JP2021048430A - Transaction recording device, transaction recording method, and transaction recording program - Google Patents

Abstract

To provide a transaction recording device, a transaction recording method, and a transaction recording program to prevent a blockchain from being enlarged.SOLUTION: A transaction recording device 10 participates in a network sharing a first blockchain, and includes an acquisition unit 21, a generation unit 22, and a registration processing unit 33. The acquisition unit acquires information from a second blockchain in which a transaction time and data related to a transaction performed at the transaction time are registered. The generation unit uses the information acquired by the acquisition unit to generate aggregated data obtained by aggregating data related to transactions performed during a predetermined period. The registration processing unit registers aggregated data in the first blockchain when the aggregated data matches other aggregated data generated from data about transactions made during a predetermined period of time in other transaction recording devices participating in the network.SELECTED DRAWING: Figure 2

Description

The present invention relates to a transaction recording device, a transaction recording method, and a transaction recording program.

There is known a blockchain technology that collects transaction records into one block and connects the blocks like a chain. Blockchain is often used in digital cryptocurrency services. In this case, transaction information (transactions) of virtual currency is collected in units called blocks, and ledger information shared by participants via a network is generated. In recent years, attempts have been made to apply blockchain technology to services other than virtual currencies, such as content management, copyright information management, supply chain, and power trading.

As a related technology, a system has been proposed in which primary information in transaction information is stored in a temporary information data storage area of a block generation verification device, and a storage block that does not include temporary information is connected to ledger data (for example, a patent). Reference 1 etc.). There is also known a signal processing method that executes a transaction for data shared by a group in which a plurality of nodes participates when an approval signal is received from a certain percentage of the nodes of the plurality of nodes (for example,). Patent Document 2 etc.). Further, a system has been proposed in which the total amount of assets delivered from the lower network to the upper network is less than or equal to the total amount of assets received from the upper network (for example, Patent Document 3).

Japanese Unexamined Patent Publication No. 2018-112827 International Publication No. 2018/154793 Japanese Unexamined Patent Publication No. 2018-166000

When blockchain technology is used for electricity trading, it is difficult to falsify data with blockchain, so it is conceivable to manage measurement data such as electricity transaction information and power generation amount with blockchain. In a blockchain, information is distributed and shared by a plurality of devices, but when a large amount of data is recorded in the blockchain, the amount of data held by each device also increases, which makes it difficult to maintain and manage the data. Therefore, if the blockchain manages measurement data such as power transaction information and power generation amount, there will be a problem that the blockchain will become bloated, but if this information is not managed using the blockchain, the information will be tampered with. There is a risk that it will end up. Similar problems occur when using blockchain not only for electricity transactions but also for various other transactions including virtual currencies. Also, using the techniques described as related techniques does not solve this problem.

One aspect of the present invention is to prevent the blockchain from becoming bloated.

A transaction recording device according to one embodiment participates in a network sharing a first blockchain and includes an acquisition unit, a generation unit, and a registration processing unit. The acquisition unit acquires information from the second blockchain in which the transaction time and the data related to the transaction performed at the transaction time are registered. The generation unit uses the information acquired by the acquisition unit to generate aggregated data that aggregates data related to the transactions performed during a predetermined period. When the registration processing unit matches the aggregated data with other aggregated data generated from the data relating to the transaction performed during the predetermined period in other transaction recording devices participating in the network. , The aggregated data is registered in the first blockchain.

Prevent blockchain bloat.

It is a figure explaining the example of the system which records the transaction concerning embodiment. It is a figure explaining the example of the structure of the transaction recording apparatus. It is a figure explaining the example of the configuration of the sub blockchain node. It is a figure explaining an example of a hardware configuration. It is a figure explaining the example of transaction data. It is a sequence diagram explaining the example of the registration process of transaction data. It is a figure explaining an example of a data aggregation model. It is a sequence diagram explaining an example of the generation process of aggregated data. It is a figure explaining an example of aggregated data. It is a sequence diagram explaining an example of a verification process. It is a figure explaining the example of the transaction which is finally issued. It is a flowchart explaining the example of the process which concerns on 1st Embodiment. It is a figure explaining the example of the system which concerns on 2nd Embodiment. It is a figure explaining the example of the configuration of the sub blockchain node. It is a figure explaining the example of the sub-blockchain switching process. It is a flowchart explaining an example of a sub-blockchain switching process.

FIG. 1 is a diagram illustrating an example of a system for recording transactions according to an embodiment. The system shown in FIG. 1 includes terminals 6 (6a to 6e), subblockchain nodes 50 (50a, 50b), transaction recording devices 10 (10a-10d), and has a main blockchain 1 and a subblockchain 5. Each of the sub-blockchain nodes 50 shall hold a distributed ledger of information recorded in the sub-blockchain 5. On the other hand, it is assumed that the transaction recording device 10 can acquire the information in the sub-blockchain 5, but does not hold the distributed ledger of the information registered in the sub-blockchain 5. Further, it is assumed that the transaction recording device 10 holds a distributed ledger of information recorded in the main blockchain 1.

Each terminal 6 transmits the information obtained by measurement or the like to the sub-blockchain node 50. For example, the terminal 6 can be any IoT (Internet of Things) device terminal. For example, when the terminal 6 is a device terminal used for power trading such as a meter for measuring the amount of power generation, the information notified from the terminal 6 to the sub-blockchain node 50 is information on the amount of power generation, the amount of electricity used, and the like. Is. The sub-blockchain node 50 registers the information received from the terminal 6 in the sub-blockchain 5. At the time of the registration process, the sub-blockchain node 50 confirms whether the terminal 6 that is the source of the data has the access right to the sub-blockchain 5, and the information received from the terminal 6 that has the access right. May be registered in the sub-blockchain 5. In the example of FIG. 1, the terminals 6a to 6c perform data registration processing via the sub-blockchain node 50a, and the terminals 6d to 6e perform data registration processing via the sub-blockchain node 50b.

Each of the transaction recording devices 10a to 10d generates aggregated data by aggregating the data of the transaction data registered in the sub-blockchain 5 during a predetermined period. For example, the aggregated data can be calculated for each terminal 6 using the data during a predetermined period. Each of the transaction recording devices 10a to 10d acquires the aggregated data calculated by the other transaction recording devices 10 for the same period for the same terminal 6, and the acquired aggregated data matches the aggregated data calculated by the own device. Determine if you want to. When notifying another transaction recording device 10 of the aggregated data calculated by the transaction recording device 10, for example, a transaction including the aggregated data (aggregated data transaction) is used. Further, each transaction recording device 10 signs when it is determined that the aggregated data in the received aggregated transaction matches the aggregated data calculated by its own device, and transmits the signed aggregated data to another transaction recording apparatus 10. .. The method of acquiring the aggregated data to be compared by the transaction recording device 10 and the method of transmitting the signed aggregated data follow the algorithm adopted in the main blockchain 1 shared between the transaction recording devices 10. It is assumed to be any method.

When a certain number or more of the transaction recording devices 10 sign the aggregated data calculated by the own device, each transaction recording device 10 determines that the aggregated data calculated by the own device is correct, and the distributed ledger of the main blockchain 1 Record in information. Therefore, among the aggregated data calculated using the information in the sub-blockchain 5, the aggregated data in which a predetermined ratio of the transaction recording devices 10 participating in the main blockchain 1 is determined to be correct is the main blockchain. Recorded in 1.

As described above, in the system shown in FIG. 1, the main blockchain 1 does not include the transaction data obtained from the terminal 6, and the aggregated data aggregated for each predetermined period is recorded. In other words, in the system shown in FIG. 1, aggregated data is recorded in the main blockchain 1 instead of individual transaction data. Therefore, the amount of information recorded in the main blockchain 1 is reduced as compared with the case of recording all of the individual transaction data obtained by the terminal 6. Further, the individual transaction data obtained by the terminal 6 is recorded in the sub-blockchain 5 which is different from the main blockchain 1. Therefore, in the system according to the embodiment, falsification of the transaction history obtained by the terminal 6 which is the basis of the calculation of the aggregated data recorded in the main blockchain 1 can be prevented.

Note that FIG. 1 is an example of a system, and the numbers of terminals 6, sub-blockchain nodes 50, and transaction recording devices 10 used in the system can all be arbitrarily changed according to the implementation. For example, the terminal 6 may be a device other than the IoT device. Further, the type of information measured by the terminal 6 can be arbitrarily changed according to the implementation. For example, the terminal 6 may measure information other than the information related to the sale of electric power, depending on the use of the system shown in FIG.

<Device configuration>
FIG. 2 is a diagram illustrating an example of the configuration of the transaction recording device 10. The transaction recording device 10 includes a control unit 15 and a storage unit 40. The storage unit 40 stores the main blockchain (BC) ledger 41, the setting information 42, and the public key information 43. The storage unit 40 also holds a private key used by the transaction recording device 10 itself for encryption.

The main blockchain ledger 41 records information shared using the main blockchain 1. Information used for calculating aggregated data, such as period information for calculating aggregated data and information on the terminal 6 to be calculated, is shared among transaction recording devices 10 using the main blockchain 1. It shall be done. The setting information 42 includes setting information such as a calculation result of aggregated data and a confirmation order when the transaction recording device 10 exchanges signed information with another transaction recording device 10. The public key information 43 is information in which the identification information of the transaction recording device 10 is associated with the public key that is a pair of the private key used for encryption by the transaction recording device 10 identified by the identification information. The public key information 43 may be shared by the main blockchain 1. When the public key information 43 is shared by the main blockchain 1, each transaction recording device 10 may acquire the public key information by referring to the main blockchain ledger 41.

The control unit 15 has an aggregation processing unit 20 and a main blockchain (BC) control unit 30. The aggregation processing unit 20 has an acquisition unit 21 and a generation unit 22. The acquisition unit 21 acquires the information shared by the sub-blockchain 5 according to the conditions shared by the main blockchain 1. The acquisition unit 21 holds in advance information such as the address of the sub-blockchain node 50 to be accessed in order to acquire the information shared by the sub-blockchain 5, or can be acquired from the storage unit 40. And. The generation unit 22 calculates the aggregated data using the information acquired by the acquisition unit 21.

The main blockchain control unit 30 includes a transaction receiving unit 31, a transaction issuing unit 32, and a registration processing unit 33. The transaction receiving unit 31 receives a transaction transmitted from another device such as another transaction recording device 10. The transaction issuing unit 32 transmits a transaction to another device such as another transaction recording device 10. The registration processing unit 33 performs verification processing of aggregated data included in the transaction received from the other transaction recording device 10. Further, the registration processing unit 33 determines that the aggregated data is correct when the calculation results of the aggregated data match between the transaction recording devices 10 having a predetermined ratio or more, and performs a process for registering the aggregated data in the main blockchain 1. Do.

FIG. 3 is a diagram illustrating an example of the configuration of the sub-blockchain node 50. The sub-blockchain node 50 includes a sub-blockchain control unit 60 and a storage unit 70. The storage unit 70 stores the sub-blockchain (BC) ledger 71. Information shared by the sub-blockchain 5 is recorded in the sub-blockchain ledger 71.

The sub-blockchain control unit 60 includes a transaction receiving unit 61, a transaction issuing unit 62, and a registration processing unit 63. The transaction receiving unit 61 receives a transaction transmitted from another device such as the terminal 6 or another sub-blockchain node 50. The transaction issuing unit 62 transmits a transaction to another device such as another sub-blockchain node 50. The registration processing unit 63 performs a process for registering the transaction data included in the transaction received from the terminal 6 in the sub-blockchain 5.

FIG. 4 is a diagram illustrating an example of a hardware configuration. Both the transaction recording device 10 and the subblockchain node 50 include a processor 101, a memory 102, a bus 105, and a network interface 109. Further, each of the transaction recording device 10 and the sub-blockchain node 50 may have one or more of the input device 103, the output device 104, the storage device 106, and the portable storage medium drive device 107. The transaction recording device 10 and the sub-blockchain node 50 can be realized by, for example, a computer, a server device, or the like.

The processor 101 is an arbitrary processing circuit, and can be, for example, a Central Processing Unit (CPU). The processor 101 can execute, for example, a program stored in the memory 102 or the storage device 106. The memory 102 appropriately stores the data obtained by the operation of the processor 101 and the data used for the processing of the processor 101. The storage device 106 stores programs, data, and the like, and appropriately provides the stored information to the processor 101 and the like. The network interface 109 performs a process for the transaction recording device 10 or the sub-blockchain node 50 to communicate with another device.

The bus 105 connects the processor 101, the memory 102, the input device 103, the output device 104, the storage device 106, the portable storage medium drive device 107, and the network interface 109 so that data can be transmitted and received to each other. The input device 103 is an arbitrary device used for inputting information such as a keyboard, mouse, microphone, and camera, and the output device 104 is an arbitrary device used for data output such as a display. The portable storage medium driving device 107 can output the data of the memory 102 and the storage device 106 to the portable storage medium 108, and can read programs, data, and the like from the portable storage medium 108. Here, the portable storage medium 108 can be any portable storage medium, including a Compact Disc Recordable (CD-R) and a Digital Versatile Disk Recordable (DVD-R).

In the transaction recording device 10, the processor 101 and the network interface 109 operate as the control unit 15. The memory 102 and the storage device 106 operate as the storage unit 40.

In the sub-blockchain node 50, the processor 101 and the network interface 109 operate as the sub-blockchain control unit 60. The memory 102 and the storage device 106 operate as the storage unit 70.

<First Embodiment>
Hereinafter, the first embodiment will be described separately for registration of transaction data, registration of data aggregation model and generation of aggregated data, and verification and registration of aggregated data. In the following description, a case where the terminal 6 is a power generation amount measuring meter and the amount of power generation used for electric power trading is measured at a predetermined cycle will be described as an example. In this case, the aggregated data is the amount of power generated within a predetermined period for each terminal 6.

Further, in the following description, in order to clarify the transaction recording device 10 or the like performing the processing, the alphabet at the end of the code of the device such as the transaction recording device 10 performing the processing may be indicated at the end of the code. is there. For example, the registration processing unit 33a is the registration processing unit 33 of the transaction recording device 10a, and the main blockchain ledger 41b is the main blockchain ledger 41 of the transaction recording device 10b.

(1) Registration of transaction data FIG. 5 is a diagram illustrating an example of transaction data. The transaction data of FIG. 5 is included in the transaction data registration transaction transmitted from the terminal 6 to the sub-blockchain node 50. In the example of FIG. 5, the transaction data registration transaction includes a transaction number, identification information (measuring instrument name) of the source device, power generation amount, and time. For example, assume that the measuring instrument name of the terminal 6a is A. Further, it is assumed that the terminal 6a measures that 0.1 kwh of power generation is performed at 15:00. Then, a transaction data registration transaction including information of measuring instrument name = A, power generation amount = 0.1 kwh, and time = 15:00 is generated. In the example of FIG. 5, the generated transaction number is 1.

FIG. 6 is a sequence diagram illustrating an example of transaction data registration processing. The terminal 6 that has issued the transaction data transaction shown in FIG. 5 transmits the issued transaction data registration transaction to the sub-blockchain node 50 (step S1). It is assumed that each terminal 6 stores in advance the address information and the like of the sub-blockchain node 50 to which the terminal 6 transmits the transaction data transaction. When the transaction receiving unit 61 of the sub-blockchain node 50 receives the transaction data registration transaction, it outputs it to the registration processing unit 63 (step S2).

It is assumed that the registration processing unit 63 stores in advance the name of the measuring instrument of the terminal 6 having the access right to the sub-blockchain 5, or can obtain it from the sub-blockchain ledger 71. The registration processing unit 63 determines whether the terminal 6 having the access right to the sub-blockchain 5 is the transmission source of the transaction data registration transaction by using the measuring instrument name included in the input transaction data registration transaction. (Step S3). If the terminal 6 having the access right to the sub-blockchain 5 is not the source of the transaction data registration transaction, the registration processing unit 63 ends the process (No in step S3). In this case, the power generation amount information notified in the transaction data registration transaction is not registered in the sub-blockchain 5.

On the other hand, when the terminal 6 having the access right to the sub-blockchain 5 is the transmission source of the transaction data registration transaction, the consensus building process is performed between the sub-blockchain nodes 50. When the consensus building process for registering the transaction is successful between the sub-blockchain nodes 50 participating in the sub-blockchain for data registration, the registration processing unit 63 registers the transaction data in the sub-blockchain ledger 71. (Yes in step S3, step S4). The transaction data registered in step S4 is power generation amount, time information, etc. included in the transaction data registration transaction.

(2) Registration of Data Aggregation Model and Generation of Aggregated Data FIG. 7 is a diagram illustrating an example of a data aggregation model. The data aggregation model is a model in which a client who intends to manage data using the main blockchain 1 registers in the main blockchain 1 using a client terminal (client terminal).

The data aggregation model shown in FIG. 7 includes identification information of the sub-blockchain 5, information of the terminal 6 for generating aggregated data, information on a period for performing aggregation processing, and an aggregation method. In the example of FIG. 7, the sub-blockchain 5 identified by the identification information "sub BC-X" is used for the calculation of the aggregated data. Further, the aggregated data is calculated individually for each of the measuring instruments whose measuring instrument names are A, B, and C, as the sum of the data measured in the period from 15:00 to 15:29.

FIG. 8 is a sequence diagram illustrating an example of aggregation data generation processing. An example of processing performed when the data aggregation model shown in FIG. 7 is registered will be described with reference to FIG. It is assumed that the client terminal 7 requests the transaction recording device 10a of the transaction recording devices 10 sharing the main blockchain 1 to register the data aggregation model (step S11). In step S11, the data aggregation model is transmitted from the client terminal 7 to the transaction recording device 10a.

When the transaction recording device 10a receives the request for registration of the data aggregation model, the transaction issuing unit 32a generates a transaction for registering the data aggregation model (data aggregation model registration transaction). The data aggregation model registration transaction may include information on the client terminal 7. The transaction issuing unit 32a transmits the data aggregation model registration transaction to the registration processing unit 33a, and also transmits the data aggregation model registration transaction to another transaction recording device 10 sharing the main blockchain 1 (step S12). In the transaction recording device 10a, the registration processing unit 33a records the data aggregation model in the main blockchain ledger 41a by using the received data aggregation model registration transaction. When the data aggregation model registration transaction includes the information of the client terminal 7, the registration processing unit 33a may authenticate whether the client terminal 7 is a device having an access right to the transaction recording device 10a. In this case, if the authentication process is successful, the registration processing unit 33a performs a consensus building process for registering the transaction between the transaction recording devices 10 participating in the main blockchain. When the consensus building process for registering the transaction is successful, the registration processing unit 33a registers the data aggregation model in the main blockchain ledger 41a.

In each of the devices other than the transaction recording device 10a that shares the main blockchain 1, the registration processing unit 33 acquires the data aggregation model registration transaction via the transaction receiving unit 31. The registration processing unit 33 records the data aggregation model in the main blockchain ledger 41 held by the device. Before the registration process, the registration processing unit 33 may perform an authentication process using the information of the client terminal 7 included in the data aggregation model registration transaction. By recording the data aggregation model in the main blockchain ledger 41 in each transaction recording device 10, the data aggregation model is registered in the main blockchain 1.

In each transaction recording device 10, the acquisition unit 21 in the aggregation processing unit 20 refers to the data aggregation model (step S13). In addition, there is a possibility that the data aggregation model includes a plurality of periods, or a plurality of data aggregation models are registered in the main blockchain 1. Therefore, the acquisition unit 21 may refer to the data aggregation model by accessing the main blockchain ledger 41 at regular intervals, for example, by polling or the like. When the aggregation period specified by the data aggregation model elapses, the acquisition unit 21 acquires transaction data associated with the time information of the aggregation period for each of the measuring instruments specified by the data aggregation model (step S14). .. For example, if the data aggregation model shown in FIG. 7 is registered in the main blockchain 1, and each device of the measuring instrument names A to C registers the power generation amount data in the subblockchain 5 every minute. To do. In this case, the acquisition unit 21 of each transaction recording device 10 has data measured by the measuring instrument A during the period from 15:00 to 15:29, and data measured by the measuring instrument B during the period from 15:00 to 15:29. Then, the data measured by the measuring instrument C during the period from 15:00 to 15:29 is acquired.

The generation unit 22 uses the data acquired by the acquisition unit 21 to generate aggregated data by the aggregation method specified in the data aggregation model (step S15). In the data aggregation model shown in FIG. 7, the sum is specified as the aggregation method. Therefore, the generation unit 22 calculates the total sum of the data measured in the period from 15:00 to 15:29 for the terminal 6 identified by the measuring instrument A. Similarly, the generation unit 22 also calculates the sum of the data measured in the period from 15:00 to 15:29 for the terminal 6 identified by the measuring instrument B and the terminal 6 identified by the measuring instrument C. calculate. The generation unit 22 outputs the obtained sum to the transaction issuing unit 32 as aggregated data (step S16).

FIG. 9 is a diagram illustrating an example of aggregated data calculated using the data aggregation model shown in FIG. 7. In the example of FIG. 9, the total amount of power generation measured by the terminal 6 identified by the measuring instrument A during the period from 15:00 to 15:29 is 4.2 kwh. The aggregated data also includes information obtained about measuring instrument B and measuring instrument C.

(3) Verification and Registration of Aggregated Data FIG. 10 is a sequence diagram illustrating an example of verification processing. FIG. 10 describes an example of verification and registration processing of aggregated data between the three transaction recording devices 10a to 10c. Further, in the following description, it is assumed that the transaction recording device 10a performs encryption using the private key KeyA. In addition, the public key that is a pair of the private key KeyA is KeyAP. Similarly, the transaction recording device 10b shall perform encryption using the private key KeyB, and the transaction recording device 10c shall perform encryption using the private key KeyC. Further, it is assumed that the public key paired with the private key KeyB is KeyBP, and the public key paired with the private key KeyC is KeyCP.

First, a consensus building method for verifying aggregated data is set between the transaction recording devices 10a to 10c, and the obtained settings are recorded as setting information 42 (step S21). In the example of FIG. 10, it is assumed that the aggregated data is presented from the transaction recording device 10a and the presented data is verified by another transaction recording device 10. As the consensus building method, any method depending on the blockchain infrastructure can be used. For example, as a consensus building method, an algorithm based on PBFT (Practical Byzantine Fault Tolelance) may be used.

After the period specified in the data aggregation model elapses after the setting of the consensus building method in step S21, each transaction recording device 10 generates aggregated data (steps S22 and S23). The process of generating the aggregated data is the same as the process described with reference to FIGS. 8 and 9. It is assumed that the transaction recording device 10a also performs the processing described with reference to FIGS. 8 and 9. The transaction issuing unit 32a of the transaction recording device 10a can specify that the transaction including the aggregated data is transmitted from the own device to the other transaction recording device 10 by referring to the setting information 42. Therefore, the transaction issuing unit 32a generates an aggregated transaction including the aggregated data (step S24). The transaction issuing unit 32a generates a signature using the private key KeyA of the transaction recording device 10a, and adds the signature to the aggregated transaction including the aggregated data (step S25). The transaction issuing unit 32a transmits the aggregated transaction after the signature to the transaction recording device 10b and the transaction recording device 10c (steps S26 and S27).

The transaction receiving unit 31b of the transaction recording device 10b outputs the received aggregated transaction to the registration processing unit 33b. The registration processing unit 33b compares the aggregated data included in the aggregated transaction with the aggregated data generated in step S23. At the time of the comparison processing of the aggregated data, the registration processing unit 33b targets the aggregated data generated under the conditions corresponding to the aggregated conditions corresponding to the aggregated data in the aggregated transaction as the comparison target. For example, when an aggregate transaction including the aggregated data shown in FIG. 9 is received, the registration processing unit 33b sets the sum of the power generation amount data of the measuring instrument name = A in the period from 15:00 to 15:29 as the measuring instrument name. Compare with the aggregated data for = A. The registration processing unit 33b also compares the aggregated data of the amount of power generation when the measuring instrument name = B and the measuring instrument name = C in the same manner. When the aggregated data included in the aggregated transaction and the aggregated data generated in step S23 match, the registration processing unit 33b encrypts the aggregated data with the private key KeyB of the transaction recording device 10b to generate a signature. In the case of aggregated data including a plurality of values related to data obtained by a plurality of devices such as the aggregated data shown in FIG. 9, if the data in the aggregated transaction and the calculated aggregated data match for all the devices, the registration process is performed. Unit 33b determines that the aggregated data match. The registration processing unit 33b adds a signature using the private key KeyB to the aggregated transaction (step S28).

When performing the verification process, the registration processing unit 33b uses the signature made by the transaction recording device 10a and the public key KeyAP of the transaction recording device 10a to determine whether or not the aggregated data in the aggregated transaction has been tampered with. Can be verified. In this case, when the aggregated data in the aggregated transaction has not been tampered with and the aggregated data in the aggregated transaction matches the aggregated data calculated by the own device, the registration processing unit 33b sets the signature of the own device into the aggregated transaction. Add.

The transaction issuing unit 32b transmits the aggregated transaction processed by the registration processing unit 33b to the transaction recording device 10a, which is the source of the transaction (step S30). The aggregated transaction after processing by the registration processing unit 33b can be said to be a verification result because the result of verification by the transaction recording device 10b is represented by the presence or absence of a signature using the private key of the transaction recording device 10b.

The transaction recording device 10c also performs the same processing as the transaction recording device 10b for the aggregated transaction. That is, when the aggregated data in the aggregated transaction and the aggregated data generated in step S22 match, the registration processing unit 33c adds the signature generated by encrypting the aggregated data with the private key KeyC to the aggregated transaction (step S29). .. The transaction issuing unit 32c transmits the aggregated transaction processed by the registration processing unit 33c to the transaction recording device 10a, which is the source of the transaction (step S30).

The registration processing unit 33a of the transaction recording device 10a receives the aggregated transaction including the verification result from all the transaction recording devices 10 sharing the main blockchain 1. The registration processing unit 33a determines whether or not a signature is included for each transaction including the verification result. The registration processing unit 33a uses the obtained verification result to issue a final transaction to be disclosed to all transaction recording devices 10 sharing the main blockchain 1. The finally issued transaction is the aggregated data aggregated transaction with all signatures included in any of the validation results added to the transaction.

FIG. 11 is a diagram illustrating an example of a transaction to be finally issued. FIG. 11 shows the final transaction generated when a signature is obtained from both the transaction recording device 10b and the transaction recording device 10c for the aggregated transaction including the aggregated data of FIG. 9 issued by the transaction recording device 10a. Is an example of. The signature is associated with the identification information of the device that signed the signature.

The registration process to the main blockchain 1 will be described again with reference to FIG. The transaction issuing unit 32a of the transaction recording device 10a transmits the final transaction to the transaction recording device 10b and the transaction recording device 10c (step S31 in FIG. 10). The registration processing unit 33a verifies each of the signatures included in the final transaction. When verifying the signature, the registration processing unit 33a can use the public key that is a pair of the private key used by the transaction recording device 10 that has signed the signature. For example, the registration processing unit 33a verifies the signature of the transaction recording device 10b using the public key KeyBP, and verifies the signature of the transaction recording device 10c using the public key KeyCP. When the correct number of signatures is the threshold value Th or more, the aggregated data included in the final transaction is registered in the main blockchain ledger 41a (step S32). The registration processing unit 33a holds in advance a threshold value to be compared with the number of signatures included in the final transaction. Further, the threshold value may be set in the setting information 42 or the like.

In the transaction recording device 10b and the transaction recording device 10c that have received the final transaction, the registration processing unit 33 processes the final transaction in the same manner as the registration processing unit 33a. That is, in both the registration processing unit 33b and the registration processing unit 33c, when the number of correct signatures included in the final transaction is equal to or greater than the threshold value, the aggregated data included in the final transaction is stored in the main blockchain ledger. Register in 41 (steps S33, S34). By registering the aggregated data in the main blockchain ledger 41 of each transaction recording device 10, the aggregated data is shared in the main blockchain 1.

Note that FIG. 10 is only an example of processing, and the order of processing and the like can be changed depending on the implementation. For example, the registration process (step S32) of the main blockchain ledger 41a may be performed in the transaction recording device 10a of the issuer of the final transaction before the final transaction is transmitted in step S31.

(4) Processing Flow FIG. 12 is a flowchart illustrating an example of processing according to the first embodiment. FIG. 12 shows an example of the processing described with reference to FIGS. 7 to 11 in chronological order.

The client registers the data aggregation model in the main blockchain 1 using the client terminal 7 (step S41). The acquisition unit 21 of each transaction recording device 10 acquires data from the sub-blockchain 5 every period specified by the aggregation model (step S42). The generation unit 22 generates aggregated data from the data acquired by the acquisition unit 21 and the data aggregation model registered in the main blockchain 1 (step S43). After that, the transaction recording devices 10 sharing the main blockchain 1 determine the transaction signature / verification order using the PBFT protocol or the like (step S44). The transaction recording device 10 in which the signature / verification order is first set signs the aggregated data using the private key of its own device, and issues a transaction (aggregated transaction) (step S45). At this time, the aggregated transaction is transmitted to all transaction recording devices 10 other than the issuer of the aggregated transaction. The registration processing unit 33 of the transaction recording device 10 that has received the aggregated transaction determines whether the aggregated data in the received aggregated transaction matches the aggregated data calculated by its own device (step S45).

It is assumed that the aggregated data in the aggregated transaction and the aggregated data calculated by the own device match (match in step S45). In this case, the registration processing unit 33 signs the aggregated transaction using the private key of its own device, and issues a transaction for transmitting the signed transaction to the issuer of the aggregated transaction (step S47).

On the other hand, it is assumed that the aggregated data in the aggregated transaction and the aggregated data calculated by the own device do not match (mismatch in step S45). In this case, the registration processing unit 33 does not sign the aggregated transaction, but issues a transaction for transmitting the received transaction to the issuer of the aggregated transaction (step S48). The issuer of the aggregated transaction issues the final transaction using the verification result received from each transaction recording device 10. The final transaction contains the signature made on the aggregated data during the aggregated transaction. The transaction issuing unit 32 of the transaction recording device 10 that issues the aggregated transaction transmits the final transaction to all the transaction recording devices 10 that share the main blockchain 1.

The registration processing unit 33 of each transaction recording device 10 verifies the signature of the finally issued transaction (step S49). When verifying the signature, the public key of the signed transaction recording device 10 is used as appropriate. The registration processing unit 33 determines whether the correct signature is equal to or greater than the threshold value (step S50). When the number of correct signatures is equal to or greater than the threshold value, the registration processing unit 33 registers the final transaction in the main blockchain ledger 41 (Yes in step S50, step S51). On the other hand, if the number of correct signatures is less than the threshold value, the registration processing unit 33 ends the process (No in step S50).

As described above, in the system according to the first embodiment, the main blockchain 1 does not include the transaction data obtained from the terminal 6, and the aggregated data aggregated for each predetermined period is recorded. That is, aggregated data is recorded in the main blockchain 1 instead of individual transaction data. Therefore, the amount of information recorded in the main blockchain 1 is reduced as compared with the case of recording all the measurement data of the individual power generation amount obtained by the terminal 6. Further, since the measurement data of the power generation amount obtained by the terminal 6 is recorded in the sub-blockchain 5 different from the main blockchain 1, there is no possibility that the measurement data of the power generation amount is falsified. In other words, in the system according to the first embodiment, falsification of the transaction history obtained by the terminal 6 which is the basis of the calculation of the aggregated data recorded in the main blockchain 1 is also prevented. Further, the registration of the aggregated data in the main blockchain 1 is performed when the calculation results of the aggregated data in the transaction recording device 10 of a predetermined number or more match. Therefore, the reliability of the data registered in the main blockchain 1 is also ensured.

<Second embodiment>
FIG. 13 is a diagram illustrating an example of the system according to the second embodiment. In the second embodiment, a case where a plurality of sub-blockchains 5 are used and transaction data is deleted after the aggregated data is registered in the main blockchain 1 will be described.

In the system according to the second embodiment, the sub-blockchain 5a and the sub-blockchain 5b are used, and the individual sub-blockchain nodes 80 (80a, 80b) share both the sub-blockchain 5a and the sub-blockchain 5b. are doing. The terminals 6 (6a to 6e) register the measurement data in the sub-blockchain 5 via the sub-blockchain node 80. In the second embodiment as well, the transaction recording device 10 (10a to 10d) shares the main blockchain 1 as in the first embodiment.

Each sub-blockchain node 80 stores transaction data received from the terminal 6 in a predetermined sub-blockchain 5 preset between the sub-blockchain nodes 80 among the shared sub-blockchains 5. For example, it is possible to register transaction data related to the time before 15:30 in the sub-blockchain 5a and register transaction data related to the time after 15:30 in the sub-blockchain 5b among all the sub-blockchain nodes 80. Suppose it is set. In this case, each sub-blockchain node 80 registers the transaction data measured before 15:30 in the sub-blockchain 5a and the transaction data measured after 15:30 in the sub-blockchain 5b. ..

FIG. 14 is a diagram illustrating an example of the configuration of the sub-blockchain node 80. The sub-blockchain node 80 includes a sub-blockchain control unit 85 and a storage unit 70. The hardware configuration of the sub-blockchain node 80 is as shown in FIG. Further, the sub-blockchain node 80 can also be realized as a computer or a server device.

The storage unit 70 stores the sub-blockchain ledger 71X and the sub-blockchain ledger 71Y. The sub-blockchain ledger 71X is identified by the identification information "sub BC-X" and holds the information shared by the sub-blockchain 5a. The sub-blockchain ledger 71Y is identified by the identification information "sub-BC-Y" and holds the information shared by the sub-blockchain 5b.

The sub-blockchain control unit 85 includes a transaction receiving unit 61, a transaction issuing unit 62, a data deletion determination unit 86, and a registration processing unit 87. The transaction receiving unit 61 and the transaction issuing unit 62 perform the same processing as the subblockchain node 50 of the first embodiment. The registration processing unit 87 performs processing related to switching of the sub-blockchain 5 for recording transaction data. The registration processing unit 87 communicates with other sub-blockchain nodes 80 and the transaction recording device 10 that share the sub-blockchain 5 as appropriate in order to perform processing related to switching of the sub-blockchain 5. It is assumed that the registration processing unit 87 holds information such as the addresses of the sub-blockchain node 50 and the transaction recording device 10 of the communication destination in advance, or can acquire the information from the storage unit 70. The registration processing unit 87 performs a process for registering the transaction data included in the transaction received from the terminal 6 in the sub-blockchain 5 associated with the measurement time of the transaction data.

The data deletion determination unit 86 performs a process for deleting the measurement data used for calculating the aggregated data registered in the main blockchain 1. For example, the data deletion determination unit 86 initially initializes the sub-blockchain ledger 71 of the sub-blockchain 5 that does not include the measurement data that is not used for the calculation of the aggregated data among the sub-blockchain 5 shared by the sub-blockchain node 80. To become. In order to match the initialization timing of the sub-blockchain ledger 71 with the other sub-blockchain nodes 80, the data deletion determination unit 86 may appropriately communicate with the other sub-blockchain nodes 80 or the transaction recording device 10. Good. Like the registration processing unit 87, the data deletion determination unit 86 also holds information on the communication destination sub-blockchain node 50 and the transaction recording device 10 in advance, or can acquire the information from the storage unit 70.

In the second embodiment, the data aggregation model includes information for specifying the migration criteria of the sub-blockchain 5 and the timing of deletion of the sub-blockchain 5. The migration criterion of the sub-blockchain 5 is arbitrary information that can specify the timing of switching the sub-blockchain 5, the sub-blockchain 5 of the migration source, and the sub-blockchain 5 of the migration destination. For example, the transition reference of the sub-blockchain 5 may be the switching time of the sub-blockchain 5. Further, the transition criterion of the sub-blockchain 5 may be a value that specifies the maximum amount of transaction data recorded in the current sub-blockchain 5. In this case, the registration processing unit 87 may determine the timing of switching the sub-blockchain 5 by appropriately transmitting and receiving transactions with the other sub-blockchain node 80. Further, the transition standard may be set so that the sub-blockchain 5 is switched at predetermined periods such as every month based on a specific time. For example, a transition standard may be set so as to switch the sub-blockchain 5 at 15:00 every month based on June 1, 2019.

For example, suppose that a data aggregation model including the following information is registered in the main blockchain 1.

Transition criteria:
Switched to 15:00 on June 1, 2019
Migration source sub-blockchain: Sub BC-Y
Migration destination sub blockchain: Sub BC-X
Deletion criteria:
Deleted at 18:00 on June 1, 2019
Blockchain for data deletion: Sub BC-Y
Aggregate information Sub BC: Sub BC-X
Aggregation target: Measuring instrument name A, Measuring instrument name B, Measuring instrument name C
Aggregation period: 15:00 to 15:29
Aggregation method: Calculate the total sum of data during the aggregation period for each measuring instrument. Also in the second embodiment, the process of registering the data aggregation model in the main blockchain 1 is the same as the process described with reference to FIG. Is. In the following description, the transaction recording device 10 that has received the data aggregation model sets the data aggregation model for any one or more of the sub-blockchain nodes 80 that the transaction recording device 10 accesses when acquiring data. You shall be notified that you have registered.

Hereinafter, an example of the processing performed in the second embodiment will be described separately for the switching process of the sub-blockchain 5 and the deletion of the information from the sub-blockchain 5 after the switching.

(A) Switching Process of Sub-Blockchain 5 FIG. 15 is a diagram illustrating an example of switching processing of the sub-blockchain 5. In the example of FIG. 15, it is assumed that the transaction recording device 10a receives the data aggregation model from the client terminal 7. Further, it is assumed that the transaction recording device 10a notifies the sub-blockchain node 80a that the data aggregation model has been received. In FIG. 15, in order to simplify the figure, the processing in the sub-blockchain node 80a and the sub-blockchain node 80b is shown. The sub-blockchain node 80 that shares the sub-blockchain 5 with the sub-blockchain node 80a shall operate in the same manner as the sub-blockchain node 80b. Further, it is assumed that the registration processing unit 87 of each sub-blockchain node 80 sets the identification information of the sub-blockchain 5 for registering the transaction data received from the terminal 6. That is, the sub-blockchain 5 identified by the identification information set by the registration processing unit 87 as the registration destination is the current sub-blockchain 5. At the first stage of FIG. 15, it is assumed that the registration processing unit 87 sets "sub BC-Y" (sub blockchain 5b) as the identification information of the registration destination in any of the subblockchain nodes 80.

By accessing the transaction recording device 10a, the registration processing unit 87a of the sub-blockchain node 80a acquires the migration standard included in the data aggregation model registered in the main blockchain ledger 41a. The registration processing unit 87a shares the migration criteria by generating a transaction for registering the migration criteria and transmitting it to another subblockchain node 80 that shares the subblockchain (step S61). Further, the registration processing unit 87a registers the transition standard in the storage unit 70a (step S62).

In the sub-blockchain node 80b that has received the transaction for registering the migration standard, the registration processing unit 87b registers the migration standard in the storage unit 70b (step S63). In each of the sub-blockchain nodes 80, the registration processing unit 87 stores the migration reference in the storage unit 70.

Until the switching process using the transition standard is performed, the registration processing unit 87 registers the measurement data received from the terminal 6 in the current sub-blockchain 5b (sub BC-Y). The process at this time is, for example, the same as the process described with reference to FIG. In parallel with the measurement data registration process, the registration processing unit 87 of each sub-blockchain node 80 satisfies the migration standard by referring to the migration standard recorded in the storage unit 70 at regular intervals. Is determined (steps S64, S65).

When it is determined that the migration criterion is satisfied, the registration processing unit 87 of each sub-blockchain node 80 sets a new sub-blockchain 5 (step S66). For example, at 15:00 on June 1, 2019, at each sub-blockchain node 80, the registration processing unit 87 determines that the transition criteria of the sub-blockchain 5 have been satisfied. Then, the registration processing unit 87 changes the identification information of the sub blockchain 5 for registering the transaction data received from the terminal 6 from "sub BC-Y" to "sub BC-X". Therefore, the registration destination of the transaction data is changed from the sub-blockchain ledger 71Y associated with the "sub BC-Y" to the sub-blockchain ledger 71X associated with the "sub BC-X". Therefore, the sub-blockchain 5 used for sharing transaction data is changed from the sub-blockchain 5b to the sub-blockchain 5a.

It is assumed that a transaction including measurement data is transmitted from the terminal 6 to the sub-blockchain node 80a after the processing of step S66. When the registration processing unit 87a acquires the measurement data during the transaction via the transaction receiving unit 61a, the registration processing unit 87a registers the measurement data in the sub-blockchain ledger 71X (step S67). Therefore, the measurement data is registered in the sub-blockchain 5a.

It is assumed that a transaction including measurement data is also transmitted from the terminal 6 to the sub-blockchain node 80b after the process of step S66. Also in this case, the registration processing unit 87b registers the measurement data during the transaction in the sub-blockchain ledger 71X (step S68). Therefore, the measurement data is registered in the sub-blockchain 5a.

Next, the process of acquiring data from each sub-blockchain 5 will be described. In the second embodiment, the acquisition unit 21 of each transaction recording device 10 identifies the sub-blockchain 5 as the data acquisition destination by using the identification information of the sub-blockchain 5 included in the data aggregation model. When requesting the data to be acquired, the acquisition unit 21 asks the sub-blockchain node 80 of the data request destination for the identification information of the sub-blockchain 5 to acquire the data, the name of the measuring instrument that measured the data, and the measurement. Notify the time. The transaction issuing unit 62 of the sub-blockchain node 80 acquires information matching the notified conditions from the sub-blockchain ledger 71 associated with the notified identification information, and sends the requesting transaction recording device 10 to the transaction recording device 10. Send.

For example, the acquisition unit 21a of the transaction recording device 10a transmits information that the identification information = sub BC-X, the aggregation target = measuring instrument names A to C, and the aggregation period = 15:00 to 15:29 to the sub blockchain node 80a. To do. Then, the transaction receiving unit 61a notifies the transaction issuing unit 62a of information such as the notified identification information. Since the transaction issuing unit 62a has the identification information = sub BC-X, the sub blockchain ledger 71X is used as the data search destination. The transaction issuing unit 62a extracts measurement data satisfying the aggregation target = measuring instrument names A to C and the aggregation period = 15:00 to 15:29 from the sub-blockchain ledger 71X, and transmits the measurement data to the transaction recording device 10a. Similarly, data acquisition processing for calculating aggregated data is performed between the other transaction recording device 10 and the sub-blockchain node 80. The generation of the aggregated data, the verification and registration of the aggregated data are performed in the second embodiment in the same manner as in the first embodiment.

(B) Deletion of Information from Sub-Blockchain 5 Next, an example of information deletion processing from sub-blockchain 5 that is no longer used for registration of measurement data after switching will be described. When the data aggregation model is registered, the data deletion determination unit 86 of each sub-blockchain node 80 refers to the deletion standard recorded in the storage unit 70 at regular intervals and satisfies the deletion standard. Judge whether or not. When it is determined that the deletion criteria are satisfied, the data deletion determination unit 86 of each sub-blockchain node 80 initializes the sub-blockchain ledger 71 of the sub-blockchain 5 that holds the data to be deleted.

For example, at 18:00 on June 1, 2019, the data deletion determination unit 86a of the sub-blockchain node 80a determines that the deletion criterion of the sub-blockchain 5 is satisfied. In the data aggregation model, the identification information of the sub-blockchain 5 that is the target of deletion based on the deletion criteria is "sub BC-Y". Therefore, the data deletion determination unit 86a deletes and initializes the information of the sub-blockchain ledger 71Y associated with the "sub BC-Y". Since the sub-blockchain nodes 80 other than the sub-blockchain nodes 80a also perform the same processing, after 18:00 on June 1, 2019, all the sub-blockchain nodes 80 sharing the sub-blockchain 5b In, the sub-blockchain ledger 71Y is initialized and the measurement data is deleted. In the initialization of the sub-blockchain ledger 71Y, not only the measurement data included in the sub-blockchain ledger 71Y but also the entire block connected by using the chain information is deleted. Therefore, by initializing the sub-blockchain ledger 71Y, the information of all the blocks included in the sub-blockchain 5b is deleted, so that the sub-blockchain 5b itself is deleted.

(C) Processing Flow FIG. 16 is a flowchart illustrating an example of switching processing of the sub-blockchain 5. The client notifies the transaction recording device 10 of the criteria for migrating or deleting the sub-blockchain 5 using the client terminal 7 (step S81). Here, the criteria for migrating or deleting the sub-blockchain 5 may be included in the data aggregation model. The registration processing unit 87 in the sub-blockchain node 80 acquires the migration standard and the deletion standard of the sub-blockchain 5 from the transaction recording device 10 (step S82). Each sub-blockchain node 80 changes the sub-blockchain ledger 71 for registering data using the migration criteria (step S83). After that, the sub-blockchain node 80 deletes the data in the sub-blockchain ledger 71 of the sub-blockchain 5 that is not currently used by using the deletion criterion (step S84).

Note that FIG. 16 is an example of processing, and the processing can be changed depending on the implementation. For example, as described with reference to FIG. 15 and the like, some sub-blockchain nodes 80 acquire deletion criteria and migration criteria from the transaction recording device 10 and share these criteria among the sub-blockchain nodes 80. You may. Further, in step S84, instead of deleting the sub-blockchain ledger 71 of the sub-blockchain 5 that is not in use, the sub-blockchain ledger 71 may be initialized.

As described above, in the system according to the second embodiment, the information of the sub blockchain 5 including the transaction data after the aggregated data is registered in the main blockchain 1 can be deleted. Therefore, according to the second embodiment, even in the sub-blockchain node 80 sharing the sub-blockchain 5, it is possible to prevent the sub-blockchain 5 from becoming bloated by continuously recording the measurement data notified from the terminal 6. Can be done. Therefore, it is possible to prevent the memory area held by the sub-blockchain node 80 from being consumed by increasing the amount of data in the sub-blockchain ledger 71 due to the enlargement of the sub-blockchain 5. Therefore, in the second embodiment, even a device having a relatively small memory capacity can be used as the subblockchain node 80.

Further, also in the second embodiment, the main blockchain 1 does not include the transaction data obtained from the terminal 6, and the aggregated data aggregated for each predetermined period is recorded. Therefore, the enlargement of the main blockchain 1 is also prevented. Here, also in the second embodiment, as in the first embodiment, registration to the main blockchain 1 is performed when the calculation results of the aggregated data in the predetermined number or more of the transaction recording devices 10 match. Therefore, the reliability of the data registered in the main blockchain 1 is also guaranteed.

<Others>
The embodiment is not limited to the above, and can be variously modified. Some examples are given below.

In the above description, the case where the terminal 6 is a power generation amount measuring meter and the transaction data is the power generation amount has been described as an example, but the transaction data and the type of the terminal 6 can be arbitrarily changed depending on the implementation. Further, the calculation method of the aggregated data can be arbitrarily changed according to the type of transaction data and the usage pattern of the transaction data.

When the number of terminals 6 in the system is large, a plurality of sub-blockchains 5 may be used. For example, in the first embodiment, it is assumed that terminals 6f to 6n (not shown) are also measuring transaction data in addition to terminals 6a to 6e. In this state, each terminal 6 can register transaction data in the sub-blockchain 5 via the sub-blockchain node 50. For example, terminals 6f to 6i can register transaction data in the subblockchain 5b via the subblockchain nodes 50c to 50f (not shown). Further, the terminals 6j to 6n can register transaction data in the subblockchain 5c via the subblockchain nodes 50g to 50j (not shown). Even in this case, it is assumed that information such as the address of the sub-blockchain node 50 as the data acquisition destination is set in the acquisition unit 21 of each transaction recording device 10. Further, also in the second embodiment, as in the first embodiment, a plurality of sub-blockchains 5 may be used at the same time for recording measurement data.

In the above description, the transaction recording device 10 has been described as a device different from the sub-blockchain nodes 50 and 80, but the transaction recording device 10 may also operate as the sub-blockchain nodes 50 and 80. For example, a computer having a high processing capacity of the processor 101 and a large capacity of the memory 102 and the storage device 106 may operate as both the transaction recording device 10 and the subblockchain node 50.

In the above description, the case where the PBFT protocol is used for the procedure of consensus building and verification has been described as an example, but consensus building and verification can be performed according to the procedure of any blockchain protocol. Further, the number of devices (transaction recording device 10, sub-blockchain nodes 50, 80) sharing each blockchain can be arbitrarily changed according to the implementation.

In the above description, the case where the transaction recording device 10 holds the private key used for encryption has been described, but the storage method of the private key may be changed depending on the implementation. For example, some transaction recording devices 10 may be modified to acquire a private key held in another transaction recording device 10 via a network and use it for encryption.

1 Main blockchain 5 Sub-blockchain 6 Terminal 7 Client terminal 10 Transaction recording device 15 Control unit 20 Aggregation processing unit 21 Acquisition unit 22 Generation unit 30 Main blockchain control unit 31, 61 Transaction receiving unit 32, 62 Transaction issuing unit 33, 63 Registration processing unit 40, 70 Storage unit 41 Main blockchain ledger 42 Setting information 43 Public key information 50 Subblockchain node 60 Subblockchain control unit 71 Subblockchain ledger 101 Processor 102 Memory 103 Input device 104 Output device 105 Bus 106 Storage device 107 Portable storage medium drive device 108 Portable storage medium 109 Network interface

Claims (7)

A transaction recording device that participates in a network that shares the first blockchain.
An acquisition unit that acquires information from the second blockchain in which data related to the transaction time and the transaction performed at the transaction time is registered, and
Using the information acquired by the acquisition unit, a generation unit that generates aggregated data that aggregates data related to the transactions performed during a predetermined period, and a generation unit.
When the aggregated data matches other aggregated data generated from the data relating to the transaction made during the predetermined period in another transaction recording device participating in the network, the aggregated data is used. A transaction recording device including a registration processing unit for registering in the first blockchain. The transaction recording device according to claim 1, wherein the first blockchain holds the aggregated data in place of the data related to the transactions performed during the predetermined period. Further, a transaction issuing unit for issuing an aggregated transaction for notifying the aggregated data to other transaction recording devices in the network is provided.
When the registration processing unit acquires a transaction in which a predetermined number or more signatures indicating that the other transaction recording device in the network has obtained the same aggregation result as the aggregated data are added to the aggregated transaction, the aggregated data is acquired. The transaction recording device according to claim 1 or 2, wherein is determined to match the other aggregated data. When the second blockchain meets a predetermined migration criterion, a node that switches the registration destination of the transaction time and data related to the transaction acquired from the device performing the transaction from the second blockchain to the third blockchain. When the device is the communication destination of the acquisition unit, the acquisition unit
The identification information of the blockchain that records the transaction data used for the calculation of the aggregated data is acquired via the first blockchain.
A claim characterized in that data relating to the transaction performed during the predetermined period is acquired from the blockchain identified by the identification information among the second blockchain and the third blockchain. The transaction recording device according to any one of 1 to 3. When the registration processing unit acquires the information indicating the predetermined period and the calculation method of the aggregated data, the registration processing unit registers the predetermined period and the calculation method of the aggregated data in the first blockchain.
The acquisition unit acquires data on transactions performed during the predetermined period by acquiring the predetermined period via the first blockchain.
Claims 1 to 1, wherein the generation unit generates the aggregated data by processing the information acquired by the acquisition unit by using the calculation method acquired via the first blockchain. The transaction recording device according to any one of 4. A transaction recording device that participates in a network that shares the first blockchain
Information is acquired from the second blockchain in which the transaction time and the data related to the transaction performed at the transaction time are registered.
Using the acquired information, aggregate data that aggregates the data related to the transactions performed during a predetermined period is generated.
When the aggregated data matches other aggregated data generated from the data relating to the transaction made during the predetermined period in another transaction recording device participating in the network, the aggregated data is used. A transaction recording method characterized by registering in the first blockchain. For transaction recording devices that participate in networks that share the first blockchain,
Information is acquired from the second blockchain in which the transaction time and the data related to the transaction performed at the transaction time are registered.
Using the acquired information, aggregate data that aggregates the data related to the transactions performed during a predetermined period is generated.
When the aggregated data matches other aggregated data generated from the data relating to the transaction made during the predetermined period in another transaction recording device participating in the network, the aggregated data is selected. A transaction recording program characterized in that a process of registering in the first blockchain is performed.

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