Information processing method, program, and information processor

Abstract

To provide an information processing method and the like capable of issuing a receipt for a transaction using digital money such as crypto-assets in the form of an NFT (Non-Fungible Token).SOLUTION: An information processing method causes a computer to execute processing of acquiring payment information of a user using digital money, transaction history of which is recorded on a blockchain, the payment information including a wallet address of the user, and issuing, based on the payment information, an NFT in which receipt information is described, to the wallet address. Preferably, a public key of the user is acquired, and the NFT encrypted using the public key is issued.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] The use of cryptocurrencies and stable coins based on blockchain technology is increasing. For example, Patent Document 1 discloses an information processing device that, when a purchase request to purchase a product is received from a virtual store in a virtual space, outputs an instruction to pay for the purchase price with cryptocurrencies, provided that the virtual store is associated with a physical store in the real space. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2024-18861 Summary of the Invention [Problem to be solved by the invention]

[0004] In one aspect, the present invention aims to provide an information processing method, etc., that can issue receipts associated with the purchase and sale of digital money such as crypto assets in the form of NFTs (Non-Fungible Tokens). [Means for solving the problem]

[0005] In one aspect, the information processing method involves a computer acquiring payment information for a user using digital money whose transaction history is recorded on a blockchain, including the user's wallet address, and issuing an NFT containing receipt information to the wallet address based on the payment information. [Effects of the Invention]

[0006] On the one hand, receipts for purchases and sales of digital money such as cryptocurrencies can be issued using NFTs. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is an explanatory diagram showing an example configuration of an NFT issuing system. [Figure 2] FIG. 2 is a block diagram illustrating an example of the configuration of a server. [Figure 3] FIG. 10 is a diagram illustrating an example of a record layout of a seller DB. [Figure 4] FIG. 1 is a diagram showing an overview of a first embodiment. [Figure 5] 10 is a flowchart showing an example of the procedure for an NFT issuance process. [Figure 6] FIG. 10 is a diagram showing an overview of a second embodiment. [Figure 7] 10 is a flowchart showing an example of the procedure of an NFT issuing process according to the second embodiment. [Figure 8] FIG. 10 is a diagram showing an overview of a third embodiment. [Figure 9] 10 is a flowchart illustrating an example of a procedure for an NFT decryption process. DETAILED DESCRIPTION OF THE INVENTION

[0008] The present invention will be described in detail below with reference to the drawings showing embodiments thereof. (Embodiment 1) FIG. 1 is an explanatory diagram showing an example configuration of an NFT issuing system. In this embodiment, an NFT issuing system is described that issues an NFT containing receipt information when a user purchases a product or service from a seller using cryptocurrency. The NFT issuing system includes an information processing device 1, a user terminal 2, and a seller terminal 3. Each device is communicatively connected via a network N such as the Internet.

[0009] In the following explanation, it is assumed that a user purchases a product or service with a cryptocurrency, but the product or service may be purchased with other digital money such as stablecoins, CBDC (Central Bank Digital Currency), etc. In other words, it is sufficient if the user can purchase a product or service with financial value (digital money such as cryptocurrency or stablecoin) that is issued on a blockchain and whose transaction history is recorded on the blockchain.

[0010] The information processing device 1 is an information processing device capable of various information processing and sending and receiving information, such as a server computer or a personal computer. In this embodiment, the information processing device 1 is assumed to be a server computer, and for simplicity, will be referred to as server 1 below. When a user pays a seller for the purchase price of a product or service with cryptocurrency, the server 1 performs a process to issue an NFT that lists receipt information related to the purchase of the product or service.

[0011] The user terminal 2 is a terminal device used by a user (a purchaser of a product or service), such as a smartphone, personal computer, tablet terminal, etc. The user terminal 2 pays for the purchase by generating a transaction to transfer cryptocurrency from the user's wallet address to the seller's wallet address and outputting (broadcasting) the transaction to a blockchain network (not shown).

[0012] The seller terminal 3 is a terminal device used by the seller (merchant), such as a personal computer, smartphone, or tablet terminal. When the seller terminal 3 receives payment for the purchase price in cryptocurrency from a user, it transmits the payment information to the server 1. Based on the payment information, the server 1 issues an NFT containing receipt information.

[0013] 2 is a block diagram showing an example of the configuration of the server 1. The server 1 includes a control unit 11, a main memory unit 12, a communication unit 13, and an auxiliary memory unit . The control unit 11 has one or more arithmetic processing devices such as a CPU (Central Processing Unit), an MPU (Micro-Processing Unit), a GPU (Graphics Processing Unit), etc., and performs various information processing, control processing, etc. by reading and executing a program P stored in the auxiliary storage unit 14. The main storage unit 12 is a temporary storage area such as an SRAM (Static Random Access Memory) or a DRAM (Dynamic Random Access Memory), and temporarily stores data necessary for the control unit 11 to execute arithmetic processing. The communication unit 13 is a communication module for performing communication-related processing, and transmits and receives information to and from the outside.

[0014] The auxiliary storage unit 14 is a non-volatile storage area such as a large-capacity memory or a hard disk, and stores a program P (program product) and other data required for the control unit 11 to execute processing. The auxiliary storage unit 14 also stores a seller DB 141. The seller DB 141 is a database that stores seller information.

[0015] The auxiliary storage unit 14 may be an external storage device connected to the server 1. The server 1 may be a multi-computer consisting of multiple computers, or may be a virtual machine virtually constructed by software.

[0016] Furthermore, in this embodiment, the server 1 is not limited to the above configuration, and may include, for example, an input unit that accepts operation input, a display unit that displays images, etc. Furthermore, the server 1 may be provided with a reading unit that reads a portable storage medium 1a such as a CD (Compact Disk)-ROM or a DVD (Digital Versatile Disc)-ROM, and may read and execute the program P from the portable storage medium 1a.

[0017] 3 is a diagram showing an example of a record layout of seller DB 141. Seller DB 141 includes a seller ID column, a seller name column, an address column, and a registration number column. The seller ID column stores a seller ID, which is an identifier for each seller. The seller name column, address column, and registration number column each store the seller name, seller address, and seller's tax registration number (for example, an invoice system registration number (qualified bill issuer registration number)) in association with the seller ID.

[0018] 4 is a diagram showing an overview of the first embodiment. The overview of the present embodiment will be described with reference to FIG.

[0019] A user purchases a product or service provided by a seller using cryptocurrency. The cryptocurrency may be, for example, a virtual currency such as Ethereum (registered trademark) or a stablecoin, but there is no particular limitation on the type of cryptocurrency. The user terminal 2 pays for the purchase by generating a transaction to transfer cryptocurrency equivalent to the purchase price of the product or service from the user's wallet address to the seller's wallet address and outputting (broadcasting) the transaction to the blockchain network (a network in which miners communicate via P2P (Peer to Peer)).

[0020] When payment of the purchase price is accepted from the user, the seller terminal 3 transmits payment information indicating the details of the payment of the purchase price to the server 1. The payment information includes, for example, the transaction date, transaction details (such as the name and quantity of the purchased product or service, whether it is subject to a reduced tax rate, etc.), the purchase price of the product or service, the amount of tax, etc., as well as the user's wallet address.

[0021] When the payment information is acquired, Server 1 issues an NFT containing receipt information for the purchase of a product or service to the user's wallet address based on the payment information. The receipt information is information that proves that the purchase price has been received, and contains information similar to that of a general receipt.

[0022] When payment information is acquired from the seller terminal 3, the server 1 acquires seller information about the seller from which the payment information was acquired from the seller DB 141. The seller information includes the seller's name, address, and seller registration number required for tax purposes (e.g., invoice registration number). The server 1 generates receipt information required for tax purposes by adding the seller information to the payment information. The server 1 issues an NFT with a script containing the generated receipt information to the user's wallet address.

[0023] Incidentally, issuing an NFT requires a mining fee (so-called gas fee). The fee may be borne by the administrator of the system, but it may also be borne by the user and / or seller. For example, when server 1 receives payment of the fee in cryptocurrency from the user and / or seller, it issues an NFT. In this way, server 1 issues a receipt in the form of an NFT in exchange for payment of the cryptocurrency.

[0024] Generally, the fee required for issuing (mining) NFTs is not a fixed amount, but varies depending on factors such as the transaction congestion situation on the blockchain network. Therefore, for example, Server 1 may wait until a specific time period when there are fewer transactions than other time periods to process the NFT, and then issue the NFT when that specific time period arrives. This allows fees to be kept low.

[0025] Furthermore, since the NFT issued in this embodiment is used as a receipt, it is not intended that the owner (wallet address) be changed. Therefore, for example, the server 1 may issue a non-transferable token such as an SBT (SoulBound Token) as an NFT.

[0026] As described above, according to this embodiment, a receipt can be issued in NFT for payment using crypto assets.

[0027] 5 is a flowchart showing an example of the procedure for NFT issuance processing. The processing content executed by the server 1 will be described with reference to FIG. The control unit 11 of the server 1 acquires the user's payment information using cryptocurrency from the seller terminal 3 (step S11). The payment information includes the transaction date, transaction details (the name and quantity of the purchased product or service, whether it is subject to a reduced tax rate, etc.), the purchase price of the product or service, the amount of tax, etc., as well as the user's wallet address.

[0028] The control unit 11 acquires seller information about the seller who sold the product or service to the user from the seller DB 141 (step S12). The seller information includes the seller's name, the seller's address, the seller's registration number required for tax purposes (e.g., the registration number under the invoice system), etc.

[0029] The control unit 11 determines whether or not payment of the fee for issuing the NFT in cryptocurrency has been accepted from the user and / or seller (step S13). If it is determined that payment has not been accepted (S13: NO), the control unit 11 waits for processing.

[0030] If it is determined that payment of the fee has been accepted (S13: YES), the control unit 11 issues an NFT that describes receipt information based on the payment information (step S14). Specifically, the control unit 11 generates receipt information by adding seller information to the payment information, and issues an NFT that has a script that describes the receipt information. The control unit 11 then ends the series of processes.

[0031] In the above, we have stated that an NFT is issued with receipt information written in plain text, but to protect privacy, it is also possible to introduce a protocol using zero-knowledge proofs, etc., to issue an NFT with transaction details (receipt information) confidential.

[0032] As described above, according to the first embodiment, receipts for purchases and sales of crypto assets can be issued in NFT.

[0033] (Embodiment 2) In this embodiment, we will describe a form in which the NFT is encrypted with the user's public key, preventing anyone other than the user from viewing the transaction details. Note that the same reference numerals will be used to designate content that overlaps with the first embodiment, and explanations will be omitted.

[0034] 6 is a diagram showing an outline of the second embodiment. The outline of the present embodiment will be described with reference to FIG.

[0035] As in the first embodiment, when a user pays a cryptocurrency to a seller, the server 1 acquires payment information from the seller terminal 3. The server 1 then issues an NFT that includes receipt information that adds seller information to the payment information.

[0036] In this embodiment, the server 1 encrypts the NFT using the user's public key. For example, the server 1 derives a public key from the user's wallet address and encrypts the receipt information using the public key. The server 1 may also encrypt the NFT itself using the public key. The server 1 issues the NFT with the encrypted receipt information.

[0037] In this embodiment, the private key corresponding to the public key is managed within a wallet application (hereinafter referred to as "wallet") installed in the user terminal 2. To access NFT data, the user makes a decryption request to the wallet. When the decryption request is accepted, the wallet (user terminal 2) uses the private key to decrypt the NFT data and displays the decrypted data, i.e., receipt information.

[0038] 7 is a flowchart showing an example of the procedure of the NFT issuance process according to embodiment 2. When it is determined that the payment of the fee has been accepted (S13: YES), the server 1 executes the following process. The control unit 11 of the server 1 acquires the user's public key (step S201). The control unit 11 encrypts the receipt information, which is payment information plus seller information, using the user's public key (step S202). The control unit 11 then issues an NFT that encrypts the receipt information (step S203), and the series of processes ends.

[0039] As described above, according to the second embodiment, the details of transactions made by users can be protected.

[0040] (Embodiment 3) In the second embodiment, a configuration was described in which, when an NFT is encrypted, the private key required for decryption is managed within the user's wallet (user terminal 2). In the present embodiment, a configuration will be described in which the server 1 manages the user's private key and decrypts the NFT data in response to a decryption request from the user.

[0041] 8 is a diagram showing an outline of the third embodiment. The outline of this embodiment will be described with reference to FIG.

[0042] As in the second embodiment, when a user makes a payment of cryptocurrency to a seller and the server 1 receives payment information from the seller terminal 3, the server 1 issues an NFT encrypted using the user's public key. In this embodiment, the server 1 manages a private key corresponding to the public key. The server 1 issues an individual private key to each user and stores it in association with the user. The server 1 decrypts the NFT data using the private key and provides it to the user.

[0043] That is, when the server 1 receives a request to decrypt an NFT from the user terminal 2, it reads out the private key of the user who made the decryption request. The server 1 then uses the read private key to decrypt the NFT data (receipt information). The server 1 outputs the decrypted NFT data to the user terminal 2 and displays it.

[0044] The NFT issuance (encryption) process according to this embodiment is similar to the flowchart of Figure 7 described in embodiment 2, so a description of the flowchart of the NFT issuance process will be omitted in this embodiment.

[0045] 9 is a flowchart showing an example of the procedure for the NFT decryption process. The process content of the server 1 when decrypting NFT data will be described with reference to FIG. The control unit 11 of the server 1 receives a request to decrypt an NFT from the user terminal 2 (step S301). When the decryption request is received, the control unit 11 selects the private key of the user who made the decryption request from the private keys stored in association with each user (step S302). The control unit 11 decrypts the NFT data using the selected private key (step S303). The control unit 11 outputs the decrypted NFT data to the user terminal 2 (step S304), and the series of processes ends.

[0046] As described above, according to the third embodiment, the private key may be managed by a management device (server 1) on the cloud, rather than by the user's wallet.

[0047] In the above case, the private key is managed by the system, which increases the risk of the private key being leaked or lost. Furthermore, management by the system implies centralization, which goes against the decentralized concept of blockchain.

[0048] Therefore, for example, a distributed key management system (DKMS) may be adopted to manage private keys, and users themselves may be responsible for part of the key management, thereby reducing the risk of centralization.

[0049] In addition, technologies that combine security and convenience, such as multi-signatures and sharded (distributed) private keys, may be introduced.

[0050] The embodiments disclosed herein are to be considered as illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above meaning, and is intended to include all modifications within the meaning and scope of the claims.

[0051] The matters described in each embodiment can be combined with each other. Furthermore, the independent claims and dependent claims described in the claims can be combined with each other in any combination, regardless of the reference format. Furthermore, although the claims use a format in which a claim references two or more other claims (multi-claim format), this is not limited to this format. A multiple claim (multi-multi-claim) that references at least one other multiple claim may also be used. [Explanation of symbols]

[0052] 1. Server (information processing device) 11 Control section 12 Main memory 13 Communications Department 14 Auxiliary storage P Program 141 Seller DB 2. User terminal 3. Merchant terminal

Claims

1. Acquire payment information of a user using digital money whose transaction history is recorded in a blockchain, the payment information including the wallet address of the user; Based on the payment information, an NFT (Non-Fungible Token) containing receipt information is issued to the wallet address. An information processing method in which processing is performed by a computer.

2. obtaining the user's public key; Issue the NFT encrypted using the public key. The information processing method according to claim 1 .

3. a private key corresponding to the public key is stored in a storage unit in association with the user; receiving a request from the user to decrypt the NFT; When the decryption request is received, the data of the NFT is decrypted using the private key; Outputting the decrypted NFT data to the user The information processing method according to claim 2 .

4. obtaining the payment information from a merchant who sold a good or service to the user; If the payment information is acquired, acquire seller information regarding the seller; The NFT is issued with the receipt information in which the seller information is added to the payment information. The information processing method according to claim 1 .

5. Accept payment of the fee for issuing the NFT in the form of the digital money from the user or a seller who sold a product or service to the user; If payment of the fee is received, the NFT is issued. The information processing method according to claim 1 .

6. Acquire payment information of a user using digital money whose transaction history is recorded in a blockchain, the payment information including the wallet address of the user; Based on the payment information, an NFT containing receipt information is issued to the wallet address. A program that causes a computer to perform a process.

7. An information processing device including a control unit, The control unit Acquire payment information of a user using digital money whose transaction history is recorded in a blockchain, the payment information including the wallet address of the user; Based on the payment information, an NFT containing receipt information is issued to the wallet address. Information processing device.

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