WO2013008351A1

WO2013008351A1 - Data distributed storage system

Info

Publication number: WO2013008351A1
Application number: PCT/JP2011/079837
Authority: WO
Inventors: 敏文新谷; 壮一最首
Original assignee: 株式会社野村総合研究所
Priority date: 2011-07-08
Filing date: 2011-12-22
Publication date: 2013-01-17
Also published as: JP2013020313A; JP4860779B1

Abstract

[Problem] To provide a data distributed storage system that provides distributed storage, in a plurality of data centers, of a plurality of partial data segments generated from important data using secret distribution technology, and that ensures security for preventing illegal acquisition of the partial data segments between each data center. [Solution] Each server (100) has a data storage unit (110) that stores partial data segments received from a client terminal (300). The client terminal (300) has: a segmentation processing unit (310) that generates an n number of partial data segments from important data, using secret distribution technology whereby the important data cannot be restored unless at least a k number (k≦n) of partial data segments is gathered; a distribution management unit (320) that stores the n number of partial data segments in an n number of servers (100) and gathers an m number (k≦m≦n) of partial data segments for restoring the important data, from an m number of servers (100); and a restoration unit (330) that restores the important data from the m number of partial data segments, using the secret distribution technology.

Description

Distributed data storage system

The present invention relates to electronic data storage technology, and more particularly to a technology effectively applied to a data distributed storage system that generates multiple non-important data from important data by secret sharing technology and distributes and stores them at multiple sites. is there.

In a company having an information system, it is necessary to take measures to protect important data such as highly confidential data in order to prevent an information security accident such as information leakage. On the other hand, various means for realizing these have also been proposed.

As a means for protecting important data, for example, it can be considered that companies etc. store important data in a data center where security measures are applied in multiple. However, independently constructing and operating a private data center that can be accessed from the outside requires a large load in terms of technology and cost, and can not be easily realized.

On the other hand, it is also conceivable to use a data center operated by a third party and provided to the outside as a service. However, storing your company's important data in a data center operated and managed by a third party involves high security risks. Since storing important data in a virtual data center or virtual server in a cloud computing environment, which is increasingly used in recent years, is extremely risky, an information system that handles important data is called a cloud computing environment. The use and construction is one of the reasons why it does not spread easily.

On the other hand, when important data is stored, it is also practiced to take measures to conceal the data or prevent tampering. In general, it is practiced to encrypt and store important data using an encryption key, but in this case, the encrypted data contains all the information of the important data. Therefore, for example, when the encrypted data is acquired by a third party, the encryption key is also acquired by the third party for some reason, and the important data is easily restored when it is decrypted. Further, even if the encryption key is not obtained, theoretically, there is a possibility that the important data may be restored from the encrypted data after a limited number of attempts since the encryption key has a finite length.

On the other hand, so-called secret sharing technology is also used as a method for strongly concealing important data. In secret sharing, even if some non-important data is acquired by a third party by dividing and distributing the important data into non-important data that is meaningless (it is not possible to restore or estimate the important data), Recovery of important data by a third party can be theoretically impossible.

Various methods have been proposed as secret sharing methods. For example, in Japanese Patent No. 4039810 (Patent Document 1), an electronic information file is divided into a plurality of information elements, and the divided information elements are selected and combined in a different order to combine two or more information blocks. Information block that does not include all the information elements unless all the information blocks are integrated, and division information according to the method of dividing into information elements and formation information according to the method of generating the information blocks A technology that secures the safety of electronic information by generating split extraction data recording the data, storing at least one of each information block and split extraction data in the certification authority, and separately storing the other separately. Is disclosed.

On the other hand, as a method of secret sharing which can restore important data if collecting a predetermined number or more of non-important data and information blocks (hereinafter sometimes referred to as "partial data") corresponding to the important data. For example, the (k, n) threshold secret sharing method using polynomial interpolation as described in Non-Patent Document 1 has been conventionally used. According to this method, important data can be restored by collecting at least k (k ≦ n) of partial data dispersed into n. Also, various threshold secret sharing methods have been proposed which further improve this method.

In relation to this, for example, in JP 2009-139990 A (Patent Document 2), data stored in a storage device is divided by a secret sharing method in which partial data of a reference number is required at the time of restoration, In the case of dividing data into a predetermined number of partial data equal to or greater than a reference number, a transmitter that transmits partial data to another information processing apparatus and deletes it from the storage device, and data is restored to the storage device An information processing apparatus is disclosed that includes an acquisition unit that acquires partial data from an information processing apparatus and stores the partial data in a storage device, and a restoration unit that restores data on the condition that a reference number of partial data is stored in the storage device. ing.

Patent No. 4039810 JP, 2009-139990, A

In recent years, with the widespread use of portable information processing terminals such as laptop PCs (Personal Computers), the risk of information leakage accompanying the theft or loss of these terminals themselves is increasing. For example, in a company handling personal information or the like, when an employee etc. loses such a terminal, a report or report etc. may be required to the supervisory authority. However, in the past, it was almost impossible to specify the actual information leakage range, and when lost, it was forced to report that all data were leaked or that there is a possibility of that.

On the other hand, it is conceivable to reduce the risk of information leakage due to loss of a terminal or the like by storing data including important data in the terminal in an external server or the like. At this time, important data is not stored as it is in an external server etc. For example, important data is divided and dispersed into non-important data using the above-described secret sharing technique to make partial data, which is used as external data. By decentralized storage in a server or the like, it is possible to reduce the risk of information leakage even in the case of storage in, for example, a virtual data center or a virtual server in a cloud computing environment.

That is, partial data distributed and stored in each data center or the like does not make sense by itself, and the content of important data can not be restored or inferred from only the partial data. Therefore, a third party who has illegally invaded the data center or server and acquired the partial data, as well as, for example, a person inside the administrator of each data center maliciously acquires the partial data, for example Even in such a case, it is possible to prevent the content of the important data from leaking from the acquired partial data.

Here, in the case of a system configuration in which partial data are distributed and stored in a plurality of data centers etc., usually, it is necessary for the user to perform user authentication individually for each data center etc. In this case, user authentication Processing is complicated, and there is a concern that work efficiency may be reduced. On the other hand, in general, a single authentication enables the user to access a plurality of data centers, servers, etc. requiring user authentication without performing individual authentication procedures. Sign-on technology is used.

As a method for realizing a single sign-on environment, for example, each server or system communicates between servers using a Security Assertion Markup Language (SAML) protocol or the like, and authentication is performed by a specific server such as an authentication server. There is a method of making it unnecessary to repeat the authentication procedure by the user in each server etc. by automatically handing over the information of the result.

However, in the single sign-on environment based on such a method, it is premised that a trust relationship is established between servers and systems, such as an in-house system on an intranet, for example, to allow handover and acceptance of authentication information. Therefore, when the data centers, servers, etc. are operated by different operators, such a trust relationship may not be established due to security relationship etc.

In addition, if the above-described single sign-on method is used in such an environment, for example, in a certain data center or the like, authentication information acquired from an authentication server or the like for user authentication processing It is also conceivable that a person in one's own will illegally access another data center etc. and acquire partial data stored in the other data center. Therefore, in the above-described structure in which a plurality of partial data generated from the important data by the secret sharing technique are distributed and stored in each data center or the like, to prevent unauthorized acquisition of the partial data among each data center Security should also be considered.

Here, for example, in the technology described in Patent Document 1, one of secret-distributed partial data (information blocks) is entrusted to a certification authority which is a so-called "trusted third party". This makes it possible to intervene the certification authority whenever restoring important data, and to cope with unauthorized access from malicious insiders. However, it is necessary to set up a "reliable third party organization" as a system configuration, which may increase the burden in terms of cost and operation load.

On the other hand, in the technology described in Patent Document 2, the partial data is mainly stored in a distributed manner in a server or another client terminal that is geographically separated, whereby the client terminal is stolen by a third party or via a network. Although the purpose is to reduce the risk of information leakage for intrusions, no consideration is given to unauthorized access from malicious insiders (eg, owners of other client terminals).

Therefore, an object of the present invention is to distribute and store a plurality of partial data generated from important data by secret sharing technology in a plurality of data centers, and secure security for preventing unauthorized acquisition of partial data between each data center It is to provide a data distributed storage system that can be

The above and other objects and novel features of the present invention will be apparent from the description of the present specification and the accompanying drawings.

The outline of typical ones of the inventions disclosed in the present application will be briefly described as follows.

A data distribution storage system according to a representative embodiment of the present invention generates partial data, which is a plurality of non-important data, from important data at the client terminal by secret sharing technology, and each of the partial data is transmitted via a network. A distributed data storage system for storing data distributed among a plurality of connected servers and having the following features.

That is, each of the servers has a data storage unit for storing the partial data received from the client terminal, and the client terminal uses the secret data sharing technology from the important data instructed to be stored by the user. A division processing unit that generates the n pieces of partial data (k ≦ n) that can not restore the important data unless collecting the important data, and the n servers different from each other in the n pieces of partial data generated by the division processing unit A distributed management unit for storing the partial data of m pieces (k ≦ m ≦ n) for restoring the important data from the server, and instructing use from the user With respect to the said important data, the said important data is obtained from the m pieces of said partial data acquired from said distributed management unit by said secret sharing technique. And having a restoring unit for restoring the data.

The effects obtained by typical ones of the inventions disclosed in the present application will be briefly described as follows.

According to a representative embodiment of the present invention, a plurality of partial data generated from the important data by the secret sharing technique are distributed and stored in a plurality of data centers, preventing unauthorized acquisition of the partial data among the respective data centers Security can be secured.

It is the figure which showed the outline about the example of composition of the data distributed storage system which is one embodiment of the present invention. It is a figure explaining the concept of storage of data in one embodiment of the present invention. It is a figure showing about an example of selection of a server which stores partial data in a 1 embodiment of the present invention. It is the figure which showed the outline | summary about the example of the flow of the authentication process in one embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings. Note that, in all the drawings for describing the embodiments, the same reference numeral is attached to the same part in principle, and the repetitive description thereof will be omitted.

<Overview>
The data distribution storage system which is one embodiment of the present invention generates a plurality of partial data from the important data by the secret sharing technique when the user stores the important data of the user on the client terminal, Send to servers in multiple data centers for distributed storage. In addition, by implementing a single sign-on mechanism for each data center and performing authentication processing using different unique information (keys) in each data center at the time of authentication, access to each data center is made independent. Ensure security and security among data centers. As a result, even an internal person such as a manager of each data center can obtain only one partial data, and important data can not be restored or inferred from the partial data. Data can be stored.

FIG. 2 is a diagram for explaining the concept of storage of data in the data distribution storage system of the present embodiment. The data distributed storage system 1 has a configuration in which a client terminal 300 and a plurality of data centers 10 (four of 10a to 10d in the example of FIG. 2) are connected to a network 400 such as the Internet. Here, the client terminal 300 is an information processing terminal that a user normally uses for business and the like and performs processing such as input and reference of the important data 500, and, for example, a PC, a tablet type terminal, a smartphone, a mobile phone, etc. A portable terminal etc. correspond.

Further, the data center 10 is a base that stores server devices and performs operation management, and for example, a dedicated data center facility capable of storing a large number of server devices etc. and performing advanced operation management, and so-called containers It may be a portable data center such as a model or a modular type, or may be a facility that is not dedicated, such as a machine room in an office building. It may also be a virtual data center in a cloud computing environment. Each data center 10 in the present embodiment is a server 100 (FIG. 2 example) having data storage units 110 (110 a to 110 d in the example of FIG. 2) each of which is a storage device or the like for holding and storing data. In the above, one or more units 100a to 100d) are provided.

It is desirable that each of these data centers 10 be unrelated to each other geographically or systematically. That is, for example, administrators or the like physically or electronically access each other between the data centers 10, such as being in the same site or adjacent sites, or being operated by the same or related business operators, etc. It is desirable that the configuration is not possible.

When secure storage of the important data 500 existing in the client terminal 300 is performed based on an instruction from the user in the environment as described above, first, the client terminal 300 uses secret sharing technology from the important data 500. A plurality of partial data 510 (four of 510a to 510d in the example of FIG. 2) are generated. Each partial data 510 is non-important data that does not make sense by itself, as described above. The important data 500 is deleted to prevent leakage.

The secret sharing technique (secret sharing algorithm) to be used is not particularly limited. For example, if k or more of n partial data 510 are collected, the important data 500 can be restored, but if less than k, it is important in principle A so-called (k, n) threshold type (1 <k ≦ n) secret sharing technique that can not restore the data 500 can be used. In addition, the values of k and n are not particularly limited, and can be appropriately determined according to the requirements such as security strength and processing speed. Note that the value of n (the number of partial data 510 to be generated) is equal to or less than the number of data centers 10. In other words, n or more data centers 10 are prepared for n partial data 510.

The generated partial data 510 is distributed to each data center 10 and transmitted so as not to overlap, and is distributed and stored in the data storage unit 110. That is, partial data 510 generated from the same important data 500 are stored separately in different data centers 10, and any two or more partial data 510 are not stored in the same data center 10. Let's do it. The partial data 510 on the client terminal 300 is deleted to prevent leakage.

As described above, leakage of the important data 500 due to theft or loss of the client terminal 300 can be prevented by generating the partial data 510 from the important data 500 by the secret sharing technology and distributing and storing the partial data 510 in each data center 10. it can. In addition, since each data center 10 has only one partial data 510 for the important data 500, a third party invades the data center 10 and illegally acquires the partial data 510, or the data center 10 Even when an internal person such as the manager of the above acquires partial data 510, only one partial data 510 can be acquired. Since the important data 500 can not be restored / estimated only by the partial data 510, the contents of the important data 500 will not be leaked.

In addition, when each data center 10 is not related geographically or systematically, a person inside the data center 10, such as a manager of the data center 10, accesses the other data center 10. It is also difficult together with the authentication process described later. Therefore, for example, even if an internal person such as a manager of data center 10 is malicious, partial data 510 is illegally acquired from another data center 10, and k or more data are collected to restore important data 500. It is possible to prevent the situation of

<System configuration>
Below, the system configuration | structure of the data distribution storage system 1 of this Embodiment is demonstrated. FIG. 1 is a diagram showing an outline of a configuration example of a data distributed storage system 1 according to an embodiment of the present invention. The data distribution storage system 1 has a configuration in which a plurality of servers 100, a master server 200, and a client terminal 300 are connected to a network 400. Each server 100 is operated and managed in the data center 10 unrelated to each other geographically or systematically as shown in FIG. 2 described above.

The server 100 is a computer system configured by a server device, and as a file server or storage server, receives user access from a client terminal 300 or the like after user authentication and provides storage service of data (partial data 510). It has a function. The server 100 includes, for example, a data storage unit 110 made of a storage device such as a magnetic disk and an authentication processing unit 120 implemented by a software program. The data storage unit 110 reads and writes specified data based on an instruction from an OS (Operating System) or the like.

The authentication processing unit 120 performs an authentication process for access to the server 100. The authentication processing unit 120 has user information 130 consisting of account information for each user as information used when performing authentication processing. The user information 130 includes, for example, a database, a file table, etc. For example, for each user ID of a registered user, a user sheath 131 as unique information different for each user and a password are hashed according to a predetermined procedure. It has account information such as a hashed password 132. Further, the authentication processing unit 120 has a server sheath 140 as unique information which differs for each server.

In the present embodiment, as described later, the authentication processing unit 120 performs authentication processing with the client terminal 300 by a challenge / response method. That is, in response to the authentication request from the user, the server sheath 140, the user sheath 131, and a random number as a challenge are transmitted. Furthermore, a password (hash value) hashed by these is received from the client terminal 300 as a response, and the received hash value is compared with that obtained by hashing the hashed password 132 with the above-mentioned random number to perform authentication. . Therefore, the authentication processing unit 120 implements a function of random number generation and a hash algorithm. Note that various known techniques and algorithms can be used for these implementations. In the case where security of the communication path between the server 100 and the client terminal 300 is ensured, for example, another method other than the challenge / response method may be adopted.

The master server 200 is a computer system configured by a server device, a PC, and the like, and generates and provides a user sheath 131 and a server sheath 140 held in each server 100. Since it is not a so-called authentication server that performs authentication on behalf of each server 100, it has no user authentication function. Master server 200 includes, for example, a sheath generation unit 210 implemented by a software program. The sheath generation unit 210 generates a sheath based on an instruction from a manager or the like, a request from each server 100, or the like, and provides the sheath as a user sheath 131 or a server sheath 140 to the target server 100 via the network 400.

There is no particular limitation on the method of generating the seeds, the format of the seeds, and the like, but, for example, a unique character string or binary data having a predetermined length can be generated as seeds. In addition, the master server 200 may be installed in the data center 10 independent of the other servers 100, or installed in the same data center 10 as any of the servers 100 by a configuration accessible from the outside. May be

The client terminal 300 generates a plurality of partial data 510 from the important data 500 using the secret sharing technology, distributes them to each server 100 (each data center 10) and transmits them so as not to overlap each other, and the data storage unit 110 Distributed storage facilities. The client terminal 300 has, for example, a distribution status 321 including a division processing unit 310 implemented by a software program, a distribution management unit 320, a restoration processing unit 330, an authentication request unit 340, an interface unit 350, and a database or file table. And each table of setting information 301.

The division processing unit 310 generates a plurality of partial data from the important data 500 instructed by the user via the interface unit 350, which will be described later, for secure storage, and a plurality of partial data stored in each server 100 in a distributed manner by secret sharing. Generate 510 As described above, the secret sharing method is not particularly limited, and a known (k, n) threshold type secret sharing method can be used. In the setting information 301, for example, information specifying an algorithm of secret sharing to be used, and parameters such as k and n can be set in advance.

The distributed management unit 320 transmits the partial data 510 generated by the division processing unit 310 to each server 100 according to a predetermined condition based on the setting content of the setting information 301 at the time of the distributed storage of the important data 500 and distributed storing. At the same time, information related to correspondence between which partial data 510 is stored in which server 100 is recorded in the distribution status 321 and managed.

When there are more than n servers 100, various methods can be considered for selecting n servers 100 and determining which server 100 each partial data 510 should be stored.

FIG. 3 is a diagram showing an example of selection of the server 100 for storing the partial data 510. In the example of FIG. 3, four partial data 510 generated by (3, 4) threshold type secret sharing from each important data 500 (“important data α”, “important data β”, “important data γ”,...) For (“A”, “B”, “C”, “D”), select four servers 100 as storage destinations from six servers 100 (“server # 1” to “server # 6”). Show the case of assignment.

For example, the servers 100 (“server # 1” to “server # 6”) are ordered in accordance with a priority or the like based on random or spec, etc. In example 3, after excluding "server # 6" when storing "important data γ", n servers 100 may be selected in order according to the order of the list. At this time, n servers 100 may be selected from the top of the list (for example, “server # 1”) each time, and as shown in the example of FIG. The servers 100 to be selected may be rotated at intervals of 500.

By rotating the server 100 to be selected, the plurality of important data 500 can be distributed and stored in different ways in the partial data 510. As a result, for example, when acquisition of partial data 510 becomes impossible due to a failure or the like in a plurality of servers 100 (two in the example of FIG. 3, shaded "server # 1" and "server # 2") In addition, the range of the important data 500 that can not be restored can be limited to a part (in the example of FIG. 3, only "important data α"), and a situation where all the important data 500 can not be restored can be prevented.

Various methods can be considered as a method of allocating partial data 510 to the selected n servers 100. For example, as shown in the example of FIG. 3, n partial data 510 may be sequentially assigned to a list of n servers 100, or each partial data 510 may be randomly assigned. Good.

The setting information 301 includes, for example, access information (IP address, host name, etc.) for each server 100 serving as a distributed storage destination, and for selecting n servers 100 when there are more than n servers 100. Criteria and conditions (for example, the priority order of the server 100, an ordered list, a method for rotation, etc.) can be set in advance.

Further, the distribution management unit 320 is based on the contents of the distribution status 321 and the setting contents of the setting information 301 based on the request from the restoration processing unit 330 when the restoration processing unit 330 restores the important data 500 described later. According to a predetermined condition, m partial data 510 for recovering the important data 500 are collected from each server 100 and delivered to the recovery processing unit 330.

Note that the value of the number m of partial data 510 to be collected needs to be equal to or more than the number k of partial data 510 necessary to restore the important data 500, and all n partial data 510 are collected It is good also as (k <= m <= n). In the setting information 301, for example, partial data 510 from the target server 100 due to criteria or conditions for selecting the target m servers 100 when m <n and m <n are satisfied. It is possible to set in advance a determination method of the server 100 to be a substitute in the case where the acquisition can not be made.

If any of n partial data 510 can not be stored in each server 100 during distributed storage of partial data 510 due to a failure or the like of server 100, k or more can not be collected when partial data 510 is collected In this case, an error may be returned to the user. In addition, when transmitting and receiving partial data 510 to and from each server 100, the client terminal 300 and each server 100 perform predetermined encryption on the partial data 510 and then transmit and receive information. The risk of risk may be further reduced.

The restoration processing unit 330 requests the distributed management unit 320 for the partial data 510 more than the number necessary for restoring the important data 500 instructed by the user via the interface unit 350 to be used for reference, editing, etc. From the acquired partial data 510, the important data 500 is restored by the secret sharing method.

The authentication request unit 340 requests authentication of each server 100 when the distributed management unit 320 distributes and stores the partial data 510 to each server 100 and collects the partial data 510 from each server 100. For example, the input of the user ID and password is received from the user via the login screen, and as will be described later, sequentially or in parallel with the authentication processing unit 120 of each server 100 individually by a challenge / response method or the like. By performing authentication processing, the function of single sign-on is realized.

Here, as described later, based on the server sheath 140, the user sheath 131, and the random number transmitted from the authentication processing unit 120 of the server 100 in response to the transmission of the authentication request, the password designated by the user is subjected to a predetermined procedure. , And transmits it to the authentication processing unit 120 of the server 100 to perform authentication processing. Therefore, the authentication request unit 340 implements the same hash algorithm as that implemented by the authentication processing unit 120 of the server 100.

The interface unit 350 has a user interface such as screen display in the client terminal 300 and an input / output function such as transmission / reception of data. The user can use the function of the data distribution storage system 1 by using, for example, a file management screen or the like possessed by a general OS.

For example, important data is moved to a specific folder or the like on a file management screen by a simple operation such as drag and drop. With this as a trigger, the division processing unit 310 and the distribution management unit 320 automatically generate n partial data 510 from the important data 500 by (k, n) threshold type secret sharing, and each partial data 510 Distributed storage can be performed in each server 100 without the user being aware. As described above, at this time the important data 500 is deleted from the client terminal 300, but on the screen for file management, for example, a dummy file corresponding to the important data 500 is created so as not to make the user conscious. I leave it.

Also, for example, the user performs an operation such as reference or editing on the important data 500 by performing an operation on a dummy file or the like of the important data 500 managed in a specific folder on the file management screen. be able to. That is, the distribution management unit 320 and the restoration processing unit 330 automatically trigger m pieces of important data 500 corresponding to the dummy file or the like from each server 100 (k ≦ m ≦ n) with the operation on the dummy file or the like as a trigger. Partial data 510 may be collected and key data 500 may be recovered and made available to the user.

<Authentication process>
Below, the content of the authentication process in the data distribution storage system 1 of this Embodiment is demonstrated. In the data distribution storage system 1 according to the present embodiment, as described above, when storing partial data 510 in a plurality of servers 100 in a distributed manner and when collecting partial data 510 from a plurality of servers 100, the user In order to avoid the complexity involved in individual authentication processing for each server 100, a single sign-on mechanism is provided.

In the present embodiment, since each data center 10 is not related geographically or systematically, for example, the authentication result of the representative authentication server, etc. There is a mechanism that can independently and safely access each data center 10 by separately performing authentication processing using unique information (keys) different among each data center 10 instead of the authentication method that is taken over. , Secure the security between each data center 10.

As an initial state for performing the authentication process, each server 100 holds the seeds generated by the sheath generation unit 210 of the master server 200 in advance as the server sheath 140. Further, it is assumed that initial registration of account information including a user ID, a password and the like has been performed in advance by each user. At this time, as the account information, the seeds generated by the seeds generation unit 210 of the master server 200 are held as the user seeds 131 for each user ID. Further, with regard to the password, the user seeds 131 and the server seeds 140 are held as a seed value and as a hashed password 132 hashed by a predetermined hash algorithm.

By not holding the password directly, leakage of the password can be prevented. In addition, by hashing the user seeds 131 unique to each user as a seed value, for example, even when the same password is accidentally designated by a plurality of users, the hash value may be different for each user. it can.

FIG. 4 is a diagram showing an outline of an example of the flow of the authentication process in the present embodiment. First, the user makes a request for authentication (login) via the authentication request unit 340 of the client terminal 300. At this time, for example, information of a user ID and a password is designated via a login screen or the like. The authentication request unit 340 transmits a request for authentication including the designated user ID to the server 100 (S01).

The authentication processing unit 120 of the server 100 that has received the user ID generates random numbers as a challenge in the challenge / response method, further acquires seeds, and transmits these to the client terminal 300 (S02). Here, in addition to the random number, the server sheath 140 and the user sheath 131 corresponding to the user ID held in the user information 130 are acquired.

The server sheath 140 and the user sheath 131, and the authentication request unit 340 of the client terminal 300 having received the random number hash the password designated in step S01 according to a predetermined hash algorithm (S03). Further, the hash value obtained in step S03 is hashed using the user seed 131 as a seed value (S04). Further, the hash value obtained in step S04 is hashed using the server seeds 140 as a seed value (S05). Further, the hash value obtained in step S05 is made one-time by hashing the random number as a seed value, and the obtained hash value is transmitted to the server 100 (S06).

Note that the series of hashing processing procedures in the above steps S03 to S05 are only an example, and it is naturally possible to use other procedures that can obtain equivalent results, but the password may be hashed at the time of user registration in advance. It is necessary to follow the same procedure as the hashing process when acquiring the hashed password 132 by In addition, for example, when an instruction to update the password is received from the server 100 because the password expiration date has passed in step S02, the password (and the hash before executing step S03, if necessary, etc. It may be possible to update the authentication password 132).

The authentication processing unit 120 of the server 100 having received the hash value acquires the hashed password 132 corresponding to the target user ID from the user information 130 (S07), and the acquired hashed password 132 is the random number generated in step S02. Is hashed as a seed value (S08). Thereafter, the authentication process is performed by comparing the obtained hash value with the hash value received from the client terminal 300 in step S07, and the authentication result is transmitted to the client terminal 300 (S09). That is, if the comparison results in a match, the authentication is established. If the two do not match, the authentication is not established. At this time, for example, information related to the whereabouts of the sender such as the IP address is acquired from the request message from the client terminal 300, and other conditions such as whether the information is within a predetermined range indicate success or failure of authentication. It may be added to the judgment of

The authentication request unit 340 of the client terminal 300 receives the authentication result (S10), and then automatically performs the above-described series of processing automatically on the other servers 100 as needed, and performs authentication on each server 100. Do the processing. Since the authentication process in each server 100 is independent, it is also possible to perform the above-described series of processes simultaneously in parallel with respect to a plurality of necessary servers 100. The necessary information of the server 100 may be set in advance, for example, in the setting information 301 or the like of the client terminal 300, or the distributed management unit 320 selects at the time of distributed storage or collection of the partial data 510. The server 100 may be targeted.

By the above process, the user can perform the authentication process on each of the necessary servers 100 only by specifying the user ID and the password once.

By taking the method as described above, for example, an administrator or the like of a certain server 100 or data center 10 acquires account information such as the user seeds 131 of the target user and the hashed password 132 from the user information 130 of the user. Even in this case, authentication by impersonation can not be performed on another server 100 (data center 10) using such information, and security between the servers 100 is secured.

This is because the value of the hashed password 132 of the user in one server 100 is hashed by its own server 140, and the hashed password 132 of the user in the other server 100 is the same as the other server. This is because the values are different because they are hashed by the 100 server seeds 140. Therefore, even if both of them are hashed using the same random number as a seed value, they will not be the same hash value, and the authentication will not be established in step S09 of FIG. Further, even if the server seeds 140 of the other server 100 are acquired by some means, a hash value having the same value as the hashed password 132 in the other server 100 is generated unless the password of the target user is known. It is not possible.

As described above, according to the data distribution storage system 1 which is one embodiment of the present invention, the partial data 510 is generated from the important data 500 by the secret sharing technology, and is stored separately in each data center 10 It is possible to prevent the leakage of the important data 500 due to the theft or loss of the client terminal 300. In addition, since each data center 10 has only one partial data 510 for the important data 500, a third party invades the data center 10 and illegally acquires the partial data 510, or the data center 10 Even when an internal person such as the manager of the above acquires partial data 510, only one partial data 510 can be acquired. Since the important data 500 can not be restored / estimated only by the partial data 510, the contents of the important data 500 will not be leaked.

In addition, by performing authentication using unique information (server seeds 140) different for each server 100, a person such as an administrator of the data center 10 may access another data center 10 with malicious intent. Since it is difficult, it is possible to secure security for preventing unauthorized acquisition of partial data 510 between each data center 10.

In addition, single sign-on to a plurality of servers 100 can be realized by a single authentication process from a client terminal 300 by a user, and authentication by each server 100 can be performed simultaneously in parallel. Therefore, in the distributed storage of partial data 510 generated from the important data 500 and collection of the partial data 510 more than the number necessary to restore the important data 500, the time required for authentication is reduced to suppress the deterioration of the response. It is possible to

As mentioned above, although the invention made by the present inventor was concretely explained based on an embodiment, the present invention is not limited to the above-mentioned embodiment, and can be variously changed in the range which does not deviate from the gist. Needless to say.

INDUSTRIAL APPLICABILITY The present invention is applicable to a data distributed storage system that generates a plurality of non-important data from important data by secret sharing technology and distributes and stores them at a plurality of sites.

1 ... Distributed data storage system,
10, 10a-d ... data center,
100, 100a to d: server, 110, 110a to d: data storage unit, 120: authentication processing unit, 130: user information, 131: user seed, 132: hashed password, 140: server seed,
200 ... master server, 210 ... sheath generation unit,
300: client terminal, 301: setting information, 310: division processing unit, 320: distribution management unit, 321: distribution status, 330: restoration processing unit, 340: authentication request unit, 350: interface unit,
400 ... network,
500 ... important data, 510a to d ... partial data.

Claims

In the client terminal, a plurality of non-important data partial data are generated from important data using secret sharing technology, and the data distribution storage system distributes and stores the partial data on a plurality of servers connected via a network. ,
Each of the servers has a data storage unit for storing the partial data received from the client terminal.
A division processing unit that generates n pieces (k ≦ n) of partial data that can not restore the important data unless collecting k or more pieces from the important data instructed by the user by the secret sharing technique. When,
N pieces of the partial data generated by the division processing unit are respectively stored in the data storage unit of n pieces of the server, and m pieces (k ≦ m ≦ n) for restoring the important data A distributed management unit that collects the partial data of the plurality of
A data processing unit for restoring the important data by the secret sharing technique from the m pieces of partial data acquired from the distribution management unit for the important data instructed to be used by the user Distributed storage system.
In the data distribution storage system according to claim 1,
The distributed management unit of the client terminal selects the n servers selected when selecting the n servers to be stored n partial data from among the n or more servers. A data distribution storage system characterized by rotating sequentially for every said important data to store.
In the data distribution storage system according to claim 1 or 2,
Each of the servers further includes an authentication processing unit that performs authentication processing for access to the server,
In the client terminal, when the distributed management unit stores the partial data in each server and collects the partial data from each server, the user designates the user ID and the password from the user. It has an authentication request unit that receives and sends authentication requests to each of the servers sequentially or in parallel,
The authentication processing unit of the server includes a server seed which is unique information for each server, a user seed which is unique information for each user, and a password of the user for each user ID of a registered user. And the user information holding account information including a hashed password hashed in a predetermined procedure using the user's seeds and the server seeds in response to the request for the authentication received from the client terminal. Transmitting the user seeds relating to the target user and the generated random number to the client terminal;
The authentication request unit of the client terminal hashes the password designated by the user according to a predetermined procedure using the server sheath received from the server and the user sheath, and further hashs the password using the random number. Send the hash value to the server,
The authentication processing unit of the server performs authentication by comparing the hash value received from the client terminal with a value obtained by hashing the hashed password for the target user using the random number. A distributed data storage system characterized by transmitting a result to the client terminal.
In the data distribution storage system according to any one of claims 1 to 3,
Furthermore, it is connected to the said network, and the master server which produces | generates and provides the seed value used as said seed with respect to each said server based on the request | requirement from each said server is provided, The data distribution storage system characterized by the above-mentioned.
In the data distribution storage system according to any one of claims 1 to 4,
When the distributed management unit of the client terminal stores n pieces of the partial data in n pieces of the server, the distributed management unit distributes information relating to which server the partial data is stored in A data distribution storage system characterized by recording in a situation recording unit.
In the data distribution storage system according to any one of claims 1 to 5,
The client terminal selects values of k, m and n according to the secret sharing technology, access information for each server, and n pieces of servers for which the distribution management unit stores n pieces of partial data Condition, the condition that the distributed management unit selects m pieces of servers to collect the partial data, and the alternative when the distributed management unit can not acquire the partial data from the server A data distribution storage system characterized in that at least one or more pieces of information among the determination methods of the server become preset information having preset.
In the data distribution storage system according to any one of claims 1 to 6,
When the distributed management unit of the client terminal stores n pieces of the partial data in the n servers, if any of the n pieces of the partial data can not be stored in the server, or m A data distribution storage system characterized by responding an error to the user when k or more pieces of the partial data are not collected when collecting the partial data from m pieces of servers.
In the data distribution storage system according to any one of claims 1 to 7,
The data distributed storage system, wherein the client terminal and each of the servers encrypt the partial data to be transmitted by a predetermined means when transmitting and receiving the partial data.