JP2010045670A - Network system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To construct a secure and highly reliable file backup network system. <P>SOLUTION: The network system includes a plurality of client terminals 10, a master server 20, a plurality of monitoring control devices 30a, 30b, 30c and a plurality of backup devices 40a, 40b, 40c, and is characterized in that the monitoring control devices 30a, 30b, 30c are disposed in a distributed manner in accordance with information required for decoding a data file with respect to the monitoring control device that is assumed to be constituted singly. As long as any of the functionally distributed monitoring control devices 30a, 30b, 30c are not invaded from the outside, the data file can be prevented from being restored and being leaked. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a network system for file backup, and more particularly, to a secret sharing technique for information necessary for restoring a backup file using a disaster recovery technique.

  Currently, a database of information related to the construction of various systems for constructing the social infrastructure to be used and various personal information is being developed. Public facilities such as local governments and hospitals are no exception, and a database for storing various data files such as personal information and medical information of residents is required to be backed up for quick recovery in the event of a disaster.

  Various backup systems have been proposed to reduce the losses caused by system failures. For example, a system for preparing two main and secondary sites and backing up a data file to the secondary site via a communication network, or a system for backing up a large-scale data file using the GRID technology ( For example, see Patent Document 1.)

  On the other hand, regarding the secret information sharing method, Adi Shamir's (k, n) threshold secret information sharing is known (for example, see Non-Patent Document 1). This method is realized as follows using simultaneous linear equations. In this method, the encryption key K is distributed by secret sharing.

First, as an initial setting, integers x1, x2,..., X _n , K∈ (F _p ) ^* are randomly taken for a sufficiently large prime p. Here, K is an encryption key. Also, let Z be a rational integer ring, and let F _p = Z / (p), (F _p ) ^* = {x∈F | x ≠ 0}.

を用いて、ｙ_ｉ＝ａ（ｘ_ｉ）を計算し、ｎ人のメンバーに（ｘ_ｉ，ｙ_ｉ）、（ｉ＝１，２，・・・，ｎ）を配布する。 Next, information to be distributed is created. A ₁ , a ₂ ,..., A _k−1 ε (F _p ) ^* are selected at random. Polynomial

Is used to calculate y _i = a (x _i ) and distribute (x _i , y _i ), (i = 1, 2,..., N) to n members.

Finally, the encryption key K is restored from the distributed information. When k people of (i ₁ ,..., I _k ) gather and restore the encryption key K, the encryption key K is restored as K = a ₀ when the following simultaneous linear equations are solved.

As a characteristic of the Shamir equation, a threshold dispersion structure can be defined even for large k and n. However, when the prime number p is about 200 digits, the variance (x _i , y _i ) for the 200-digit key K is about 400 digits each, so the total variance is 400 n digits of data. In addition, since the calculation amount solves simultaneous linear equations of an integer of several hundred digits, it requires about O (k ³ ) operations and is not fast enough to be calculated in real time. For this reason, it is practically impossible to use the data file for backup.
Japanese Patent Laid-Open No. 2006-67412 Stinson, Douglas, “Cryptography: Theory and practice”, CRC Press, Inc. , USA, 1995

  In a conventional network system, information necessary for decoding a data file is concentrated on one monitoring control device. Therefore, it becomes a problem to establish a method for maintaining and backing up the information when a failure or the like occurs in the monitoring control device. In addition, when a malicious third party intrudes into the monitoring and control device, there is a risk that information stored in the backup destination will be restored as well as leakage and destruction of information necessary for decrypting the data file Also existed.

  Accordingly, an object of the present invention is to construct a safe and highly reliable network system for file backup.

  In order to achieve the above object, the network system according to the present invention distributes the monitoring control device according to the information necessary for decoding the data file, to the monitoring control device that is assumed to be configured as a single unit. It is characterized by deployment. As long as all the function-distributed supervisory control devices are not invaded from the outside, restoration and leakage of data files can be prevented.

Specifically, a network system according to the present invention is a network system in which at least one master server, a plurality of monitoring control devices, and a plurality of client terminals are connected to each other via a communication network.
The master server encrypts the data file with a first encryption key, divides the encrypted file data into a plurality of divided data, duplicates the divided data, and copies the duplicated divided data to a second encryption key. Encryption means for encrypting and outputting, encrypted division information transmission means for sending encrypted division information output by the anonymization means to the plurality of client terminals, and encryption using the first encryption key The file sequence information and the first encryption key, each of which records the procedure of the concealment means from the division of the file data to the encryption of the divided data with the second encryption key, are copied, and the plurality of monitoring A concealment information transmitting means for transmitting to a different monitoring control device among the control devices,
The plurality of client terminals include an encrypted division information receiving unit that receives the encrypted division information transmitted by the encrypted division information transmission unit, and the encrypted unit that is received by the encrypted division information reception unit. Encrypted division information storage means for storing division information, and
The plurality of monitoring control devices include: a concealment information receiving unit that receives the file sequence information or the first encryption key transmitted by the concealment information transmitting unit; and the file sequence received by the concealment information receiving unit. And concealment information storage means for storing information or the first encryption key.

  Since the data file is concealed and distributed to a plurality of client terminals, and the file sequence information and the first encryption key are stored in different monitoring control devices, the data is stored unless each monitoring control device is intruded from the outside. File restoration and leakage can be prevented. Further, by providing the concealment information transmitting means, the file sequence information and the first encryption key can be logically distributed and deployed so as not to concentrate on one monitoring control device or one area. Even when not only the master server but also the monitoring control device is damaged, the data file can be restored by collecting information stored in the client terminal and the monitoring control device that are not damaged.

The network system according to the present invention further comprises a plurality of backup devices connected to the monitoring control device via a communication network,
The monitoring control device integrates the file sequence information stored in the concealment information storage unit or the first encryption key by dividing the file sequence information into a plurality of pieces and performing a reversible calculation on each other, and using a secret sharing method Secret sharing processing means for distributing the backup information, and backup information transmitting means for transmitting the backup information from the secret sharing processing means to a different backup device among the plurality of backup devices,
The backup device further comprises backup information receiving means for receiving the backup information transmitted by the backup information transmitting means, and backup information storage means for storing the backup information received by the backup information receiving means,
In the secret sharing method, the number of backup devices to which the secret sharing information transmitting means transmits the secret sharing information is n, and the file sequence information or the first encryption key required to restore the file When the number of backup devices is k, the completely substituted table S (k, n, d) is set to 0 in the nth column of the completely substituted table S (k-1, n-1, d). It is preferable that the added table and the table in which 1 is added to the n-th column of the completely substituted table S (k, n-1, d).

Also, when backing up supervisory control devices, secret information is distributed by combining integration and secret sharing methods, and distributed deployment is simultaneously performed on multiple supervisory control devices that are functionally equivalent. The backup function of the monitoring control device itself can be realized. In this case, the file sequence information and the first encryption key can be prevented from leaking as long as they are not invaded into a plurality of monitoring control devices at the same time, and the security of the network system can be greatly improved.
Furthermore, since the secret sharing method according to the present invention can recursively obtain the completely permuted table S (k, n), the number of operations is small and high-speed processing is possible. For this reason, it is possible to provide a secret information distribution method that can be used in the backup of data files. Furthermore, it is possible to conceal information with a low calculation load and high safety by combining an integrated process with a low calculation load.

In the network system according to the present invention, the master server includes a file sequence secret sharing processing unit that divides the file sequence information into a plurality of pieces and integrates them by performing a reversible operation with each other, and distributes the file sequence information using a secret sharing method. The first encryption key is further divided into a plurality of pieces and integrated by performing reversible operations on each other, and further comprising encryption key secret sharing processing means for distributing using the secret sharing method,
The concealment information transmitting means transmits the file sequence information and the first encryption key from the file sequence secret sharing processing means and the encryption key secret sharing processing means,
In the secret sharing method, when the number of the backup devices is n and the number of the backup devices necessary for restoring the file sequence information or the first encryption key is k, the table of the complete replacement system is used. S (k, n, d) is a table in which 0 is added to the n-th column of the fully substituted table S (k-1, n-1, d), and a completely substituted table S (k, n) -1, d) is preferably represented by a table in which 1 is added to the n-th column.

  When backing up the file sequence information and the first encryption key, the secret information is distributed by combining the integration and secret sharing methods, and distributed and deployed simultaneously to multiple monitoring and control devices that are functionally equivalent. By performing the above, a backup function can be realized by the monitoring control device itself. In this case, it is possible to prevent the data file from being leaked due to the leakage of the file sequence information and the first encryption key as long as they are not invaded into a plurality of monitoring control devices at the same time, and dramatically improve the security of the network system. Can do.

In the network system according to the present invention, the monitoring control device transmits a client terminal status report request for requesting transmission of client terminal status information indicating the status of the client terminal to the plurality of client terminals. A client terminal status information receiving means for receiving the client terminal status information transmitted from the client terminal; a client terminal status information received by the client terminal status information receiving means; and the client terminal status report request. A means for measuring the throughput between the client terminal and the client received by the client terminal status information receiving means based on a response time from when the client terminal status information is received to when the client terminal status information is received Further comprising a client terminal list transmitting means for transmitting to the master server the measured throughput of the terminal status information and the throughput or the like measuring device as a client terminal list, and
When the client terminal receives the client terminal status report request transmitted by the client terminal status report request transmitting means, the client terminal detects the status of the client terminal and outputs client terminal status information; and the resource information transmission Client terminal status information transmitting means for transmitting the client terminal status information output by the means to the monitoring control device,
The master server, based on a client terminal list transmitted by the client terminal list transmission unit, transmits a divisional copy number determination unit that determines a division number and a copy number in the concealment unit, and the client terminal list transmission unit transmits Further comprising: a transmission destination determination unit that determines the client terminal that transmits the encrypted division information in the encrypted division information transmission unit based on a client terminal list, and the concealment unit includes the division duplication Dividing and replicating into the number of divisions and the number of copies determined by the number determining means, and the encrypted division information transmitting means transmits the encrypted division information to the client terminal determined by the transmission destination determining means. preferable.

  According to the present invention, the monitoring and control apparatus can transmit and receive data on a trial basis, estimate the priority order of client terminal groups for efficiently performing backup at the time of a disaster, and notify the master server. The master server can shorten the backup time of the file data by determining the destination client terminal group and the client terminal based on this information. In addition, it is possible to protect the database in the distributed monitoring and control apparatus in a safer and more reliable form by distributing geographically by selecting geographically equally.

  According to the present invention, the data file is distributed after being encrypted, and the information necessary for decrypting the data file is distributed according to the content of the information. Since these are distributed in combination, a safe and highly reliable file backup network system can be constructed.

Embodiments of the present invention will be described with reference to the accompanying drawings. The embodiment described below is an example of the configuration of the present invention, and the present invention is not limited to the following embodiment.
(Embodiment 1)
FIG. 1 is a schematic configuration diagram of a network system according to the present embodiment. The network system according to the present embodiment includes a plurality of client terminals 10, a master server 20, a plurality of monitoring control devices 30a, 30b, and 30c, and a plurality of backup devices 40a, 40b, and 40c. Connected with. In this embodiment, in order to facilitate understanding, only one client terminal 10 is shown in FIG. 1 and the others are omitted. Moreover, although the example of the three monitoring control apparatuses 30a, 30b, and 30c is demonstrated, any of two or more monitoring control apparatuses may be sufficient.

  In the network system according to the present embodiment, the monitoring control devices 30a, 30b, and 30c are divided according to function. In addition, a database storing identification information and survival confirmation information of the client terminal 10, a database storing a first encryption key used when a data file stored in the master server is encrypted, and data file encryption After the conversion, a database such as a database storing a second encryption key that is further divided into a plurality of files and used for each divided file is obtained from a terminal that can access the monitoring control devices 30a, 30b, and 30c. Using a means for accessing through a network, the backup devices 40a, 40b, and 40c installed in a plurality of different regions are separated for each database, and the backup devices 40a, 40b, and 40c installed in the plurality of regions are redundant. The data base required on the supervisory control device side is copied and transferred to The information of the scan, characterized by functional distributed deployment.

  The master server 20 conceals the file data, generates encrypted division information, and transmits it to the plurality of client terminals 10. And the master server 20 transmits the information regarding concealment to the different monitoring control apparatuses 30a and 30b. For example, the first encryption key is transmitted to the monitoring control apparatus 30a, and the file sequence information is transmitted to the monitoring control apparatus 30b. Since the first encryption key and the file sequence information are information necessary for restoring the file data, the security can be improved by distributing the functions.

  The client terminal 10 receives and stores the encrypted division information from the master server 20. It is preferable that the plurality of client terminals 10 are dispersed in the region for quick disaster recovery. And it is preferable that the client terminal 10 transmits survival confirmation information and self identification information to the monitoring control apparatus 30c.

  The plurality of monitoring control devices 30a, 30b, 30c receive and store information necessary for restoring file data. For example, the monitoring control device 30a receives and stores the first encryption key. The monitoring control device 30b receives and stores the file sequence information.

  In addition, at least one monitoring control device 30c among the plurality of monitoring control devices 30a, 30b, and 30c receives the survival confirmation information and the identification information from the client terminal 10 and stores them. The survival confirmation information and identification information are preferably performed by a specialized monitoring control device 30c. Furthermore, the monitoring control devices 30a, 30b, and 30c store the information related to concealment in the backup devices 40a, 40b, and 40c in a distributed manner.

  The plurality of backup devices 40a, 40b, 40c store a copy of information stored in the monitoring control devices 30a, 30b, 30c. In order to speed up disaster recovery, the backup devices 40a, 40b, and 40c are preferably arranged in regions that are geographically different from the plurality of monitoring control devices 30a, 30b, and 30c, respectively.

  Here, for the safety of the system, it is preferable that none of the information stored in the plurality of monitoring control devices 30a, 30b, and 30c is provided in any of the backup devices 40a, 40b, and 40c. . For example, the backup device 40a stores a partial copy of information stored in the monitoring control device 30a and a partial copy of information stored in the monitoring control device 30b. The backup device 40b stores a partial copy of the information stored in the monitoring control device 30a and a partial copy of the information stored in the monitoring control device 30c. The backup device 40c stores a partial copy of the information stored in the monitoring control device 30b and a partial copy of the information stored in the monitoring control device 30c. Each of the monitoring control devices 30a, 30b, and 30c shows an example in which information backup is performed by at least two of the plurality of backup devices 40a, 40b, and 40c via the communication network 100. However, the present invention is not limited to this example, and information backup may be performed by three or more backup devices.

  The information transmitted by the master server 20 to the monitoring control devices 30a, 30b, 30c is concealed information transmitting means (reference numeral 24 in FIG. 2), and various information corresponding to each is sent to the monitoring control devices 30a and 30b. Function distributed and deployed. The encrypted division information is transferred to the client terminal 10 using the encrypted division information transmission means (reference numeral 23 in FIG. 2), and thereafter, the client terminal 10 transmits the survival confirmation information transmission means (FIG. 3 is transferred to the dedicated monitoring control device 30 for storing the survival confirmation information of the client terminal 10, and stored and held here.

  The monitoring control device 30a receives the first encryption key as the concealment information from the master server 20, and the monitoring control device 30b receives the file sequence information as the concealment information from the master server 20. The monitoring control device 30 c receives the survival confirmation information from the client terminal 10. In order to combine and decrypt important information distributed and distributed in the client terminal 10, it is necessary to have all the existence confirmation information, file sequence information, and the first encryption key, so three monitoring control devices Unless all the databases held in 30a, 30b, and 30c are accessible, the leakage of the important information does not occur.

  As a means for creating a replica of the database, for example, a method of increasing the number of monitoring control devices, for example, twice or three times, and installing a plurality of devices that hold the same database contents in completely the same functional unit is also conceivable. . Alternatively, a method is also conceivable in which a plurality of backup devices 40a, 40b, and 40c for the database are provided in geographically different regions to replicate the database of the monitoring control devices 30a, 30b, and 30c. In FIG. 1, three backup devices 40a, 40b, and 40c are provided for three monitoring control devices 30a, 30b, and 30c, and database backup is performed for at least two monitoring control devices 30a. This is realized by combining and using at least two backup devices 40a, 40c for one backup device 40a, 40b and one monitoring control device 30b, and for any backup device 40a, 40b, 40c, the monitoring control device Allocate the databases 30a, 30b, and 30c so that they do not all come together.

  Next, details of each configuration will be described with reference to FIGS. 1, 2, 3, 4, 5, and 6. 2, 3, 4, 5, and 6 are schematic configuration diagrams illustrating examples of a master server, a client terminal, a monitoring control device, and a backup device according to the present embodiment, respectively.

  The master server 20 shown in FIG. 2 includes information storage means 21, concealment means 22, encrypted divided information transmission means 23, and concealment information transmission means 24.

  The information storage unit 21 stores file data, a first encryption key, a second encryption key, identification information, and file sequence information. Here, the file sequence information is information necessary for restoring the data file, and is, for example, a record of execution procedures of the dividing unit 22-3, the duplicating unit 22-4, and the second encryption unit 22-5. . The file sequence information may be a record of an execution procedure in the entire concealment unit 22. Furthermore, the recording of the execution procedure of the encrypted division information transmission unit 23 may be combined. Each configuration is output as a log of the execution procedure. For example, the division information created using the division unit 22-3, the duplicate information created using the duplication unit 22-4, the second encryption key used for the second encryption unit 22-5, and the encryption This information is a combination of the identification information of the client terminal to which the encrypted division information transmission means 23 has transmitted the encrypted division information. In the present embodiment, as an example, information to be distributed to the monitoring control device will be described as a first encryption key and file sequence information.

  The concealment unit 22 encrypts the data file read from the information storage unit 21 with the first encryption key, divides the encrypted file data into a plurality of pieces and performs reversible operations on each other, and integrates the file data Is divided into a plurality of pieces of divided data, the divided data is copied, the copied divided data is encrypted with the second encryption key, and encrypted divided information is generated and output. Here, the number of divisions and the number of copies may be determined in advance, or may be different numbers depending on the capacity of the file data. The first encryption key and the second encryption key may be read from the information storage unit 21 or may be generated by each encryption unit. Then, the encrypted division information transmission unit 23 transmits the encrypted division information output from the concealment unit 22 to the plurality of client terminals 10.

  The concealment unit 22 includes, for example, a first encryption unit 22-1, an integration unit 22-2, a division unit 22-3, a duplication unit 22-4, and a second encryption unit 22-5. And comprising. In this case, the first encryption unit 22-1 encrypts the data file with the first encryption key. The integration unit 22-2 integrates the file data from the first encryption unit 22-1 by dividing the file data into a plurality of pieces and performing a reversible operation on each other. The dividing unit 22-3 divides the file data from the integrating unit 22-2. The duplicating unit 22-4 duplicates the divided data from the dividing unit 22-3. The second encryption unit 22-5 encrypts the divided data copied from the copy unit 22-4 with the second encryption key, and outputs the encrypted division information.

  FIG. 3 is a schematic configuration diagram illustrating another example of the concealment unit of the master server. In the concealment means 22 shown in FIG. 3, the integration means 22-2 is omitted. In general, it is preferable that the concealment unit 22 includes the integration unit 22-2. However, when the strength of the first encryption key used in the first encryption unit 22-1 is sufficient, the integration unit 22-2. May be omitted. By omitting the integration unit 22-2, the processing speed can be improved. In this case, the concealment information transmission means 24 is a file sequence that records the procedure of the concealment means 22 from the division of the file data encrypted with the first encryption key to the encryption of the divided data with the second encryption key. The information and the first encryption key are copied and transmitted to different monitoring control devices among the plurality of monitoring control devices.

  The concealment information transmission unit 24 duplicates the file sequence information and the first encryption key that record the procedure of the concealment unit 22 from the division of the integrated file data to the encryption of the divided data with the second encryption key. Each of them is transmitted to a different monitoring control device among the plurality of monitoring control devices. The file sequence information is a list of concealment procedures performed by the concealment unit 22 on the data file. For example, the file sequence information includes the division unit 22-3, the duplication unit 22-4, and the second encryption unit 22-5. It is a log.

The client terminal 10 shown in FIG. 4 includes encrypted division information receiving means 11, information storage means 12, and survival confirmation information transmitting means 13. The encrypted division information receiving unit 11 receives the encrypted division information transmitted by the encrypted division information transmission unit 23. The information storage unit 12 has a function as an encrypted divided information storage unit. The encrypted division information storage unit stores the encrypted division information received by the encrypted division information reception unit 11. The survival confirmation information transmitting unit 13 transmits survival confirmation information indicating that the client terminal 10 is in an operating state to the master server 20.
Here, the survival confirmation information is information indicating that the client terminal 10 is in an operating state. As a specific example of the “survival confirmation information”, for example, the monitoring control devices 30a, 30b, and 30c use a protocol such as UDP or TCP, and as the inquiry information to the destination client terminal 10, a self-confidence IP address and port number Is notified to the destination client terminal 10, the destination client terminal 10 confirms the above address information and then registers the IP address of the destination client terminal 10 registered in advance in the monitoring control devices 30 a, 30 b, 30 c. By returning the address and the port number within a specified time, the monitoring control devices 30a, 30b, and 30c can recognize that the destination client terminal 10 is operating normally. By this operation, “survival confirmation” of the destination client terminal can be realized. Note that the client program of the destination client terminal uses, for example, a specific character string “KEEP Alive”, “IP address”, “port number”, etc. as data information when responding to the monitoring control devices 30a, 30b, 30c. It can be configured to be included as part.

  The monitoring control device 30 shown in FIG. 5 stores a database in the information storage unit 32, receives the file sequence information or the first encryption key from the master server 20, and receives the received file sequence information or the first encryption key. Is provided with a function of transmitting backup information for creating a copy of the database. Specifically, the monitoring control device 30 includes an information receiving unit 31, an information storing unit 32, and an information transmitting unit 33.

  The information receiving unit 31 has a function as a concealment information receiving unit. The concealment information receiving unit has a function of receiving the file sequence information or the first encryption key transmitted by the concealment information transmitting unit 24. Also, the survival confirmation information transmitted by the survival confirmation information transmitting means 13 is received. The information storage unit 32 has a function as a concealment information storage unit. The concealment information storage unit is a function of storing the file sequence information received by the information reception unit 31 or the first encryption key. In addition, the survival confirmation information received by the information storage unit 32 is stored. The information transmission unit 33 has a function as a backup information transmission unit. The backup information transmission unit has a function of transmitting the confidential information stored in the information storage unit 32 to the plurality of backup devices 40.

  For example, in the monitoring control device 30a shown in FIG. 1, the information receiving unit 31, the information storing unit 32, and the information transmitting unit 33 receive, store, and transmit the first encryption key, respectively. In the case of the monitoring control device 30b, the information receiving unit 31, the information storing unit 32, and the information transmitting unit 33 receive, store, and transmit file sequence information, respectively. In the case of the monitoring control device 30c, the information receiving unit 31, the information storing unit 32, and the information transmitting unit 33 receive, store, and transmit the survival confirmation information, respectively.

  The backup device 40 shown in FIG. 6 has a function of receiving database backup information from the monitoring control device 30, a function of reflecting backup information in the database, a function of receiving database backup information from the monitoring control device 30, It has a function to reflect backup information in the database. Then, a part of the information stored in the plurality of monitoring control devices 30a, 30b, 30c, for example, information of two units is backed up. Specifically, the backup device 40 includes backup information receiving means 41-1 and 41-2 and backup information storage means 42-1 and 42-2.

  The backup information receiving units 41-1 and 41-2 receive different concealment information transmitted from the plurality of monitoring control devices 30a, 30b, and 30c, respectively. The backup information storage means 42-1 and 42-2 store the concealment information received by the backup information reception means 41-1 and 41-2, respectively. The backup information storage means 41-1 and 41-2 may have a common configuration. The backup information storage means 42-1 and 42-2 may be common information storage means for storing two databases.

  For example, in the case of the monitoring control device 30a shown in FIG. 1, the backup information receiving unit 41-1 and the backup information storage unit 42-1 each receive and store the first encryption key. The backup information receiving unit 41-2 and the backup information storage unit 42-2 each receive and store file sequence information. In the case of the monitoring control device 30b, the backup information receiving unit 41-1 and the backup information storage unit 42-1 each receive and store the first encryption key. The backup information receiving unit 41-2 and the backup information storage unit 42-2 each receive and store the survival confirmation information. In the case of the monitoring control device 30c, the backup information receiving unit 41-1 and the backup information storage unit 42-1 receive and store file sequence information, respectively. The backup information receiving unit 41-2 and the backup information storage unit 42-2 each receive and store the survival confirmation information.

  In the configuration example described above, the first encryption key transmitted from the master server 20 is first received by the monitoring control device 30a, and the database stored in the information storage means 32 in the monitoring control device 30a is updated. Later, backup information for creating a copy of the database is created and transmitted to the backup device 40a and the backup device 40b. The backup device 40a that has received the backup information of the database of the monitoring control device 30a updates the database of the backup information storage means 42-1 based on the information. Similarly, the backup device 40b that has received the backup information of the database of the monitoring control device 30a updates the database of the backup information storage unit 42-1 based on the information.

  The database update process described above is performed in the same manner when the file control information is received by the monitoring control device 30b from the master server 20 and when the monitoring control device 30c receives the survival confirmation information from the client terminal 10. Is done. As a result of these series of processes, the first encryption key, file sequence information, and survival confirmation information are obtained when three monitoring control devices 30a, 30b, 30c and three backup devices 40a, 40b, 40c are used. The information sharing relationship between the monitoring control devices 30a, 30b, and 30c and the backup devices 40a, 40b, and 40c is as follows. The monitoring control device 30a stores the first encryption key, the monitoring control device 30b stores file sequence information, and the monitoring control device 30c stores survival confirmation information. The backup device 40a stores the first encryption key and the file sequence information, the backup device 40b stores the first encryption key and the existence confirmation information, and the backup device 40c stores the file sequence information and the existence confirmation information.

Due to the information sharing relationship described above, individual information is distributed and distributed to three of the monitoring control devices 30a, 30b, 30c and the backup devices 40a, 40b, 40c. Even important information can be recovered completely.
In the above example, the monitoring control devices 30a, 30b, and 30c have one type of necessary information related to backup of important information even when a malicious third party intrudes, and the backup device Since there are only two types, there is a risk that important information distributed to the client terminals 10 will leak even if one of the monitoring control devices 30a, 30b, 30c or the backup devices 40a, 40b, 40c is invaded Can be avoided.

(Embodiment 2)
The network system according to the present embodiment communicates the file sequence information and the first encryption key stored in the monitoring control devices 30a, 30b, and 30c from the monitoring control devices 30a, 30b, and 30c in the network system shown in FIG. Using a means for accessing through the network 100, after converting into a plurality of secret sharing information using the integration process and secret sharing method, each secret sharing information is installed in different areas, or one or a combination of them The database information required for restoration on the monitoring control devices 30a, 30b, and 30c side is deployed in a threshold secret sharing manner by transferring them to the backup devices 40a, 40b, and 40c. For example, in FIG. 1, a database stored in the supervisory control device 30a is generated with (2, 3) threshold secret information sharing processing to generate three pieces of secret sharing information, and the three backup devices 40a, 40b, and 40c are separated. Back up.

  Here, (2, 3) threshold secret information is a notation when the backup of the database stored in the monitoring control device 30a is completely expressed if any two of the three are normal. Means the law. In the present embodiment, an example of (2, 3) threshold secret information distribution processing is shown, but it goes without saying that the present invention is not limited to this case. For example, in the (k, n) threshold secret information distribution process, n is arbitrary, and k can also be an arbitrary integer equal to or smaller than n. Further, the threshold secret information distribution may be complete threshold secret information distribution or incomplete threshold secret information distribution. The incomplete threshold secret information distribution is, for example, threshold ramp type secret distribution. Since complete threshold secret information distribution cannot be restored unless a certain number of pieces of distributed information are collected, it is possible to improve confidentiality. Incomplete threshold secret information distribution allows some secret information to be deciphered even if a certain number of distributed information does not gather. The threshold secret information distribution may be secret information distribution by a complete replacement system that is not integrated or encrypted.

  FIG. 7 is a schematic configuration diagram illustrating an example of a monitoring control device according to the present embodiment. The monitoring control device 30 according to the present embodiment further includes secret sharing processing means 34 in the monitoring control device 30 according to the first embodiment shown in FIG. The secret sharing processing unit 34 is provided between the information storing unit 32 and the information transmitting unit 33, and integrates the file sequence information or the first encryption key by dividing the file sequence information or the first encryption key by performing a reversible operation with each other. Is used to distribute to multiple backup information. The information transmission unit 33 transmits the backup information distributed by the secret sharing processing unit 34 to the backup devices 40a, 40b, and 40c. For example, the monitoring control device 30a shown in FIG. 1 includes the information storage unit 32, a function of receiving the first encryption key from the master server 20, and the received first encryption key in the information storage unit 32. The function, the function of generating (3) threshold secret sharing processing for the first encryption key stored in the information storage means 32 and generating three backup information, and the generated backup information are different. It has the function to transmit to backup device 40a, 40b, 40c.

  FIG. 8 is a schematic configuration diagram illustrating an example of a backup device according to the present embodiment. The backup device 40 according to the present embodiment further includes a backup information receiving unit 41-3 and a backup information storage unit 42-3 in the backup device 40 according to the first embodiment illustrated in FIG. Similarly to the first embodiment, the backup information receiving units 41-1, 41-2, and 41-3 respectively receive backup information transmitted from different monitoring control devices among the plurality of monitoring control devices 30a, 30b, and 30c. Receive. The backup information storage means 42-1, 42-2 and 42-3 store the secret sharing information received by the backup information receiving means 41-1, 41-2 and 41-3.

  For example, in the case of the backup device 40a shown in FIG. 1, the function of receiving the first secret key that has been secretly distributed from the monitoring control device 30a and the received first secret key that has been secretly distributed are stored in the database. A function for receiving the secret-distributed file sequence information from the monitoring control device 30b, a function for storing the received secret-distributed file sequence information in the database 30b, and a secret sharing from the monitoring control device 30c. A function for receiving the liveness confirmation information that has been received and a function for storing the received liveness confirmation information that has been secret-distributed in a database. It should be noted that all information types used in the network system constituted by the three backup devices 40a, 40b, and 40c are common to various database information stored in the backup device 40c.

  In the configuration of FIG. 1, the information on the first encryption key transmitted from the master server 20 is first received by the monitoring control device 30a and stored in a database inside the monitoring control device 30a. Next, the monitoring control device 30a reads the first encryption key newly stored in the database, performs (2,3) threshold secret sharing processing, and obtains the three secret sharing first encryption keys. Generate and send one to each of the three backup devices 40a, 40b, 40c. The backup device 40a that has received the first secret key that has been subjected to secret sharing from the monitoring control device 30a stores the first secret key that has been subjected to secret sharing in a database inside the backup device 40a. Similarly for the backup devices 40b and 40c, the first encryption key that has been secret-distributed and transmitted from the monitoring control device 30a is stored in a database inside each device. Similar storage processing is performed when the monitoring control apparatus 30b receives file sequence information from the master server 20 and when the monitoring control apparatus 30c receives survival confirmation information from the client terminal 10.

  As a result of the series of processes, the first encryption key, the file sequence information, the survival confirmation information, and the secret sharing information obtained by performing the secret sharing process on each of them are the three monitoring control devices 30a, 30b, 30c, and three The backup devices 40a, 40b, and 40c are provided. (2, 3) Since it is generated by the threshold secret sharing process, if two or more of the three secret sharing information distributed and deployed in the three backup devices 40a, 40b, 40c are collected, the data file is restored. be able to. That is, if the monitoring control devices 30a, 30b, and 30c and backup devices 40a, 40b, and 40c installed in the same area are in the range of up to two, even if the devices are damaged at the same time due to a natural disaster or the like, important information data A complete backup of the file can be realized. In addition, when a malicious third party is invaded, even if one of the monitoring control devices 30a, 30b, and 30c and the backup devices 40a, 40b, and 40c is intruded, the client terminal 10 is distributed. It is possible to prevent the encrypted divided information from leaking at the same time. This is because the backup devices 40a, 40b, and 40c have all three pieces of information, but (2, 3) only the information that one backup device 40a, backup device 40b, or backup device 40c has by the secret sharing process. This is because an algorithm that cannot be returned to the information before the secret sharing process is used.

  An example of the secret sharing method according to this embodiment will be described. The secret sharing method according to the present embodiment is based on the (k, n) threshold secret information sharing method using a complete replacement system. Here, (k, n) means that metadata can be restored if at least k pieces of information among n pieces of information that are secretly distributed are arranged. That is, k corresponds to a threshold value for restoration, and n may be considered as the total number of secret sharing members, that is, the backup devices 40a, 40b, and 40c shown in FIG.

  FIG. 9 is a flowchart showing an example of the operation of the secret sharing processing means. The metadata held by the monitoring control device 30, that is, the first encryption key, the file sequence information, or the survival confirmation information is integrated, and the conditions relating to the reliability of the data backup of the network administrator or the user are taken into consideration. And n are set, and a table S (k, n, d) of a complete replacement system for realizing secret sharing is created using this information. Here, d is an array expressing the presence or absence of possession in the storage space. This will be specifically described below.

表Ｓ（ｋ，ｎ，ｄ）のうち、各列がバックアップ情報を保有するメンバーを、各行がバックアップ情報の情報種別番号を表す。メンバーは、分散場所、あるいは、バックアップ情報を保有するバックアップ装置に対応する。バックアップ情報の情報種別番号は、メタデータＢが分散される分散Ｂ_１，・・・，Ｂ_Ｎに対応する。行列ｄの配列要素の中で、「１」が記されている箇所は、バックアップ情報を保有していることを意味し、ｉ番目のメンバーは表のｉ列の１の立っている情報種別番号のバックアップ情報を保持する。 In step S101, the metadata is integrated. Integration refers to dividing the metadata into a plurality of pieces and performing a reversible operation on each other, which can be said to be a spatial dispersion of data. The reversible operation is, for example, addition, subtraction, EOR, or a combination thereof. The number of divisions is, for example, the number n for secret sharing. In step S102, k and n in the complete substitution table S (k, n, d) are acquired. In step S103, a completely permuted table S (k, n, d) is created using k and n acquired in step S102. Specifically, in the case of S (3, 4), the table S (k, n, d) is expressed by the following equation.

In the table S (k, n, d), each column represents a member holding backup information, and each row represents an information type number of backup information. The member corresponds to a distributed location or a backup device that holds backup information. The information type number of the backup information corresponds to the distribution B ₁ ,..., B _{N in} which the metadata B is distributed. In the array element of the matrix d, the part marked with “1” means that backup information is held, and the i-th member is the information type number where 1 stands in the i column of the table. Retain backup information.

具体的には、Ｓ（３，４）の場合、Ｓ（３，４，ｄ）は６行４列であり、Ｎ＝６となる。分散Ｂ_１，Ｂ_２，Ｂ_３，Ｂ_４，Ｂ_５及びＢ_６の作成方法は任意だが，一例としてメタデータＢを６等分に分割する方法が有る。 In step S104, the distribution B ₁ ,..., B _N of the metadata B after integration obtained in step S101 is created. Since the table S (k, n, d) created in step S103 has n rows and N columns, the metadata B is divided into N pieces represented by the following equation. As a result, secret-distributed backup information is obtained.

Specifically, in the case of S (3,4), S (3,4, d) has 6 rows and 4 columns, and N = 6. A method of creating the distributions B ₁ , B ₂ , B ₃ , B ₄ , B ₅ and B ₆ is arbitrary, but as an example, there is a method of dividing the metadata B into six equal parts.

  In step S105, the backup information obtained in step S104 is transmitted to the members, that is, the backup devices 40a, 40b, and 40c shown in FIG. In step S105, the backup information having the information type number that stands at 1 in the table S (k, n, d) is sent to the member. For example, the backup information of information type numbers 2, 3 and 6 is transmitted to the third member.

  In step S103, when the number of backup devices to which the information transmission means 33 transmits backup information is n and the number of backup devices necessary for restoring the first encryption key or file sequence information is k. A completely substituted system table S (k, n, d) is obtained by adding 0 to the nth column of the completely substituted system table S (k-1, n-1, d), and a completely substituted system In Table S (k, n-1, d), it is preferably represented by Table d1 in which 1 is added to the nth column. Hereinafter, an example of creating a completely substituted table S (k, n, d) when n is 3 will be described.

を作成する。このとき、３つのバックアップ装置が同じバックアップ情報を保有していることを意味する。 FIG. 10 is a flowchart illustrating an example of a complete replacement system table creation algorithm. In step S201, it is determined whether or not the input k is equal to 1. If k = 1, the process proceeds to step S202, and if k = 1, the process proceeds to step S203. In step S202, a matrix of (1, 1,..., 1) of 1 row and n columns is created as the matrix d. For example, when k = 1, the matrix d is

Create At this time, it means that the three backup devices have the same backup information.

を作成する。このとき、３つの各々のバックアップ装置が別々の分割されたバックアップ情報を保有していることを意味する。 In step S203, it is determined whether or not the input k is equal to n. If k = n, the process proceeds to step S204, and if k = n, the process proceeds to step S205. In step S204, a unit matrix of n rows and n columns is created as the matrix d. For example, when k = 3, the matrix d is

Create At this time, this means that each of the three backup devices has separate divided backup information.

In step S205, a complete substitution table S (k-1, n-1, d) is created.
For example, when k = 2, S (k-1, n-1, d), that is, S (1, 2, d) is created. Specifically, it is expressed by the following formula.

In step S206, 0 is added to the nth column of each row in S (k-1, n-1, d). For example, when k = 2, 0 is added to each row of the nth column of S (1,2, d), and is expressed by the following equation.

In step S207, a completely substituted table S (k, n-1, d) is created. For example, when k = 2, S (k, n-1, d), that is, S (2, 2, d) is created. Specifically, it is expressed by the following formula.

In step S208, 1 is added to the n-th column of each row in the completely permuted table S (k, n-1, d) to form a matrix d1. For example, when k = 2, 1 is added to each row of the nth column of S (2, 2, d), and is expressed by the following equation.

ｄとして縦Ｎ＝Ｎ０＋Ｎ１、横ｎの配列を取り、１行目からＮ０行目までに０を追加済のｄ０を、（Ｎ０＋１）行目から（Ｎ０＋Ｎ１）行目までに１を追加済のｄ１を格納してｄを生成する。例えば、ｋ＝２の場合、数式（８）及び数式（１０）から、次式で表される行列ｄが得られる。

In step S209, d1 obtained in step S206 is added below d0 obtained in step S204 to create a matrix d as a table of a completely permuted table S (k, n, d). d0 has an array of vertical N0 and horizontal n. d1 has an arrangement of N1 in the vertical direction and n in the horizontal direction.

d is an array of vertical N = N0 + N1 and horizontal n as d, d0 with 0 added from the first line to the N0 line, and d1 with 1 added from the (N0 + 1) line to the (N0 + N1) line To generate d. For example, when k = 2, a matrix d represented by the following equation is obtained from Equation (8) and Equation (10).

  In the processing from step S205 to step S209, the method for obtaining the completely substituted table S (2,3) when k = 2 and n = 3 is the same as the table S (1,2) and the completely substituted table S It means that it is obtained by S (2, 2). This means that the general way of obtaining the fully substituted table S (k, n) is obtained recursively.

  FIG. 11 is an explanatory diagram of a complete replacement system table creation algorithm. If the table S (2,3, d) is a fully substituted system, it is obtained from the tables S (1,2) and S (2,2) of the fully substituted system. If the table S (2,4, d) is a completely substituted system, it is obtained from the tables S (1,3) and S (2,3) of the fully substituted system. If it is Table S (3,4, d) of the complete substitution system, it is obtained from Table S (2,3) and Table S (3,3) of the complete substitution system. If it is Table S (3, 5, d) of the complete substitution system, it is obtained from Table S (2, 4) and Table S (3, 4) of the complete substitution system. Thus, the completely permuted table d includes the matrix d0 obtained from the completely permuted table S (k-1, n-1, d) and the completely permuted table S (k, n-1, d). ) Is recursively obtained using the matrix d1 obtained from (1). Thus, since the secret sharing method according to the present embodiment does not need to solve simultaneous linear equations, the use of the secret sharing method in data file backup can be made realistic.

  In the secret information distribution method according to the present embodiment, there is no Shamir method, and when the key data (metadata) K has 200 digits, the distribution does not exceed 200 digits. In addition, since the substantial calculation is only an integrated calculation, it is about O (m) when the size of the metadata is m, and a large K can be calculated at high speed. However, since the backup information needs to have a size of 16 bytes or more, the values of k and n cannot be increased. About n = 20 is considered a practical limit.

(Embodiment 3)
The network system according to the present embodiment is the same as the network system according to the first embodiment shown in FIG. 1 except that the monitoring control devices 30a, 30b, and 30c are installed in a plurality of different areas, and the master server 20 is the first one. After the encryption key and file sequence information are converted into a plurality of secret information using a secret sharing method, each of the secret information is installed in a different area, and one or a combination of monitoring control devices 30a, 30b , 30c, the monitoring control devices 30a, 30b, 30c themselves are deployed with threshold secret sharing.

  The master server 20 transmits the first encryption key and the file sequence information subjected to secret sharing to all the monitoring control devices 30a, 30b, and 30c by (2, 3) threshold secret information sharing processing. The survival confirmation information transmitted from the client terminal 10 is sent only to the monitoring control apparatus 30c, and the monitoring control apparatus 30c preferably retransmits the received survival confirmation information to the monitoring control apparatus 30a and the monitoring control apparatus 30b. There is, however, not limited to this case.

  FIG. 12 is a schematic configuration diagram illustrating an example of a master server according to the third embodiment. The master server 20 according to the third embodiment further includes a file sequence secret sharing processing unit 25-1 and an encryption key secret sharing processing unit 25-2 in the master server according to the first embodiment illustrated in FIG. The file sequence secret sharing processing unit 25-1 and the encryption key secret sharing processing unit 25-2 are connected between the concealment unit 22 and the concealment information transmission unit 24, respectively. Moreover, the concealment means 22 shown in FIG. 12 can also use the configuration of FIG. 3 in which the integration means 22-2 is omitted.

  The file sequence secret sharing processing means 25-1 divides the file sequence information into a plurality of pieces and integrates them by performing a reversible operation with each other, and distributes them using the secret sharing method. The encryption key secret sharing processing unit 25-2 divides the first encryption key into a plurality of pieces and integrates them by performing a reversible operation, and distributes them using a secret sharing method. For example, after the first encryption key is stored in the main memory or the hard disk, it is converted into three pieces of secret sharing information by (2, 3) threshold secret information sharing processing. The three secret-decentralized first encryption keys are transmitted by the concealment information transmission unit 24 to the three different monitoring control devices 30a, 30b, and 30c shown in FIG. Similarly, the file sequence information is transmitted to three different monitoring control devices 30a, 30b, 30c after the (2, 3) threshold secret information distribution processing.

  Here, for the sharing by the secret sharing method, the same method as in the second embodiment can be used. However, in this embodiment, since the distribution destinations are a plurality of monitoring control devices 30a, 30b, and 30c, the members in the secret sharing process are calculated by changing from the backup devices 40a, 40b, and 40c to the monitoring control devices 30a, 30b, and 30c. To do. In the present embodiment, an example of (2, 3) threshold secret information distribution processing is shown, but it goes without saying that the present invention is not limited to this case. As in the second embodiment, the threshold secret information distribution may be complete threshold secret information distribution or incomplete threshold secret information distribution. The threshold secret information distribution may be secret information distribution by a complete replacement system that is not integrated or encrypted.

  In the monitoring control devices 30a, 30b, and 30c according to the third embodiment, the file sequence information and the first encryption key received by the information receiving unit 31 shown in FIG. 5 are secretly distributed. It is preferable that the information receiving unit 31 further receives the survival confirmation information from the monitoring control device 30c. The information storage unit 32 includes three databases, and stores secret-distributed file sequence information received by the information reception unit 31, the first encryption key, and the survival confirmation information.

  As a result of a series of processing by the master server 20 and the monitoring control device 30, the file sequence information and the first encryption key are subjected to (2, 3) threshold secret information distribution processing in the three monitoring control devices 30a, 30b, 30c. The survival confirmation information holds the duplicated copy in the three monitoring control devices 30a, 30b, and 30c. Even if one of the monitoring control devices 30a, 30b, and 30c fails or is damaged, the first encryption key and the file sequence information are the remaining two pieces of information, and the survival confirmation information is any one of the pieces. It is clear from the fact that (2, 3) threshold secret information distribution processing has been performed, it is possible to recover from the information and to reconfigure the monitoring control device. In the above example, even if a malicious third party intrudes into one of the monitoring control devices 30a, 30b, 30c, only the survival confirmation information is leaked, but the first encryption key and file The fact that the sequence information cannot be deciphered is apparent from (2, 3) threshold secret information distribution processing. From this, it is possible to avoid the risk of leakage of important information distributed to the client terminals 10.

(Embodiment 4)
The network system according to the present embodiment is the same as the network system according to the first embodiment shown in FIG. 1, from the master server 20 to each transfer destination where the client terminals 10 are distributed, for each region or for each client terminal 10. As for the method of distributed deployment of the encrypted divided information, the destination to be transferred is appropriately selected based on the throughput of the client terminal 10 to the monitoring control devices 30a, 30b, 30c, the response delay time measurement result, or the like. It is characterized by redundant transfer so that it can be determined.

  FIG. 13 is a schematic configuration diagram illustrating an example of a network system according to the present embodiment. In the network system according to the present embodiment, the monitoring control device 30 shown in FIG. 5 further includes a client terminal status report request transmission means 37-1, a client terminal status information reception means 37-2, and a throughput measurement means 37-. 3 and a client terminal list transmission means 38, and a new function is added to the information storage means 32. The client terminal 10 shown in FIG. 4 further includes client terminal status report request receiving means 14-1, resource information transmitting means 15, and client terminal status information transmitting means 14-2. The master server 20 shown in FIG. 2 further includes a client terminal list receiving unit 26, a divided copy number determining unit 27, and a transmission destination determining unit 28, and a new function is added to the information storage unit 21.

  The client terminal status report transmission means 37-1 shown in FIG. 13 transmits a client terminal status report request for requesting transmission of client terminal status information to each client terminal 10. The client terminal state information is information indicating the state of the client terminal 10, and indicates the resource management state of the client terminal itself. The client terminal status report request receiving unit 14-1 receives the client terminal status report request transmitted by the client terminal status report request transmitting unit 37-1. When the client terminal state report request receiving unit 14-1 receives the client terminal state report request, the resource information transmission unit 15 detects the state of the client terminal 10 and outputs the client terminal state information. The client terminal state information transmission unit 14-2 transmits the client terminal state information output from the resource information transmission unit 15 to the monitoring control device 30.

  Here, the client terminal state information is resource information managed by the client terminal 10, and is, for example, a client terminal ID, CPU usage management information, memory free area information, and hard disk free area information. Each client terminal has individual client terminal ID information, whereby the monitoring control apparatus identifies each client terminal. For each client terminal ID, its own resource management state is managed as resource management information. Here, the state of resource management is, for example, a CPU usage rate, a memory free area, and a hard disk free area. The CPU usage rate is preferably managed in units of%, the memory free area is managed in GB (gigabytes), and the hard disk free area is preferably managed in GB gigabytes, but is not limited to this unit. The resource information transmission means 15 corresponds to a function provided in a general information terminal such as a personal computer. The client terminal 10 measures its own resource management state, writes it in the client terminal state file, and transmits a resource management file indicating the client terminal state to the monitoring control apparatus 30 as a client terminal list.

  The client terminal ID is an ID used when the master server 20 and the monitoring control device 30 identify the client terminal 10. The client terminal ID usually has a one-to-one relationship with the IP address possessed by the client terminal ID. For example, in the client terminal ID expressed by a 5-digit number, the first two digits are the identification information of the region, and the last three digits are the identification information of the client terminal for identifying the client terminal in the region. It is.

  The client terminal state information receiving unit 37-2 illustrated in FIG. 13 receives the client terminal state information transmitted from the client terminal 10. The throughput measurement unit 37-3 measures the throughput with the client terminal 10. Here, the throughput is, for example, a response from when the client terminal state report request transmitting unit 37-1 transmits the client terminal state report request until the client terminal state information receiving unit 37-2 receives the client terminal state information. Measure based on time. At this time, it is preferable to consider the client terminal state information transmitted from the client terminal 10. The information storage means 32 stores the client terminal status information received by the client terminal status information receiving means 37-2 and the throughput measured by the throughput measuring means 37-3 in the information storage means 32 as client terminal list information. . The client terminal list transmission unit 38 in the monitoring control device 30 transmits the client terminal list stored in the information storage unit 32 to the master server 20.

  For example, the monitoring control device 30 measures the time required to receive the client terminal status, and measures the throughput between the client terminal 10 and the monitoring control device 30, the response time, and the like. If the monitoring control device 30 determines that the resource management state of the client terminal 10 exceeds a presumed threshold, registration information indicating that fact is stored in a database in the monitoring control device. (FIG. 14). If the monitoring control device 30 cannot receive a data file such as test data, the client terminal 10 considers that the data file cannot be used, and notifies that fact.

  Further, when the response within the predetermined specified timing is not received from the client terminal 10, the client terminal 10 uses the information storage unit 32 to perform registration processing indicating that the client terminal 10 cannot be used. In addition, when a response within a predetermined specified timing is received from the client terminal, three conditions, which are indices indicating the resource usage status of the client terminal, are based on return data from the client terminal, Only when it becomes clear that all are satisfied, the client terminal confirms that the client terminal can be used “normally”, and performs registration processing to the effect of “normal” using the information storage means 32 carry out. The three conditions are that, firstly, the CPU usage rate is less than or equal to the threshold, secondly, the memory free area is less than the threshold, and thirdly, the hard disk free area is sufficient. If any of the above three conditions cannot be satisfied by the return data from the client terminal, the client terminal confirms that the client terminal is abnormal and enters the “abnormal” state. A registration process to that effect is performed using the information storage means 32 (FIG. 15).

The information storage means 32 shown in FIG. 13 preferably stores the throughput for each client terminal. For example, based on the data acquired for each client terminal ID using the measuring means 37-3 such as the throughput, information on the usable terminal group is stored in the information storage means 32. Here, generally, the client terminals 10 are distributed and deployed in a plurality of regions (for example, J ₁ , J ₂ ,... J _N ). The information storage means 32 in the monitoring control device 30 stores the throughput for each client terminal ID, for example, in units of Mb / s. As a result, the monitoring control device 30 can determine which client terminal 10 can be used. The monitoring control device 30 selects a usable terminal group based on the client terminal state information acquired in the above procedure, and further determines a client terminal list for determining whether or not the encrypted divided information can be received. Create and send to the master server 20.

  Here, the client terminal list is a transfer destination terminal list that is stored in the information storage unit 21 and is suitable as a data transfer destination of the encrypted division information, and is divided for each area group ID. A list showing each client terminal group is preferable. Specifically, for example, the area group is divided into # 1, # 2,..., #N (less than 100), and a 2-digit integer (01, 02,..., N is used for identifying each area. For example, a 3-digit integer can be used for terminal identification within the same region.

  The client terminal list receiving unit 26 shown in FIG. 13 receives the client terminal list transmitted by the client terminal list transmitting unit 38. The information storage unit 21 stores the client terminal list received by the client terminal list reception unit 26. The divided replication number determination means 27 in the master server 20 determines the division number and the replication number in the concealment means 22 based on the client terminal list transmitted by the client terminal list transmission means 38. The concealment unit 22 in the master server 20 divides and replicates the number of copies and the number of copies determined by the divided copy number determination unit. The transmission destination determination unit 28 in the master server 20 determines the client terminal 10 that transmits the encrypted division information based on the client terminal list transmitted by the client terminal list transmission unit 38.

  The divided data described here indicates output data from the dividing means (reference numeral 22-3 shown in FIG. 2). The file name given to the divided data is expressed by, for example, a two-digit number, and it can be identified by what number the data file is divided by the two-digit number. The divided duplicate data indicates output data from the second encryption means (reference numeral 22-5 shown in FIG. 2), that is, encrypted divided information. The file name of the divided replication data is expressed by, for example, a four-digit number, and the first two digits indicate the division number for identifying what number the data file is divided into, and what is the latter two digits? The duplicate data number for identifying whether the divided data is the second duplicated data. For example, when the number of divisions is 2 and the number of duplications is 2, a total of 4 pieces of divided replication data are generated, and the file names can be expressed as 0101, 0102, 0201, and 0202, respectively. It goes without saying that the divided duplicate data are all encrypted with different encryption keys, so that they appear to be completely different files. A division number is assigned to the divided duplicate data, and a duplicate data number is also assigned to the duplicated file, and these values are set so as not to overlap each other. Apparently, a number of separate files corresponding to (number of divisions) × (number of copies) are generated for one original file, and each is encrypted with another different encryption key. .

  The master server 20 comprehensively determines the information of the client terminal group list, the capacity of the data file to be transmitted, etc., and deletes the client terminal 10 whose throughput is below a certain value from the client terminal group list, It is preferable to keep it in the database. FIG. 16 shows a flow for registering whether or not the client terminal 10 can be used by the transmission destination determining means 28. As a result of the above procedure, the transmission destination determination means 28 divides a client terminal list that is considered appropriate as a data transfer destination for each regional group ID, and creates a client terminal group list for each regional group.

  Thereafter, the encrypted division information is appropriately shuffled to create a final divided copy data file name list for data transfer. Here, in shuffling, if the number of divisions is 2 and the number of replicas is 2, four pieces of encrypted division information are generated. In this case, 4 types of encrypted division information are arranged 4! One of these combinations can be arbitrarily selected each time the encrypted divided information is updated. FIG. 17 shows an embodiment for random rearrangement of encrypted division information in the transmission destination determination means 28 in general. As an example, a setting example of the character string X (p) when the division number α is 10 will be described.

  An embodiment for shuffling the transmission destinations of the encrypted divided information at random in the transmission destination determination means 28 shown in FIG. 13 will be described below. For example, the following parameters exist as various parameters necessary for shuffling. The first is the division number α, the second is the replication number β, the third is the random number p, the fourth is the random number q, the fifth is the seed for the random number p, the sixth is the seed for the random number q, and the seventh is the character string X The eighth is a character string Y, and the ninth is a character string XY obtained by concatenating the character string X and the character string Y. The random number p is randomly selected from the elements (1, 2, 3,..., Α). The random number q is randomly selected from the elements (1, 2, 3,..., Β). Here, based on the values of the number of divisions and the number of replicas, it is necessary to perform registration processing in the order in which the files are generated sequentially in the split replica data file name list. For example, when the number of divisions is 2 and the number of replicas is 2, a total of four files are generated as encrypted division information. In this case, the registration processing is performed in the order of divided copy data 0101, 0102, 0201, and 0202.

  The divided / replicated data transfer destination list generated / registered needs to correspond to the client terminal list divided for each area group. As an example of the above shuffling in this case, for example, when distributing in the order of the client terminal list, when the division number is 4 and the replication number is 3, the file to be transferred to the client terminal 10 There are a total of 12 (= 3 × 4) numbers, and one piece of the divided copy data is extracted from the divided copy data file name list, and sequentially corresponded to the client terminal group list for each region group, and divided copy Create a data transfer destination list. At this time, the arrangement of the divided duplicate data expressed in the generation order is 0101, 0102, 0103, 0201, 0202, 0203, 0301, 0302, 0303, 0401, 0402, 0403. This order is, for example, In each area, 0302, 0403, 0102, 0103, 0203, 0101, 0401, 0303, 0402, 0202, 0201, and 0301 are obtained at the next update. The information of the divided duplicate data transfer destination list is not fixedly held. For example, the client terminal list is transmitted from the monitoring control device 30 as needed. Needless to say, it can be changed arbitrarily based on the information of the client terminal list that changes from time to time.

  Each of the divided duplicate data file name lists is composed of a pair of a division number and a duplicate data number of the original file data, and these are registered for each region. Accordingly, each client terminal uses the encrypted divided information transmission means 23 of the master server 20 in the order of divided duplicate data 0302, 0403, 0102, 0103, 0203, 0101, 0401, 0303, 0402, 0202, 0201, 0301. 10 is transmitted, and safety can be improved. At this time, the master server 20 uses the encryption information used when encrypting the data file and the divided copy data transfer destination list as sequence information to the monitoring control device 30 at the same time using the concealment information transmission unit 24. ,Send. When the monitoring control device 30 restores the original data file, the necessary encrypted division information can be collected and restored by referring to the divided duplicate data transfer destination list and selecting the client terminal 10.

  A transmission example of the encrypted division information to the client terminal in consideration of the regional group in the transmission destination determination unit 28 shown in FIG. 13 will be described. It is assumed that the number of area groups is 4, and the number of client terminals in each area group is 4, 1, 3, 2 for area number 01, area number 02, area number 03, and area number 04, respectively. An example is shown. In this case, when the identification numbers of the terminals in the area group are displayed as three-digit numbers, the names of the four client terminals having the area number 01 can be displayed as 01001, 01002, 01003, and 01004, respectively. The client terminal that can be used for each area number is, in advance, the response time at the time of test data transmission from the monitoring control device 30 satisfies the reference value, or the throughput value from the terminal that can be estimated is It is assumed that only those that satisfy the reference value are registered so that the higher priority transfer destination is indicated in the list for each region. The rearrangement method for constructing the list in the order of higher priority can be easily realized by applying commonly used techniques such as bubble sort, method, and quick sort method.

  The client terminal that can be used for each region normally assumes that the encrypted division information is distributed and transferred as uniformly as possible for each region using the encrypted division information transmission unit 23. The average number of files transferred for each region is 3 (= 12 ÷ 4). For example, the divided replica data is 0302 at the first, 0403 at the second, 0102 at the third, 0102 at the fourth, 0103 at the fourth, 0203 at the fifth, 0101 at the sixth, 0401 at the seventh, 0303 at the eighth, 0402, 0202 at the 10th, 0201 at the 11th, 0301 at the 12th, and 0301 in the order. The first, second, third, and fourth are distributed in order to the area numbers 01, 02, 03, and 04. Next, the 5th, 6th, 7th and 8th are similarly distributed to the area numbers 01, 02, 03 and 04. Finally, the ninth, tenth, eleventh, and twelfth are also distributed to the region numbers 01, 02, 03, and 04 in the same manner.

  Here, when the number of client terminals that can be used in the same area number is small, such as the area numbers 02, 03, and 04, and less than 3, a plurality of encrypted division information is stored in one client terminal. When it is transferred. Accordingly, in the area number 01, the divided copy data 0302, 0203, 0402 are stored. In addition, since there are two client terminals 04002 and 04001 available at the location corresponding to the area number 04, the first divided duplicate data 0103 is transferred to the client terminal 04002 in the fourth order. Next, the divided duplicate data 0303 transferred to the same area number 04 is transferred to the client terminal 04001 in the eighth order. Further, the divided copy data 0301 transferred to the same area number 04 is transferred to the client terminal 04002 in the 12th order. In addition, since there is only one usable terminal of the client terminal 02001 in the area number 02, the divided copy data 0403, 0101, and 0202 are distributed and transferred to the second, sixth, and tenth, respectively.

  In this example, an example in which the area is equally divided is shown. However, it is needless to say that a method of distributed transfer by changing the weight for each area is also possible. In addition, it is possible to easily realize a method of scatter-transferring at random, ignoring the balance at the time of distributed transfer for each region. Further, when the total number of divided replicas (α · β) = 400 and the number of regions is 10, it is sufficient that 40 or more terminals can be used for each region, and the practicality for industrial use is sufficiently high. Conceivable. As described above, the client terminal name and the divided and duplicated data file name list rearranged at random need to be transferred in consideration of the correspondence.

  As described above, it is necessary to transfer the client terminal and the divided copy data rearranged at random in consideration of the association. FIG. 18 shows a flow of processing for transferring divided duplicate data to client terminals in the regional group. It is assumed that data is transferred to the client terminal for each priority. In actual operation, the idea to prevent all of the encrypted division information from being collected in one regional group is data on how the divided data files are deployed for each region. It is easily possible by referring to.

  As described above, the first encryption key, file sequence information, client terminal information, etc. are controlled from the monitoring control device side to different regions or physically different servers in the same region. By providing a network mechanism that can be freely controlled by a command or the like, it is possible to dramatically improve the safety and reliability of the disaster recovery system using the grid computing technology.

FIG. 14 is a flowchart illustrating an example of the operation of the monitoring control device according to the present embodiment.
In step S <b> 301, the client terminal status report request transmission unit 37-1 transmits a client terminal status report request to each client terminal 10. Here, the client terminal status report request is a request for transmitting the client terminal status stored in the resource information transmission means 15. The client terminal state is information indicating the state of the client terminal 10 itself, and is, for example, the usage rate of the CPU, the memory, and the free capacity of the hard disk.
In step S302, the throughput measuring unit 37-3 determines whether or not the client terminal state information is received from the client terminal state transmitting unit 14-2 within a specified time. If the measuring means 37-3 for throughput etc. determines that the client terminal status information is received from the client terminal status information transmitting means 14-2 within the specified time, the process proceeds to step S303. On the other hand, when the throughput measuring unit 37-3 determines that the client terminal state information is not received from the client terminal state information transmitting unit 14-2 within the specified time, the process proceeds to step S305.

In step S303, the throughput measuring unit 37-3 measures the response time from the transmission of the client terminal state report request in step S301 to the reception of the client terminal state information from the client terminal state information transmitting unit 14-2.
In step S304, the throughput measuring unit 37-3 calculates the throughput from the received client terminal state information and the measured response time. Here, the throughput is, for example, when the measurement data amount transmitted by the measuring means 37-3 such as the throughput is X (bit), and a response time of Y (seconds) is required until a response to this reply request. , (X / Y) (bit / s) is calculated as a throughput value. The throughput measuring unit 37-3 stores the received client terminal state information, the measured response time, and the throughput in the information storage unit 32.
In step S305, the throughput measurement unit 37-3 confirms that the client terminal state information has not been received within the specified time from the client terminal state information transmission unit 14-2, and determines that the client terminal 10 cannot be used. To do. Here, the confirmation is performed, for example, by recognizing that the reception is not normally performed in the client terminal state report request receiving unit 14-1.
In step S306, the information storage unit 32 registers that the client terminal 10 is “unusable”. In addition to the case where the file cannot be received within the specified time in step S305, “normal”, “impossible” or “abnormal” of the client terminal 10 may be confirmed by the following procedure.

FIG. 15 is a flowchart showing an example of an operation in which the throughput measuring means 37-3 confirms “normal”, “impossible”, or “abnormal” of the client terminal.
In step S401, the client terminal status report request transmitting unit 37-1 transmits the client terminal status report request to the client terminal status report request receiving unit 14-1.
In step S402, the throughput measuring unit 37-3 determines whether or not there is a response from the client terminal state report request receiving unit 14-1 within a specified timing. If there is a response, the process proceeds to step S403, and if there is no response, the process proceeds to step S407.
In step S407, the measurement means 37-3 such as the throughput determines that the client terminal 10 having the ID that has not responded within the specified timing in step S402 is “unusable”, and notifies that ID to that ID. And register.

In step S403, the throughput measuring unit 37-3 determines whether or not the CPU usage rate is equal to or less than a threshold value. Here, the threshold value is set to an appropriate value in order to realize a state in which the client terminal 10 does not receive the encrypted division information from the master server 20 under a high CPU usage rate. For example, if the CPU usage rate is 20% or less, it can be used if it is determined that there is no significant effect on the execution of other processes, or if the request condition from the client terminal 10 is this value. 20% is set as the threshold value.
In step S404, the throughput measuring means 37-3 determines whether or not the client terminal 10 can be used by determining whether or not the client terminal 10 has sufficient free memory. Here, the threshold value is set to an appropriate value in order to realize a state in which the client terminal 10 cannot receive the encrypted division information from the master server 20 under a small free memory area. For example, when the client terminal 10 having 2 GB of memory as a whole has 1 GB, which is 50% of the free memory area, if the memory free area is 1 GB or more, the execution of other processes is greatly affected. 1GB is set as the threshold value when it is determined that the request is not given, or when there is a separate contract indicating that the request condition from the client terminal 10 can be used if the value is this value.
In step S405, the throughput measurement unit 37-3 determines whether the client terminal 10 can be used by determining whether the client terminal 10 has a sufficient hard disk space. Here, for example, if a client terminal having a hard disk area of 100 GB as a whole has 80 GB, which is 80% of the free hard disk space, if the hard disk space is 80 GB or more, If it is determined that there is no significant impact on the execution of other processes, or if there is a separate contract that can be used if the requirement from the client terminal 10 is this value, It is determined that 80 GB is sufficient as the threshold value.

In step S406, the throughput etc. measuring means 37-3 determines that the judgment in steps S403 to S405 is normal, and registers that fact for the ID.
In step S408, the throughput measurement unit 37-3 determines that any of the determinations from step S403 to step S405 is not satisfied for the client terminal having the ID as “abnormal”. That fact is registered for the ID. Here, the confirmation is performed by collating the contents of the message returned to the throughput measuring means 37-3. In the registration process, “normal”, “abnormal”, and “impossible” are identified in the information storage unit 32 for all the client terminal 10 IDs, and related detailed information (for example, resource information) is stored. Create an included list. For example, if it can be confirmed that the determinations in steps S403 to S405 are normal, the result indicating that the normal registration processing has been performed for the client terminal 10 is stored.

FIG. 16 is a flowchart illustrating an example of registration of availability of the client terminal 10.
In step S501, the data file is initialized. Initial settings include the file size of the data file to be backed up, the failure rate of the client terminal 10, the number of divisions according to the encryption strength requested by the client, the backup probability corresponding to the number of encrypted pieces of division information, and availability The number of client terminals is read from the information storage unit 21 and comprehensively determined to determine the number of file divisions and the number of copies of the divided files.

For example, in the concealment unit 22, the number of data file divisions by the division unit is n, the number of replications per division file by the duplication unit is m, and the failure rate of the client terminal 10 is p (<< 1). Assuming that the client terminal 10 fails randomly, the restoration probability of the file when the master server 20 fails is recovery rate≈ (1−P ^m ) ⁿ ≈1−nP ^m . Therefore, if a data file of a total of 100 MB is backed up, the number of client terminals 10 that can be used is 200 and the failure rate of the client terminals 10 is 20% (= 1/5). Assume that the recovery probability when a disaster occurs is 99.999% or more. At this time, if the number of divisions n is set to 20 and the number of copies m is set to 10, the recovery rate≈1-nP ^m = 0.999998, which satisfies the requirements of the backup requester.

In step S502, the transmission destination determination unit 28 determines and sets an effective line speed threshold required between the client terminal and the monitoring control device. Here, the threshold value is set so that the monitoring control device 30 estimates a necessary and sufficient time so that the collection time of the divided data when a disaster occurs in the master server 20 is not significantly delayed. (Alternatively, in some cases, the monitoring control device 30) sets.
In step S <b> 503, the transmission destination determination unit 28 reads and confirms the client terminal state information in the all client terminal list transferred from the monitoring control device 30. Here, the client terminal list is acquired from the information storage unit 21. In the client terminal list, the throughput, CPU usage rate, free memory area, free hard disk size, “normal”, “abnormal”, “unusable” status, etc. are written. Preferably, “normal” information is stored.

In step S504, the transmission destination determination unit 28 reads the response time or throughput of the client terminal 10 to register whether or not the client terminal 10 is usable, and determines whether or not this value satisfies a preset threshold value. . Here, the threshold value is set with the goal that the client terminal 10 can perform backup processing so that it does not affect the execution of other processes and can be executed so that quick backup can be realized. To do.
In step S505, the transmission destination determination unit 28 registers that the client terminal 10 can be used. For example, the information storage means 21 stores information indicating that it is “normal”, that is, in a usable state. Information indicating “normal” is preferably associated with a client ID, a CPU usage rate, a free hard disk capacity, a response time, and the like.
Steps S503 to S505 are repeated until the value of i changes from 2 to N, and the process ends when the value of i becomes N.
On the other hand, in step S506, the transmission destination determination unit 28 registers that the client terminal 10 is unusable. For example, information indicating “abnormal” or “impossible” is stored in the information storage unit 21. Information indicating “abnormal” or “impossible” is preferably associated with the client ID, CPU usage rate, free hard disk capacity, response time, and the like. If the processing for all the clients has not been completed after this registration, the terminal list number is incremented by 1, and the process proceeds to the processing for reading the i-th row of the client terminal list (S503).

FIG. 17 is a flowchart showing an example of an embodiment for random rearrangement of encrypted division information by the transmission destination determination means 28.
In step S601, the division number α and the replication number β are set based on the information on the encryption strength, the recovery time, and the number of available terminals. In step S602, random number seeds S1 and S2 are set. Thereby, it is possible to perform processing related to which distributed client terminals 10 are appropriately shuffled and transferred. Here, the random number seeds S1 and S2 are the types of random numbers generated in step S603, and are created using, for example, an integer random number generation algorithm of about 5 digits. Basically, it is sufficient to select a material whose periodicity cannot be estimated easily. Even in the initial setting, it may be performed on the basis that periodicity cannot be estimated. For example, the upper 5 digits when the current time is expressed in seconds are sufficient.

In step S603, random numbers p and q are generated as preparations for generating a character string X (p) and a character string Y (q) that are encryption keys. For example, random numbers p and q according to a uniform distribution are generated within a range of (0.1). In step S604, character strings X (p) and Y (q) are generated and connected. For example, assuming that the division number α is 10 and the random number p is 0.33, the character string X (p) is obtained by the following equation.

  Here, assuming that the character string X (p) is expressed by, for example, a two-digit decimal number, the character string X (p) = “04”. Actually, it can be similarly expressed in the case of expressing with three or more digits depending on the size of the division number. Also, the character string Y (q) can be determined in the same manner by setting the number of copies β, and the final character string combination can be obtained by combining X (p) and Y (q) in combination. X (p) and Y (q) can be generated as

In step S605, newly generated X (p) and Y (q) refer to a series of combinations that have already been generated, and whether or not new character strings X (p) and Y (q) have already been registered. Determine whether. In step S605, if the character string X (p) and the character string Y (q) are already registered, the process proceeds to step S609, and if not registered, the process proceeds to step S606.
In step S606, a character string X (p) and a character string Y (q) are registered. For example, the character string X (p) and the character string Y (q) are stored in the information storage unit 21 or the transmission destination determination unit 28.
In step S607, the total number N of registered combinations is counted up. In step S608, it is determined whether or not the total number N of registered combinations has reached the required number (α · β).
In step S609, the numerical values of random numbers S1 and S2 necessary for generating new random numbers p and q are counted up.

FIG. 18 is a flowchart showing an example of operations in the transmission destination determination unit 28 and the encrypted division information transmission unit 23 according to the present embodiment.
In step S701, the divided copy number determination unit 27 sets the divided number and the copy number for the file data. Here, the setting is performed based on the information on the encryption strength, the recovery time, and the number of available terminals described above. For example, the division number is set according to the capacity of the read data file after reading the data file from the information storage unit 21. In step S702, the concealment unit 22 conceals the data file, and then the transmission destination determination unit 28 performs processing related to which distributed client terminals 10 are appropriately shuffled and transferred. Create a split duplicate data file name list.

In step S <b> 703, the transmission destination determination unit 28 reads and checks information related to resources in the all client terminal list transferred from the monitoring center 30. The client terminal list is acquired from the information storage unit 21. The information storage means 21 stores regional information together with the identification information of each client terminal 10 and determines whether or not it belongs to a regional group based on the regional information.
In step S704, the encrypted division information transmission unit 23 transmits the encrypted division information to the client terminal associated in step S703.
In step S705, the encrypted division information transmission unit 23 determines whether transmission to all of the client terminals 10 associated with the divisional duplicate data file name list has been completed. If the transmission has not ended, the process proceeds to step S704, and steps S704 and S705 are repeated again. On the other hand, if the transmission ends in step S705, the process ends.

  The present invention uses a communication network to distribute database information including metadata necessary for data file recovery to a database server including metadata that is super-distributed and distributed on the network. As a result, important data files managed by the master server can be backed up safely and efficiently, protecting large-scale and important databases from disasters, and improving the safety and reliability of groundbreaking. Both can be provided to industry. In particular, in addition to the backup method for distributed PCs, the utility given to the industry by using portable terminals as grid client nodes is immeasurable.

1 is a schematic configuration diagram illustrating an example of a file backup network system according to a first embodiment. It is a schematic block diagram which shows an example of the master server which concerns on Embodiment 1. FIG. It is a schematic block diagram which shows another example of the concealment means of a master server. 2 is a schematic configuration diagram illustrating an example of a client terminal according to Embodiment 1. FIG. 1 is a schematic configuration diagram illustrating an example of a monitoring control device according to a first embodiment. 1 is a schematic configuration diagram illustrating an example of a backup device according to a first embodiment. It is a schematic block diagram which shows an example of the monitoring control apparatus which concerns on Embodiment 2. FIG. 3 is a schematic configuration diagram illustrating an example of a backup device according to a second embodiment. It is a flowchart which shows an example of operation | movement of a secret sharing process means. It is a flowchart which shows an example of the table preparation algorithm of a complete replacement system. It is explanatory drawing of the table preparation algorithm of a complete replacement system. It is a schematic block diagram which shows an example of the master server which concerns on Embodiment 3. FIG. 10 is a schematic configuration diagram illustrating an example of a file backup network system according to a fourth embodiment. 10 is a flowchart illustrating an example of the operation of the monitoring control device according to the fourth embodiment. It is a flowchart which shows an example of the operation | movement which the measurement means 37-3, such as a throughput, confirms "normal", "impossible", or "abnormal" of a client terminal. 4 is a flowchart illustrating an example of registration of availability of the client terminal 10. It is a flowchart which shows an example of the Example for the random rearrangement of the encryption division | segmentation information in the transmission destination determination means. 10 is a flowchart showing an example of operations in a transmission destination determination unit 28 and an encrypted division information transmission unit 23.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Client terminal 11 Encrypted division | segmentation information reception means 12 Information storage means 13 Survival confirmation information transmission means 14-1 Client terminal status report request reception means 14-2 Client terminal status information transmission means 15 Resource information transmission means 20 Master server 21 Information Storage means 22-1 First encryption means 22-2 Integration means 22-3 Dividing means 22-4 Duplicating means 22-5 Second encryption means 23 Encrypted divided information transmitting means 24 Confidential information transmitting means 25- DESCRIPTION OF SYMBOLS 1 File sequence secret sharing processing means 25-2 Encryption key secret sharing processing means 26 Client terminal list receiving means 27 Divided copy number determining means 28 Transmission destination determining means 30, 30a, 30b, 30c Monitoring control device 31 Information receiving means 32 Information storage Means 33 Information transmission means 34 Secret sharing processing means 37 -1 Client terminal status report request transmission means 37-2 Client terminal status information reception means 37-3 Throughput measurement means 38 Client terminal list transmission means 40, 40a, 40b, 40c Backup device 41-1, 41-2, 41- 3 Backup information receiving means 42-1, 42-2, 42-3 Backup information storage means 100 Communication network

Claims (4)

In a network system in which at least one master server, a plurality of monitoring control devices, and a plurality of client terminals are connected to each other via a communication network,
The master server is
A data file is encrypted with a first encryption key, the encrypted file data is divided into a plurality of divided data, the divided data is copied, and the copied divided data is encrypted with a second encryption key and output. Concealment means,
Encrypted division information transmission means for transmitting the encrypted division information output by the concealment means to the plurality of client terminals;
File sequence information recording the procedure of the concealment means from the division of the file data encrypted with the first encryption key to the encryption of the divided data with the second encryption key, and the first encryption key Respectively, and concealment information transmitting means for transmitting to a different monitoring control device among the plurality of monitoring control devices,
The plurality of client terminals are:
Encrypted divided information receiving means for receiving encrypted divided information transmitted by the encrypted divided information transmitting means;
An encrypted division information storage means for storing the encrypted division information received by the encrypted division information reception means,
The plurality of monitoring and control devices include:
Concealment information receiving means for receiving the file sequence information or the first encryption key transmitted by the concealment information transmitting means;
A network system comprising: concealment information storing means for storing the file sequence information received by the concealment information receiving means or the first encryption key. A plurality of backup devices connected to the supervisory control device via a communication network;
The monitoring and control device includes:
A secret that is divided into a plurality of pieces of backup information using a secret sharing method by dividing the file sequence information or the first encryption key stored in the concealment information storage unit into a plurality of pieces and integrating them by a reversible operation. Distributed processing means;
Backup information transmission means for transmitting the backup information from the secret sharing processing means to a different backup device among the plurality of backup devices, and
The backup device is
Backup information receiving means for receiving the backup information transmitted by the backup information transmitting means;
Backup information storage means for storing the backup information received by the backup information receiving means,
In the secret sharing method, the number of backup devices to which the secret sharing information transmitting means transmits the secret sharing information is n, and the file sequence information or the first encryption key required to restore the file When the number of backup devices is k, the completely substituted table S (k, n, d) is set to 0 in the nth column of the completely substituted table S (k-1, n-1, d). 2. The network system according to claim 1, wherein the network system is represented by an added table and a table in which 1 is added to the n-th column of the completely substituted table S (k, n−1, d). The master server is
File sequence secret sharing processing means for dividing the file sequence information into a plurality of pieces and integrating them by performing reversible operations on each other, and distributing using a secret sharing method;
The first encryption key is further divided into a plurality of pieces, integrated by performing reversible operations on each other, and further comprising encryption key secret sharing processing means for distributing using the secret sharing method,
The concealment information transmitting means transmits the file sequence information and the first encryption key from the file sequence secret sharing processing means and the encryption key secret sharing processing means,
In the secret sharing method, when the number of the backup devices is n and the number of the backup devices necessary for restoring the file sequence information or the first encryption key is k, the table of the complete replacement system is used. S (k, n, d) is a table in which 0 is added to the n-th column of the fully substituted table S (k-1, n-1, d), and a completely substituted table S (k, n) The network system according to claim 1 or 2, wherein the network system is represented by a table in which 1 is added to the n-th column of (-1, d). The monitoring and control device includes:
Client terminal status report request transmitting means for transmitting a client terminal status report request for requesting transmission of client terminal status information indicating the status of the client terminal to the plurality of client terminals;
Client terminal state information receiving means for receiving the client terminal state information transmitted from the client terminal;
Based on the client terminal status information received by the client terminal status information receiving means, and the response time from the transmission of the client terminal status report request to the reception of the client terminal status information. Measuring means such as throughput for measuring the throughput of
A client terminal list transmitting means for transmitting the client terminal status information received by the client terminal status information receiving means and the throughput measured by the measuring means such as the throughput to the master server as a client terminal list; and
The client terminal is
When receiving the client terminal status report request transmitted by the client terminal status report request transmitting means, resource information transmitting means for detecting the status of the client terminal and outputting the client terminal status information;
Client terminal status information transmitting means for transmitting the client terminal status information output by the resource information transmitting means to the monitoring control device, and
The master server is
Based on the client terminal list transmitted by the client terminal list transmission means, the division replication number determination means for determining the division number and the replication number in the concealment means;
Based on a client terminal list transmitted by the client terminal list transmitting means, further comprising a transmission destination determining means for determining the client terminal for transmitting the encrypted divided information in the encrypted divided information transmitting means,
The concealment means divides and duplicates the number of divisions and the number of duplications determined by the division / duplication number decision means,
4. The network system according to claim 1, wherein the encrypted division information transmission unit transmits the encrypted division information to the client terminal determined by the transmission destination determination unit. 5.

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