JP2012190268A - Content using terminal, content management system, content management method, content management program, and server device - Google Patents

Abstract

Convenience is improved by making it possible to use encrypted content at a plurality of content use terminals while protecting the copyright of the encrypted content.
A content management system 10 includes a terminal 1, a server 13, a customer DB 14, and a PC 15. While the user is browsing the encrypted content 8d on the terminal 1, the server 13 is inquired of whether or not browsing is possible for each variable waiting time T. If it is determined that browsing is impossible, the waiting time T is set. The frequency is gradually shortened to increase the frequency of warning display to the user. Further, when the user changes the setting of the terminal 1 that the user desires to browse on the content management screen, the server 13 checks whether the setting change is an error and reflects the check result on the content management screen.
[Selection] Figure 1

Description

  The present invention relates to a content use terminal, a content management system, a content management method, a content management program, and a server device that can browse digital content such as an electronic book or an electronic comic.

  With the low price and low power consumption of liquid crystal display devices equipped with touch panel functions, digital content such as e-books and e-comics can be transferred to portable electronic devices such as mobile phones and smartphones, and personal computers (hereinafter collectively referred to as “collection”). New content providing services that can be easily browsed by electronic devices) are rapidly spreading (see Patent Document 1).

  Digital contents such as electronic books are highly convenient because they can provide a large amount of information without deterioration, but copyright protection becomes a problem.

  In order to protect copyright, it is desirable to protect digital contents so that they can be browsed only by electronic devices registered in advance. However, many users possess a plurality of electronic devices, and the actual situation is that these electronic devices are arbitrarily used in different environments such as a workplace or home. In such a case, if only one of the digital contents can be browsed, the usability is remarkably deteriorated.

  From the user's point of view, as long as it is an electronic book that has been properly purchased by the user, it can be argued that the user is free to use which electronic device to view. In addition, if the number of electronic devices that can be browsed is limited to one, there is a possibility that the electronic book will not be spread due to the difficulty.

Japanese Patent No. 44059161

  Patent Document 1 described above stores electronic book data in an archive server, and downloads and browses electronic book data from the archive server when necessary. In the case of this patent document 1, when accessing a library server from an electronic book terminal, verification is not performed based on the terminal ID of the electronic book terminal but based on the user's own ID or password. For this reason, as long as the user's own ID and password can be obtained, the electronic book data can be downloaded from any electronic book terminal, which may impair copyright protection.

  As described above, conventionally, there has not been established a method for improving convenience by making it possible to use encrypted content at a plurality of content use terminals without impairing copyright protection of the encrypted content.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to make it possible to use encrypted content on a plurality of content use terminals while protecting the copyright of the encrypted content. An object is to provide an improved content use terminal, content management system, content management method, content management program, and server device.

In order to solve the above problem, an aspect of the present invention provides an encrypted content acquisition unit that downloads encrypted content from a server device;
A decryption key acquisition unit for downloading a decryption key for decrypting the encrypted content from the server device;
A content decryption unit for decrypting the encrypted content using the decryption key;
An availability inquiry unit that inquires of the server device whether the encrypted content is available each time a variable waiting time elapses;
As a result of the inquiry by the availability inquiry unit, an availability determination unit that determines whether or not the encrypted content is unavailable,
A use prohibition control unit that prohibits the use of the encrypted content inquired of the availability, when the number of times determined that the server communication impossibility is determined to be unusable reaches a predetermined number of times;
A warning display control unit that permits use of the encrypted content inquired of the availability together with a predetermined warning display when it is determined that the usage is not possible, but the number of times does not reach the predetermined number. And a content use terminal characterized by comprising:

Further, according to one aspect of the present invention, in a content management system including a content use terminal and a server device that perform communication via a predetermined network,
A customer database device for registering identification information of an owner of the content use terminal and information for identifying encrypted content permitted to be used by the owner;
The content using terminal is:
An encrypted content acquisition unit that downloads encrypted content from the server device;
A decryption key acquisition unit for downloading a decryption key for decrypting the encrypted content from the server device;
A content decryption unit for decrypting the encrypted content using the decryption key;
An availability inquiry unit that inquires of the server device whether the encrypted content is available each time a variable waiting time elapses;
As a result of the inquiry by the availability inquiry unit, an availability determination unit that determines whether or not the encrypted content is unavailable,
A use prohibition control unit that prohibits the use of the encrypted content inquired of the availability, when the number of times determined that the server communication impossibility is determined to be unusable reaches a predetermined number of times;
A warning display control unit that permits use of the encrypted content inquired of the availability together with a predetermined warning display when it is determined that the usage is not possible, but the number of times does not reach the predetermined number. And having
The server device
When there is a query from the availability query unit, based on the result of referring to the customer database device, a availability determination unit that determines the availability of the encrypted content that has been queried.
A use availability information response unit that responds to the content use terminal with the use availability information of the encrypted content that has been inquired about use based on the determination result of the use determination unit; A management system is provided.

Further, according to one aspect of the present invention, in a server device that communicates with a content using terminal via a predetermined network,
Based on the registration information in the customer database device in which the identification information of the owner of the content using terminal that requested the download of the encrypted content and the identification information of the encrypted content permitted to be used by the owner are registered. A decryption key generation unit for generating a decryption key for decrypting the encrypted content;
Whenever a variable waiting time elapses from the content use terminal that has decrypted the encrypted content using the decryption key, whenever the inquiry about the availability of the encrypted content is made, Based on registration information of the customer database device, an availability determination unit that determines whether to permit the use of encrypted content to the content usage terminal;
A use availability information response unit that responds to the content use terminal with the use availability information of the encrypted content that has been inquired about the use availability based on the determination result of the use determination unit; A device is provided.

  According to the present invention, it is possible to improve convenience by making it possible to use encrypted content at a plurality of content use terminals while protecting the copyright of the encrypted content.

The block diagram which shows schematic structure of the content utilization terminal 1 which concerns on one Embodiment of this invention. The figure explaining the utilization condition of this embodiment. 1 is a block diagram showing a schematic configuration of a content management system 10 according to the present embodiment. The flowchart which shows the process sequence at the time of the initial purchase which concerns on this embodiment. The figure which matched the information transmitted / received between the server 13 and the terminal 1 with each step of FIG. The figure which shows an example of a content management screen. The detailed flowchart of step S12 and S13 of FIG. The detailed flowchart of a server inquiry process. The figure which shows an example of a content information file. The flowchart which shows an example of the process which the server 13 performs. The flowchart which shows an example of the update procedure of a content management screen.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a block diagram showing a schematic configuration of a content use terminal 1 according to an embodiment of the present invention. The content use terminal 1 in FIG. 1 mainly assumes portable electronic devices such as a mobile phone, a smartphone, and a PDA, but may be a stationary general-purpose personal computer. That is, it has a communication function for communicating with the server, a function for storing various digital contents downloaded from the server, a display function for displaying the downloaded digital contents, and a function for receiving user operations. For example, the realization form does not matter.

  Therefore, the schematic configuration of the content use terminal 1 has a degree of freedom and is not necessarily limited to the one shown in FIG. 1, but the content use terminal 1 in FIG. 1 will be described below as an example. Hereinafter, the content use terminal 1 is simply referred to as a terminal 1 for short.

  The digital content that can be browsed by the terminal 1 in FIG. 1 is not particularly limited, such as an electronic book, an electronic comic, stream data, and various types of AV data. Hereinafter, an example of browsing an electronic book will be described. .

  The terminal 1 in FIG. 1 includes a CPU 2, an input unit 3, a communication unit 4, a display control unit 5, a display memory 6, a display unit 7, and a storage unit 8. The input unit 3 may be a keyboard, and when a touch panel is provided, the touch detection unit corresponds to the input unit 3.

  The communication unit 4 communicates with the server and may be wireless or wired. Also, since the form of the communication line is not particularly limited, a public line or a dedicated line may be used, or a close proximity wireless communication line such as a wireless LAN, Bluetooth, or infrared, or a wired Ethernet (registered trademark) may be used. Good.

  The display unit 7 is a flat display device such as a liquid crystal display device or an EL display device, and in some cases, a touch panel is attached to the display panel surface.

  The storage unit 8 includes a ROM, a RAM, and the like (not shown). When the power is turned on, the CPU 2 activates an operating system (hereinafter referred to as OS) 8a stored in the ROM, and further activates the bookshelf application 8b on the OS 8a. When the bookshelf application 8b is activated, a list of electronic books that can be browsed by the user of the terminal 1 is displayed. When the user selects a desired electronic book from the list by using the input unit 3, the viewer application 8c is activated, and when a predetermined condition described later is satisfied, the electronic application selected by the user on the viewer application 8c. The book can be browsed.

  Each electronic book includes an encrypted content 8d obtained by encrypting the electronic book data body, a decryption key 8e for decrypting the encrypted content 8d, and user reading data 8f.

  The encrypted content 8d cannot be browsed without an appropriate decryption key 8e and the viewer application 8c. Even if only the encrypted content 8d is acquired, it cannot be decrypted without the decryption key 8e. In this embodiment, the encrypted content 8d can be downloaded without a purchase procedure. However, a modification in which user authentication or the like is performed when the encrypted content 8d is downloaded is also conceivable.

  The decryption key 8e is key information that is given by the seller to a user who has purchased the desired encrypted content 8d through a seller such as a sales site. The encrypted content 8d generally has a large amount of data (for example, several megabytes), but the amount of data of the decryption key 8e is not so large, for example, about several hundred to several kilobytes.

  The reading data 8f is associated with each encrypted content 8d, and is progress information indicating how far the user has browsed, information such as a bookmark, a character size, a font used, and the like. Since there is no need to protect the copyright, these may be sent and received as plain text data that is not encrypted. However, in order to improve processing efficiency, the encrypted content 8d may be encrypted in the same manner and decrypted in combination with the encrypted content 8d.

  As described above, in this embodiment, since anyone can download the encrypted content 8d regardless of whether or not it is purchased, for example, a user who has downloaded the encrypted content 8d has a plurality of terminals owned by the user. It is possible to copy the encrypted content 8d between the units without any problem. The same applies to the reading data 8f.

  On the other hand, the decryption key 8e and the viewer application 8c cannot be copied to another terminal 1 unless an authentication procedure is performed by the server. As a result, even if the encrypted content 8d that the user was browsing on a certain terminal 1 is copied to another terminal 1, the copied encrypted content 8d is not copied unless a predetermined procedure described later is performed. Cannot browse.

  The viewer application 8c holds a user ID for identifying individual users and a terminal ID for identifying individual terminals 1. The viewer application 8c authenticates with the server using the user ID and the terminal ID, and acquires the decryption key 8e from the server only when the authentication is successful.

  The viewer application 8c is downloaded from a server that sells the encrypted content 8d. The viewer application 8c itself is often provided free of charge, but since the user ID and terminal ID information is held in the viewer application 8c, it cannot be copied directly to another terminal 1 as described above. .

  The decryption key 8e is key information necessary for decrypting the encrypted content 8d (including the reading data 8f in some cases). Specifically, a fixed bit length obtained by performing a hash operation using a user ID, a terminal ID, a content ID for identifying encrypted content 8d, content expiration date information, system-specific control information, etc. as a seed. Key information. The decryption key 8e itself assumes data with a relatively small capacity.

  As will be described later, in the present embodiment, the same electronic book can be browsed (hereinafter referred to as simultaneous reading) on a plurality of terminals 1 possessed by the user under a predetermined condition. Since the number of terminals 1 that can be read simultaneously is different for each encrypted content 8d, information on the upper limit number of terminals 1 that can be simultaneously viewed is included in the seed for generating the decryption key 8e. Also good. In this case, it is conceivable to control the frequency of inquiring the server as to whether or not browsing on the terminal 1 is allowed according to the upper limit number capable of simultaneous reading.

  Further, by controlling the content expiration date embedded in the seed of the decryption key 8e, for example, a browsing mode that allows browsing only for a limited time, a rental mode that allows browsing only for a predetermined period, and a period It is also possible to provide a purchase mode that allows browsing without limitation. In this case, it is conceivable to increase the usage price in the order of the browsing mode, the rental mode, and the purchase mode. By setting the usage price in the browsing mode and rental mode to be significantly lower than the purchase price, the user base can be expanded.

  As can be seen from the above description, in this embodiment, purchasing an electronic book does not acquire the specific encrypted content 8d itself, but purchases a decryption key 8e that can decrypt the specific encrypted content 8d. Means that.

  FIG. 2 is a diagram for explaining the usage status of this embodiment. FIG. 2 shows an example in which a user having a plurality of terminals 1 purchases a plurality of encrypted contents 8d. Individual terminals 1 possess different terminal IDs. As long as the users are the same, the user ID is the same. The password for accessing the server is also the same. The plurality of encrypted contents 8d purchased by the user have different content IDs and different reading data 8f, and also have expiration date information for each content individually.

  Thus, the terminal ID and the user ID (password) are in a many-to-one relationship, and the user ID (password) and the content ID (reading data 8f, expiration date information) are in a one-to-many relationship.

  FIG. 3 is a block diagram showing a schematic configuration of the content management system 10 according to the present embodiment. The content management system 10 of FIG. 3 shows an example in which the terminal 1 shown in FIG. 1 performs wireless communication with the base station 11 and accesses the server 13 via the Internet 12. Although only one server 13 is not necessarily provided, only one server is illustrated in FIG. 3 for simplification. The illustrated server 13 is a vendor that sells electronic books, and is connected to a customer database device (hereinafter referred to as customer DB) 14. The customer DB 14 stores user attribute information such as the user ID, password, and terminal ID of the user who purchased each encrypted content 8d. Further, history information on the purchase of encrypted content 8d by each user, reading data 8f of each encrypted content 8d, and the like are also stored in the customer DB 14.

  The content management system 10 of FIG. 3 includes a PC 15 connected to the Internet 12. The PC 15 is not necessarily required. For example, the PC 15 is used when the user first accesses the sales site and registers the user attribute information described above. The reason for using the PC 15 is that registration of user attribute information is assumed to be performed by accessing a specific sales site using a general-purpose web browser activated under the management of the OS on the PC 15. The user attribute information may be registered in the customer DB 14 at any terminal 1 owned by the user. In this case, the PC 15 is unnecessary. Further, when the electronic book is browsed not by the terminal 1 but by the PC 15, the terminal 1 is not necessary.

  When the user purchases the specific encrypted content 8d, the server 13 refers to the user attribute information stored in the customer DB 14 and generates a decryption key 8e used for decrypting only the specific encrypted content 8d. , It is transmitted to the specific terminal 1 on which the user has performed the purchase procedure. When the server 13 generates the decryption key 8e, the decryption key 8e, the content ID, the reading data 8f, and the like are associated with each other.

  In the customer DB 14, the terminal ID of each terminal 1 possessed by the user is also registered. When the user downloads the viewer application 8c to the specific terminal 1 and accesses the server 13 using the viewer application 8c, the server 13 registers the terminal ID in the customer DB 14.

  FIG. 4 is a flowchart showing a processing procedure at the time of initial purchase according to the present embodiment. FIG. 5 is a diagram in which information transmitted and received between the server 13 and the terminal 1 is associated with each step of FIG. As illustrated in FIG. 5, the server 13 includes a viewer application storage unit 21, an encrypted content storage unit 22, a decryption key generation unit 23, and a reading data acquisition unit 24.

  Next, a processing procedure at the time of initial purchase will be described in order with reference to the flowchart of FIG. First, for example, the user activates a general-purpose browser or the like on the PC 15 to access the sales site, and registers user attribute information such as a user ID, a password, and payment information (step S1). The server 13 that operates the sales site stores the user attribute information registered by the user in the customer DB 14.

  Next, the user accesses a sales site using a specific terminal 1 (or PC 15) possessed by the user, and downloads the viewer application 8c from the sales site (step S2). Next, the user activates the downloaded viewer application 8c and accesses the sales site. At this time, the user inputs the user ID and password registered in step S1. When the server 13 confirms that the user ID and the password match the registration information, the server 13 acquires the terminal ID of the terminal 1 that is running the viewer application 8c and registers it in the customer DB 14 (step S3).

  Next, the user downloads the desired encrypted content 8d on the viewer application 8c (step S4, encrypted content acquisition unit). In parallel with step S4, the decryption key generation unit 23 in the server 13 refers to the customer DB 14, and at least two of the user ID, terminal ID, content ID, content expiration date, and control information unique to the system 10 are included. The decryption key 8e is generated using the above as a seed (step S5, decryption key generation unit).

  When the download of the encrypted content 8d in step S4 is completed, the user downloads the decryption key 8e generated by the server 13 in step S5 (step S6, decryption key acquisition unit).

  The server 13 acquires the reading data 8f of the encrypted content 8d downloaded by the user in step S4 from the customer DB 14 before and after the generation of the decryption key 8e in step S5 (step S7). The user downloads the reading data 8f acquired by the server 13 in step S7 before and after downloading the decryption key 8e in step S6 (step S8).

  When the decryption key 8e in step S6 and the reading data 8f in step S8 are downloaded to the terminal 1 that has downloaded the encrypted content 8d in step S4, the decryption process of the encrypted content 8d is automatically performed and can be browsed. (Step S9, content decryption unit). If the encrypted content 8d and the decryption key 8e do not match, browsing is impossible, and unauthorized browsing can be prevented.

  Thereafter, the terminal 1 uploads the reading data 8f indicating the browsing progress of the user to the sales site at a preset frequency (step S10). The server 13 stores the received reading data 8f in the customer DB 14 (step S11). That is, the reading data 8f in the customer DB 14 is updated.

  The terminal 1 inquires of the server 13 whether or not the encrypted content 8d being browsed can be browsed every time the waiting time calculated by the calculation formula described later elapses (step S12). Step S12 will be described in detail later.

  Then, based on the result of the inquiry in step S12, it is determined whether to continue browsing or to forcibly terminate the viewer application 8c (step S13). Step S13 will also be described in detail later.

  In the present embodiment, a plurality of terminals 1 possessed by a user can be simultaneously read within a preset number of units. For example, when the encrypted content 8d downloaded in step S4 of FIG. 4 is browsed on another terminal 1, the process after step S2 is performed on this new terminal 1. At that time, instead of downloading the encrypted content 8d from the server 13, the processing in step S4 may be directly copied from the terminal 1 that has been browsed so far.

  In order to enable simultaneous reading, the server 13 creates a content management screen shown in FIG. 6 for each user and provides it to the user side. This content management screen is provided on a sales site accessed by a browser or the like.

  The content management screen in FIG. 6 displays a list of names of all the encrypted contents 8d purchased by the user and information indicating on which terminal 1 each of the encrypted contents 8d can be viewed by the user. ing.

  More specifically, for each combination of the encrypted content 8d and the terminal 1, there is provided a button 25 that allows the user to arbitrarily add or remove a check mark. The user can select or remove the check mark by touching the button 25 with a finger. In the example of FIG. 6, a portion with a check mark indicates that the corresponding encrypted content 8d is viewed on the terminal 1 corresponding to the portion.

  The button 25 is a check box, and each time the user selects it, check marks are alternately added or deleted. Thereby, the user can easily set the encrypted content 8d and the terminal 1 to be simultaneously read.

  When the user changes the setting of the button 25 on the content management screen, the server 13 checks whether there is a problem with the user setting. For example, since the limit number of terminals 1 that allow simultaneous reading differs for each encrypted content 8d, if the user puts a check mark exceeding the limit number, it is determined that an error has occurred and the content management screen is set. Forcibly restores to the original state. The processing of the server 13 will be described in detail later.

  The user may change the setting on the content management screen on the terminal 1 or on the PC 15. It is desirable that the content setting screen is displayed and the setting can be changed only when collation of the user ID and the password is successful so that the setting of the content management screen of another person is not arbitrarily changed.

  Next, the processing in steps S12 and S13 in FIG. 4 will be described in more detail. When the user starts browsing the encrypted content 8d via the viewer application 8c, the terminal 1 executes main processing shown in the flowchart of FIG. This main process corresponds to steps S12 and S13 in FIG. The contents of the main process will be described below based on the flowchart of FIG.

  First, server inquiry processing is performed (step S11, availability inquiry part). The detailed processing procedure of this server inquiry processing is shown in the flowchart of FIG. Hereinafter, the server inquiry process in step S11 will be described with reference to FIG.

  First, the waiting time T is calculated (step S21). The calculation method of the waiting time T differs depending on the immediately preceding inquiry result to the server 13. As a result of the inquiry to the server 13 immediately before, when it is determined that the encrypted content 8d being browsed is viewable, the waiting time T is calculated based on the following formula (1), and when it is determined that browsing is impossible: The waiting time T is calculated based on the following equation (2).

  Here, “unviewable” means a case where an answer indicating that the encrypted content 8d being viewed cannot be viewed is obtained from the server 13, or a case where communication with the server 13 cannot be performed due to some reason.

T = a × b × (60 × 60 × 24) × m (1)
T = a × {1 / (c + 1)} × (60 × 60) × n (2)
Here, a is the upper limit number of terminals 1 that can be browsed simultaneously, b is the number of times that the server 13 determines that browsing is possible, and c is the number of times that browsing is not possible. That is, c is the number of times that the reply indicating that the encrypted content 8d being browsed cannot be browsed is obtained from the server 13, or the number of times that communication with the server 13 cannot be performed due to some circumstances. m is an OK weighting factor when browsing is possible, and n is an NG weighting factor when browsing is impossible.

  When the waiting time T is calculated by the above-described equation (1) or (2), the portion after the decimal point may be rounded.

  Immediately after starting browsing of the specific encrypted content 8d on the terminal 1 owned by the user, there is no inquiry result to the immediately preceding server 13, so in such a case, a predetermined initial waiting time is set. .

  The information on the variables m and n and the initial waiting time described above may be included in advance in the content information file attached to the decryption key 8e. FIG. 9 is a diagram showing an example of a content information file. The content information file in FIG. 9 includes a user ID 31, a device ID 32, bibliographic information 33, an upper limit number 34 corresponding to the variable a described above, an OK weighting factor 35 corresponding to the variable m described above, and the variable n described above. NG weighting coefficient 36 corresponding to, a threshold value 37 described later, and the initial waiting time 38 described above. Since the information included in the content information file is user attribute information and needs to be protected, it is downloaded from the server 13 in a state encrypted with the decryption key 8e.

  As can be seen from the above-described equation (1), when the server 13 determines that the encrypted content 8d being browsed is viewable, the waiting time T becomes longer as the number of times b determined to be viewable is larger. . In other words, if it is determined that browsing is possible, it is considered that it is legitimate use, so that the server 13 is not frequently inquired. Thereby, the frequency with which the terminal 1 makes an inquiry to the server 13 can be reduced, and the terminal 1 does not have to waste power consumption.

  On the other hand, as can be seen from the above-described equation (2), the waiting time T is shortened as the number of times c that cannot be viewed increases. The fact that the number of times c cannot be browsed is large when the server 13 determines that browsing is impossible or when the server 13 cannot communicate with the server 13 for some reason. In any case, there is a possibility that the browsing is illegal. Therefore, the server 13 is inquired more frequently so that unauthorized browsing does not last for a long time.

  When the waiting time T is calculated in step S21 of FIG. 8, it is next determined whether or not the calculated waiting time T has been reached (step S22). It remains in step S22 until the waiting time T is reached, and when the waiting time T is reached, it is determined whether or not communication with the server 13 is possible (step S23). If communication with the server 13 cannot be performed due to some circumstances, the above-mentioned variable c for counting the number of times the browsing is impossible is incremented by 1 (step S24), and the process returns to step S21.

  If it is determined in step S23 that communication with the server 13 is possible, the server 13 is inquired whether the encrypted content 8d being browsed is viewable (step S25). Thus, the server inquiry process in step S11 of FIG. 7 ends.

  When this server inquiry process is completed, it is determined whether or not the encrypted content 8d being browsed next can be browsed (step S12 in FIG. 7, an unusable decision unit). In this step S12, when the reply that the encrypted content 8d being browsed cannot be browsed is obtained from the server 13, or when communication with the server 13 cannot be performed for some reason, it is determined that browsing is impossible. Conversely, if there is an answer from the server 13 that browsing is possible, it is determined that browsing is possible.

  If it is determined in step S12 that browsing is possible, a message indicating that browsing is permitted is displayed on the display screen of the terminal 1 (step S13). This display form is not particularly limited. In some cases, the display may be omitted.

  Next, the variable b used when calculating the waiting time T by the above-described equation (1) is incremented by 1 (step S14). When step S14 is completed, the processing after step S11 is repeated. Since the variable b is increased in step S14, the waiting time T calculated in step S11 is longer than the previous value.

  On the other hand, if it is determined in step S12 that browsing is not possible, the variable c for counting the number of times browsing cannot be performed is incremented by 1 (step S15). Next, it is determined whether or not the variable c is larger than a predetermined threshold value K (step S16). If the variable c is equal to or less than the threshold value K, a warning display indicating that browsing is not possible is performed (step S17, warning display control unit), and the processes after step S11 are repeated. In step S17, although warning display is performed, browsing itself is permitted.

  If it is determined in step S16 that the variable c is larger than the threshold value K, the viewer application 8c that has been activated on the terminal 1 is forcibly terminated to make it unviewable (step S18, use prohibition control unit).

  As described above, in the main processing of FIG. 7, every time the variable waiting time T elapses during browsing of the encrypted content 8d, the server 13 is inquired of whether or not browsing is possible, and the waiting time T is determined according to the inquiry result. In order to control the length of the browsing, it is possible to frequently query the server 13 for browsing that is suspected of fraud so that the unauthorized browsing does not continue for a long time. Can be reduced.

  Next, processing performed by the server 13 in response to the inquiry to the server 13 in step S25 of FIG. 8 will be described based on the flowchart of FIG. First, it is determined whether or not there is a usage inquiry from the terminal 1 (step S31).

  Next, request information from the terminal 1 is acquired (step S32). If the request information indicates whether or not the encrypted content 8d can be browsed, the customer DB 14 is searched to determine whether or not browsing is possible (step S33, availability determination unit). And the response information containing the judgment result is produced | generated, and it transmits to the terminal 1 which sent the request (step S34, use availability information response part).

  Next, it is determined whether or not to end the processing of the server 13 (step S35), and the processing after step S31 is repeated until the processing is ended.

  As described above, the server 13 provides a content management screen to the user on the sales site, and when the user newly changes the setting of the button 25 in this screen, the server 13 immediately changes the setting. The process to determine whether there is an error in. The processing procedure of the server 13 in this case is represented by the flowchart of FIG. First, it is determined whether or not the user has changed the setting of the content management screen of FIG. 6 on the PC 15 or the terminal 1 (step S41). If the setting has been changed, the changed information is acquired (step S42). Here, information on the setting change of the check mark by the user is acquired on the content management screen of FIG.

  Next, it is checked whether or not there is an error at a check mark setting change place by the user (step S43, error check unit). At this time, the customer DB 14 is accessed, the number of terminals that can be read simultaneously for each encrypted content 8d is acquired, and it is checked whether the number of check marks in the content management screen exceeds the upper limit. .

  If the user adds more check marks than the maximum number that can be read simultaneously for the specific encrypted content 8d, it is determined as an error (step S44). If it is determined that there is an error, the check mark on the content management screen is automatically returned to the state before the user changes the setting, and a display indicating that the setting change is an error is displayed. And the process after step S41 is repeated.

  On the other hand, if it is determined in step S43 that there is no error, the customer DB 14 is updated based on the setting change information on the content management screen by the user (step S45). That is, the terminal information currently read simultaneously and the number of terminals simultaneously read are stored in the customer DB 14. Then, the content management screen is newly updated (step S46, content management screen creation unit). If necessary, it may be displayed that the user's setting change has been accepted.

  Next, it is determined whether or not to end the processing of the server 13 (step S47), and the processing after step S41 is repeated until the processing is ended.

  Thus, in the present embodiment, a content management screen is provided for each encrypted content 8d so that the user can arbitrarily change the setting of the terminal 1 to be browsed until the maximum number that allows simultaneous reading is reached. Then, when the user changes the setting of the terminal 1 that the user desires to browse on the content management screen, the server 13 checks whether the setting change is an error and reflects the check result on the content management screen. As long as there is no error in the setting change, the user can freely switch the terminal 1 to be browsed, so that the user can browse the encrypted content 8d purchased by the terminal 1 he / she desires when he / she likes, User convenience is improved. Even if the user changes the setting of the content management screen, the server 13 always checks whether there is an error in the setting change and allows simultaneous reading only within a predetermined range. It is possible to protect the copyright of the digitized content 8d.

  Further, in the present embodiment, while the user is browsing the encrypted content 8d on the terminal 1, the server 13 is inquired of whether or not browsing is possible at every variable waiting time T, and it is determined that browsing is impossible. In such a case, the waiting time T is gradually shortened to increase the frequency of displaying warnings to the user, and finally the browsing is disabled. Accordingly, unauthorized browsing can be surely prevented, and copyright protection of the encrypted content 8d can be achieved. On the other hand, if it is determined that browsing is possible as a result of inquiring the server 13, the city time T is gradually lengthened, so that it is not necessary to inquire the server 13 frequently, and the power consumption of the terminal 1 is not wasted. .

  In the above-described embodiment, browsing an electronic book was considered, but the present invention is not limited to an electronic book, but various digital contents such as an electronic comic, photo data, or various audio and moving image data. Widely applicable to the use of For voice and moving image data, the act of viewing voice or video corresponds to the use described above.

  In the embodiment described above, an example in which the server 13 and the customer DB 14 are provided separately has been described, but the customer DB 14 may be integrated with the server 13.

  At least a part of the content management system described in the above-described embodiment may be configured by hardware or software. When configured by software, a program for realizing at least a part of the functions of the content management system may be stored in a recording medium such as a flexible disk or a CD-ROM, and read and executed by a computer. The recording medium is not limited to a removable medium such as a magnetic disk or an optical disk, but may be a fixed recording medium such as a hard disk device or a memory.

  Further, a program that realizes at least a part of the functions of the content management system may be distributed via a communication line (including wireless communication) such as the Internet. Further, the program may be distributed in a state where the program is encrypted, modulated or compressed, and stored in a recording medium via a wired line such as the Internet or a wireless line.

  Based on the above description, those skilled in the art may be able to conceive additional effects and various modifications of the present invention. Accordingly, aspects of the present invention are not limited to the individual embodiments described above. Various additions, modifications, and partial deletions can be made without departing from the concept and spirit of the present invention derived from the contents defined in the claims and equivalents thereof.

  1 content browsing terminal, 2 CPU, 3 input unit, 4 communication unit, 5 display control unit, 6 display memory, 7 display unit, 8 storage unit, 10 content management system, 11 base station, 12 Internet, 13 server, 14 customer DB, 15 PC

Claims (12)

An encrypted content acquisition unit that downloads encrypted content from the server device;
A decryption key acquisition unit for downloading a decryption key for decrypting the encrypted content from the server device;
A content decryption unit for decrypting the encrypted content using the decryption key;
An availability inquiry unit that inquires of the server device whether the encrypted content is available each time a variable waiting time elapses;
As a result of the inquiry by the availability inquiry unit, an availability determination unit that determines whether or not the encrypted content is unavailable,
A use prohibition control unit that prohibits the use of the encrypted content inquired of the availability, when the number of times determined that the server communication impossibility is determined to be unusable reaches a predetermined number of times;
A warning display control unit that permits use of the encrypted content inquired of the availability together with a predetermined warning display when it is determined that the usage is not possible, but the number of times does not reach the predetermined number. And a content use terminal comprising:   The unusable determination unit is used in at least one of a case where a reply indicating that the encrypted content is unusable is received from the server device and a case where communication with the server device cannot be performed. The content use terminal according to claim 1, wherein the content use terminal is determined to be impossible.   3. The method according to claim 1, wherein the availability inquiry unit shortens the waiting time and increases the frequency of making an inquiry to the server device every time it is determined that the availability is not newly available. Content usage terminal.   The availability inquiry unit increases the waiting time and decreases the frequency of making an inquiry to the server device every time a new response indicating that the encrypted content is available is received from the server device. The content use terminal according to any one of claims 1 to 3.   The content according to any one of claims 1 to 4, wherein the availability inquiry unit increases the time interval for querying the server device for encrypted content having a larger upper limit number of terminals that allow simultaneous use. Terminal used. The encrypted content is an electronic book that requires copyright protection,
The availability inquiry unit inquires of the server device whether or not the electronic book can be browsed,
The unusability determining unit determines whether the electronic book is not viewable,
The use prohibition control unit, when the predetermined number of times has been reached, prohibits browsing of the electronic book inquiring whether or not browsing is possible,
The warning display control unit is determined to be unviewable by the unusable determination unit, but when the number of times has not reached the predetermined number, a predetermined warning display is displayed for browsing the electronic book inquiring whether or not browsing is possible. The content use terminal according to claim 1, wherein the content use terminal is allowed together with the content use terminal. In a content management system including a content use terminal and a server device that perform communication via a predetermined network,
A customer database device for registering identification information of an owner of the content use terminal and information for identifying encrypted content permitted to be used by the owner;
The content using terminal is:
An encrypted content acquisition unit that downloads encrypted content from the server device;
A decryption key acquisition unit for downloading a decryption key for decrypting the encrypted content from the server device;
A content decryption unit for decrypting the encrypted content using the decryption key;
An availability inquiry unit that inquires of the server device whether the encrypted content is available each time a variable waiting time elapses;
As a result of the inquiry by the availability inquiry unit, an availability determination unit that determines whether or not the encrypted content is unavailable,
A use prohibition control unit that prohibits the use of the encrypted content inquired of the availability, when the number of times determined that the server communication impossibility is determined to be unusable reaches a predetermined number of times;
A warning display control unit that permits use of the encrypted content inquired of the availability together with a predetermined warning display when it is determined that the usage is not possible, but the number of times does not reach the predetermined number. And having
The server device
When there is a query from the availability query unit, based on the result of referring to the customer database device, a availability determination unit that determines the availability of the encrypted content that has been queried.
A content management unit comprising: a content availability information response unit that responds to the content usage terminal with the availability information of the encrypted content that has been inquired about availability based on the determination result of the availability determination unit. system. The customer database device includes, for each user, information for identifying each content use terminal possessed by each user, and information for identifying the encrypted content permitted to be used in each content use terminal. Register with the customer database device;
The server device
Corresponding to each user, information on all the content use terminals possessed by each user registered in the customer database device and information on the encrypted content permitted to be used in each registered content use terminal A content management screen creation unit for creating a content management screen and providing it to the user;
When the user changes the setting of the content use terminal that uses the encrypted content permitted to be used on the content management screen, refer to the customer database device to see if there is an error in the setting change. An error confirmation unit to confirm,
8. The content management system according to claim 7, wherein the content management screen creation unit updates the content management screen according to the confirmation result of the error confirmation unit. The content that communicates via a predetermined network using a customer database device that registers identification information of the owner of the content use terminal and information for identifying the encrypted content permitted to be used by the owner In a content management method for managing encrypted content between a user terminal and a server device,
A customer database device for registering identification information of an owner of the content use terminal and information for identifying encrypted content permitted to be used by the owner;
The content using terminal is:
Downloading encrypted content from the server device;
Downloading a decryption key for decrypting the encrypted content from the server device;
Decrypting the encrypted content using the decryption key;
Each time a variable waiting time elapses, the server device is inquired whether the encrypted content can be used;
Determining whether the encrypted content is unusable as a result of inquiring whether the encrypted content is available;
If the number of times that the encrypted content is determined to be unusable has reached a predetermined number of times, prohibiting the use of the encrypted content that has been inquired about the availability;
If it is determined that the encrypted content is unusable, but the number of times has not reached the predetermined number, the use of the encrypted content inquired about the availability is permitted together with a predetermined warning display. And
The server device
When there is an inquiry from the availability inquiry unit, refer to the customer database device in which the identification information of the owner of the content use terminal and the information for identifying the encrypted content permitted to be used by the owner are registered. Determining whether to use the encrypted content that has been inquired for availability based on the results obtained; and
And a step of responding to the content use terminal with the use availability information of the encrypted content inquired of the use availability based on the determination result of the availability of the encrypted content. The content that communicates via a predetermined network using a customer database device that registers identification information of the owner of the content use terminal and information for identifying the encrypted content permitted to be used by the owner In a content management program for managing encrypted content between a user terminal and a server device,
Downloading encrypted content from the server device;
Downloading a decryption key for decrypting the encrypted content from the server device;
Decrypting the encrypted content using the decryption key;
Each time a variable waiting time elapses, the server device is inquired whether the encrypted content can be used;
Determining whether the encrypted content is unusable as a result of inquiring whether the encrypted content is available;
If the number of times that the encrypted content is determined to be unusable has reached a predetermined number of times, prohibiting the use of the encrypted content that has been inquired about the availability;
When it is determined that the encrypted content cannot be used, but the number of times does not reach the predetermined number, the use of the encrypted content inquired about the availability is permitted together with a predetermined warning display;
When there is an inquiry from the availability inquiry unit, refer to the customer database device in which the identification information of the owner of the content use terminal and the information for identifying the encrypted content permitted to be used by the owner are registered. Determining whether to use the encrypted content that has been inquired for availability based on the results obtained; and
A content management program for causing a computer to execute the step of responding to the content use terminal with the use availability information of the encrypted content inquired about the use availability based on the determination result of the availability of the encrypted content. In a server device that communicates with a content use terminal via a predetermined network,
Based on the registration information in the customer database device in which the identification information of the owner of the content using terminal that requested the download of the encrypted content and the identification information of the encrypted content permitted to be used by the owner are registered. A decryption key generation unit for generating a decryption key for decrypting the encrypted content;
Whenever a variable waiting time elapses from the content use terminal that has decrypted the encrypted content using the decryption key, whenever the inquiry about the availability of the encrypted content is made, Based on registration information of a customer database device, an availability determination unit that determines whether to allow the content usage terminal to use the encrypted content;
A use availability information response unit that responds to the content use terminal with the use availability information of the encrypted content that has been inquired about the use availability based on the determination result of the use determination unit; apparatus. Corresponding to each user, information on all the content use terminals possessed by each user registered in the customer database device and information on the encrypted content permitted to be used in each registered content use terminal A content management screen creation unit for creating a content management screen and providing it to the user;
When the user changes the setting of the type of the content use terminal that uses the encrypted content permitted to be used on the content management screen, the customer database device is referred to whether there is no error in the setting change. And an error confirmation unit to be confirmed.
The server apparatus according to claim 11, wherein the content management screen creation unit updates the content management screen according to a confirmation result of the error confirmation unit.

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