, the operation of the present embodiment will be described in detail with reference to the drawings. FIG. 18 is a processing sequence diagram showing information exchanged between the use permission server 6 and the playback device 5 in chronological order. FIG. 19 is a flowchart showing a processing example of the playback device 5, and FIG. 20 is a flowchart showing a processing example of the use permission server 6.

When the user inputs a digital content playback request, the playback device 5 performs steps 203 to 20 in FIG. 3 performed by the playback device 2 in the first embodiment.
6, a component set C to be reproduced is determined, and a license request for the component set C is transmitted to the license server 6.

When the license request is sent from the playback device 5, the license server 6 performs steps 301 to 30 of FIG. 4 performed by the license server 1 in the first embodiment.
By performing the same processing as in No. 4, it is determined whether or not the condition in the license request satisfies the use condition stored in the use condition description management unit 63. If the usage conditions are satisfied, the server-side key scheduling unit 62
The process of step 2104 of 0 is performed.

In step 2104, the server-side key scheduling unit 62 generates a seed S using a random number, and further, from the usage condition description management unit 63, uses the upper limit N of the number of use times of the component set C to be reproduced this time. Is extracted.

In the next step 2105, the server-side key scheduling unit 62 sets the type S and the upper limit N
And the following recurrence formulas (3), (4), and (5), the temporary key sequence σ = σS [1], S [2],.
[N]｝ is generated (step 2105).

S [0] = S (3) S [N] = H (S [0]) (4) S [i−1] = H (S [i]) (2 ≦ i ≦ N) … (5)

Here, H is a one-way hash function such as MD5.

In the next step 2106, the server-side key scheduling section 62 uses the serial number newly generated by the usage certificate generation section 14 as a key, as a seed S, an upper limit N of use times, a temporary key sequence σ, The number of times “0” is stored in the schedule table management unit 621. FIG. 21 is a diagram showing an example of the contents of the schedule table management unit 621, and includes "serial number", "seed", "temporary key sequence", "use upper limit",
“Use frequency” is stored.

Although the seed S may be random binary data, for example, by using the user information as described above, it is possible to prevent the seed S from being illegally leaked to a third party.

Thereafter, the license generating unit 14 sets the type S and the upper limit N of the number of times of use in addition to the fields (content name, author name, etc.) of the license according to the first embodiment of the present invention. Generate a second license having fields. FIG. 22 shows a configuration example of the second license.
The second license is transmitted to the playback device 5 via the communication control unit 11 (step 2107).

When the second license is received from the license server 6, the usage control unit 54 in the playback device 5 checks the second license and the components whose use is permitted by the license. The ID of the set C and the license serial number are stored in the second license management unit 53 (FIG. 19, step 1901). As shown in FIG. 23, the second license management unit 53 stores, in addition to the area for storing the ID of the component set, the second license, and the license serial number,
It has an area for storing “the number of times of use” and “temporary key sequence”. When storing a new second license,
The use control unit 54 sets 0 as an initial value of the number of uses.

Thereafter, the use control unit 54 extracts the seed S and the upper limit N of the number of use times in the use permit and inputs them to the terminal-side key scheduling unit 52 (step 1902).

In the terminal-side key scheduling section 52, based on the input seed S and the upper limit N of the number of times of use, the temporary key sequence σ is calculated based on the recurrence formulas (3), (4), and (5).
{S [1], S [2],..., S [N]} are generated (step 1903).

[0128] The temporary key sequence generated in this way is output to use control unit 54. Using the license code included in the license as a key, the usage control unit 54 registers the temporary key sequence at an appropriate position in the second license management unit 53 (step 1904). Thereafter, the usage control unit 54 instructs the third decryption key sequence request generation unit 51 to generate a decryption key sequence request.

Thus, the third decryption key sequence request generation unit 51 obtains an appropriate temporary key from the second license management unit 53. At this time, the third decryption key sequence request generation unit 51
Adds 1 to the number of uses UC stored in the second license management unit 53, and then extracts a temporary key S [UC] from the temporary key sequence σ using the updated UC ( Step 1905). Then, the third decryption key sequence request generation unit 51 generates a decryption key sequence including the extracted temporary key as a second modified use permission code MUPC ′ instead of the use permission code in the first embodiment. Generate a request,
The request is transmitted to the use permission server 6 (step 1907).
If a temporary key matching the condition cannot be extracted in step 1905 (step 1906 is NO), the output unit 22
Is used to notify the user that the use of the component set C has not been permitted.

The condition determining unit 64 in the use permission server 6
Upon receiving the decryption key sequence request from the playback device 5, the second modified use permission code MU included in the decryption key sequence request
PC ′ is extracted and input to the third use permission code authentication unit 61 together with the decryption key sequence request (FIG. 20, step 2101).

The third license code authentication section 61 inputs the license serial number SN in the decryption key sequence request to the server-side key scheduling section 62. Then, the server-side key scheduling unit 62 extracts a set of (the license serial number SN, the number of uses UC, and the temporary key sequence σ) from the schedule table management unit 621 using the SN as a key, and sets the value of the number of uses UC as a value. After adding 1, it refers to the temporary key S [UC] corresponding to the number of uses UC, and outputs the value to the third use permission code authentication unit 61 (step 2102).

Then, the third use permission code authentication section 61
Then, it is verified that the following equation (6) holds for the second modified use permission code MUPC 'and the temporary key S [UC].

MUPC '= S [UC] (6)

When the relationship shown in Expression (6) holds, the third use permission code authenticating unit 61 determines that the decryption key sequence request is “valid”, and when it does not hold, determines that it is “illegal” ( Step 2103).

As in the case of the use permission server 1 in the first embodiment, when the second modified use permission code is “valid”, a decryption key sequence is generated and transmitted to the playback device 3. And if it is "illegal," an error message notifying that the decryption key sequence request is invalid is transmitted to the reproducing device 3.

When the decryption key sequence is sent from the use permission server 6, the playback device 5 decrypts the content data to be played back, as in the playback device 2 of the first embodiment, and outputs the decrypted content data. 22.

[0137]

A first effect is that the configuration of a set of constituent elements can be changed after content distribution.

The reason is that a use permission code is assigned to each component set, and a set of decryption keys of component data belonging to the component set is assigned to the use permission code. This is because the correspondence relationship with can be changed at any time.

[0139] The second effect is that illegal transfer of the right to use the content by the user can be prevented.

The reason is that, in the request for the decryption key sequence, instead of the use permission code, a modified use permission code generated using user information which may be disadvantageous to the user if notified to a third party is included. Information closely related to user-specific information will be safely shared on both the playback device side and the usage permission server side, and if a valid modified usage permission code is leaked to a third party, the user will be leaked. This is because the use permission server can easily detect the origin.

A third effect is that the number of times the content can be used can be reliably restricted even when there is a person who intends to commit fraud.

The reason is that by including the modified use permission code extracted from the temporary key sequence having a finite length in the decryption key sequence request, a valid modified use permission code exceeding the length of the temporary key sequence can be obtained. Is impossible to generate.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration example of a first embodiment of the present invention.

FIG. 2 is a processing sequence diagram according to the first embodiment.

FIG. 3 is a flowchart showing a processing example of a reproducing apparatus 2;

FIG. 4 is a flowchart showing a processing example of the use permission server 1;

FIG. 5 is a diagram illustrating an example of property information.

FIG. 6 is a diagram showing an example of a license request.

FIG. 7 is a diagram illustrating an example of a usage condition description.

FIG. 8 is a diagram showing an example of a usage certificate.

FIG. 9 is a diagram illustrating an example of a dialog box presented to a user when an unauthorized use license is obtained by the playback device 2.

FIG. 10 is a diagram illustrating an example of a dialog box presented to the user when the reproduction device 2 does not satisfy the use condition.

FIG. 11 is a diagram showing an example of the structure of a decryption key sequence.

FIG. 12 is a block diagram illustrating a configuration example of an output unit 22 when the playback apparatus 2 has a plurality of output devices.

FIG. 13 is a block diagram illustrating a configuration example of a second embodiment of the present invention.

FIG. 14 is a processing sequence diagram according to the second embodiment.

FIG. 15 is a flowchart showing a processing example of the playback device 3;

FIG. 16 is a flowchart showing a processing example of the use permission server 4.

FIG. 17 is a block diagram illustrating a configuration example of a third embodiment of the present invention.

FIG. 18 is a processing sequence diagram of the third embodiment.

FIG. 19 is a flowchart showing a processing example of the playback device 5;

FIG. 20 is a flowchart showing a processing example of the use permission server 6;

FIG. 21 is a diagram illustrating an example of contents of a schedule table management unit 621.

FIG. 22 is a diagram showing an example of a second license.

FIG. 23 is a diagram showing an example of contents of a second use license management unit 53;

[Explanation of symbols]

 0 ... Network 1 ... Use permission server in the first embodiment of the present invention 11 ... Communication control unit 12 ... Use condition description management unit 13 ... Condition determination unit 14 ... Use certificate generation unit 15 ... Decryption key sequence generation unit 16 ... Use Authorization code authentication unit 17 Latest property acquisition unit 2 Playback device in the first embodiment of the present invention 21 Input unit 22 Output unit 23 Content management unit 24 License management unit 25 Usage control unit 26 Usage Permit request generation unit 27 Decryption key sequence request generation unit 28 Decryption unit 29 Communication control unit 221 Device selection device 222 Display device 223 Printing device 224 Secondary storage device 3 Second embodiment of the present invention Playback device 31 ... second decryption key sequence request generation unit 32 ... terminal side user information management unit 33 ... use control unit 4 ... license in the second embodiment of the present invention Server 41: second use permission code authentication unit 42: server-side user information management unit 43: condition determination unit 5: playback device 51 according to the third embodiment of the present invention 51: third decryption key sequence request generation unit 52: terminal Side key scheduling unit 53 Second use license management unit 54 Use control unit 6 Use permission server 61 in the third embodiment of the present invention 61 Third use permission code authentication unit 62 Server key scheduling unit 621 ... Schedule table management unit 63 ... Usage condition description management unit 64 ... Condition determination unit K1-K6 ... Recording medium

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) H04L 9/14 H04L 9/00 641

Claims (13)

[Claims] 1. A digital content use control method for controlling use of digital content in a system in which a playback device and a use permission server are connected via a network, wherein the digital content is encrypted with different encryption keys. The use permission server manages the respective component data of the digital content by dividing the data into a plurality of component sets, and further includes a use permission code for each of the component sets and the respective component. A decryption key for each data is managed, and when a license request specifying a set of components to be played back is sent from the playback device, a usage including a license code corresponding to the designated set of components is received. Sending a license to the playback device, wherein the playback device receives the license from the license server When a request for a decryption key sequence including the use permission code in the license is sent to the use permission server, the use permission server sends the decryption key sequence when the request for the decryption key sequence is sent from the playback device. After performing authentication based on the use permission code in the request and the use permission code managed by the own server, a decryption key of each component data included in the component set corresponding to the use permission code is obtained. A digital content use control method, wherein the method is transmitted to the playback device. 2. A digital content usage control method for controlling usage of digital content in a system in which a playback device and a usage permission server are connected via a network, wherein the digital content is encrypted with different encryption keys. The use permission server manages the respective component data of the digital content by dividing the data into a plurality of component sets, and further includes a use permission code for each of the component sets and the respective component. A decryption key for each data is managed, and when a license request specifying a set of components to be played back is sent from the playback device, a usage including a license code corresponding to the designated set of components is received. Sending a license to the playback device, wherein the playback device receives the license from the license server At this time, a modified use permit code is generated based on the use permit code in the use permit and the user information managed by the own device, and the decryption key sequence request including the modified use permit code and the user information are transmitted to the device. When the decryption key sequence request is sent from the playback device, the usage permission server sends the modified use permission code in the decryption key sequence request and the user sent from the playback device. After performing authentication based on the information and the use permission code managed by the own server, the decryption key of each component data included in the component set corresponding to the use permission code is transmitted to the playback device. A method for controlling the use of digital content, characterized by sending. 3. A digital content usage control method for controlling usage of digital content in a system in which a playback device and a usage permission server are connected via a network, wherein the digital content is encrypted with a different encryption key. The use permission server manages the constituent data of the digital content by dividing the constituent data into a plurality of constituent element sets, and further includes a use permission code for each of the constituent element sets, and each of the constituent elements. Manages the upper limit of the number of times of use for each set, and the decryption key for each of the component data, and, when a license request specifying the component set is sent from the playback device, the specified component set A license containing the upper limit of the number of uses and the seed are transmitted to the playback device, and the upper limit of the number of uses and the seed are And generating and storing a temporary key sequence including the same number of temporary keys as the use count upper limit corresponding to different use counts up to the use count upper limit. If the license for the set of components to be reproduced has not been received, a license request specifying the set of components to be reproduced is sent to the license server. The use count upper limit corresponding to different use counts up to the use count upper limit, respectively, based on the use count upper limit and the seed in the license issued from the use permit server in response to the request. A temporary key sequence including the same number of temporary keys is generated and stored, and decryption is performed on the reproduction target component set including a temporary key corresponding to the current number of uses in the temporary key sequence. If a series request is sent to the use permission server and a license for the set of components to be reproduced has been received, a temporary key corresponding to the number of times of use this time in the temporary key series stored at the time of receiving the use license is received. A decryption key sequence request for the set of components to be reproduced including a key is sent to the use permission server, and the use permission server sends a request for a decryption key sequence to the set of components to be reproduced from the reproduction device.
After performing authentication based on the temporary key in the request for the decryption key sequence and the temporary key corresponding to the number of times of use this time in the temporary key sequence stored in the server, it is included in the set of components to be reproduced. Transmitting a decryption key of each constituent element data to the playback device. 4. A digital content use control system comprising a playback device and a use permission server connected via a network and controlling the use of digital content including a plurality of component data encrypted with different encryption keys. The use permission server manages the component data of the digital content by dividing the component data into a plurality of component sets, and uses a use permission code for each of the component sets and a decryption key for each of the component data. When a license request specifying a component set to be played back is sent from the playback device, the license containing the license code corresponding to the designated component set is played back. Device, and when a decryption key sequence request is sent from the playback device, the use permission code in the decryption key sequence request and the own server After performing authentication based on the managed use authorization code, the configuration has a configuration in which the decryption key of each component data included in the component set corresponding to the use authorization code is sent to the playback device, The playback device sends a license request specifying a component set to be played back to the license server when the component set is played, and when a license is sent from the license server, A digital content use control system, characterized by having a configuration in which a decryption key sequence request including a use permission code in a use certificate is sent to the use permission server. 5. The digital content use control system according to claim 4, wherein the use permission server includes a component included in each component set when each component data of the digital content is divided into a plurality of component sets. A use condition description management unit that manages information indicating element data, a use permission code of each of the component sets, and a decryption key of each of the component data, and designates a component set to be reproduced from the reproduction device; When the usage license request is sent, the usage license code corresponding to the specified component set is obtained from the usage condition description management unit, and the usage license including the obtained usage license code is reproduced. A license generating unit to be sent to the device, and when a decryption key sequence request is sent from the playback device,
A use permission code authentication unit that performs authentication based on the use permission code in the decryption key sequence request and the use permission code managed by the use condition description management unit; A decryption key sequence generation unit that obtains a decryption key of each component data included in the component set corresponding to the use authorization code obtained from the use condition description management unit and sends the decryption key to the playback device. The apparatus includes: a license request generation unit that sends a license specifying a component set to be played back to the license server when the component set is reproduced; and a license is transmitted from the license server. And a decryption key sequence request generation unit for sending a decryption key sequence request including a use permission code in the license to the use permission server when the use is permitted. system. 6. A digital content use control system comprising a playback device and a use permission server connected via a network, and controlling the use of digital content including a plurality of component data encrypted with different encryption keys. The use permission server manages the component data of the digital content by dividing the component data into a plurality of component sets, and uses a use permission code for each of the component sets and a decryption key for each of the component data. When a license request specifying a component set to be played back is sent from the playback device, the license containing the license code corresponding to the designated component set is played back. To the device, when a decryption key sequence request is sent from the playback device, a modified use permission code in the decryption key sequence request,
After performing authentication based on the user information sent from the playback device and the use permission code managed by the own server, each component included in the component set corresponding to the use permission code Having a configuration for sending a decryption key for data to the playback device, wherein the playback device sends a license request specifying a component set to be played back to the usage license server when the component set is played, When a license is sent from the license server, a modified license code is generated based on the license code in the license and the user information managed by the own device. And transmitting the decryption key sequence request and the user information to the use permission server. 7. The digital content use control system according to claim 6, wherein the use permission server includes a component included in each component set when each component data of the digital content is divided into a plurality of component sets. A use condition description management unit that manages information indicating element data, a use permission code of each of the component sets, and a decryption key of each of the component data, and designates a component set to be reproduced from the reproduction device; When the usage license request is sent, the usage license code corresponding to the specified component set is obtained from the usage condition description management unit, and the usage license including the obtained usage license code is reproduced. A license generating unit to be sent to the device, and when a decryption key sequence request is sent from the playback device,
A use permission code authentication unit for performing authentication based on the modified use permission code in the decryption key sequence request, the user information sent from the playback device, and the use permission code managed by the server; A decryption key for acquiring the decryption key of each component data included in the component set corresponding to the use authorization code determined to be valid by the use authorization code authentication unit from the use condition description management unit and sending the decryption key to the playback device A sequence generating unit, wherein the reproducing device transmits a license request specifying a component set to be reproduced to the license server at the time of reproducing the component set; When the license is sent from the license server, a modified license code is generated based on the license code in the license and the user information managed by the own device. A decryption key sequence request including a decryption key sequence request including a usage permission code and the user information to the license server. 8. A digital content use control system comprising a playback device and a use permission server connected via a network, and controlling the use of digital content including a plurality of component data encrypted with different encryption keys. Wherein the use permission server manages the constituent data of the digital content by dividing the constituent data into a plurality of constituent sets, a use permission code for each of the constituent sets, and a use count for each of the constituent sets. Manages an upper limit value and a decryption key for each of the component data, and when a use license request specifying a component set is sent from the playback device, an upper limit of the number of times of use of the specified component set And a usage certificate including the seed and the seed, and the usage count based on the usage count upper limit and the seed, respectively. A temporary key sequence including the same number of temporary keys as the use count upper limit corresponding to different use counts up to the limit value is generated and stored, and a decryption key sequence request for the reproduction target component set is sent from the playback device. Authentication, based on the temporary key in the decryption key sequence request and the temporary key corresponding to the number of times of use this time in the temporary key sequence stored in the server itself, It has a configuration in which a decryption key of each component data included in the set is sent to the playback device, and the playback device receives a license for the component set to be played back when the component set is played back. If not, a license request specifying the set of components to be reproduced is sent to the license server, and then sent from the license server in response to the license request. Generating a temporary key sequence including the same number of temporary keys as the use count upper limit corresponding to different use counts up to the use count upper limit based on the use count upper limit and the seed in the license. A request for a decryption key sequence for the set of components to be reproduced, which includes a temporary key corresponding to the number of times of use in the temporary key sequence and which is stored in the temporary key sequence, is sent to the use permission server. Is received, the decryption key sequence request for the set of components to be reproduced including the temporary key corresponding to the current use count in the temporary key sequence stored at the time of receiving the license is sent to the license server. A digital content use control system having a configuration. 9. The digital content use control system according to claim 8, wherein the use permission server includes a component included in each component set when each component data of the digital content is divided into a plurality of component sets. Information indicating element data, a use permission code of each of the component sets, and an upper limit on the number of times of use of each of the component sets,
A use condition description management unit that manages a decryption key of each of the component data, and a license request specifying a component set is sent from the playback device, the use condition description management unit The use count upper limit value corresponding to different use counts up to the use count upper limit value based on the use count upper limit value and the seed, respectively, while obtaining the use count upper limit value of the set of component elements. A server-side key scheduling unit that generates and stores a temporary key sequence including the same number of temporary keys as: a maximum number of times of use obtained by the server-side key scheduling unit and a seed generated by the server-side key scheduling unit A license generating unit that sends a usage certificate including the license to the playback device, and a decryption key sequence request for a set of components to be played back is sent from the playback device. License authentication unit for performing authentication based on the temporary key in the key sequence request and the temporary key corresponding to the number of times of use in the temporary key sequence stored in the server, and the usage authorization code authentication unit And a decryption key sequence generation unit that sends a decryption key of each component data included in the playback target component set to the playback device when it is determined that the playback device is valid. A license request for sending a license request specifying the component set to be reproduced to the license server when the set has not been received at the time of reproducing the set. A generation unit, based on the upper limit of the number of uses and the type in the license sent from the license server, each of which corresponds to a different number of uses up to the upper limit of the number of uses. A terminal-side key scheduling unit for generating and storing a temporary key sequence including the same number of temporary keys as the limit value, and, when reproducing the component set, receiving a license for the component set to be reproduced, Upon receiving the usage certificate, the terminal-side key scheduling unit sends a decryption key sequence request for the set of components to be reproduced including the temporary key corresponding to the current use count in the temporary key sequence stored to the usage permission server. A digital content use control system comprising a decryption key sequence request generation unit. 10. The digital content use control system according to claim 9, wherein the server-side key scheduling unit has a configuration for generating a seed using a random number. 11. A computer for use permission server, wherein each component data of digital contents including a plurality of component data encrypted with different encryption keys is managed by dividing into a plurality of component sets, and each of said component components is managed. A process of managing a use permission code for each set and a decryption key for each of the component data; and, when a license request specifying a component set to be reproduced is transmitted from the reproduction device computer, the specification is performed. Sending a license containing a license code corresponding to the set of constituent elements to the playback device computer, and when a decryption key sequence request is sent from the playback device computer, the decryption key sequence request After performing authentication based on the use permission code of the user and the use permission code managed by the own computer, Sending the decryption key of each component data included in the set of constituent elements to the playback device computer, and causing the playback device computer to play back the set of components when playing back the set of components. Sending a license request to the license server computer, and a decryption key sequence including a license code in the license when the license is transmitted from the license server computer. A machine-readable recording medium on which a program for performing a process of sending a request to the computer for use permission server is recorded. 12. A computer for use permission server, wherein each component data of digital contents including a plurality of component data encrypted with different encryption keys is divided into a plurality of component sets, and each component is managed. A process of managing a use permission code for each set and a decryption key for each of the component data; and, when a license request specifying a component set to be reproduced is transmitted from the reproduction device computer, the specification is performed. Sending a license containing a license code corresponding to the set of constituent elements to the playback device computer; and when a decryption key sequence request is sent from the playback device computer, the decryption key sequence request Correction use permission code, the user information sent from the playback device computer, and the use permission managed by the own computer. Sending the decryption key of each component data included in the component set corresponding to the use permission code to the playback device computer after performing the authentication based on the permission code. Sending a license request specifying the component set to be played back to the license server computer at the time of playback of the component set to the component computer; and sending the license from the license server computer. The modified license code is generated based on the license code in the license and the user information managed by the computer, and a decryption key sequence request including the modified license code and the user information And a computer-readable recording medium on which a program for performing a process of sending the program to the use permission server computer is recorded. 13. A computer for use permission server, wherein each component data of digital contents including a plurality of component data encrypted with different encryption keys is managed by dividing into a plurality of component sets and each of said component components is managed. A process of managing a use permission code for each set, an upper limit of the number of use times for each of the component sets, and a decryption key for each of the component data; Is sent, a license including the upper limit of the number of uses of the specified component set and a seed are transmitted to the playback device computer, and based on the upper limit of the number of uses and the seed. A process of generating and storing a temporary key sequence including the same number of temporary keys as the upper limit of the number of uses, each corresponding to a different number of uses up to the upper limit of the number of uses. When a decryption key sequence request for a set of components to be reproduced is sent from the reproduction device computer, the temporary key in the decryption key sequence request and the temporary key sequence stored in the own computer are used in the temporary key sequence. After performing authentication based on the temporary key corresponding to the number of times, a process of sending a decryption key of each component data included in the set of components to be played back to the computer for the playback device is performed. If the use computer does not receive a license for the set of components to be reproduced when the component set is reproduced, the use computer specifies the set of components to be reproduced to the use permission server computer. Sending a license request, and thereafter, the number of times of use in the license sent from the license server computer in response to the license request And generating and storing a temporary key sequence including the same number of temporary keys as the use frequency upper limit value corresponding to different use times up to the use frequency upper limit value, based on the limit value and the seed. Sending a decryption key sequence request for the set of components to be reproduced including the temporary key corresponding to the number of times of use to the computer for the license server, and receiving a license for the component set to be reproduced. If there is, a process of transmitting a decryption key sequence request for the set of components to be reproduced including a temporary key corresponding to the current use count in the temporary key sequence stored at the time of receiving the license to the license server computer And a machine-readable recording medium recording a program for performing the above.