JP2008217057A - Material distribution system and material distribution program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a material distribution system capable of using a file being materials at the point of distributing the file, and incapable of acquiring the content thereafter. <P>SOLUTION: When it is decided that the secrecy level of a file exceeds a set value by a secrecy level deciding part 32, a save area preparation part 33 prepares an RAM disk as a storage area in a semiconductor memory composing a storage part 34 of a computer C for a terminal, and a material storage part 36 stores a file in the RAM disk. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a material distribution system, a material distribution program, and a material distribution method for distributing materials to a communication terminal connected to a communication network.

  Similar to the material distribution system described above, an information providing terminal, a center server, and a client (communication terminal of the present invention) are connected to a communication network, and a specific file or program on the information providing terminal (the present invention). The information providing terminal sends an update file signal to the center server, and the center server that receives the update file updates the client. Some perform file distribution (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 2000-148641 (paragraph numbers [0011] to [0025], FIGS. 1 to 8)

  Although what is described in Patent Document 1 automatically distributes files to communication terminals, it is highly necessary to distribute information from the server to the communication terminals. For example, all employees in a company It is conceivable to distribute information to a specific operator or information to a specific operator.

  As a means to convey information to the person who operates the communication terminal, for example, an organization such as a company or a school generally distributes communication items using e-mail, and the e-mail depends on the importance of the contents. It is also possible to display the importance of the mail in the mailer that receives the e-mail. However, since the contents of the e-mail are stored in the inbox or the like, for example, the contents of the e-mail can be viewed even when another person operates the communication terminal at a later date.

  In order to eliminate such inconvenience, when transmitting information to a communication terminal, for example, a temporary directory for distribution is created on the hard disk of the communication terminal, and a document file or the like is distributed to the temporary directory. It may be possible to temporarily use the document file. However, even if it is a temporary directory, the file information remains on the hard disk, and although the operation is somewhat complicated, there is room for improvement in that the contents of the file can be viewed by operating the communication terminal. is there.

  In particular, when considering information to be contacted by an organization such as a company or a school, there are many items whose contents should be kept secret, and countermeasures are required according to the confidentiality level of the information.

  The object of the present invention is to rationally provide a material distribution system in which a material that can be used when a material with a high confidentiality level is distributed and then cannot be acquired. The point is to configure.

A feature of the present invention is a material distribution system that distributes materials to communication terminals connected to a communication network.
A security level determination unit that determines a security level of the material, and a storage area creation unit that creates a storage area in the volatile storage area of the communication terminal when the security level determination unit determines a security level that exceeds a set value. And a material storage unit for storing the material in the storage area.

  According to this configuration, when it is determined that the confidential level of the document exceeds the set value, the document is stored in a storage area constituted by, for example, a RAM as the volatile storage area of the communication terminal. While it is possible to display the contents of the material stored in the storage area while the terminal is kept in the ON state, the data in the storage area will be displayed when the communication terminal is turned off. Since it disappears, it becomes impossible to acquire the contents of the material after that. As a result, when a document with a high confidentiality level is distributed, the material can be used when it is distributed, and thereafter, the content cannot be acquired with the power off operation. In terms of security, an excellent material distribution system was reasonably constructed.

  In the present invention, the storage area creation unit may form a virtual disk as the storage area in the RAM type semiconductor memory of the communication terminal. According to this configuration, since the storage area functions as a virtual disk, the material operation can be performed in the communication terminal in the same operation mode as that for accessing information to the hard disk, for example.

  The present invention may include a material erasing unit that erases the virtual disk from the semiconductor memory by an operation via a communication network. According to this configuration, the material distributed to the communication terminal can be erased together with the virtual disk by remote operation without turning off the power of the communication terminal, and the restoration of the material on the virtual disk is impossible.

  The present invention may include a material erasing unit that erases the material stored in the storage area by an operation via a communication network. According to this configuration, even a document distributed to a communication terminal that is used for a long time without turning off the power of the communication terminal can be deleted by remote operation.

  The present invention includes a notification processing unit that notifies the communication terminal of the existence of the material to be distributed, and after this notification, the communication that has transmitted the distribution request information based on the distribution request information transmitted from the communication terminal. The material may be transmitted to the terminal. According to this configuration, even when distributing materials to a large number of communication terminals, for example, when a process being executed in the communication terminal is being executed, a distribution request is not performed, and when the processing weight is reduced, By sending a distribution request from the communication terminal when the processing is completed, the material can be transmitted without affecting the processing executed on the communication terminal.

  The present invention obtains a security level as a judgment standard from the security level set for the operator operating the communication terminal and the security level of the material, and determines that the security level as the judgment standard exceeds a set value. In this case, the storage area creation unit may create a storage area in the volatile storage area of the communication terminal. According to this configuration, for example, when the confidential level of the operator is higher than the confidential level of the document, the confidential level that is the determination criterion is set to a value that does not exceed the set value. If the security level is low, it is possible to set the confidentiality level that is a criterion for determination to a value that exceeds the set value. Specifically, in a communication terminal of an operator with a long service year and a high confidentiality level, the distributed material is stored in a normal storage such as a hard disk, and distributed to an operator communication terminal with a short service life and a low confidentiality level. The stored material can be stored in a storage area created in the volatile area, and the material can be stored in a storage format reflecting the operator's security level and the security level of the material.

The present invention provides a material distribution program for distributing a material to a communication terminal connected to a communication network.
Let the computer execute a security level judgment function for judging the security level of the material, and create a storage area in the volatile storage area of the communication terminal when a security level exceeding the set value is judged by this security level judgment function The computer may execute a storage area creation function for saving and a material storage function for saving the material in the storage area.

  According to this configuration, when it is determined that the confidential level of the document exceeds the set value, the document is stored in a storage area constituted by, for example, a RAM as the volatile storage area of the communication terminal. While the power of the terminal is maintained in the ON state, the contents of the material stored in the storage area can be displayed, but when the communication terminal is operated in the OFF state, the material in the storage area disappears. After that, it becomes impossible to obtain the contents of the material. As a result, when a material with a high confidentiality level is distributed, the material can be used when the material is distributed, and after that, the content cannot be obtained with the power off operation. An excellent program was constructed.

The present invention relates to a material distribution method for distributing a material to a communication terminal connected to a communication network.
When it is determined that the confidential level of the material exceeds a set value, a storage area may be created in the volatile storage area of the communication terminal, and the material may be stored in the storage area.

  According to this method, when it is determined that the confidential level of the material exceeds the set value, the material is stored in a storage area constituted by, for example, a RAM as the volatile storage area of the communication terminal. While it is possible to display the contents of the material stored in the storage area while the terminal is kept in the ON state, the data in the storage area will be displayed when the communication terminal is turned off. Since it disappears, it becomes impossible to acquire the contents of the material after that. As a result, when a material with a high confidentiality level is distributed, the material can be used when the material is distributed, and after that, the content cannot be obtained with the power off operation. An excellent document distribution method was constructed in terms of

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Data distribution system]
As shown in FIG. 1, document distribution is performed by connecting a server computer A, a management computer B that controls the server computer, and a plurality of terminal computers C as communication terminals to a communication network L. The system is configured.

  The communication network L is constructed as a LAN (Local Area Network) in a limited facility such as a company or a school. The server computer A includes a computer main body 1, a monitor 2, a keyboard 3, etc., the management computer B includes a computer main body 4, a monitor 5, a keyboard 6, etc., and the terminal computer C includes a computer main body 7, a monitor. 8, keyboard 9 and the like.

  In this material distribution system, the management computer B issues a material distribution instruction to the server computer A, so that the server computer A supplies the material to a designated one of the plurality of terminal computers C. Implement the distribution process. In particular, when this distribution is performed, a storage area is formed in the volatile storage area of the terminal computer C for a document whose confidential level is high, and the power is turned off by storing the document in this storage area. The material can be completely erased when operated on.

  In order to realize this processing, in this material distribution system, the functional elements of the server computer A, the management computer B, and the terminal computer C can be shown as shown in FIG. The flow of information when distributing a file (for example, a document file) can be shown as shown in FIG.

[Distribution of files]
In other words, when distributing a file as a material, a distribution material creation unit 11 of the management computer B creates a file for distribution, the security level setting unit 12 gives a security level to the file, and the distribution destination. A distribution destination is set by the setting unit 13 and transmitted from the material transmission unit 14 to the server computer A via the communication network L.

  The information transmitted in this way is shown as a distribution instruction in FIG. 3. This distribution instruction is received by the information management unit 21 of the server computer A, and a distribution material storage composed of a hard disk or RAM (semiconductor memory) is stored. Stored in the unit 22. When receiving a distribution instruction in this way, the material distribution unit 23 (also used as a notification processing unit) applies to the terminal computer C designated as the distribution destination among the plurality of terminal computers C. Notification of distribution.

  This distribution notification includes information indicating the file name, the security level, and the storage location of the file. In the terminal computer C, the storage management unit 31 receives the distribution notification, and the security level determination unit 32 (security level). An example of a determination function) determines a confidential level. If the security level determination unit 32 determines that the security level exceeds a preset setting value, the storage area creation unit 33 (an example of a storage area creation function) is stored in the volatile storage area of the storage unit 34. Create a storage area. When it is determined that the security level determined by the security level determination unit 32 does not exceed the set value, the storage region creation unit 33 sets a storage region in the nonvolatile region of the storage unit 34.

  The volatile storage area is constituted by a RAM disk (an example of a virtual disk) formed in a volatile semiconductor memory provided in a computer such as a RAM, and the nonvolatile area is constituted by a hard disk provided in the computer. .

  After the storage area is created or set in this way, the terminal information transmission unit 35 of the terminal computer C transmits copy request information (an example of distribution request information) to the server computer A via the communication network L. .

  When this copy request information is received, the terminal identification unit 24 of the server computer A identifies the terminal computer C and allows copying of the file stored in the distribution material storage unit 22 (performs distribution). The file that is allowed to be copied in this manner is acquired by the terminal computer C via the communication network L, and the material storage unit 36 stores it in the storage unit 34.

  When the material storage unit 36 stores a file in the storage unit 34, if the security level of the file exceeds a set value, the file is stored in the RAM disk as the storage unit 34, If the security level does not exceed the set value, the file is stored in the hard disk as the storage unit 34.

  In the present invention, the process of simply saving the file to the volatile storage area is not performed, but by creating a RAM disk, the operating system (OS) provided in the terminal computer C causes the RAM disk to be stored. It is recognized as storage, and saving of the file to the RAM disk is realized by processing in the operating system. Further, when the file stored in the RAM disk is a document file for transmitting a message, the operator can grasp the content of the message by displaying the document on the editor, word processor, browser or the like of the terminal computer C. it can.

  As long as the power of the terminal computer C is maintained in the ON state, this RAM disk maintains the function of the RAM disk and maintains the file. Thereafter, when the power supply of the terminal computer C is turned off, the file in the storage area disappears completely when reaching the OFF state, so that it becomes impossible to acquire the contents of the file thereafter. Even when another person operates the terminal computer C, it becomes impossible to view or copy the contents of the file.

  In the above-described processing, the material distribution unit 23 executes file distribution by permitting copying of the file stored in the distribution material storage unit 22. The material distribution unit 23 performs the distribution of the file. The processing mode may be set so that the file stored in the file 22 is transmitted to the terminal computer C designated as the distribution destination.

[Delete File]
In this material distribution system, the management computer B transmits to the server computer A, along with the file name, information on a deletion instruction for deleting the material via the communication network L, whereby the server computer A And the deletion instruction unit 25 transmits the information on the deletion instruction to the terminal computer C via the communication network L.

  The information management unit 21 of the terminal computer C receives this deletion instruction information, and the material deletion unit 37 deletes the file stored in the storage unit 34. As described above, when the material erasing unit erases the file, if the file is stored in the RAM disk as the storage unit 34, the file may be erased together with the RAM disk. In other words, by erasing the RAM disk, it becomes impossible to restore the file in the terminal computer C. It is ideal to erase the RAM disk, but it is ideal to erase all the information in the storage area where the RAM disk is created out of the storage area of the RAM type semiconductor memory. It is also possible to prevent the operating system (OS) of the terminal computer C from recognizing it as storage by deleting the drivers to be used.

  In the present invention, the management computer B is not an essential configuration, and the processing mode may be set so that a file is created in the server computer A and distributed to the terminal computer C. Further, the information management unit 21, the material distribution unit 23, and the terminal identification unit 24 provided in the server computer A are configured by software, but may be configured by a combination of software and hardware. You may comprise only wear. Similarly, the storage management unit 31, the security level determination unit 32, the storage area creation unit 33, the terminal information transmission unit 35, the material storage unit 36, and the material deletion unit 37 provided in the terminal computer C are configured by software. However, it may be configured in combination with hardware, or may be configured only by hardware.

  Further, the storage management unit 31, the security level determination unit 32, the storage area creation unit 33, the terminal information transmission unit 35, the material storage unit 36, and the material deletion unit 37 provided in the terminal computer C are not necessarily provided in the terminal computer C. However, a part may be provided in the server computer A, or a part may be provided in the server computer A if processing is possible.

[Another embodiment of file distribution]
In the present invention, when distributing a file, the processing mode at the time of distribution may be set so that the confidential level is determined based on the confidential level of the file and the confidential level of the operator who operates the terminal computer C. The flow of information when a file (for example, a document file) is distributed as a material in the system according to another embodiment can be shown as shown in FIG.

  That is, when distributing a file in which document data is stored as distribution material, the processing in the management computer B stores distribution instruction information in the distribution material storage unit 22 as described above. Next, the server computer A obtains the confidential level of the distribution destination (operator's confidential level) from the user attribute database based on the information of the distribution destination, and determines the determination criteria based on the confidential level and the confidential level of the file. Ask for a level of confidentiality.

  An example of the confidential level of the operator and the confidential level of the file (material) will be specifically described. The operator's confidentiality level and the file (material) confidentiality level are assumed to be integers that can be calculated easily. Specifically, the higher the years of service and the higher the position, the greater the negative (minus) for that operator. ), And the higher the confidentiality level of a file (material), the larger the positive (plus) value. Then, when determining the confidential level, the numerical value corresponding to the confidential level of the operator and the numerical value of the confidential level of the file (material) are added, and the numerical value of the addition result is set as the confidential level as a determination criterion. In other words, when the file management level is a fixed numerical value, the higher the operator's confidential level, the smaller the numerical value of the confidential level that is a criterion.

  Next, a distribution notification including information such as the confidentiality level and the file name as a determination criterion obtained in this manner is sent to the terminal computer C. When receiving the distribution notification in this way, the terminal computer C determines the security level, and if it is determined that the security level exceeds a preset value, the semiconductor memory is used. A RAM disk (an example of a virtual disk) is created as a storage area in a volatile storage area such as a DRAM and a file is stored. If it is determined that the security level does not exceed the set value, the file is stored in the hard disk of the terminal computer C. As a result, the file can be stored in a storage format that reflects the confidential level of the operator and the confidential level of the file.

  In this way, by setting the distribution form based on the confidential level of the file and the confidential level of the operator, for example, in the case of an operator with a long service year or an operator with a high job title, the file is stored on a hard disk as a nonvolatile storage area. For an operator with a short service year or an operator with a low job title, the file is stored in a RAM disk as a volatile storage area, and the file distribution is excellent in terms of security.

  Here, the processing for obtaining the confidential level as a determination criterion based on the confidential level of the file and the confidential level of the operator has been described as an operator's confidential level, the confidential level of the file, and an integer. For example, the file security level is given as a positive (plus) value, and the operator security level is a value between “1” and “0”. A processing form may be set so as to multiply the numerical value corresponding to the confidential level of the operator and the numerical value of the confidential level of the material when determining the confidential level.

  By performing multiplication in this way, for example, when the confidential level of the file is a fixed value, the higher the operator's confidential level, the smaller the result of multiplication, and the operator's confidential level and the file's confidential level. You can save the file in a save format that reflects. It should be noted that the values indicating the operator security level and the file security level need not be integers.

  In this alternative embodiment, if it is determined that the security level does not exceed the set value, a storage area is set in the hard disk as a nonvolatile storage area of the terminal computer C, and the file is stored in the storage area. Will do.

[Concept of the Invention]
As described above, according to the present invention, when distributing a material, if the confidential level of the material exceeds the set value, a RAM disk is created in a volatile storage area such as a RAM of the terminal computer C, and the RAM Since the file is stored on the disk, the file is stored as long as the power of the terminal computer C is maintained in the ON state. If the file stored on the RAM disk is a document file that conveys a message, the message can be displayed by displaying it on the editor, word processor, browser, or the like of the terminal computer C.

  If the operating system of the terminal computer C recognizes the RAM disk as storage as long as the power of the terminal computer C is maintained in the ON state, the terminal computer C is turned off after that. Since the file in the storage area disappears completely when the state is reached, it becomes impossible to obtain the contents of the file thereafter. For example, even when another person operates the terminal computer C, the contents of the file are viewed. And operations such as copying cannot be performed.

  Furthermore, it is also possible to delete the file stored in the terminal computer C. For example, the confidentiality of the file can be further improved by deleting the file after a set time has elapsed since distribution. . When erasing a file, if the file is saved in a storage area created in a volatile storage area like a RAM disk, the RAM disk is erased to ensure that the file is Ensure confidentiality.

  In particular, as shown in another embodiment, in the case of obtaining a confidential level as a determination criterion based on the confidential level of a file and the confidential level of an operator operating the terminal computer C, for example, the service years are long and security is required. The file to be distributed to a somewhat reliable operator is stored on a hard disk as a non-volatile storage area, and the file to be distributed to an operator who has a short service period and has some security concerns is stored on a RAM disk as a volatile storage area. Realize distribution of files in line with security.

Diagram showing the structure of the document distribution system Block diagram showing the functions of the document distribution system Diagram showing the flow of information in the document distribution system The figure which shows the flow of information of the data distribution system of another embodiment

Explanation of symbols

23 Notification Processing Department (Material Distribution Department)
32 Security level determination unit 33 Storage area creation unit 36 Material storage unit 37 Material deletion unit C Communication terminal (terminal computer)
L Communication network

The present invention relates to a material distribution system, a material distribution program, and a material distribution method for distributing a material consisting of electronic information to any one of a plurality of communication terminals connected to a communication network.

A feature of the present invention is a material distribution system that distributes a material consisting of electronic information to any of a plurality of communication terminals connected to a communication network via the communication network .
The communication terminal creates a storage area in the volatile storage area of the communication terminal when the security level determination unit that determines the security level of the material and the security level determination unit determines a security level that exceeds a set value. a storage region creating section, Rutotomoni a document storage unit for storing the article in the storage area, the storage area creating unit, to the RAM-type semiconductor memory as the volatile storage area, said storage area Creating a virtual disk that the operating system of the communication terminal recognizes as storage, and the communication terminal erases the virtual disk from the semiconductor memory when receiving information on the deletion instruction via the communication network It is in the point provided with the erasure part .

According to this configuration, when it is determined that the confidential level of the material exceeds the set value, the operating system of the communication terminal is used as a storage area for the RAM type semiconductor memory as the volatile storage area of the communication terminal. Creates a virtual disk that is recognized as storage, and the material is stored in this virtual disk, so that not only can the material be stored in the virtual disk by the processing by the operating system, but the power of the communication terminal is maintained in the ON state. during although it is possible to display the contents of the stored documents to the virtual disk, since the power supply of the communication terminal disappears article virtual disk when it is operated in the OFF state, thereafter, documentation It becomes impossible to get the contents. In addition, when there is a deletion instruction via the communication network, the virtual disk is deleted, and thus the material stored in the virtual disk is also deleted. As a result, if the secret level is distributed high article, when subjected to distribution, it is possible to use the article, since it reliably eliminated the article with the virtual disk, also excellent resource in terms of security The distribution system was reasonably configured.

According to the present invention, a server computer that distributes the material to the communication terminal is connected to the communication network, and the server computer distributes the material to the communication terminal of the distribution destination before distributing the material. A notification processing unit that notifies the confidential level of the material to be transmitted via the communication network, and the communication terminal creates the storage region based on the notification from the notification processing unit, The distribution request information is transmitted from the communication terminal to the server computer via the communication network, and the server computer receiving the distribution request information receives the distribution request information from the communication terminal to the communication terminal that has transmitted the distribution request information. May be distributed . According to this configuration, the communication terminal that has received the notification receives the distribution of the material from the server computer by creating the storage area based on the confidential level of the material and then transmitting the distribution request information to the server computer. Is possible.

In the present invention, the material distribution unit may distribute the material by permitting a copy of the material stored in the distribution material storage unit of the server computer to the communication terminal that has transmitted the distribution request information. . According to this configuration, it is possible to receive distribution of materials by copying from a communication terminal.

In the present invention, the storage area creation unit may set a storage area in a hard disk as a nonvolatile area of the communication terminal when the security level determination unit determines a security level that does not exceed the set value. good. According to this configuration, when the security level does not exceed the set value, the material is stored in the storage area set in the hard disk, so that the material can be stored .

A feature of the present invention is a material distribution system for distributing a material consisting of electronic information to any one of a plurality of communication terminals connected to a communication network via the communication network,
A server computer that distributes the material to the communication terminal is connected to the communication network, and the server computer provides confidential information to be distributed to the communication terminal of the distribution destination before distributing the material. A notification processing unit that notifies the level via the communication network, and the communication terminal determines a security level of the material based on a notification from the notification processing unit, and the security level determination A storage area creation unit that creates a storage area in the volatile storage area of the communication terminal when a security level exceeding a set value is determined in the unit, and a material storage unit that stores the material in the storage area, The communication terminal, after the storage area creation unit creates a storage area based on the notification from the notification processing unit, from the communication terminal to the communication network The distribution request information is transmitted to the server computer via the server computer, and the server computer receiving the request information distributes the material to the communication terminal that transmitted the distribution request information. The material storage unit stores the stored material in the storage area.
According to this configuration, when the confidential level notified from the server computer exceeds the set value, a storage area is created in the volatile storage area of the communication terminal, and then the distribution request information is transmitted from the communication terminal to the server computer. , The communication terminal receives distribution of the material from the server computer, and the material is stored in the storage area. Since this storage area is formed in a volatile area, it is possible to display the contents of the material stored in the storage area while the power of the communication terminal is maintained in the ON state. Since the material in the storage area disappears when the terminal is turned off, it becomes impossible to acquire the content of the material. As a result, distribution based on the notification becomes possible, and when a document with a high confidentiality level is distributed, the material can be used at the time of distribution, and then the power is turned off. With this, it becomes impossible to obtain the contents, so a material distribution system that is superior in terms of security was reasonably constructed.

In the present invention, the storage area creation unit creates a virtual disk that is recognized as a storage by the operating system of the communication terminal as the storage area for the RAM type semiconductor memory as the volatile storage area. The terminal may include a material erasing unit that erases the virtual disk from the semiconductor memory when receiving information on the deletion instruction via the communication network. According to this configuration, the material can be stored in the virtual disk by the processing by the operating system, and the material can be surely erased together with the virtual disk.

The present invention provides a material distribution program for distributing a material consisting of electronic information to any one of a plurality of communication terminals connected to a communication network via the communication network .
In the communication terminal, wherein is secret level determination function to the computer thus realizing determining the sensitivity level of the article, the volatile storage area of the communication terminal when the security level that exceeds the set value is determined in the security level determination function A storage area creating function for creating a virtual disk that is recognized as storage by the operating system of the communication terminal is realized by a computer for the RAM type semiconductor memory as the virtual disk created by the storage area creating function. the article computer thus to realize the article storage capabilities to store, when receiving the information of the deletion instruction through the communication network, is allowed realized by a computer the article erasing function of erasing the virtual disk from the semiconductor memory May be.

According to this configuration, when it is determined that the confidential level of the document exceeds the set value, the operating system of the communication terminal serves as a storage for the RAM type semiconductor memory as the volatile storage area of the communication terminal. Since a virtual disk to be recognized is created and data is saved in this virtual disk, not only can the data be saved in the virtual disk by processing by the operating system, but also while the power of the communication terminal is maintained in the ON state, Although it is possible to display the contents of the material stored in the storage area, the data in the storage area disappears when the communication terminal is turned off. It becomes impossible to do. In addition, when there is a deletion instruction via the communication network, the virtual disk is erased, so that the material stored in the virtual disk is also erased. As a result, if a highly confidential document is distributed, the document can be used at the time of distribution, and the document can be erased with the virtual disk. Was configured.

The present invention provides a material distribution method for distributing a material consisting of electronic information to any of a plurality of communication terminals connected to a communication network via the communication network .
The communication terminal creates a storage area in the volatile storage area of the communication terminal when the security level determination unit that determines the security level of the material and the security level determination unit determines a security level that exceeds a set value. A storage area creation unit; and a material storage unit that stores the material in the storage area, and the storage area creation unit serves as the storage area for a RAM-type semiconductor memory serving as the volatile storage area. When a virtual disk that is recognized as storage by the operating system of the communication terminal is created and information on a deletion instruction is received via the communication network, the material erasure unit may erase the virtual disk from the semiconductor memory. good.

According to this configuration, when it is determined that the confidential level of the material exceeds the set value, the operating area of the communication terminal is used as the storage area for the RAM type semiconductor memory as the volatile storage area of the communication terminal. A virtual disk that the system recognizes as storage is created, and the material is saved in this virtual disk. Therefore, the contents of the material saved in the storage area are displayed while the communication terminal is powered on. However, since the virtual disk material disappears when the power of the communication terminal is turned off, it becomes impossible to obtain the content of the material thereafter. In addition, when there is a deletion instruction via the communication network, the virtual disk is deleted, and thus the material stored in the virtual disk is also deleted. As a result, when a document with a high confidentiality level is distributed, the document can be used when the document is distributed, and then the content cannot be acquired when the power is turned off. Since the material can be securely erased together with the virtual disk , an excellent material distribution method in terms of security has been constructed.

Claims (8)

A data distribution system that distributes data to communication terminals connected to a communication network,
A security level determination unit that determines a security level of the material, and a storage area creation unit that creates a storage area in the volatile storage area of the communication terminal when the security level determination unit determines a security level that exceeds a set value. A material distribution system comprising: a material storage unit that stores the material in the storage area.   The material distribution system according to claim 1, wherein the storage area creation unit forms a virtual disk as the storage area in a RAM type semiconductor memory of the communication terminal.   The material distribution system according to claim 2, further comprising a material erasing unit that erases the virtual disk from the semiconductor memory by an operation via a communication network.   3. The material distribution system according to claim 1, further comprising a material erasing unit that erases the material stored in the storage area by an operation via a communication network.   A notification processing unit for notifying the communication terminal of the existence of the material to be distributed is provided. After the notification, based on the distribution request information transmitted from the communication terminal, the communication terminal transmitting the distribution request information to the communication terminal The material distribution system according to any one of claims 1 to 4, wherein the material is transmitted.   When a confidentiality level that is a determination criterion is obtained from the confidentiality level set by the operator who operates the communication terminal and the confidentiality level of the material, and when it is determined that the confidentiality level that is the determination criterion exceeds a set value, The material distribution system according to any one of claims 1 to 5, wherein the storage area creation unit creates a storage area in a volatile storage area of the communication terminal. A data distribution program for distributing data to communication terminals connected to a communication network,
Let the computer execute a security level judgment function for judging the security level of the material, and create a storage area in the volatile storage area of the communication terminal when a security level exceeding the set value is judged by this security level judgment function A material distribution program for causing a computer to execute a storage area creating function for storing and a material storage function for storing the material in the storage area. A data distribution method for distributing data to communication terminals connected to a communication network,
A material distribution method for creating a storage area in a volatile storage area of the communication terminal and storing the material in the storage area when it is determined that a confidential level of the material exceeds a set value.

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