Information processing method, information processing system, and server system

Abstract

To prevent double counting of the value attached to electricity generated by a given generation method. [Solution] The information processing system 10 includes a first platform 16 on which power information is registered, and a second platform 26 on which value information representing a value associated with electricity is issued. A transaction indicating that value information will be issued when a value R is disclosed is registered on the second platform 26, and a transaction indicating that power information will be discarded when the value R is disclosed is registered on the first platform 16. Then, when a first information processing terminal 14 discloses the value R to the first platform 16, power information corresponding to the value information to be issued is discarded. Furthermore, when a second information processing terminal 24 discloses the value R to the second platform 26, value information corresponding to the power information to be discarded is issued.

Description

[Technical Field]

[0001] The present invention relates to an information processing method, an information processing system, and a server system. [Background technology]

[0002] Blockchain technology has been known for some time (for example, Non-Patent Document 1). Transaction information representing transactions related to Bitcoin, for example, is written in each block of a blockchain, making it difficult to tamper with the transaction information. Due to these characteristics, blockchain technology is being applied to various fields. For example, a P2P energy trading platform that utilizes blockchain technology is known (for example, Non-Patent Document 2). [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] Satoshi Nakamoto, "Bitcoin: A Peer-to-Peer Electronic Cash System",2008 [Non-patent document 2] Minden Electric Power Co., Ltd., "Development of a P2P Energy Trading Platform Utilizing Blockchain," [online], February 28, 2018, [Retrieved July 30, 2019], Internet〈URL: https: / / minden.co.jp / wp-content / uploads / 2018 / 02 / 20180228_release.pdf〉 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, various laws have been enacted to reduce carbon dioxide emissions, and renewable energy sources such as solar, wind, and geothermal energy have been attracting attention. Unlike electricity generated by fossil fuels such as petroleum, electricity generated by renewable energy sources has environmental value in that it does not emit carbon dioxide.

[0005] Against this background, efforts are underway to certify environmental values ​​in accordance with various renewable energy laws. For example, environmental values ​​such as "Green Power Certificates," "Non-Fossil Certificates," and "J Credits" are already being bought and sold, and a market for environmental values ​​is beginning to take shape.

[0006] Within these systems, there are third-party organizations (or the government) that certify environmental value, and if the environmental value of the amount of electricity reported by the power generation company is recognized, that environmental value is documented and sold to retail electricity companies or consumers.

[0007] Meanwhile, new methods of selling electricity are emerging outside the environmental value market. A typical example is the electricity purchasing service with tracking using blockchain technology, as shown in Non-Patent Document 2 above.

[0008] Blockchain technology is based on a distributed ledger, and can build a database that guarantees transparency to consumers without relying on third-party credit evaluations. By directly obtaining data such as the amount of electricity generated from renewable energy sources using devices such as smart meters and recording it in blocks, the data becomes difficult to tamper with. This allows consumers to access the records, eliminating the need to rely on third-party certification organizations to guarantee the reliability of transactions.

[0009] Previously, electricity generated by renewable energy sources and its environmental value were traded separately. Under these circumstances, a need arose to circulate environmental value equivalent to the amount of electricity generated by renewable energy sources in the market. This led to the adoption of a method in which certification organizations received reports from generators to confirm the amount of electricity generated by renewable energy sources. Furthermore, measures have been taken to prevent duplication of environmental value for unique electricity between different environmental value certificates, such as assigning a serial number to the certified environmental value and disclosing it to certification organizations for other certificates.

[0010] However, as the spread of blockchain technology and other factors increases the number of transactions involving environmental value without the involvement of a third party, it is expected that traditional certification schemes will no longer be able to fully grasp environmental value. Furthermore, there are other values ​​associated with electricity, such as the value of the source of electricity and the value of a specific power source. These values ​​are also expected to be traded in the future.

[0011] In this case, for example, there is a problem in that the value associated with electricity generated through a third-party institution and the value associated with electricity not generated through a third-party institution may coexist, resulting in double-counting of the value associated with electricity generated by a specified power generation method.

[0012] The present invention has been made in consideration of the above circumstances, and aims to provide an information processing method, an information processing system, and a server system that can prevent double counting of value associated with electricity generated by a specified power generation method. [Means for solving the problem]

[0013] In order to achieve the above-mentioned object, the information processing system of the present invention is an information processing system comprising a first platform which is a system for registering power information representing the amount of power generated by a predetermined power generation method, and a second platform which is a system for issuing value information representing the value associated with electricity corresponding to the power information, wherein a transaction representing that the value information will be issued when a predetermined value R is disclosed is registered in the second platform, a transaction representing that the power information will be discarded when the predetermined value R is disclosed is registered in the first platform, a first information processing terminal discloses the predetermined value R to the first platform, thereby executing a transaction representing that the power information will be discarded, and the power information corresponding to the value information to be issued is discarded, and a second information processing terminal discloses the predetermined value R to the second platform, thereby executing a transaction representing that value information will be issued, and value information corresponding to the power information to be discarded is issued.

[0014] Furthermore, the information processing method of the present invention is an information processing method executed in an information processing system having a first platform, which is a system for registering power information representing the amount of power generated by a predetermined power generation method, and a second platform, which is a system for issuing value information corresponding to the power information, in which a transaction representing that the value information will be issued when a predetermined value R is disclosed is registered in the second platform, a transaction representing that the power information will be discarded when the predetermined value R is disclosed is registered in the first platform, a transaction representing that the power information will be discarded by a first information processing terminal disclosing the predetermined value R to the first platform is executed, and the power information corresponding to the value information to be issued is discarded, and a transaction representing that value information will be issued by a second information processing terminal disclosing the predetermined value R to the second platform is executed, and value information corresponding to the power information to be discarded is issued.

[0015] Furthermore, the first server system of the present invention is a server system representing the second platform of an information processing system comprising a first platform, which is a system for registering power information representing the amount of power generated by a predetermined power generation method, and a second platform, which is a system for issuing value information corresponding to the power information, wherein a transaction representing that the value information will be issued when a predetermined value R is disclosed is registered in the second platform, a transaction representing that the power information will be discarded when the predetermined value R is disclosed is registered in the first platform, the first information processing terminal discloses the predetermined value R to the first platform, thereby executing a transaction representing that the power information will be discarded, and the power information corresponding to the value information to be issued is discarded, and the server system, which is the second platform, executes a transaction representing that value information will be issued when the predetermined value R is disclosed from the second information processing terminal, and issues value information corresponding to the power information to be discarded.

[0016] The second server system of the present invention is a server system representing the first platform of an information processing system comprising a first platform, which is a system for registering power information representing the amount of power generated by a predetermined power generation method, and a second platform, which is a system for issuing value information corresponding to the power information, wherein a transaction representing that the value information will be issued when a predetermined value R is disclosed is registered in the second platform, and a transaction representing that the power information will be discarded when the predetermined value R is disclosed is registered in the first platform, and the server system, which is the first platform, executes a transaction representing that the power information will be discarded when the predetermined value R is disclosed from the first information processing terminal, and discards the power information corresponding to the value information to be issued, and the second information processing terminal discloses the predetermined value R to the second platform, thereby executing a transaction representing that value information will be issued, and value information corresponding to the power information to be discarded is issued. [Effects of the Invention]

[0017] According to the present invention, it is possible to obtain an effect of suppressing double counting of the value associated with electricity generated by a predetermined power generation method. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a diagram illustrating an example of a schematic configuration of an information processing system according to an embodiment of the present invention. [Figure 2] FIG. 2 is a diagram illustrating an example of a schematic configuration of power information according to the present embodiment. [Figure 3] FIG. 1 is a schematic block diagram of a computer that functions as each device constituting an information processing system. [Figure 4] FIG. 2 is an explanatory diagram illustrating a process executed by the information processing system according to the present embodiment. [Figure 5] FIG. 2 is an explanatory diagram for explaining processing executed by the information processing system of the first embodiment. [Figure 6] FIG. 2 is an explanatory diagram for explaining processing executed by the information processing system of the first embodiment. [Figure 7] FIG. 10 is an explanatory diagram for explaining processing executed by an information processing system according to a second embodiment. [Figure 8] FIG. 10 is an explanatory diagram for explaining processing executed by an information processing system according to a second embodiment. [Figure 9] FIG. 10 is an explanatory diagram for explaining processing executed by an information processing system according to a third embodiment. [Figure 10] FIG. 10 is an explanatory diagram for explaining processing executed by an information processing system according to a fourth embodiment. [Figure 11] FIG. 10 is a diagram illustrating a modified example of the information processing system according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, the embodiments will be described in detail with reference to the drawings.

[0020] [First embodiment]

[0021] <System configuration of information processing system>

[0022] FIG. 1 is a block diagram showing an information processing system 10 according to this embodiment. As shown in FIG. 1, the information processing system 10 according to this embodiment includes an electric power generation amount recording device 12, a first information processing terminal 14, a first platform 16, a second information processing terminal 24, and a second platform 26. The devices in the information processing system 10 are connected to one another via a network 30, such as the Internet. The electric power generation amount recording device 12 is managed by the second information processing terminal 24, and sequentially records the amount of electricity generated by the electric power generation device managed by the second information processing terminal 24. The electric power generation device managed by the second information processing terminal 24 generates electricity using a predetermined power generation method (for example, a method of generating electricity using renewable energy). The first platform 16 and the second platform 26 are an example of a server system according to the present invention.

[0023] The first platform 16 and the second platform 26 are configured to include a plurality of information processing terminals. Specifically, the first platform 16 is configured to include a plurality of first blockchain nodes 18A, 18B, and 18C. Note that although three first blockchain nodes 18A, 18B, and 18C are shown in FIG. 1, the first platform 16 may include more blockchain nodes.

[0024] A first blockchain as a distributed ledger is stored in the memory unit (not shown) of the first blockchain nodes 18A, 18B, and 18C. Each block of the first blockchain stored in the memory unit (not shown) of the first blockchain nodes 18A, 18B, and 18C stores power information indicating the amount of electricity generated by a predetermined power generation method. The power information will be described later. Note that, except when describing a specific node among the multiple first blockchain nodes 18A, 18B, and 18C, the first blockchain node will be simply referred to as the "first blockchain node 18."

[0025] The first platform 16 is a platform for managing power information that indicates the amount of power generated by a predetermined power generation method. The first platform 16 is a platform for managing or trading power information, operated by, for example, a third-party organization that certifies environmental value or an entity certified by the government.

[0026] The second platform 26 is configured to include a plurality of second blockchain nodes 28A, 28B, and 28C. Although three second blockchain nodes 28A, 28B, and 28C are shown in Fig. 1, the second platform 26 may include more blockchain nodes.

[0027] A second blockchain as a distributed ledger is stored in the memory unit (not shown) of the second blockchain nodes 28A, 28B, 28C. Value information representing the value associated with electricity is stored in each block of the second blockchain stored in the memory unit (not shown) of the second blockchain nodes 28A, 28B, 28C. The value information will be described later. Note that, except when describing a specific node among the multiple second blockchain nodes 28A, 28B, 28C, the second blockchain node will be simply referred to as the "second blockchain node 28."

[0028] The second platform 26 is a platform where value information that represents the value associated with electricity is issued. At present, there are three types of "value associated with electricity": the environmental value of non-fossil fuel certificates, the value of the source of production, and the value of a specific power source. In the future, it is possible that a value that combines these may be created by the ingenuity of businesses (for example, on the Internet).<https: / / www.emsc.meti.go.jp / activity / emsc_system / pdf / 030_03_00.pdf> (See "Ministry of Economy, Trade and Industry, 30th System Design Expert Meeting, Secretariat Submission Materials - Review of Power Source Labeling Rules, etc., Following the Introduction of Indirect Auctions, etc. (Basic Direction of Revisions) - Tuesday, May 29, 2018.") "Environmental value" encompasses "non-fossil value" in accordance with the Energy Supply Structure Sophistication Act, "zero-emission value" in accordance with the Global Warming Countermeasures Act, and "environmental labeling value," which is the right of retail electricity businesses to display and assert their added value to consumers.

[0029] In this embodiment, an example is described in which the first platform 16 and the second platform 26 use blockchain technology, but this is not limited to this, and the first platform 16 and the second platform 26 may be realized by a single server.

[0030] The information processing system 10 of this embodiment prevents double counting of value associated with electricity by using the first platform 16 and the second platform 26. Specifically, the following processing is executed in the first platform 16 and the second platform 26 of the information processing system 10 of this embodiment.

[0031] (1) The first information processing terminal 14 that manages the first platform 16 of the information processing system 10 permits the second information processing terminal 24, which is a participant in the second platform 26, to issue value information (also referred to as an asset) for power information of a certain amount of electricity generated by renewable energy. The issued value information corresponds to the power information. (2) When the second information processing terminal 24, which is a participant of the second platform 26, issues value information corresponding to power information, it is treated as having been approved by the first information processing terminal 14 that manages the first platform 16. (3) In order to confirm that the content of the value information issued by the second information processing terminal 24 is correct, the second information processing terminal 24 obtains approval from the first information processing terminal 14 for the value it defines (for example, environmental value, production area value, or specific power source value, etc.).

[0032] In this embodiment, the data representing the power information includes, for example, as shown in Figure 2, the power generation type, which is identification information representing the power generation method, location information representing the location where the power was generated (or identification information of the power plant), and the amount of power generated.

[0033] Specifically, the information processing system 10 of this embodiment uses the following techniques to prevent double counting of value information.

[0034] The information processing system 10 uses AtomicSwap, an existing technology, between (participants in) the common ledger of the first transaction on the first platform 16 and participants in the second transaction on the second platform 26. AtomicSwap is a protocol for exchanging assets between different blockchains. By using the AtomicSwap technology, asset exchange is carried out under consensus (also known as multi-signature, for example) among the parties exchanging assets.

[0035] In this embodiment, this AtomicSwap consensus is used to record an agreement to release new value information into the market. As a result, on this shared ledger, value information can be transferred to another market only with the agreement of both parties. It also becomes possible to identify the transfer destination of the value information. Therefore, the power information on the first platform 16 is appropriately converted into value information on the second platform 26.

[0036] Furthermore, in this embodiment, when the power information on the first platform 16 is transferred to the second platform 26 as value information, the power information indicating the amount of power recorded on the first platform 16 is discarded (hereinafter also referred to as Burn). As a result, the power information on the first platform 16 that has been converted into value information on the second platform 26 is lost, making it virtually impossible to double-count the value associated with electricity.

[0037] Furthermore, by keeping a record of the transfer of value information in this way using AtomicSwap, it is possible to verify the movement of assets between different blockchains (i.e., between platforms), making it easy to connect different platforms in a way that allows the transfer of value to be verified.

[0038] Furthermore, the information processing system 10 of this embodiment uses blockchain technology, making transaction records on the platform difficult to tamper with and ensuring transparency.

[0039] When power information X of electricity generated by renewable energy is certificated and converted into value information Y, the second information processing terminal 24, a participant on the second platform, can also link information such as the type of power source and the location of the power source obtained via communication devices such as meters installed at power plants to the blockchain on the first platform 16. This makes it technically possible for the first information processing terminal 14, a participant on the first platform 16, to confirm that the electricity is generated by renewable energy based on that information.

[0040] Each device included in the information processing system 10 is realized by a computer including a CPU (Central Processing Unit), a ROM (Read Only Memory) that stores programs for implementing each processing routine, a RAM (Random Access Memory) that temporarily stores data, memory as a storage means, a network interface, etc.

[0041] The power generation amount recording device 12, the first information processing terminal 14, the first blockchain node 18, the second information processing terminal 24, and the second blockchain node 28 can be realized, for example, by a computer 70 shown in FIG. 3. The computer 70 includes a CPU 71, a memory 72 as a temporary storage area, and a non-volatile storage unit 73. The computer 70 also includes an input / output interface (I / F) 74 to which input / output devices (not shown) are connected, and a read / write (R / W) unit 75 that controls reading and writing of data from and to a recording medium. The computer 70 also includes a network I / F 76 that is connected to a network such as the Internet. The CPU 71, the memory 72, the storage unit 73, the input / output I / F 74, the R / W unit 75, and the network I / F 76 are connected to one another via a bus 77.

[0042] The storage unit 73 can be realized by a hard disk drive (HDD), a solid state drive (SSD), a flash memory, etc. The storage unit 73 as a storage medium stores a program for causing the computer 70 to function. The CPU 71 reads the program from the storage unit 73, expands it in the memory 72, and sequentially executes the processes contained in the program.

[0043] <Operation of the information processing system 10>

[0044] Next, a description will be given of the operation of the information processing system 10 of this embodiment. First, the power generation amount recording device 12 of the information processing system 10 sequentially records, for example, the amount of electricity generated by renewable energy.

[0045] The power value recorded by the first power generation amount recording device 12 is transmitted to the first information processing terminal 14 and registered on the first platform 16 as power information.

[0046] For example, on the first platform 16 side of the information processing system 10, the sequence shown in FIG. 4 is executed.

[0047] In step S80, the power generation amount recording device 12 transmits the power value obtained by the power generation to the first information processing terminal .

[0048] In step S82, the first information processing terminal 14 acquires the power value transmitted in step S80. Then, the first information processing terminal 14 generates power information according to the acquired power value and broadcasts it to the first blockchain node 18 constituting the first platform 16.

[0049] In step S84, the first blockchain node 18 acquires the power information broadcast in step S82 and records it in the first blockchain stored in its own memory. In this case, after a consensus is reached among multiple first blockchain nodes 18, the power information transaction information is stored in a block of the first blockchain. This makes it difficult to tamper with the power information transaction information.

[0050] Under such circumstances, consider a case where the second information processing terminal 24 converts its own power information managed in the first platform 16 into value information traded in the second platform 26. In this case, the information processing system 10 executes the sequences shown in Figs. 5 and 6.

[0051] It is assumed that the following preconditions are set for the first platform 16 and the second platform 26 in this embodiment.

[0052] The public key of the first information processing terminal 14, which is a participant of the first platform 16, is K, its private key is k, and signature information obtained by signing a value N using the private key k is sign(N, k).

[0053] The public key of the second information processing terminal 24, which is a participant of the second platform 26, is defined as M, the private key as m, and signature information obtained by signing a value N using the private key m as sign(N, m).

[0054] The first information processing terminal 14 and the second information processing terminal 24 hold wallet addresses for the first blockchain and the second blockchain, respectively. Note that in the following description, no distinction will be made between wallet addresses for each blockchain.

[0055] Let H(x) be an arbitrary hash function, and H_S be the hash value of the value S. The wallet address of the second information processing terminal 24 is a hash value of the total amount X MAX It is assumed that the power information is held.

[0056] Furthermore, there are two methods for issuing new value information on the second platform 26, as follows.

[0057] The first method is a method of newly generating arbitrary value information. In this case, arbitrary value information can be generated on the second blockchain of the second platform 26 using the private key k of the first information processing terminal 14, which is the administrator of the first platform 16. Therefore, in this case, the second platform 26 has the function of issuing new value information when the private key k and an arbitrary hash value are presented.

[0058] The second method is a method in which the transfer of value information is regarded as the issuance of value information. In this case, the private key k and address of the first information processing terminal 14 are created in advance on the second blockchain of the second platform 26. Then, it is assumed that an arbitrary amount of value information is held in the address of the first information processing terminal 14.

[0059] The following describes an example in which the second information processing terminal 24 converts power information X stored in its own address into value information Y. When the second information processing terminal 24 converts power information X stored in its own address into value information Y, the sequences shown in Figs. 5 and 6 are executed.

[0060] In step S100, the second information processing terminal 24 randomly generates a secret value R.

[0061] In step S102, the second information processing terminal 24 generates a hash value H_R of the secret value R generated in step S100.

[0062] In step S104, the second information processing terminal 24 transmits the hash value H_R generated in step S102 to the first information processing terminal 14, which is the administrator of the first platform 16.

[0063] In step S106, the second information processing terminal 24 generates transaction TX1. This transaction TX1 is a transaction indicating that the power consumption information X will be transmitted to the address of the first information processing terminal 14 when the secret value R, the signature information sign(TX1,k) of the first information processing terminal 14, which is the destination of the power consumption information X, and the signature information sign(TX1,m) of the second information processing terminal 24, which is the source of the power consumption information X, are disclosed. Once the power consumption information X is transmitted to the address of the first information processing terminal 14, the power consumption information X is later discarded (burned). Note that this power consumption information X is information that should be equal in amount to the value information, which is the added value desired to be expressed. Specifically, transaction TX1 is expressed by the following (1-1) and (1-2).

[0064] (1-1) The power information X is transmitted to the address of the information processing terminal that has disclosed the signature information sign and the secret value R, which satisfy the condition (1-1) sign==sign(TX1,k) && H_R == H(R). (1-2) The power information X is transmitted to the address of the information processing terminal that has disclosed the signature information sign1 and the signature information sign2, which satisfy the relationship sign1==sign(TX1,k) && sign2==sign(TX1,m).

[0065] Next, in step S108, the second information processing terminal 24 generates transaction TX2. This transaction TX2 is a transaction that indicates that, if the signature information sign(TX2,m) of the second information processing terminal 24 is disclosed, execution of transaction TX1 will be stopped 48 hours after the disclosure, and power information X will be transmitted to the address of the first information processing terminal 14. Note that 48 hours is an example of the first time period of the disclosed technology. Specifically, transaction TX2 is expressed by the following (2).

[0066] (2) If a sign that satisfies sign == sign(TX2, m) is disclosed, power information X is transmitted from transaction TX1 to the address of the second information processing terminal 24 that has public key M after 48 hours.

[0067] In step S110, the second information processing terminal 24 transmits the transaction TX2 generated in step S108 to the first information processing terminal 14.

[0068] In step S112, the first information processing terminal 14 receives the transaction TX2 transmitted in step S110.

[0069] In step S114, the first information processing terminal 14 attaches signature information sign(TX1,k) to the transaction TX2 received in step S112 above and transmits it to the second information processing terminal 24. This signature information sign(TX1,k) represents agreement to the registration of the power information X in the transaction TX1.

[0070] In step S116, the second information processing terminal 24 broadcasts the transaction TX1 generated in step S106 to the first blockchain node 18 of the first platform 16. As a result, the multiple first blockchain nodes verify the transaction and register the transaction TX1 in the blockchains they own. As a result, the second information processing terminal 24 registers the transaction TX1, which indicates that the power information X will be transmitted if the secret value R is disclosed, in the first platform.

[0071] In this case, the transaction TX1 is verified by the first blockchain node 18. Therefore, the value represented by the power information X is the total amount X represented by the power information held in the wallet of the second information processing terminal 24. MAX If the power information is larger than , the broadcast fails because there is insufficient power information to be transmitted.

[0072] Next, in step S118, the first information processing terminal 14 generates transaction TX3. Transaction TX3 is a transaction representing that value information Y will be transmitted to the address of the second information processing terminal 24 when the secret value R, the signature information sign(TX3, m) of the second information processing terminal 24 that is the destination of value information Y, and the signature information sign(TX3, k) of the first information processing terminal 14 that is the source of value information Y are disclosed. Specifically, transaction TX3 is represented by the following (3-1) and (3-2). By executing transaction TX3, value information Y is issued as a certificate.

[0073] (3-1) Issue value information Y to an information processing terminal that has disclosed sign and secret value R, such that sign == sign(TX3, m) && H_R == H(R). (3-2) Value information Y is issued to an information processing terminal that has disclosed sign1 and sign2 that satisfy sign1 == sign(TX3, k) && sign2 == sign(TX3, m).

[0074] In step S120, the first information processing terminal 14 generates transaction TX4. Transaction TX4 is a transaction that indicates that, when the signature information sign(TX3,k) of the first information processing terminal 14 is disclosed, execution of transaction TX3 will be stopped 24 hours after the disclosure, and value information Y will be sent to the address of the first information processing terminal 14. Note that 24 hours is an example of the second time period of the disclosed technology. Therefore, transaction TX4 is expressed by the following (4).

[0075] (4) If a sign that satisfies sign == sign(TX3, k) is disclosed, value information Y is transmitted from transaction TX3 to the address of the first information processing terminal 14 that has public key K after 24 hours have passed.

[0076] In step S122, the first information processing terminal 14 transmits the transaction TX4 generated in step S120 to the second information processing terminal 24.

[0077] In step S124, the second information processing terminal 24 receives the transaction TX4 transmitted in step S122, and transmits the transaction TX4 to the first information processing terminal 14 with signature information sign(TX3,m) attached thereto.

[0078] In step S126, the first information processing terminal 14 broadcasts the transaction TX3 generated in step S118 to the multiple second blockchain nodes 28 of the second platform 26. As a result, the multiple second blockchain nodes 28 verify the transaction and register the transaction TX3 in the second blockchain that they own. As a result, the first information processing terminal 14 registers the transaction TX3, which indicates that the value information Y will be transmitted if the secret value R is disclosed, in the second platform.

[0079] In step S128, the second information processing terminal 24 generates transaction TX5 when the second information processing terminal 24 attempts to convert power information X on the first platform 16 into value information Y. Transaction TX5 indicates that when transaction TX3 is executed, the secret value R is disclosed and the value information Y is sent to a predetermined address. The predetermined address is set by the second information processing terminal 24. In this embodiment, the address of the second information processing terminal 24 is set as the predetermined address.

[0080] In step S130, the second information processing terminal 24 broadcasts the transaction TX5 generated in step S128 above to the second platform 26. The second information processing terminal 24 discloses the signature information sign(TX3,m) of the second information processing terminal 24, which is the destination of the secret value R and the value information Y, thereby executing the transaction TX3 and the transaction TX5. As a result, the secret value R is disclosed, and the value information Y is sent to the address of the second information processing terminal 24.

[0081] Furthermore, when the second information processing terminal 24 discloses the signature information sign(TX3,m) of the second information processing terminal 24 to which the secret value R and the value information Y are to be sent, the condition (3-1) above is satisfied and the transaction TX3 is executed.

[0082] If transactions TX3 and TX5 are not executed, the secret value R is not disclosed, and therefore the power information X on the first platform 16 also remains unused. In this case, the power information X is not discarded.

[0083] In step S132, the first information processing terminal 14 acquires the secret value R disclosed by the execution of transaction TX5 in step S130. This makes it possible to discard the power information X of transaction TX1 registered in the first blockchain on the first platform 16. Therefore, the first information processing terminal 14 executes transaction TX1 by disclosing the acquired secret value R and the signature information sign(TX1,k) of the first information processing terminal 14, which is the destination of the power information X. As a result, the power information X is transmitted to the address of the first information processing terminal 14.

[0084] In addition, when the first information processing terminal 14 discloses the secret value R and the signature information sign(TX1,k) of the first information processing terminal 14 to which the power information X is to be sent, the condition (1-1) above is satisfied and the transaction TX1 is executed.

[0085] In step S134, the first information processing terminal 14 discards (burns) the power information X transmitted to its own address. This prevents double counting of the environmental value of electricity generated by, for example, renewable energy, which is an example of a predetermined power generation method, between the first platform 16 and the second platform 26.

[0086] The first information processing terminal 14 selects a method for discarding (burning) the power information X from the following three methods.

[0087] For example, one method of destroying (burning) power information X is to burn it in a way that makes it completely unrecoverable. In this case, for example, in the case of Bitcoin, a method of setting a script with only OP_RETURN as the output destination can be used.

[0088] Another example of a method for burning the power information X is to transmit the power information X to an address from which it is difficult to deduce the private key (for example, an address such as DENRYOKUPLATFORMxx).

[0089] Another example of a method for burning power information X is to divide it into smaller amounts so that the amount of power information paid as a fee to the blockchain node is greater than the amount of power information being traded, and then send the power information X to the address multiple times.

[0090] If the condition (1-2) above is satisfied while the above process is being executed, the process of converting the power information X into the value information Y is deemed to have been stopped, the power information X is sent to the address of the first information processing terminal 14, and the first information processing terminal 14 is able to recover the power information X. If the condition (3-2) above is satisfied, the process of converting the power information X into the value information Y is deemed to have been stopped, the value information Y is sent to the first information processing terminal 14, and the first information processing terminal 14 is able to recover the value information Y.

[0091] Furthermore, if the above condition (2) is satisfied while the above process is being executed, the process of converting power information X into value information Y is deemed to have been stopped, and the power information X in transaction TX1 is sent to the address of the second information processing terminal 24. Similarly, if the above condition (4) is satisfied, the process of converting power information X into value information Y is deemed to have been stopped, and the value information Y in transaction TX4 is sent to the address of the first information processing terminal 14.

[0092] As described above, the information processing system according to this embodiment includes a first platform, which is a system for registering power information representing the amount of power generated by a predetermined power generation method, and a second platform, which is a system for issuing value information representing a value associated with the electricity corresponding to the power information. In the information processing system according to this embodiment, a transaction representing the issuance of value information when a predetermined value R is disclosed is registered in the second platform, and a transaction representing the discarding of power information when the predetermined value R is disclosed is registered in the first platform. The first information processing terminal then discloses the predetermined value R to the first platform, thereby executing a transaction representing the discarding of the power information, and discarding the power information corresponding to the value information to be issued. The second information processing terminal then discloses the predetermined value R to the second platform, thereby executing a transaction representing the issuance of value information, and issuing value information corresponding to the power information to be discarded. This makes it possible to prevent double counting of value associated with electricity generated by a predetermined power generation method.

[0093] [Second embodiment]

[0094] Next, a second embodiment will be described. The configuration of the information processing system according to the second embodiment is similar to that of the first embodiment, and therefore the same reference numerals are used and the description thereof will be omitted. The second embodiment differs from the first embodiment in that the first information processing terminal 14 discards the power information X first.

[0095] <Operation of the information processing system 10>

[0096] Consider a case where the second information processing terminal 24 converts power information managed or traded on the first platform 16 into value information managed or traded on the second platform 26. In this case, the information processing system 10 executes the sequences shown in Figs. 7 and 8.

[0097] In step S200, the first information processing terminal 14 randomly generates a secret value R.

[0098] In step S202, the first information processing terminal 14 generates a hash value H_R of the secret value R generated in step S200.

[0099] In step S204, the first information processing terminal 14 transmits the hash value H_R generated in step S202 to the second information processing terminal 24, which is a participant of the second platform 26.

[0100] In step S206, the first information processing terminal 14 generates transaction TX1'. This transaction TX1' is a transaction indicating that value information Y will be transmitted to the address of the second information processing terminal 24 when the secret value R, the signature information sign(TX1', m) of the second information processing terminal 24 that is the destination of value information Y, and the signature information sign(TX1', k) of the first information processing terminal 14 that is the source of value information Y are disclosed. Specifically, transaction TX1' is represented by the following (1-1)' and (1-2)'.

[0101] (1-1) Value information Y is transmitted to the address of the information processing terminal that has disclosed the signature information sign and the secret value R, which satisfy the condition 'sign == sign(TX1', m) && H_R == H(R). (1-2) The power information X is transmitted to the address of the information processing terminal that has disclosed the signature information sign1 and the signature information sign2, which satisfy the condition 'sign1 == sign(TX1', k) && sign2 == sign(TX1', m).

[0102] Next, in step S208, the first information processing terminal 14 generates transaction TX2'. This transaction TX2' is a transaction that indicates that, if the signature information sign(TX1', k) of the first information processing terminal 14 is disclosed, execution of transaction TX1' will be stopped 48 hours after the disclosure, and value information Y will be sent to the address of the first information processing terminal 14. Transaction TX2' indicates a timeout. Note that 48 hours is an example of the first time period of the disclosed technology. Specifically, transaction TX2' is expressed by the following (2).

[0103] (2) If a sign that satisfies 'sign == sign(TX1', k) is disclosed, value information Y will be sent from transaction TX1' to the address of the first information processing terminal 14 that has public key K 48 hours later.

[0104] In step S210, the first information processing terminal 14 transmits the transaction TX2′ generated in step S208 to the second information processing terminal 24.

[0105] In step S212, the second information processing terminal 24 receives the transaction TX2' transmitted in step S210.

[0106] In step S214, the second information processing terminal 24 attaches signature information sign(TX1',m) to the transaction TX2' received in step S212 above, and transmits it to the first information processing terminal 14. This signature information sign(TX1',m) represents agreement to the registration of value information Y in transaction TX1'.

[0107] In step S216, the first information processing terminal 14 broadcasts the transaction TX1' generated in step S206 to the second blockchain node 28 of the second platform 26. As a result, the multiple second blockchain nodes verify the transaction and register the transaction TX1' in the blockchains they own. As a result, the first information processing terminal 14 registers the transaction TX1', which indicates that the value information Y will be transmitted if the secret value R is disclosed, in the second platform.

[0108] Next, in step S218, the second information processing terminal 24 generates transaction TX3'. Transaction TX3' is a transaction indicating that power information X will be transmitted when the secret value R, the signature information sign(TX3', k) of the first information processing terminal 14 that is the destination of the power information X, and the signature information sign(TX3', m) of the second information processing terminal 24 that is the source of the power information X are disclosed. Specifically, transaction TX3' is represented by the following (3-1)' and (3-2)'. Execution of transaction TX3' causes the power information X to be transmitted.

[0109] Power information X is issued to an information processing terminal that has disclosed sign and secret value R, which satisfies (3-1)' sign == sign(TX3', k) && H_R == H(R). (3-2)' Power information X is issued to an information processing terminal that has disclosed sign1 and sign2 that satisfy sign1 == sign(TX3', k) && sign2 == sign(TX3', m).

[0110] In step S220, the second information processing terminal 24 generates transaction TX4'. Transaction TX4' is a transaction that indicates that if the signature information of the second information processing terminal 24 is disclosed, transaction TX3' will be canceled 24 hours after the disclosure, and power information X will be sent to the address of the second information processing terminal 24. Note that 24 hours is an example of the second time period of the disclosed technology. Therefore, transaction TX4' is represented by the following (4)'.

[0111] (4) If a sign that satisfies 'sign == sign(TX4', m) is disclosed, power information X is transmitted to the second information processing terminal 24 that has the public key M after 24 hours have passed.

[0112] In step S222, the second information processing terminal 24 transmits the transaction TX4′ generated in step S220 to the first information processing terminal 14.

[0113] In step S224, the first information processing terminal 14 receives the transaction TX4′ transmitted in step S222, and transmits the transaction TX4′ to the second information processing terminal 24 with signature information sign(TX3′,k) attached thereto.

[0114] In step S226, the second information processing terminal 24 broadcasts the transaction TX3' generated in step S218 to the multiple first blockchain nodes 18 of the first platform 16. As a result, the multiple first blockchain nodes 18 verify the transaction and register the transaction TX3' in the first blockchain that they hold. As a result, the transaction TX3' indicating that the power information X will be transmitted when the secret value R is disclosed by the second information processing terminal 24 is registered in the first platform. Note that in this case, the first blockchain node 18 verifies the transaction TX3'. Therefore, the value represented by the power information X is equal to the total amount X represented by the power information held in the wallet of the second information processing terminal 24. MAXIf the power information is larger than , the broadcast fails because there is insufficient power information to be transmitted.

[0115] In step S228, the first information processing terminal 14 generates a transaction TX5'. The transaction TX5' is a transaction indicating that the secret value R is disclosed and the power information X is discarded when the transaction TX3' is executed.

[0116] In step S230, the first information processing terminal 14 broadcasts the transaction TX5' generated in step S228 to the second platform 26. The first information processing terminal 14 discloses the secret value R and the signature information sign(TX3', k) of the first information processing terminal 14 to which the power information is to be transmitted, thereby executing the transactions TX3' and TX5'. As a result, the secret value R is disclosed, and the power information X of the address of the first information processing terminal 14 is discarded.

[0117] Furthermore, when the first information processing terminal 14 discloses the secret value R and the signature information sign(TX3', k) of the first information processing terminal to which the power information X is to be sent, the condition (3-1)' above is satisfied and the transaction TX3' is executed.

[0118] If transaction TX3' and transaction TX5' are not executed, the secret value R is not disclosed, and therefore the power information X on the first platform 16 also remains unused. In this case, the power information X is not discarded.

[0119] In step S232, the second information processing terminal 24 obtains the secret value R disclosed by the execution of transaction TX5' in step S230 above. This makes it possible to obtain value information Y of transaction TX1' registered in the second blockchain on the second platform 26. Therefore, the second information processing terminal 24 generates transaction TX6' indicating that transaction TX1' will be executed by disclosing the secret value R and the signature information sign(TX1', m) of the second information processing terminal 24, which is the destination of the value information Y. As a result, the value information Y is transmitted to the address of the second information processing terminal 24 or an arbitrary address.

[0120] For this reason, in step S234, the second information processing terminal 24 generates a transaction TX6' that transmits the value information Y from the transaction TX1' to an arbitrary address. Note that in this embodiment, an example will be described in which the arbitrary address is the address of the second information processing terminal 24.

[0121] In step S236, the second information processing terminal 24 broadcasts the transaction TX6′ generated in step S234 to the second platform 26. As a result, the value information Y is transmitted to the address of the second information processing terminal 24.

[0122] As a result, double counting of the value associated with electricity generated by a predetermined power generation method between the first platform 16 and the second platform 26 is prevented.

[0123] As described above, the information processing system according to the second embodiment can prevent double counting of the value associated with electricity generated by a predetermined power generation method by having the second information processing terminal 24 acquire value information Y after the first information processing terminal 14 discards power information X.

[0124] [Third embodiment]

[0125] Next, a third embodiment will be described. The configuration of the information processing system according to the third embodiment is the same as that of the first embodiment, and therefore the same reference numerals will be used and the description will be omitted. The third embodiment differs from the first and second embodiments in that a known smart contract is used to prevent double counting of power information X and value information Y.

[0126] <Operation of the information processing system 10>

[0127] In the third embodiment, a smart contract such as Ethereum, which is a known technology, is used to prevent double counting of power information X and value information Y on the platform. For this reason, the following conditions are assumed to be implemented by the smart contract:

[0128] Smart contract SC1 has been deployed on the first blockchain. Smart contract SC2 has been deployed on the second blockchain. Each function of smart contract SC1 and each function of smart contract SC2 can be executed by both the first information processing terminal 14 and the second information processing terminal 24. However, the issuance of power information of smart contract SC1 and the issuance of value information Y of smart contract SC2 can only be executed by the first information processing terminal 14.

[0129] The timeout period is set as follows: If the power information X and the value information Y are not exchanged within a predetermined timeout period, the power information X and the value information Y are each returned to their original owners.

[0130] TIMEOUT_N = 48 hours TIMEOUT_M = 24 hours

[0131] A smart contract SC1 has been deployed on the first blockchain of the first platform 16. Specifically, a function representing the issuance of power information, a function representing the registration of a conditional discard request for power information, a function representing the withdrawal of a conditional discard request for power information, and a function representing the discard of power information are registered on the first platform 16. The function of each function will be described below.

[0132] (Function that represents the issuance of power information X)

[0133] [Required parameters]

[0134] Amount of power information issued D -Address of the information processing terminal that issued the power information

[0135] [Processing content]

[0136] The function representing the issuance of power information X is configured to be executable only from the address of the first information processing terminal 14. For the function representing the issuance of power information, the amount D of power information to be issued is added to a hash table using the address as a key. This makes it possible to check the amount of power information held at the address. For example, the function representing the issuance of power information functions as follows:

[0137] Address A:100 Address B:50

[0138] In the above case, when a function representing the issuance of power information is executed with the amount of power information D=20 and address=A as parameters, the result is as follows.

[0139] Address A:120 Address B:50

[0140] (Function for registering a conditional discard request for power information)

[0141] [Required parameters]

[0142] Discard power information X H_R Addresses that allow destruction to be performed

[0143] [Processing content]

[0144] The function representing the registration of a conditional discard request for power information records six values: the power information to be discarded X, H_R, the address at which the discard is permitted to be executed, the timestamp at the time of the discard request, the value of the discard request flag, and the address of the information processing terminal that created the discard request.

[0145] (Function for canceling a conditional discard request for power information)

[0146] The function representing the cancellation of the conditional discard request for power information is registered in advance in the first platform 16 by the second information processing terminal 24.

[0147] [Processing content]

[0148] The function representing the cancellation of the conditional discard request for power information executes the following process.

[0149] -Check that the discard request flag is True. Check whether the address of the information processing terminal that created the transaction that called the function representing the cancellation of the conditional discard request for power information matches the address of the information processing terminal that created the conditional discard request for any power information X. ·Check whether the current time is TIMEOUT_N hours or more after the timestamp at which the conditional discard request for any power information X was registered. If all of the above checks are successful, set the discard request flag to False.

[0150] (Function for discarding power information)

[0151] [Required parameters]

[0152] Secret value R Signature information

[0153] [Processing content]

[0154] The function representing the discarding of power information executes the following process.

[0155] Check whether the discard request flag is True. If the discard request flag is False, interrupt the process. Check whether H(R) == H_R holds. If not, stop processing. Check whether the address that allows execution can be restored from the signature information sign. If a different address or the signature information is invalid, the process is aborted. If all of the above checks are successful, discard power information X.

[0156] A smart contract SC2 has been deployed on the second blockchain of the second platform 26. Specifically, the second platform 26 has registered therein a function representing the issuance of value information Y, a function representing the registration of the conditions for the transfer of value information Y, a function representing the revocation of the conditions for the transfer of value information Y, and a function representing the conditions for the transfer of value information Y.

[0157] (Function representing the issuance of value information Y)

[0158] [Required parameters]

[0159] -Hash value representing the content of value information Y

[0160] [Processing content]

[0161] The function representing the issuance of value information Y is configured so that it can only be executed from the address of the first information processing terminal 14. The function representing the issuance of value information Y then registers the hash value input as a parameter, and issues an arbitrary, unique ID as a token ID. The information processing terminal that is the holder of this token becomes the address of the executor of this function. For example, it is registered as the following data structure:

[0162] Token information structure example Token ID of value information Y Hash value Address of value information Y

[0163] (Function that represents the registration of the conditions for the transfer of value information Y)

[0164] [Required parameters]

[0165] Token ID of value information Y to be transferred H_R Address of the destination information processing device

[0166] [Processing content]

[0167] The function representing the registration of the conditions for the transfer of value information Y records six items: the token ID of the value information Y to be transferred, H_R, the address of the information processing terminal to which the transfer is to be made, the timestamp when the transfer conditions were registered, the value of the transfer flag (the value of the flag is True when the transfer is registered), and the address of the information processing terminal that registered the transfer conditions.

[0168] (A function that expresses the withdrawal of the conditions for the transfer of value information Y)

[0169] The function representing the revocation of the condition for the transfer of value information is registered in advance in the second platform 26 by the first information processing terminal 14.

[0170] [Processing content]

[0171] -Check that the discard request flag is True. Check whether the address of the information processing terminal that created the transaction TX that called the function representing the cancellation of the conditions for the transfer of value information Y matches the address of the information processing terminal that created the conditional discard request for any power information X. ·Confirm whether the current time has passed TIMEOUT_M hours or more from the timestamp of the registration of the transfer conditions of any value information Y. If all of the above checks are successful, set the discard request flag to False.

[0172] (A function that represents the conditions for the transfer of value information Y)

[0173] [Required parameters]

[0174] Secret value R Signature information

[0175] [Processing content]

[0176] The function representing the discarding of power information executes the following process.

[0177] Check whether the discard request flag is True. If the discard request flag is False, interrupt the process. Check whether H(R) == H_R holds. If not, stop processing. Check whether the address recovered from the signature information sign is the address of the transfer destination. If it is a different address or the signature information is invalid, the process is aborted. If all of the above confirmation processes are successful, the value information Y is sent to the transfer destination address.

[0178] There are two possible methods for burning a smart contract:

[0179] The first method is to delete (subtract) the power information X from the smart contract. In this case, the total amount of power information managed by the smart contract also decreases.

[0180] The second method is to send the power information X to an address corresponding to an arbitrary public key (e.g., 0x0) that is not generated from a private key and is theoretically impossible to extract. In this case, the total amount of power information managed in the smart contract does not change.

[0181] Under such circumstances, consider a case where the second information processing terminal 24 converts the power information managed or traded in the first platform 16 into value information managed or traded in the second platform 26. In this case, the information processing system 10 executes a sequence as shown in Fig. 9. Note that each of the above functions corresponds to a transaction.

[0182] In step S300, the second information processing terminal 24 generates a secret value R.

[0183] In step S302, the second information processing terminal 24 generates a hash value H_R of the secret value R generated in step S300.

[0184] In step S304, the second information processing terminal 24 transmits the hash value H_R generated in step S302 to the first information processing terminal 14.

[0185] In step S306, the second information processing terminal 24 transmits a transaction SC_TX1, which has as parameters the power information X to be destroyed, the hash value H_R of the secret value R, and the address of the first information processing terminal 14 to which destruction is permitted, to the first platform 16, and which represents registration of a conditional destruction request for the power information X. The first blockchain node of the first platform 16 registers the transaction SC_TX1 in the first blockchain.

[0186] In step S308, the first information processing terminal 14 confirms that the conditional discard request for the power information X has been registered in the first platform 16 in step S306.

[0187] In step S310, the first information processing terminal 14 transmits to the second platform 26 a transaction SC_TX2 which has the hash value of the value information Y as a parameter and which indicates that the value information Y will be issued.

[0188] In step S312, the first information processing terminal 14 transmits to the second platform 26 a transaction SC_TX3 which has as parameters a token ID representing the identification information of the value information Y, a hash value H_R of the secret value R, and the address of the second information processing terminal 24, and which represents the registration of the conditions for the transfer of the value information Y.

[0189] In step S314, the second information processing terminal 24 transmits a transaction SC_TX4, which has as parameters the secret value R and signature information sign(R, m) generated from the secret value R and the private key m of the second information processing terminal 24, and which indicates the transfer of value information Y, to the second platform 26. As a result, the value information Y is transmitted to the address of the second information processing terminal 24.

[0190] In step S316, the first information processing terminal 14 obtains the secret value R disclosed by the execution of transaction SC_TX4.

[0191] In step S318, the first information processing terminal 14 transmits a transaction SC_TX5, which has as parameters the secret value R and signature information sign(R, k) generated from the secret value R and the private key k of the first information processing terminal 14, and which indicates that the power information X will be discarded, to the first platform 16. As a result, the power information X is discarded.

[0192] It should be noted that if, while the above process is being executed, the second information processing terminal 24 generates a transaction TX_TD indicating the withdrawal of the conditional discard request for the power information X and sends the transaction TX_TD to the first platform, the process of converting the power information X to the value information Y is deemed to have been stopped.

[0193] Specifically, when the second information processing terminal 24 transmits transaction TX_TD to the first platform, it is determined that the address of the information processing terminal that generated transaction TX_TD matches the address of the information processing terminal that generated transaction SC_TX1. Then, if the current time is TIMEOUT_N hours after the timestamp indicating the time when transaction SC_TX1 was registered, the request to discard power information X is revoked. TIMEOUT_N hours is an example of the first time.

[0194] Similarly, if, while the above process is being executed, the first information processing terminal 14 generates a transaction TX_TK representing the withdrawal of the conditions for the transfer of value information Y and transmits the transaction TX_TK to the second platform, the process of converting power information X to value information Y is deemed to have been stopped.

[0195] Specifically, when the first information processing terminal 14 transmits transaction TX_TK to the second platform, it is determined that the address of the information processing terminal that generated transaction TX_TK matches the address of the information processing terminal that generated transaction SC_TX3. Then, if the current time has passed TIMEOUT_M from the timestamp that indicates the time when transaction SC_TX3 was registered, the transfer of value information Y is revoked. TIMEOUT_M is an example of the second time.

[0196] As described above, according to the third embodiment, by exchanging power information X and value information Y using a smart contract, it is possible to prevent double counting of the value associated with electricity.

[0197] Additionally, authentication processes are automated using smart contracts, minimizing operational costs and setting reasonable platform usage fees.

[0198] [Fourth embodiment]

[0199] Next, a fourth embodiment will be described. The configuration of the information processing system according to the fourth embodiment is the same as that of the first embodiment, and therefore the same reference numerals are used and the description thereof will be omitted. The fourth embodiment differs from the third embodiment in that the first information processing terminal 14 first discards the power information X by a known smart contract. The description of the same processes as those in the third embodiment will be omitted.

[0200] The timeout period in the fourth embodiment is set as follows.

[0201] TIMEOUT_N = 24 hours TIMEOUT_M = 48 hours

[0202] <Operation of the information processing system 10>

[0203] Consider a case where the second information processing terminal 24 converts power information managed or traded on the first platform 16 into value information managed or traded on the second platform 26. In this case, the information processing system 10 executes a sequence as shown in FIG.

[0204] In step S400, the first information processing terminal 14 generates a secret value R.

[0205] In step S402, the first information processing terminal 14 generates a hash value H_R of the secret value R generated in step S400.

[0206] In step S404, the first information processing terminal 14 transmits the hash value H_R generated in step S402 to the second information processing terminal 24.

[0207] In step S406, the first information processing terminal 14 transmits to the second platform 26 a transaction SC_TX1′ which has the hash value of the value information Y as a parameter and which indicates that the value information Y will be issued.

[0208] In step S408, the first information processing terminal 14 transmits to the second platform 26 a transaction SC_TX2' which has parameters of a token ID representing the identification information of the value information Y, a hash value H_R of the secret value R, and the address of the second information processing terminal 24, and which represents the registration of the conditions for the transfer of the value information Y.

[0209] In step S410, the second information processing terminal 24 confirms that the conditions for transferring the value information Y have been registered to the second platform 26 in step S308.

[0210] In step S412, the second information processing terminal 24 sends a transaction SC_TX3' to the first platform 16, which has as parameters the power information X to be destroyed, the hash value H_R of the secret value R, and the address of the first information processing terminal 14 to which destruction is permitted. The transaction SC_TX3' indicates that a conditional destruction request for the power information X is to be registered.

[0211] In step S414, the first information processing terminal 14 transmits a transaction SC_TX4′, which has as parameters the secret value R and signature information sign(R, k) generated from the secret value R and the private key k of the first information processing terminal 14, and which indicates that the power information X will be discarded, to the first platform 16. As a result, the power information X is discarded.

[0212] In step S416, the second information processing terminal 24 obtains the secret value R disclosed by the execution of transaction SC_TX4'.

[0213] In step S418, the second information processing terminal 24 transmits a transaction SC_TX5′, which has as parameters the secret value R and signature information sign(R, m) generated from the secret value R and the private key m of the second information processing terminal 24, and which indicates the transfer of value information Y, to the second platform 26. As a result, the value information Y is transmitted to the address of the second information processing terminal 24.

[0214] It should be noted that if, while the above process is being executed, the first information processing terminal 14 generates a transaction TX_TK indicating the cancellation of the transfer of value information and transmits the transaction TX_TK to the second platform, the process of converting power information X to value information Y is deemed to have been stopped.

[0215] Specifically, when the first information processing terminal 14 transmits transaction TX_TK to the second platform, it is determined that the address of the information processing terminal that generated transaction TX_TK matches the address of the information processing terminal that generated transaction SC_TX2'. Then, if the current time has passed TIMEOUT_N hours since the timestamp indicating the time when transaction SC_TX2' was registered, the transfer of value information Y is revoked. TIMEOUT_N hours is an example of the first time.

[0216] Furthermore, if, while the above process is being executed, the second information processing terminal 24 generates a transaction TX_TD indicating a withdrawal of the request to discard the power information and sends the transaction TX_TD to the first platform, the process of converting the power information X into the value information Y is deemed to have been stopped.

[0217] Specifically, when the second information processing terminal 24 transmits transaction TX_TD to the first platform, it is determined that the address of the information processing terminal that generated transaction TX_TD matches the address of the information processing terminal that registered transaction SC_TX3'. Then, if the current time is TIMEOUT_M hours after the timestamp indicating the time when transaction SC_TX3' was registered, the request to discard power information X is revoked. TIMEOUT_M hours is an example of the second time.

[0218] As described above, according to the fourth embodiment, by exchanging power information X and value information Y using a smart contract, it is possible to prevent double counting of the value associated with electricity.

[0219] The present invention is not limited to the above-described embodiment, and various modifications and applications are possible without departing from the spirit and scope of the present invention.

[0220] For example, in each of the above embodiments, the first platform 16 and the second platform 26 are described as being configured with a plurality of blockchain nodes and blockchains, but this is not limiting. For example, each of the first platform 16 and the second platform 26 may be configured with a single server, as shown in FIG. 11 . The first platform 16 and the second platform 26 may also be configured with a single server. In the example shown in FIG. 11 , the first platform of the information processing system 210 is configured with the first server 216, and the second platform is configured with the second server 226. In this case, a transaction indicating that the power information will be discarded if the secret value R is disclosed is stored in the memory of the first server 216, which is the first platform, and a transaction indicating that the value information will be issued if the secret value R is disclosed is stored in the memory of the second server 226, which is the second platform. Then, when the first information processing terminal 14 transmits the predetermined value R to the first server 216, the first server 216 executes the transaction indicating that the power information will be discarded and discards the power information corresponding to the value information to be issued. Furthermore, when the second information processing terminal 24 transmits a predetermined value R to the second server 226, the second server 226 executes a transaction indicating that value information will be issued, and issues value information corresponding to the power information to be discarded. This makes it possible to prevent double counting of value associated with electricity.

[0221] Furthermore, although the present specification has been described as an embodiment in which the program is pre-installed, the program may also be provided by being stored on a computer-readable recording medium. [Explanation of symbols]

[0222] 10,210 Information Processing Systems 12 Power generation recording device 14 First information processing terminal 16 Platform 1 18 First Blockchain Node 24 Second information processing terminal 26 Second Platform 28 Second Blockchain Nodes 30 Network 70 Computer 72 memory 73 Memory section

Claims

1. An information processing system comprising a plurality of first blockchain nodes and a plurality of second blockchain nodes, The first blockchain node is a computer having a storage unit in which a first blockchain is stored, and the second blockchain node is a computer having a storage unit in which a second blockchain is stored, The first blockchain registers a transaction record of electricity information representing generated electricity, A transaction record of value information representing a value associated with electricity corresponding to the power information is registered in the second blockchain, In response to a request signal requesting an exchange of the power information and the value information being output from a first information processing terminal operated by a first user who holds the power information or a second information processing terminal operated by a second user who manages the value information, the first blockchain node and the second blockchain node execute an exchange of the power information and the value information by discarding the power information and issuing the value information according to an atomic swap technique; When executing the exchange of the power information and the value information, the second blockchain node issues the value information linked to the amount of power of the electricity corresponding to the power information and the generation type of the electricity corresponding to the power information. An information processing system that executes processing.

2. The second blockchain node issues the value information linked to location information of the power generation amount recording device that generated the power information. The information processing system according to claim 1 .

3. A first transaction indicating that the power information will be discarded is registered in the first blockchain; A second transaction indicating that the value information will be issued is registered in the second blockchain; In response to the request signal being output, the first blockchain node and the second blockchain node execute the first transaction and the second transaction according to an atomic swap technique, thereby discarding the power information and issuing the value information, and exchanging the power information and the value information.

3. The information processing system according to claim 1.

4. An information processing method executed by an information processing system having a plurality of first blockchain nodes and a plurality of second blockchain nodes, The first blockchain node is a computer having a storage unit in which a first blockchain is stored, and the second blockchain node is a computer having a storage unit in which a second blockchain is stored, The first blockchain registers a transaction record of electricity information representing generated electricity, A transaction record of value information representing a value associated with electricity corresponding to the power information is registered in the second blockchain, In response to a request signal requesting an exchange of the power information and the value information being output from a first information processing terminal operated by a first user who holds the power information or a second information processing terminal operated by a second user who manages the value information, the first blockchain node and the second blockchain node execute an exchange of the power information and the value information by discarding the power information and issuing the value information according to an atomic swap technique; When executing the exchange of the power information and the value information, the second blockchain node issues the value information linked to the amount of power of the electricity corresponding to the power information and the generation type of the electricity corresponding to the power information. Information processing methods.

5. A second blockchain node in an information processing system having a plurality of first blockchain nodes and a plurality of second blockchain nodes, The first blockchain node is a computer having a storage unit in which a first blockchain is stored, and the second blockchain node is a computer having a storage unit in which a second blockchain is stored, The first blockchain registers a transaction record of electricity information representing generated electricity, A transaction record of value information representing a value associated with electricity corresponding to the power information is registered in the second blockchain, In response to a request signal requesting an exchange of the power information and the value information being output from a first information processing terminal operated by a first user who holds the power information or a second information processing terminal operated by a second user who manages the value information, the first blockchain node and the second blockchain node execute an exchange of the power information and the value information by discarding the power information and issuing the value information according to an atomic swap technique; When executing the exchange of the power information and the value information, the second blockchain node issues the value information linked to the amount of power of the electricity corresponding to the power information and the generation type of the electricity corresponding to the power information. Second blockchain node.

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