JP2014130412A - Data management method and data management device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent reconstruction of distributed data to original data even if a third party performs invalid access to a distributed information storage section.SOLUTION: A data management device (104_1) includes a storage section for storing distributed data. When the data management device 104_1 receives a registration request of a set of a main key and data from a network, it calculates a plurality of hash values from the main key, divides the data to create distributed data, creates a plurality of data pairs of the hash values and the distributed data, irreversibly converts the hash values to the addresses in the storage section, and stores, at the address, the distributed data pairing up with the address.

Description

  The present invention relates to a data management method and a data management apparatus for implementing the method.

  In general, in an information system, it is desirable to safely manage people and things, or information related to them (hereinafter referred to as personal information). For example, if a member's insurance information is leaked from an insurance company, the privacy of the member may be violated. If a member's membership number is leaked, there is a possibility of spoofing.

  When managing personal information in an information system, it is common to assign an identifier (hereinafter referred to as an ID) to a management target so that the information system can uniquely identify a management target such as a person or an object. is there. For example, in order to manage the information of the driver license holder, each driver license holder is assigned a unique driver license number, and using the driver license number, personal information relating to the driver license holder Perform the operation. Therefore, a data management technique capable of managing personal information as a main key for searching for IDs while managing personal information safely is required.

  As a technique related to data safety management, for example, a technique has been proposed in which document data is converted into encrypted data by an encryption technique, and an index and the encrypted data are associated with each other and managed in a database (for example, Patent Document 1). reference).

  However, in the technique disclosed in Patent Document 1, the encryption key for encrypting the document data needs to be managed safely, and the management of the encryption key is a complicated and difficult problem. Has been proposed (see, for example, Patent Document 2). According to this technique, document data is converted into secret shared data by the threshold-type secret sharing method, and the document ID is associated with each secret shared data and managed by the distributed information storage unit of each distributed data storage device.

JP 2007-52698 A JP 2009-180912 A

  According to the technique disclosed in Patent Document 2, since document data is converted into secret shared data, the document data cannot be restored from the secret shared data alone, but unauthorized access to the distributed information storage unit by a third party, etc. When the document ID is acquired by this, there is a risk that the document data is restored by collecting all secret sharing data from the document ID.

  The present invention has been made in view of such circumstances, and a data management method that makes it difficult to restore the distributed data to the original data even if there is an unauthorized access to the distributed information storage unit by a third party And it aims at providing a data management device.

  A typical example of the present invention is as follows. That is, the present invention is a data management method for managing a set of a primary key and data in a data management apparatus connected to a network. The data management device has a storage unit for storing distributed data. When the data management device receives a registration request of a primary key and data set from the network, it calculates a plurality of hash values from the primary key, divides the data to generate distributed data, and the hash A process of generating a plurality of data pairs of a value and the distributed data, a process of performing irreversible conversion from the hash value to an address in the storage unit, and storing the distributed data paired with the address at the address; It is characterized by implementing.

  According to the present invention, even if there is an unauthorized access to the distributed information storage unit by a third party, it is possible to make it difficult to restore the distributed data to the original data.

It is an example of the block diagram of the ID management system in a present Example. It is an example of the block diagram of the client apparatus 101 in a present Example. It is an example of a block diagram of the dispersion | distribution management apparatus 102 in a present Example. It is an example of a block diagram of the data management apparatus 104_1 thru | or 104_n in a present Example. It is an example of a hardware block diagram of the client device 101, the distributed management device 102, and the data management devices 104_1 to 104_n in the present embodiment. It is an example of the sequence diagram of ID registration processing in a present Example. It is an example of the message transmitted / received in the ID registration process in a present Example. It is an example of obfuscation and secret sharing in a present Example. It is an example of the hash value generation 604 in a present Example. This is a configuration example of the data management device information storage area 316 and the hash function storage area 317 of the storage unit 315 of the distributed management apparatus 102 in this embodiment. It is a figure explaining the process which determines the data management apparatus which adds data from data management apparatus 104_1, 104_2, ..., 104_n in a present Example. It is an example of the meta information 1201 in a present Example. It is an example of the memory | storage part 413 of the data management apparatus 104_1 at the time of ID registration in a present Example. It is an example of the sequence diagram of ID conversion processing in a present Example. It is an example of the message transmitted / received in the ID conversion process in a present Example. It is an example of the memory | storage part 413 of the data management apparatus 104_1 at the time of ID conversion in a present Example. This is an example of secret sharing restoration 1409 and readable 1410 in this embodiment. It is an example of the sequence diagram of ID deletion process in a present Example. It is an example of the message transmitted / received in the ID deletion process in a present Example. It is an example of the memory | storage part 413 of the data management apparatus 104_1 at the time of ID deletion in a present Example.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited thereby.

  In the present embodiment, an example of an ID management system that enables conversion from a specific ID to a specific ID will be described.

  FIG. 1 is a diagram illustrating a configuration example of an ID management system in the present embodiment. The ID management system is configured such that a distributed management apparatus 102 connected to a client apparatus 101 can communicate with each of a plurality of data management apparatuses 104_1 to 104_n via a network 103. The user uses the function of the ID management system via the client device 101. The client apparatus 101 and the distributed management apparatus 102 are not limited to one, and there may be a plurality of cases depending on the embodiment. Further, the client apparatus 101 and the distributed management apparatus 102 do not need to be directly connected, and may be connected via a network or a gateway apparatus depending on the embodiment. The network 103 is, for example, a closed intra network that is not open to the public.

  FIG. 2 is an example of a configuration diagram of the client apparatus 101 in the present embodiment. The client device 101 includes a control unit 201, an input / output unit 205, and a transmission / reception unit 206. The control unit 201 includes an ID registration request unit 202, an ID conversion request unit 203, and an ID deletion request unit 204. The ID registration request unit 202 receives an ID registration request from the user via the input / output unit 205, transmits an ID registration request message to the distributed management apparatus 102 via the transmission / reception unit 206, and distributes via the transmission / reception unit 206. A processing unit that receives an ID registration response message from the management apparatus 102 and notifies the user of the ID registration result via the input / output unit 205. The ID conversion request unit 203 receives an ID conversion request from the user via the input / output unit 205, transmits an ID conversion request message to the distributed management apparatus 102 via the transmission / reception unit 206, and distributes via the transmission / reception unit 206. It is a processing unit that receives an ID conversion response message from the management apparatus 102 and notifies the user of the ID conversion result via the input / output unit 205. The ID deletion request unit 204 receives an ID deletion request from the user via the input / output unit 205, transmits an ID deletion request message to the distributed management apparatus 101 via the transmission / reception unit 206, and distributes via the transmission / reception unit 206. The processing unit receives an ID deletion response message from the management apparatus 102 and notifies the user of the ID deletion result via the input / output unit 205. The input / output unit 205 controls input from the user via an interface such as a keyboard, and controls output to the user via an interface such as a monitor. The transmission / reception unit 206 transmits / receives information via the network 103. FIG. 3 is an example of a configuration diagram of the distributed management apparatus 102 in the present embodiment. The distributed management apparatus 102 includes a control unit 301, a storage unit 315, and a transmission / reception unit 318. The control unit 301 includes a data management device information management unit 302, an ID registration processing unit 303, an ID conversion processing unit 304, an ID deletion processing unit 305, an obfuscation unit 306, a readable unit 307, a secret distribution unit 308, and a secret distribution restoration. 309, a hash value generation unit 310, a data management device determination unit 311, a data addition request unit 312, a data reference request unit 313, a data update request unit 315, and a data deletion request unit 316.

  The data management device information management unit 302 communicates with the data management devices 104_1 to 104_n via the transmission / reception unit 318, and connection information (node ID) of the data management devices 104_1 to 104_n stored in the data management device information storage area 316. , IP address, port number, etc.). The node ID is a unique number assigned to the data management apparatuses 104_1 to 104_n, and the format is not limited. The ID registration processing unit 303 receives an ID registration request message from the client device 101 via the transmission / reception unit 318, performs ID registration processing, and transmits an ID registration response message to the client device 101 via the transmission / reception unit 318. It is. The ID conversion processing unit 304 receives an ID conversion request message from the client device 101 via the transmission / reception unit 318, performs ID conversion processing, and transmits an ID conversion response message to the client device 101 via the transmission / reception unit 318. It is. The ID deletion processing unit 305 receives an ID deletion request message from the client device 101 via the transmission / reception unit 318, performs ID deletion processing, and transmits an ID deletion response message to the client device 101 via the transmission / reception unit 318. It is. The obfuscation unit 306 is a processing unit that accepts a primary key or data from another processing unit in the control unit 301, generates an obfuscation intermediate value from the primary key or data, and returns this. The primary key is information for uniquely identifying a set of data sets (records) from the data storage area. The readable section 307 is a processing section that receives an obfuscated intermediate value from another processing section in the control section 301, makes the obfuscated intermediate value readable to a primary key or data, and returns this. The secret sharing unit 308 is a processing unit that receives an obfuscated intermediate value from another processing unit in the control unit 301, generates a secret sharing main key or secret sharing data from the obfuscated intermediate value, and returns this. The secret sharing restoration unit 309 receives the secret sharing primary key or secret sharing data from the other processing unit in the control unit 301, restores the obfuscation intermediate value from the secret sharing primary key or secret sharing data, and returns this It is a processing unit. The hash value generation unit 310 is a processing unit that receives data from other processing units in the control unit 301, calculates a plurality of hash values from the data, and returns the calculated hash values. The data management device determination unit 311 receives a hash value from another processing unit in the control unit 301, determines a data management device that performs data processing among the data management devices 104_1 to 104_n from the hash value, and stores data management device information A processing unit that returns connection information of the determined data management apparatus by referring to the storage area 316. The data addition request unit 312 receives secret sharing data and hash values from other processing units in the control unit 301, and sends a data addition request message to the data management device determined by the data management device determination unit 311 via the transmission / reception unit 318. This is a processing unit that transmits and receives a data addition response message from the determined data management apparatus via the transmission / reception unit 318 and returns a data addition result. The data reference request unit 313 receives secret sharing data and hash values from other processing units in the control unit 301, and sends a data reference request message to the data management device determined by the data management device determination unit 311 via the transmission / reception unit 318. It is a processing unit that transmits and receives a data reference response message from the determined data management apparatus via the transmission / reception unit 318 and returns a data reference result. The data deletion request unit 314 receives secret sharing data and hash values from other processing units in the control unit 301, and sends a data deletion request message to the data management device determined by the data management device determination unit 311 via the transmission / reception unit 318. This is a processing unit that transmits and receives a data deletion response message from the determined data management apparatus via the transmission / reception unit 318 and returns a data deletion result.

  The storage unit 315 includes a data management device information storage area 316 and a hash function storage area 317. The data management device information storage area 316 is an area for storing connection information of the data management devices 104_1 to 104_n. The connection information is synchronized by the data management device information management unit 302, so that the same value as the data management devices 104_1 to 104_n is shared. The hash function storage area 317 is an area for storing a plurality of hash functions used by the hash value generation unit 310. The hash function may be a function that guarantees irreversibility, and the number of hash functions matches the number of divisions performed by the secret sharing unit 308. Further, the division number (that is, the number of hash functions) may be an integer of 2 or more. It is assumed that an item number is assigned to this hash function.

  The transmission / reception unit 318 transmits / receives information via the network 103.

  FIG. 4 is an example of a configuration diagram of the data management devices 104_1 to 104_n in the present embodiment. The data management devices 104_1 to 104_n include a control unit 401, a storage unit 413, and a transmission / reception unit 418. The control unit 401 includes a data management device information management unit 402, a data addition processing unit 403, a data reference processing unit 404, a data deletion processing unit 405, an index generation unit 406, an empty address acquisition unit 407, a meta information generation unit 408, and a head address. The storage processing unit 409, the head address acquisition processing unit 410, the data storage processing unit 411, and the data acquisition processing unit 412 are configured.

  The data management device information management unit 402 communicates with the distributed management device 102 via the transmission / reception unit 418 to synchronize the connection information of the data management devices 104_1 to 104_n stored in the data management device information storage area 414. Part. The data addition processing unit 403 receives a data addition request message from the distributed management apparatus 102 via the transmission / reception unit 418, performs data addition processing, and transmits a data addition response message to the distribution management apparatus 102 via the transmission / reception unit 418. It is a processing unit. The data reference processing unit 404 receives a data reference request message from the distributed management apparatus 102 via the transmission / reception unit 418, performs data reference processing, and transmits a data reference response message to the distribution management apparatus 102 via the transmission / reception unit 418. It is a processing unit. The data deletion processing unit 405 receives a data deletion request message from the distributed management apparatus 102 via the transmission / reception unit 418, performs data deletion processing, and transmits a data deletion response message to the distribution management apparatus 102 via the transmission / reception unit 418. It is a processing unit. The index generation unit 406 is a processing unit that receives a hash value from another processing unit in the control unit 401, generates an index from the hash value, and returns the index. The empty address acquisition unit 407 is a processing unit that refers to the data management information storage area 415 and returns the address of the empty area in the data storage area 417. The meta information generation unit 408 is a processing unit that receives secret sharing data and hash values from other processing units in the control unit 401, generates meta information from the secret sharing data and hash values, and returns the meta information. The start address storage processing unit 411 is a processing unit that receives an index and an address from other processing units in the control unit 401 and writes the received address at the corresponding index position in the start address storage area 416. The start address acquisition processing unit 410 is a processing unit that receives an index from another processing unit in the control unit 401 and reads an address from the corresponding index position in the start address storage area 416. The data storage processing unit 411 is a processing unit that receives an address, meta information, and secret sharing information and writes the received meta information and secret sharing information at a corresponding address in the data storage area 417. The data acquisition processing unit 412 is a processing unit that receives an address, reads meta information and secret sharing information of the corresponding address in the data storage area 417, and returns the read meta information and secret sharing information.

  The storage unit 413 includes a data management device information storage area 414, a data management information storage area 415, a head address storage area 416, and a data storage area 417. The data management device information storage area 414 is an area for storing connection information of the data management devices 104_1 to 104_n. The connection information is synchronized by the data management device information management unit 402 so that the same value as that of the distributed management device 102 is shared. The data management information storage area 415 is an area for storing free area information in the data storage area 417. The start address storage area 416 is an area for storing addresses. The start address storage area 416 has an index arrangement structure, and an address is stored at a position determined by the index. The data storage area 417 is an area for storing meta information and secret sharing data. The data storage area 417 stores data at a specified address.

  The transmission / reception unit 418 transmits / receives information via the network 103.

  FIG. 5 is an example of a hardware configuration diagram of the client device 101, the distributed management device 102, and the data management devices 104_1 to 104_n in the present embodiment. Each device can be realized by a general computer 501 and includes a CPU 502, a memory 503, an external storage device 504, a transmission / reception device 505, an input device 506, and an output device 507 as shown in FIG. These are connected by BUS (bus). The processing unit of each device described above is realized by a program and stored in the external storage device 504. The CPU 502 loads a necessary program from the external storage device 504 to the memory 503 and executes it. The storage units 315 and 413 of the distributed management device 102 and the data management devices 104_1 to 104_n are realized by the memory 503 and the external storage device 504. The transmission / reception units 206, 318, and 418 of each device are realized by the transmission / reception device 505. The input / output unit 205 of the client device 101 is realized by an input device 506 and an output device 507.

  A series of processes executed by the client apparatus 101, the distributed management apparatus 102, and the data management apparatus 104_1 when performing the ID registration process will be described with reference to FIGS. In this example, in order to enable conversion from ID “123456789” to ID “ABCDEHGHI”, ID “123456789” is used as a primary key and ID “ABCDEHGHI” is registered as data in the ID management system. In order to enable conversion in the reverse direction, a process in which ID “123456789” and ID “ABCDEHGHI” in this process are exchanged may be performed.

  FIG. 6 is an example of a sequence diagram of ID registration processing in the present embodiment. First, the client apparatus 101 transmits an ID registration request message 601 to the distributed management apparatus 102.

  FIG. 7 is an example of messages transmitted and received during the ID registration process in this embodiment. As shown in FIG. 7, the ID registration request message 601 includes two parameters, a primary key 701 and data 702. In the example of FIG. 6, ID “123456789” is the primary key 701 and ID “ABCDEHGHI” is data 702.

  Returning to FIG. 6, the description will be continued. Next, the distribution management apparatus 102 performs obfuscation 602 and secret sharing 603 on the primary key 701 and the data 702, respectively. The key 701 obfuscated 602 and secret shared 603 is the secret shared main key 704, and the data 702 obfuscated 602 and secret shared 603 is the secret shared data 705.

  FIG. 8 is an example of obfuscation and secret sharing in this embodiment. In the obfuscation 602, first, a random number 801 having a predetermined length is generated by a random number generator, and an exclusive OR of the target data (primary key 701 or data 702) and the random number 801 is calculated. The calculation result and the random number 801 are combined to generate an obfuscated intermediate value 802. In the example of FIG. 8, the exclusive OR of the primary key 701 “123456789” and the random number 801 “2or203ru2” is taken to generate “xo389j238”, which is obfuscated by combining it with the random number 801 “2or203ru2”. The intermediate value 802 “xo389j2382or203ru2” is generated. In the secret sharing 603, secret-distributed data (secret sharing main key 704 or secret sharing data 705) is generated by dividing the obfuscation intermediate value 802 by the number of divisions. In the example of FIG. 8, the obfuscated intermediate value 802 “xo389j2382 or 203ru2” is divided into six, so that the secret sharing primary keys 704 “xo3 704_1”, “89j 704_2”, “238 704_3”, “2or 704_4”, “203704_5”, “Ru2 704 — 6” is generated. Similarly, in this embodiment, the ID “ABCDEHGHI” is obfuscated 602 and secret-distributed 603, so that secret-sharing data 705_1 “r68”, 705_2 “02w”, 705_3 “m2z”, 705_4 “lwq”, 705_5 “Mnv”, 705 — 6 “cdr” is obtained. The number of divisions in the secret sharing 603 is a number designed in advance by the system designer according to the requirements. In this embodiment, the number of divisions is 6. However, the number of divisions is not limited to 6, and may be any value as long as it is an integer of 2 or more. In addition, the primary key 701 and the data 702 may be divided in plain text and secretly distributed without performing the obfuscation 602. For example, the secret key 704_1 and the secret shared data 705_1 to the primary key 701, There is a risk that a part of the data 702 may be read. Obfuscation 602 has an effect of partially preventing the danger of reading the primary key 701 and the data 702.

  Returning to FIG. 6, the description will be continued. Next, the distribution management apparatus 102 performs hash value generation 604. FIG. 9 is an example of the hash value generation 604 in the present embodiment. In the hash value generation 604, the distribution management apparatus 102 first acquires six hash functions 902 from the hash function storage area 317, and uses the six hash functions 902 from the primary key 901 to use the six hash values 703_1 and 703_2. , 703_6 are generated. In the example of FIG. 9, the hash value 703_1 “1584” and the like are generated from the primary key 701 “123456789”. The number of hash functions 902 matches the number of divisions in the secret sharing 603. In this embodiment, since the number of divisions of the secret sharing 603 is 6, the number of hash functions 902 is 6.

  FIG. 10 is a configuration example of the data management device information storage area 316 and the hash function storage area 317 of the storage unit 315 of the distributed management apparatus 102 in this embodiment. In the hash function storage area 317, hash functions 902_1, 902_2,..., 906_6 are stored in association with item numbers. Since the hash function is a one-way function, the primary key 701 cannot be estimated from any hash value of the hash values 703_1, 703_2, ..., 703_6.

  Returning to FIG. 6, the description will be continued. The distributed management apparatus 102 selects six secret sharing primary keys 704_1, 704_2,..., 704_6 and six secret sharing data 705_1, 705_2,. The hash values 703_1, 703_2,..., 703_6 are selected in the order of the item numbers, and the secret sharing primary key, the hash value, and the secret sharing data are associated with each other and divided into six sets. Then, the distributed management apparatus 102 performs from the subsequent data management apparatus determination 605 to the data addition response message 612 for each group. In this embodiment, since the number of divisions is 6, it is divided into 6 groups, and the data management device determination 605 to the data addition response message 612 are repeated 6 times.

  The distributed management apparatus 102 performs data management apparatus determination 605.

  FIG. 11 is a diagram for explaining processing for determining a data management device to which data is added from the data management devices 104_1, 104_2,..., 104_n in the present embodiment. In the data management device determination 605, node IDs 1001_1, 1002_2,... And connection information 1002_1, 1002_2,... Are obtained from the data management device information storage area 316, and the data management device having the smallest node ID equal to or greater than the hash value is obtained. Decide with the person in charge. If the hash value is larger than any node ID, the data management device having the smallest node ID is determined as the person in charge. In the example of FIG. 11, since the hash value 703_1 “1584” is equal to or greater than the node ID 1001_1 “1152” and less than the node ID 1001_2 “2084”, the data management device 104_1 is determined as the person in charge.

  Returning to FIG. 6, the description will be continued. Next, the distributed management apparatus 102 transmits a data addition request message 606 to the data management apparatus 104_1 determined as the person in charge. An example of the data addition request message 606 is shown in FIG. As shown in FIG. 7, the data addition request message 606 includes three parameters: a hash value 703_1, a secret sharing main key 704_1, and secret sharing data 705_1.

  Next, the data management apparatus 104_1 performs index generation 607. An index means a subscript of an array of start addresses stored in an array structure in the start address storage area. The meaning of the head address will be described later. In the index generation 607, a remainder obtained by dividing the hash value by the maximum value of the index is calculated, and the remainder is used as an index. In this embodiment, the maximum value of the index is “100”, and the index “84” is generated from the hash value 703 — 1 “1584”. The maximum value of the index is a constant determined before system operation.

  Next, the data management apparatus 104_1 performs empty address acquisition 608. In empty address acquisition 608, the data management information storage area 415 is referred to, and an additional write address 1301 that is an empty area is acquired. The additional write address means a place where a new record is added in the data storage area. An example of the data management information storage area 415 is shown in FIG. FIG. 13 is an example of the storage unit 413 of the data management apparatus 104_1 before ID registration in the present embodiment. In the example of FIG. 13, since there is an empty area for 9023 bytes starting from the address “133289”, “133289” is set as the additional address 1301_1.

  Returning to FIG. 6, the description will be continued. Next, the data management apparatus 104_1 performs meta information generation 609. The meta information is information related to the hash value, secret sharing primary key, and secret sharing data stored in the data management device 104_1, and is intermediate information used by the data management device 104_1 in internal processing.

  FIG. 12 is an example of the meta information 1201 in the present embodiment. In the meta information generation 609, the data size of the secret sharing primary key and secret sharing data is set to the secret sharing primary key length 1203 and the secret sharing data length 1204, the “null” address is set to the next address 1202, the hash value 703_1, and the next address 1202 respectively. The meta information 1201 is generated by combining the secret sharing main key length 1203 and the secret sharing data length 1204 as one data string. In the example of FIG. 12, “1584”, “null”, “3” (character string length of “xo3”), and “3” (character string length of “r68”) are the meta information 1201. The next address 1202 will be described later.

  Returning to FIG. 6, the description will be continued. Next, the data management device 104_1 performs the head address storage 610. In the start address storage 610, conditional branching is performed depending on the presence or absence of an address at the index position of the start address storage area 416, and two types of processing are performed. If the address does not exist, the additional address 1301_1 is written as the head address at the index position. When the address already exists, the head address existing at the index position is read. An example of the head address storage area 416 is shown in FIG. In the example of FIG. 13, since the head address already exists in the index “84”, the head address 1302 “90238” is read from the index position.

  Returning to FIG. 6, the description will be continued. Next, the data management device 104_1 performs data storage 611. In this embodiment, the meta information 1201, the secret sharing primary key 704_1, and the secret sharing data 705_1 are stored as one record in the data storage area 417. An example of the data storage area 417 is shown in FIG. In the data storage area 417, records having the same index are stored in a link structure by the index generation 607. Therefore, the head address means the address of the record that is the head of the link structure, and the next address means the address of the next record in the link structure. In the data storage 611, in order to realize the link structure, first, meta information 1201 (a hash value 703_1, a next address 1202, a secret sharing main key length 1203, a secret sharing data length 1204) is added to the additional write address 1301_1 of the data storage area 417. And secret sharing main key 704_1 and secret sharing data 705_1 are written as one record. Second, when the head address is written in the head address storage 610, the data storage 611 is terminated, and the subsequent third and fourth processes are not performed. Third, the record corresponding to the head address 1302 is read, and the end record is searched by following the link structure of the record. As a search for the end record, the record indicated by the next address 1202 in the record is referred to in order from the top address, and the record having the next address 1202 of “null” becomes the end record of the link structure. Fourth, the additional address 1301_1 is written to the next address 1202 of the end record. In the example of FIG. 13, meta information (“1584”, “null”, “3”, “3”), a secret sharing primary key 704_1 (“xo3”), secret sharing data 705_1 (“ r68 "), and the next address 1303 in the meta information of the head address 1302" 90238 "is" null ", so it is rewritten to" 133289 ". By adopting such a link structure, it is possible to cope with a case where indexes collide. In this embodiment, since the maximum index value is “100”, the hash values “1584” and “3584” have the same index. Therefore, if a link structure is taken and a hash value is included in the meta information 1202, a record can be uniquely specified for the hash value. The reason why the secret sharing primary key is included in the record is to cope with collision of hash values. Details thereof will be described in detail in the description of the example of the ID conversion processing.

  Returning to FIG. 6, the description will be continued. Next, the data management apparatus 104_1 transmits a data addition response message 612 to the distributed management apparatus 102. An example of the data addition response message 612 is shown in FIG. The data addition response message 612 is composed of parameters of the data registration result 707.

  Returning to FIG. 6, the description will be continued. Next, the distributed management apparatus 102 transmits an ID registration response message 613 to the client apparatus 101. An example of the ID registration response message 613 is shown in FIG. The ID registration response message 613 is composed of parameters of the ID registration result 706.

  By storing data in this way, the information stored in one record is only the hash value, secret sharing primary key, and meta information related to the secret sharing data, and other secret sharing corresponding from the information in the record. It is impossible to specify the record in which the primary key and secret sharing data are stored. As described above, since the hash function is a one-way function, it is impossible to specify the primary key from the hash value. Therefore, according to this structure, only when the primary key is known, it is possible to calculate a hash value from the primary key and specify a record in which the corresponding secret shared data is stored.

  The above is a series of processes executed by the client apparatus 101, the distributed management apparatus 102, and the data management apparatus 104_1 when performing the ID registration process. In the present embodiment, conversion from ID to ID is taken as an example, but conversion may be made by adding domain information to ID and adding domain information to ID.

  An example of a series of processes executed by the client apparatus 101, the distributed management apparatus 102, and the data management apparatus 104_1 when performing the ID conversion process will be described with reference to FIGS. Here, an example is shown in which the corresponding data is acquired from the ID management system using ID “123456789” as the primary key.

  FIG. 14 is an example of a sequence diagram of ID conversion processing in the present embodiment. First, the client apparatus 101 transmits an ID conversion request message 1401 to the distributed management apparatus 102. An example of the ID conversion request message 1401 is shown in FIG. FIG. 15 is an example of messages transmitted and received during the ID conversion process in the present embodiment. The ID conversion request message 1401 includes the parameters of the primary key 1501.

  Returning to FIG. 14, the description will be continued. Next, the distribution management apparatus 102 performs hash value generation 1402. This process is the same as the hash value generation 604 at the time of the ID registration process. In this embodiment, the hash value 1502 “1584” and the like are acquired from the primary key 1501 “123456789”. The distributed management apparatus 102 performs the subsequent data management apparatus determination 1403 to the data reference response message 1408 for each hash value. In this embodiment, since the number of divisions is 6, the process from the data management device determination 1403 to the data reference response message 1408 is repeated 6 times. Next, the distributed management apparatus 102 performs data management apparatus determination 1403. This process is the same as the data management apparatus determination 605 at the time of the ID registration process. Next, the distributed management apparatus 102 transmits a data reference request message 1404 to the determined data management apparatus 104_1. An example of the data reference request message 1404 is shown in FIG. The data reference request message 1404 includes a parameter having a hash value 1502.

  Next, the data management apparatus 104_1 performs index generation 1405. This process is the same as the index generation 607 during the ID registration process. In this embodiment, the index “84” is generated from the hash value 1502 “1584”. Next, the data management apparatus 104_1 performs the start address acquisition 1406. In the start address acquisition 1406, the start address 1601 of the index position in the start address storage area 416 is read. An example of the start address acquisition 1406 is shown in FIG. FIG. 16 is an example of the storage unit 413 of the data management apparatus 104_1 at the time of ID conversion in the present embodiment. In the example of FIG. 16, the head address 1601 “90238” is read from the index “84” of the head address storage area 416.

  Returning to FIG. 14, the description will be continued. Next, the data management apparatus 104_1 performs data acquisition 1407. In the data acquisition 1407, the data management apparatus 104_1 follows the link structure in order from the record indicated by the head address 1601 of the data storage area 417, and the given hash value 1502 matches the hash values 1602_1, 1602_2,. Search the record, and acquire the secret sharing primary key and secret sharing data of the record. Since hash values may collide, there may be a plurality of records having a hash value that matches a given hash value 1502, but here all of the records that match are acquired. An example of data acquisition 1407 is shown in FIG. In the example of FIG. 16, a record that starts from the head address 1601 “90238”, follows the link structure in order of the next address 1603_1 “133289”, the next address 1603_2 “209384”, and has a hash value that matches “1584” (Secret sharing main key length, secret sharing data length) = (“xo3”, “r68”) (“9ji”, “q30”).

  Returning to FIG. 14, the description will be continued. Next, the data management apparatus 104_1 transmits a data reference response message 1408 to the distributed management apparatus 102. An example of the data reference response message 1408 is shown in FIG. The data reference response message 1408 includes a data reference result 1505, secret sharing primary keys 1506_1, 1506_2,..., And secret sharing data 1507_1, 1507_2,.

  Returning to FIG. 14, the description will be continued. Next, the distribution management apparatus 102 selects secret sharing primary keys one by one from the received data reference response message 1408, and performs secret sharing restoration 1409 and readable 1410 for all combinations. Then, the distributed management apparatus 102 determines that the combination in which the restored primary key matches the primary key 1501 given first is the correct combination. In the present embodiment, the distribution management apparatus 102 uses (“xo3” or “9ji”), (“89j”), (“238”), (“2or”) as secret sharing primary keys from six data reference response messages 1408. ), (“203”), (“ru2”) and (“xo3” “89j” “238” “2or” “203” “ru2”) and (“9ji” “89j” “238” “2or” “203” “ru2”) is subjected to secret sharing restoration 1409 and readable 1410, and since the restored primary key matches the primary key included in the ID conversion request message 1401, the former combination Is determined to be correct.

  Specifically, first, in the secret sharing restoration 1409, the distribution management apparatus 102 arranges and combines the acquired secret sharing primary keys in the order of the item numbers of the hash function. An example of the secret sharing restoration 1409 is shown in FIG. FIG. 17 shows an example of secret sharing restoration 1409 and readable 1410 in this embodiment. In the example of FIG. 17, the distribution management apparatus 102 combines the acquired secret sharing primary keys 1701_1 “xo3”, 1701_2 “89j”, 1701_3 “238”, 1701_4 “2or”, 1701_5 “203”, and 1701_6 “ru2”. The obfuscated intermediate value 1702 “xo389j2382 or 203ru2” is generated.

  Returning to FIG. 14, the description will be continued. In the readable 1410, the distribution management apparatus 102 acquires the random number 1703 from the end of the obfuscated intermediate value 1702, and calculates the exclusive OR of the part other than the random number of the obfuscated intermediate value 1702 and the random number 1703. 1704 is generated. In the example of FIG. 17, the random number 1703 “2or203ru2” is acquired from the obfuscated intermediate value 1702 “xo389j2382or203ru2”, and the exclusive OR of “xo389j238” and the random number 1703 “2or203ru2” is calculated, thereby restoring the primary key 1704 “123456789”. ”Is generated.

  Next, when there is a combination that matches the primary key included in the ID conversion request message 1401, the distribution management apparatus 102 selects secret shared data according to the combination, performs secret distribution restoration 1409, and readable 14101507. 1504 is acquired. If there is no combination that matches the primary key included in the ID conversion request message 1401, the distributed management apparatus 102 sets the ID conversion result 1503 to “False”.

  Next, the distributed management apparatus 102 transmits an ID conversion response message 1411 to the client apparatus 101. An example of the ID conversion response message 1411 is shown in FIG. The ID conversion response message 1411 includes an ID conversion result 1503 and data 1504 parameters.

  The above is a series of processes executed by the client apparatus 101, the distributed management apparatus 102, and the data management apparatus 104_1 when performing the ID conversion process. The reason for performing processing for all combinations of secret sharing primary keys from secret sharing restoration 1409 to readable 1410 is to solve the hash value collision problem. In general, the hash function may obtain the same hash value from different values with a very low probability. Therefore, if the hash value collision problem is not dealt with, there is a possibility that an irrelevant record is acquired from the primary key. In this embodiment, the secret sharing primary key is stored in the record, and the secret sharing primary key is restored at the time of reference, so that the record corresponding to the primary key is uniquely identified, and the hash value collision problem is solved. ing. Although this process appears to be inefficient at first glance, the hash function is originally designed so that the collision is sufficiently small, and if the appropriate design is made, the combination of the secret sharing primary key 1506 will not be born. It is rare and does not pose a problem as calculation efficiency.

  An example of a series of processes executed by the client apparatus 101, the distributed management apparatus 102, and the data management apparatus 104_1 when performing the ID deletion process will be described with reference to FIGS. Here, an example of deleting a record having ID “123456789” as a primary key and ID “ABCDEHGHI” as data is shown.

  FIG. 18 is an example of a sequence diagram of ID deletion processing in the present embodiment. First, the client apparatus 101 transmits an ID deletion request message 1801 to the distributed management apparatus 102. An example of the ID deletion request message 1801 is shown in FIG. FIG. 19 is an example of messages transmitted and received during the ID deletion process in this embodiment. The ID deletion request message 1801 includes a primary key 1901 and data 1902 parameters.

  Returning to FIG. 18, the description will be continued. Next, the distributed management apparatus 102 uses the primary key 1901 to perform ID conversion processing. Therefore, the process from the hash value generation 1802 to the readable 1810 is a process necessary for the ID conversion process, and is the same as the hash value generation 1402 to the readable 1410 during the ID conversion process. By this processing, the distribution management apparatus 102 generates a hash value 1903 and acquires the address 1904 of the record in which the secret sharing primary key and the secret sharing data are stored as shown in the data reference response message of FIG. In this embodiment, a hash value 1903 “1584” or the like is generated, and an address 1904 “133289” is acquired.

  Next, the distributed management apparatus 102 transmits a data deletion request message 1811 to the data management apparatus 104_1. An example of the data deletion request message 1811 is shown in FIG. The data deletion request message 1811 includes parameters of a hash value 1903 and an address 1904.

  Returning to FIG. 18, the description will be continued. Next, the data management apparatus 104_1 performs index generation 1812. This process is the same as the index generation 607 during the ID registration process. Next, the data management apparatus 104_1 performs start address acquisition 1813. This process is the same as the start address acquisition 1406 during the ID conversion process. Next, the data management apparatus 104_1 performs data deletion 1814. An example of data deletion 1814 is shown in FIG. FIG. 20 is an example of the storage unit 413 of the data management device 104_1 when deleting an ID in this embodiment. In the data deletion 1812, first, the record indicated by the address 1904 in the data storage area 417 is referred to, the next address 2003_2 is acquired, and the record is deleted. Second, the link structure is sequentially traced from the record pointed to by the start address 2001 of the data storage area 417, a record in which the given address 1904 matches the next address 2003_2 in the record is searched, and the next address 2003_1 is changed to the next address 2003_2. replace. Third, if the given address 1904 matches the start address 2001, the start address 2001 in the start address storage area 416 is replaced with the next address 2003_2. In the example of FIG. 18, since the address 1904 “133289” is given, the next address 2003_2 “209384” is acquired and the record is deleted. Second, the link structure is traced from the head address 2001 “90238”, a record in which the next address 2003_1 is “133289” is searched, and the next address 2003_1 of the same record is replaced with the next address 2003_2 “209384”. The third process is not performed because the start address 2001 “90238” does not match the given address 1904 “133289”.

  Returning to FIG. 18, the description will be continued. Next, the data management apparatus 104_1 transmits a data deletion response message 1815 to the distributed management apparatus 102. An example of the data deletion response message 1815 is shown in FIG. The data deletion response message 1815 includes the parameter of the data deletion result 1906.

  Returning to FIG. 18, the description will be continued. Next, the distributed management apparatus 102 transmits an ID deletion response message 1816 to the client apparatus 101. An example of the ID deletion response message 1816 is shown in FIG. The ID deletion response message 1816 includes a parameter of the ID deletion result 1905.

  The above is a series of processes executed by the client apparatus 101, the distributed management apparatus 102, and the data management apparatus 104_1 when performing the ID deletion process.

  The embodiment of the present invention has been described above. According to the above embodiment, even if there is an unauthorized access to the distributed information storage unit by a third party, the primary key cannot be obtained, so that it is difficult to restore the distributed data to the original data. . Therefore, only the user who knows the primary key can refer to the data.

  In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

  Each of the above-described configurations, functions, processing units, processing means, and the like may be realized by hardware by designing a part or all of them with, for example, an integrated circuit. Each of the above-described configurations, functions, and the like may be realized by software by interpreting and executing a program that realizes each function by the processor. Information such as programs, tables, and files for realizing each function can be stored in a memory, a hard disk, a recording device such as an SSD (Solid State Drive), or a recording medium such as an IC card, an SD card, or a DVD.

  Further, the control lines and information lines indicate what is considered necessary for the explanation, and not all the control lines and information lines on the product are necessarily shown. Actually, it may be considered that almost all the components are connected to each other.

DESCRIPTION OF SYMBOLS 101 ... Client apparatus, 102 ... Distributed management apparatus, 103 ... Network, 104_1, 104_n ... Data management apparatus, 201, 301, 401 ... Control part, 315, 413 ... Storage part 205, I / O unit, 206, 318, 418 ... Transmission / reception unit, 501 ... Computer, 502 ... CPU, 503 ... Memory, 504 ... External storage device, 505 ... Transmission / reception device, 506... Output device, 507... Input device.

Claims (14)

A data management method for managing a set of primary keys and data in a data management device connected to a network,
The data management device has a storage unit for storing distributed data,
By the data management device,
When receiving a registration request of a primary key and data set from the network, a plurality of hash values are calculated from the primary key, the data is divided to generate distributed data, and a plurality of hash values and the distributed data are generated. Processing to generate data pairs;
Performing irreversible conversion from the hash value to an address in the storage unit, and storing the distributed data paired with the address at the address;
A data management method characterized by the above. By the data management device,
When receiving a reference request for data corresponding to a primary key from the network, a process of calculating a plurality of hash values from the primary key;
A process of performing irreversible conversion from the hash value to an address in the storage unit, and obtaining the distributed data existing at the address;
Performing the process of combining the acquired distributed data to restore the data and transmitting the data to the network;
The data management method according to claim 1, wherein: By the data management device,
A random number is generated by a random number generator, an exclusive OR of the random number and the data is calculated to generate an obfuscated intermediate value, and the obfuscated intermediate value and the random number are combined to generate combined data, A process of dividing the combined data to generate distributed data;
The data management method according to claim 2, wherein: By the data management device,
A process of generating combined data by combining the distributed data, obtaining an obfuscated intermediate value and a random number from the combined data, calculating an exclusive OR of the obfuscated intermediate value and the random number, and restoring the data Carry out the
The data management method according to claim 3, wherein: The storage unit has a data storage area for storing distributed data at a specified address, and a start address storage area for storing a start address of distributed data having a link structure by an index array structure,
By the data management device,
Select an arbitrary address from addresses indicating free areas in the data storage area, store distributed data and hash values at the addresses in the data storage area, and calculate an index from the hash values using remainder calculation The first address is obtained from the index of the first address storage area, and the address is stored at the end of the link structure by sequentially tracing from the first address.
The data management method according to claim 2, wherein: By the data management device,
An index is calculated from a hash value using a remainder calculation, a head address is obtained from a position indicated by the index in the head address storage area, a link structure is sequentially traced from the head address, and the hash value is stored in the data storage area. Implement the process to obtain the distributed data that matches the stored hash value,
The data management method according to claim 5, wherein: By the data management device,
Processing to split the primary key to generate a distributed primary key;
Performing the process of storing the distributed primary key, the distributed data, and a hash value in the data storage area;
The data management method according to claim 6. By the data management device,
For all combinations of a plurality of distributed primary keys, the primary key is restored by combining the distributed primary keys, a combination that matches the primary key and the primary key included in the reference request is determined, and distributed by the combination Perform processing to combine data and restore data,
The data management method according to claim 7, wherein: By the data management device,
A random number is generated by a random number generator, an exclusive OR of the random number and the primary key is calculated to generate an obfuscated primary key, and the obfuscated primary key and the random number are combined to generate a primary key , Executing a process of generating a distributed primary key by dividing the primary key;
The data management method according to claim 8, wherein: By the data management device,
Combine the distributed primary keys to generate a primary key, obtain an obfuscated primary key and a random number from the primary key, and calculate an exclusive OR of the obfuscated primary key and the random number to restore the primary key Execute the process to
The data management method according to claim 9. A data management device connected to a network,
A control unit and a storage unit for storing distributed data;
The controller is
When receiving a registration request of a primary key and data set from the network, a plurality of hash values are calculated from the primary key, the data is divided to generate distributed data, and a plurality of hash values and the distributed data are generated. Generate data pairs,
Performing irreversible conversion from the hash value to an address in the storage unit, and storing the distributed data paired with the address in the address;
A data management apparatus characterized by that. The controller is
When receiving a reference request for data corresponding to the primary key from the network, a plurality of hash values are calculated from the primary key,
Performs irreversible conversion from the hash value to the address in the storage unit, and obtains the distributed data existing at the address,
Combining the plurality of distributed data to restore the data and sending the data to the network;
The data management apparatus according to claim 11. The data management device further includes a random number generator for generating a random number,
The controller is
An exclusive OR of the random number generated by the random number generator and the data is calculated to generate an obfuscated intermediate value, and the obfuscated intermediate value and the random number are combined to generate combined data, the combined data To generate distributed data,
The data management apparatus according to claim 12, wherein: The controller is
Combining the distributed data to generate combined data, obtaining an obfuscated intermediate value and a random number from the combined data, calculating an exclusive OR of the obfuscated intermediate value and the random number, and restoring the data;
The data management management device according to claim 13.

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