Computer system and method executed by computer

Abstract

To identify a destination of a digital asset.SOLUTION: The disclosed method includes a computer system generating a non-fungible token associated with a received digital asset, and the computer system identifying the owner of the non-fungible token as a destination of the digital asset.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a method executed by a computer system and a computer system. This application claims priority based on Japanese Patent Application No. 2020-50245 filed on March 19, 2020, and incorporates all the descriptions described in the Japanese patent application.

Background Art

[0002] Patent Document 1 discloses Ethereum. Ethereum is a platform for building decentralized applications and smart contracts. Smart contracts are implemented on a blockchain to automatically execute protocols such as contracts.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] One aspect of the present disclosure is a method executed by a computer system for depositing and returning a first tradable digital asset.

[0005] Another aspect of the present disclosure is a method executed by a computer system.

[0006] Another aspect of the present disclosure is a computer system configured to execute a process for depositing and returning a first tradable digital asset.

[0007] Another aspect of the present disclosure is a computer system configured to execute a process.

[0008] Another aspect of the present disclosure is a method comprising: a computer system generating a non-fungible token associated with a received digital asset; and the computer system identifying an owner of the non-fungible token as a destination of the digital asset.

[0009] Another aspect of the present disclosure is a computer system configured to execute a process, the process comprising: generating a non-fungible token associated with a received digital asset; and identifying an owner of the non-fungible token as a destination of the digital asset.

[0010] Another aspect of the present disclosure is a computer system or a method thereof configured to execute a generation process and a transmission process of a non-fungible token when receiving a digital asset from a source via a computer network.

[0011] The present disclosure also includes other aspects other than those described above. Further details will be described as embodiments below.

Brief Description of Drawings

[0012]

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Mode for Carrying Out the Invention

[0013] <1. Outline of the Method Executed by the Computer System and the Computer System>

[0014] Digital assets may be temporarily deposited by a third party other than the owner of the digital assets. Digital assets may be deposited, for example, as collateral for a loan. Also, the deposit of digital assets may be to receive a loan. The deposited digital assets will be returned in the future.

[0015] In order to increase the value of digital assets, even when the digital assets are temporarily deposited with a third party, it is desirable that the right to have the deposited digital assets returned (typically, the ownership of the digital assets) be tradable.

[0016] However, if the right to have the deposited digital assets returned is tradable, it will be cumbersome for the person who has deposited the digital assets. That is, if the right to have the deposited digital assets returned is tradable, the person who has deposited the digital assets needs to manage the change in the return destination of the digital assets. Such management is cumbersome.

[0017] Accordingly, it is desirable to solve such problems. In one aspect of the present disclosure, such problems can be solved by generating a non-fungible token associated with a digital asset and identifying the owner of the non-fungible token as the return destination of the digital asset.

[0018] (1) The method according to the embodiment is a method executed by a computer system for depositing and returning a tradable first digital asset. The method according to the embodiment receives, by the computer system, the first digital asset transmitted from the user's account in order to deposit the first digital asset from the user, generates, by the computer system, a second non-fungible token associated with the first digital asset, wherein the owner is recorded in a blockchain, transmits, by the computer system, the generated second non-fungible token to the user's account, and when the computer system determines that the return condition of the first digital asset is satisfied, transmits, by the computer system, the first digital asset to the owner account of the second non-fungible token associated with the first digital asset in order to return the first digital asset.

[0019] (2) The blockchain is preferably configured to record the owner account of the second non-fungible token, and the computer system is preferably configured to identify the owner account of the second non-fungible token associated with the first digital asset by referring to the blockchain.

[0020] (3) The second non-fungible token generated by the computer system preferably has data related to the first digital asset.

[0021] (4) Preferably, the first digital asset is a first non-fungible token in which transactions are recorded on the blockchain.

[0022] (5) Receiving the first digital asset from the user preferably means that the computer system holds the first non-fungible token as collateral for repayment of the loan borrowed by the user.

[0023] (6) Preferably, the first digital asset is a first fungible token in which transactions are recorded on the blockchain.

[0024] (7) Receiving the first digital asset from the user preferably means that the computer system holds the first fungible token as a loan by the user.

[0025] (8) The method according to the embodiment may be a method executed by a computer system. The method according to the embodiment receives, by the computer system, a first non-fungible token transmitted from the account of the first user in order to hold collateral for repayment of a loan borrowed by the first user, and receives, by the computer system, the loan amount transmitted from the account of the second user in order to hold a loan by the second user, and generates, by the computer system, a second non-fungible token associated with the first non-fungible token, the second non-fungible token in which the owner is recorded in the blockchain, and a third non-fungible token associated with the loan amount, the third non-fungible token in which the owner is recorded in the blockchain, transmits, by the computer system, the generated second non-fungible token to the account of the first user as a deposit certificate for the first non-fungible token, transmits, by the computer system, the generated third non-fungible token to the account of the second user as a deposit certificate for the loan amount, transmits, by the computer system, the first non-fungible token to the owner account of the second non-fungible token associated with the first non-fungible token in order to return the first non-fungible token when the computer system determines that the return condition of the first non-fungible token is satisfied, and transmits, by the computer system, the loan amount to the owner account of the third non-fungible token associated with the loan amount in order to return the loan amount when the computer system determines that the return condition of the loan amount is satisfied. It may be provided with this.

[0026] (9) The computer system according to the embodiment may be configured to execute processing for depositing and returning a first digital asset that can be traded. The processing includes receiving, by the computer system, the first digital asset transmitted from the user's account in order to deposit the first digital asset from the user, generating, by the computer system, a second non-fungible token associated with the first digital asset, where the owner is recorded in the blockchain, and transmitting, by the computer system, the generated second non-fungible token to the user's account. When the computer system determines that the return condition of the first digital asset is satisfied, the processing may further include transmitting, by the computer system, the first digital asset to the owner account of the second non-fungible token associated with the first digital asset in order to return the first digital asset.

[0027] (10) The computer system according to the embodiment may be configured to execute processing. The processing may include receiving, by the computer system, a first non-fungible token transmitted from the account of a first user for the purpose of depositing collateral for repayment of a loan borrowed by the first user, and receiving, by the computer system, the loan amount transmitted from the account of a second user for the purpose of depositing the loan amount by the second user. The computer system may generate a second non-fungible token associated with the first non-fungible token, where the second non-fungible token is recorded with an owner in a blockchain, and a third non-fungible token associated with the loan amount, where the third non-fungible token is recorded with an owner in the blockchain. The computer system may transmit the generated second non-fungible token to the account of the first user as a deposit certificate for the first non-fungible token, and transmit the generated third non-fungible token to the account of the second user as a deposit certificate for the loan amount. When the computer system determines that the return condition of the first non-fungible token is satisfied, the computer system may transmit the first non-fungible token to the owner account of the second non-fungible token associated with the first non-fungible token for returning the first non-fungible token. When the computer system determines that the return condition of the loan amount is satisfied, the computer system may transmit the loan amount to the owner account of the third non-fungible token associated with the loan amount for returning the loan amount. It may be provided with the above.

[0028] (11) The method according to the embodiment may include a computer system generating a non-fungible token associated with a received digital asset, and the computer system identifying the owner of the non-fungible token associated with the digital asset as the destination of the digital asset. It is preferable that the computer system transmits the generated non-fungible token outside the computer system.

[0029] (12) The computer system according to the embodiment may be configured to execute a process. The process may include generating a non-fungible token associated with a received digital asset, transmitting the non-fungible token outside the computer system, and identifying the owner of the non-fungible token associated with the digital asset as the destination of the digital asset.

[0030] (13) The computer system according to the embodiment is configured to execute generation processing and transmission processing when receiving a digital asset from a source via a computer network. The generation processing includes generating a non-fungible token in which the owner is recorded in a blockchain and that is for transmission to the source. The transmission processing preferably includes transmitting the non-fungible token generated by the generation processing to the source. In this case, when the source transmits a digital asset to the computer system, it can receive and own the non-fungible token. Since the computer system executes the generation processing of the non-fungible token to be transmitted to the source after receiving the digital asset, it does not need to have non-fungible tokens in advance. That is, when the generation processing triggered by the reception of the digital asset is not provided, the computer system needs to have a large number of non-fungible tokens for transmission in advance. However, the computer system according to the embodiment generates a non-fungible token after receiving the digital asset, so it does not need to have a large number of non-fungible tokens for transmission in advance.

[0031] (14) The generation processing preferably includes obtaining data to be added to the non-fungible token, and the non-fungible token generated in the generation processing preferably has the obtained data.

[0032] (15) The data preferably includes an image to be added to the non-fungible token.

[0033] (16) The data preferably includes information about the non-fungible token as the digital asset.

[0034] (17) The data is preferably determined according to the received digital asset.

[0035] <2. Method and Computer System Executed by a Computer System for Depositing and Returning Digital Assets>

[0036] FIG. 1 shows the procedure of a method executed by a computer system for depositing and returning digital assets. The method executed by a computer system for depositing and returning digital assets is implemented in the computer system. In other words, the method is implemented in and executed by the computer system.

[0037] The computer system is configured to execute processing for depositing and returning digital assets. This processing is executed according to a program installed on one or more computers constituting the computer system. The number of computers constituting the computer system may be one or more. A plurality of computers are connected via a network and cooperate to execute processing for depositing and returning digital assets. A plurality of computers connected via a network may be referred to as a computer network.

[0038] FIG. 1 shows an example of the procedure of processing for managing borrowing and lending (borrowing / lending processing) as an example of processing for depositing and returning digital assets. The borrowing / lending processing shown in FIG. 1 is executed, for example, by a smart contract.

[0039] The smart contract 20 is implemented in the blockchain 10 shown in FIG. 2. The blockchain 10 is constituted by a P2P computer network. That is, the borrowing and lending process shown in FIG. 1 may be executed by a computer system constituting the blockchain. In addition, a computer program for causing the computer system to function as the smart contract 20 is installed in the computer system that executes the borrowing and lending process. In the embodiment, the computer system for executing the process for depositing and returning digital assets may include one or more computers in the computer network constituting the smart contract.

[0040] Note that the computer system that executes the borrowing and lending process may further include other computers. For example, the computer system may further include at least one or more computers selected from the group consisting of the management server 100, the issuer server 200, and the intermediary server 300 described later. The computer system may include the management server 100 and the intermediary server 300. The computer system may include all of the management server 100, the issuer server 200, and the intermediary server 300.

[0041] In the embodiment, the objects of borrowing and lending are digital assets that can be traded in the computer network to which the computer system of the embodiment is connected. Here, the computer network is, for example, the Internet. Here, the computer network may include, for example, the computer network constituting the blockchain 10. The computer network may include computers outside the blockchain 10.

[0042] The digital asset may be fiat currency or other money, but is preferably a cryptocurrency (virtual currency) that can be used in the blockchain 10. The cryptocurrency that can be used in the blockchain 10 is easy to operate by the smart contract 20. That is, the digital asset is preferably tradable in the blockchain 10, and in this case, the transaction of the digital asset is recorded in a referenceable manner in the blockchain 10. The digital asset may be referred to as a token.

[0043] The digital asset may be fungible or non-fungible. The fungible digital asset is also called a fungible token (fungible token; FT). The non-fungible digital asset is also called a non-fungible token (non-fungible token; NFT). Note that the non-fungible token may be issued in association with a physical asset. In this case, the entity of value exists not in the non-fungible token as a digital asset but in the physical asset. In the present disclosure, the non-fungible token associated with a valuable physical asset is also defined as a digital asset.

[0044] With borrowing and lending, in the smart contract 20 (specifically, a computer system functioning as a smart contract), operations for depositing and returning digital assets are executed. That is, in the embodiment, the object of deposit and return is a digital asset. In the embodiment, when the user A, who is the borrower, borrows, the smart contract 20 deposits the digital asset owned by the user A as collateral for the repayment of the borrowed amount. The digital asset deposited as collateral is, for example, a non-fungible token (NFT) that is tradable in the blockchain 10.

[0045] In the embodiment, when lending by user B who is the lender, the smart contract 20 holds, as the loan amount, the digital assets owned by user B. The digital assets held as the loan amount are, for example, fungible tokens (FTs) that can be traded on the blockchain 10, and preferably, cryptocurrency (virtual currency) that can be traded on the blockchain 10. In the embodiment, the loan amount deposited from user B becomes the borrowing by user B.

[0046] As described above, the digital assets (tokens) held by the smart contract 20 may be fungible tokens (FTs) or non-fungible tokens (NFTs). The digital assets held by the smart contract 20 are returned when the smart contract 29 determines that the return conditions of the digital assets are satisfied.

[0047] In the embodiment, the blockchain 10 is, as an example, Ethereum. The cryptocurrency (virtual currency) used in Ethereum is called Ether. Ether can be used for payments such as payment of consideration and can be exchanged with fiat currency, and thus has the nature of a currency. Since Ether has fungibility (fungible) similar to fiat currency, Ether is a type of fungible token.

[0048] In the embodiment, the money (digital assets) subject to borrowing and lending is preferably a fungible token such as Ether. That is, the borrowing and the loan amount are preferably fungible tokens. Fungible tokens can be used for payments such as payment of consideration and can be exchanged with fiat currency. In FIG. 1, user A who is the borrower can borrow the required fungible tokens, and user B who is the lender can lend the surplus fungible tokens.

[0049] The object of borrowing is called the borrowed amount, and the object of lending is called the lent amount. The fungible token that serves as the object of borrowing and lending (borrowed amount or lent amount) may be a stablecoin that can be used on the blockchain 10. A stablecoin is a cryptocurrency with a relatively stable price. The stablecoin may be a fiat-collateralized stablecoin or a cryptocurrency-collateralized stablecoin. An example of a fiat-collateralized stablecoin is PAX. An example of a cryptocurrency-collateralized stablecoin is DAI. Since stablecoins also have fungibility, they are fungible tokens.

[0050] As tokens that can be used on the blockchain 10 such as Ethereum (Ethereum tokens), in addition to fungible tokens, there are the aforementioned non-fungible tokens (non-fungible tokens; Non-Fungible Token: NFT). The token that serves as the object of borrowing and lending (borrowed item or lent item) may be a non-fungible token.

[0051] A non-fungible token (NFT) is a token that does not have fungibility, unlike a fungible token (FT). Since an NFT does not have fungibility, its value may be different from other non-fungible tokens. An NFT is issued, for example, as a digital asset traded in a computer game. An NFT may have a unique value that distinguishes it from other NFTs. For this reason, an NFT has a unique identifier for the purpose of enabling distinction from other NFTs. The identifier of an NFT is also called, for example, NFT-ID. Note that a fungible token such as Ether has the same value as other fungible tokens and does not require distinction, so it does not have an identifier such as NFT-ID.

[0052] An NFT also has an address. The address is, for example, an Ethereum address. An Ethereum address is composed of a plurality of alphanumeric characters starting with 0x. Since the address that an NFT has is unique to one NFT, it can also function as an identifier.

[0053] Similar to fungible tokens, NFTs can be traded on blockchain 10. The trading history of NFTs is recorded on blockchain 10. On blockchain 10, the owners and ownership history of NFTs are also recorded.

[0054] NFTs are tokens issued, for example, in accordance with the Ethereum Request for Comments (ERC) 721 standard. NFTs compliant with the ERC721 standard are called NFT-721 tokens. In this embodiment, as an example, NFTs will be described as being NFT-721 tokens.

[0055] In the embodiment, the NFT71 owned by user A who is the borrower is used as collateral for the repayment of the loan. The collateral NFT71 is, for example, a valuable game item. When borrower user A repays the loan, the collateral NFT71 (collateral NFT) is returned to user A.

[0056] NFT71 can be traded (ownership changed) and has its own value. Since the owner and trading history of NFT71 are recorded on blockchain 10, it is valid as collateral. Moreover, since NFT71 is managed on blockchain 10, there is no risk of it being a counterfeit or stolen item, and it is valid as collateral. By using valuable NFT71 as collateral, there is no need to review the borrower's credit.

[0057] In the embodiment, in addition to being used as collateral 71, NFTs are also used as certificates 72, 73 (certificate NFTs) to prove borrowing or lending. By using NFTs as collateral 71 and certificates 72, 73, borrowing and lending using blockchain 10 are smoothly implemented.

[0058] In an embodiment, the certificate NFTs 72, 73 are also receipts for digital assets (collateral NFTs 71, loan amounts 81) deposited in the smart contract 20. The certificate NFTs 72, 73 indicate the right to receive the deposited digital assets 71, 81 back. That is, the owner of the certificate NFTs 72, 73 is the right holder of the right to receive the deposited digital assets 71, 81 back. The owner of the certificate NFTs 72, 73 is recorded in a manner that can be referenced in the blockchain 10. Therefore, by referring to the blockchain 10, information about the owner of the certificate NFTs 72, 73 (for example, the owner account) can be obtained.

[0059] Since the owner of the certificate NFTs 72, 73 is recorded in a manner that can be referenced in the blockchain 10, it is easy to confirm the owner of the certificate NFTs 72, 73. Also, since the right holder of the right to receive the digital assets 71, 81 back is recorded in the blockchain 10, and moreover, the smart contract 20 and other computers constituting the computer system according to the embodiment do not need to remember or manage the right holder of the right to receive the digital assets 71, 81 back, which is advantageous.

[0060] The smart contract 20 determines whether the return conditions for the collateral NFT 71 (collateral digital asset) are satisfied, and when the return conditions are satisfied, returns the deposited collateral NFT 71 to the owner of the certificate NFT 72. That is, when the return conditions are satisfied, the smart contract 20 sends the collateral digital asset 71 to the owner of the certificate NFT 72. The return conditions will be described later.

[0061] Since the certificate NFT 72 can be traded (owner change) in the computer network, the owner of the certificate NFT 72 can change. That is, the subject of the right to receive the collateral NFT 71 back can change. The change of the owner is recorded in the blockchain 10. The collateral NFT 71 is sent to the owner of the certificate NFT 72 when the return conditions are satisfied.

[0062] As described above, when the borrower, User A, repays the loan before the repayment due date or when the return conditions of the collateral NFT71 are met, the collateral NFT71 is returned to User A. However, the return destination of the collateral NFT71 is not limited to User A and may also be the transferee of the certificate NFT72.

[0063] In addition, when the conditions to be transferred to the owner of the certificate NFT73 (the quality transfer conditions of the deposited digital asset 71) are met, the smart contract 20 sends the deposited digital asset 71 to the owner of the certificate NFT73. The quality transfer conditions will be described later.

[0064] Since the certificate NFT73 is tradable in the computer network, the owner of the certificate NFT73 can change. That is, the subject of the right to receive the repayment of the loan 81 can change. The change of the owner is recorded in the blockchain 10. The repayment amount for the loan 81 is sent to the owner of the certificate NFT73 when the return conditions are met.

[0065] As described above, when the repayment conditions of the loan 81 (the conditions for repaying the loan from the smart contract 20) are met, such as when the loan 81 is repaid by User A or others before the repayment due date, the loan 81 is returned to User B. However, the return destination of the loan 81 is not limited to User B and may also be the transferee of the certificate NFT73.

[0066] Note that the owners of the certificate NFT72 and 73 can buy and sell the certificate NFT72 and 73 in, for example, an NFT market using a computer network. That is, the right to receive the return of the collateral NFT71 or the loan 81 is tradable.

[0067] As shown in FIG. 2, a blockchain 10 such as Ethereum has addresses 30, 40, 50 that manage tokens (cryptographic assets) such as fungible tokens 81 and NFTs 71. These addresses 30, 40, 50 are called Ethereum addresses in Ethereum. The addresses 30, 40, 50 for managing cryptographic assets are also user accounts in the blockchain 10. Fungible tokens or NFTs owned by the user are associated with the addresses 30, 40, 50 (accounts) in the blockchain 10.

[0068] In the blockchain 10 shown in FIG. 2, the address 30 of user A, the address 40 of user B, and the address 50 of the administrator are shown. Transactions (transfers) of fungible tokens 81 or NFTs 71 are carried out between these addresses 30, 40, 50. An address is also referred to as an account. In the following description, user A is the borrower and has the address 30 (user A's account). User B is the lender and has the address 40 (user B's account). The administrator is the person (management company) who manages the mediation of borrowing and lending and has the address 50 (administrator's account).

[0069] The borrower, user A, has an NFT 71 (collateral NFT) that can be used as collateral. On the blockchain 10, the NFT 71 is associated with the address 30 of user A. The lender, user B, has fungible tokens 81 (loan amount) that can be lent. The fungible tokens 81 are associated with the address 40 of user B.

[0070] User A and User B can refer to tokens 71 and 81 associated with their respective addresses 30 and 40, for example, via wallet applications 130A and 140A for managing cryptocurrency assets. The wallet applications 130A and 140A are installed on terminals 130 and 140 owned by User A and User B, respectively. The terminals 130 and 140 are, for example, smartphones, tablets, or personal computers. The wallet applications 130A and 140A display the tokens 71 and 81 associated with their respective addresses 30 and 40 on the terminals 130 and 140. Also, User A and User B can use the wallet applications 130A and 140A to perform operations related to the tokens 71 and 81, such as transactions (e.g., sending tokens) of the tokens 71 and 81 associated with their respective addresses 30 and 40.

[0071] An operation related to the tokens 71 and 81 is, for example, an operation where User A sends the token 71 that User A owns to User B. When that operation is performed in the wallet application 130A, the token 71 is sent from the address 30 (User A's account) of User A on the blockchain 10 to the address 40 (User B's account) of User B on the blockchain 10.

[0072] Note that the administrator can also access the blockchain 10 via the management server 100 and perform reference and transactions of the tokens associated with the address 50. The management server 100 can communicate with the issuer server 200 of the collateral NFT 71 via a network. The management server 100 is composed of a computer including a processor and a memory connected to the processor. A computer program is stored in the memory. The computer program is executed by the processor to operate the computer as the management server 100.

[0073] The issuer server 200 is, for example, the server of the operator of an online game in which NFTs 71 as game items are issued. The issuer server 200 is composed of a computer including a processor and a memory connected to the processor. A computer program is stored in the memory. By being executed by the processor, the computer program operates the computer as the issuer server 200. Note that the issuer server 200 may be operated by the administrator of the management server 100, or may be operated by a person other than the administrator (for example, the operator of the online game).

[0074] The management server 100 can acquire information 71A (NFT information) regarding the collateral NFT 71 from the issuer server 200 via the network. The NFT information 71A is, for example, an image associated with the NFT 71. When the NFT 71 is a game item, the image is, for example, an image of the game item. The image associated with the NFT 71 may be an image of the NFT 71 itself. The NFT information 71A may be other information that the NFT 71 has, such as information indicating the characteristics of the game item, or other information associated with the NFT 71.

[0075] The NFT information 71A acquired by the management server 100 may be an identifier of the NFT. The NFT information acquired by the management server 100 may be at least one of the NFT-ID and the address of the NFT. The NFT information 71A acquired by the management server 100 may be both the NFT-ID and the address of the NFT.

[0076] The management server 100 may acquire the NFT information 71A from at least one selected from the group consisting of the smart contract 20, the issuer server 200, the intermediary server 300, and the user terminal 130. The management server 100 may acquire the NFT information 71A from multiple locations.

[0077] For example, when the guarantee NFT 71 is sent to the smart contract 20 in order for the management server 100 to deposit the guarantee NFT 71 into the smart contract 20, the management server 100 can obtain the NFT information 71A from the smart contract 20. When the mediation server 300 has the NFT information 71A, the management server 100 may obtain the NFT information 71A from the mediation server 300.

[0078] In the embodiment, processing for matching the borrower and the lender and matching the contract conditions is performed in the mediation server 300. The mediation server 300 is managed by, for example, the aforementioned administrator. The mediation server 300 is, for example, a server on the Internet, and a large number of users who can be borrowers or lenders can access it. The user can access the mediation server 300 via, for example, the wallet applications 130A and 140A installed on the terminals 130 and 140.

[0079] User A who wants to be a borrower accesses the mediation server 300 via the terminal 130 and registers a contract condition proposal for borrowing with the mediation server 300. The contract condition proposal can include, for example, the NFT 71 to be used as collateral, the amount of money to be borrowed, the interest, and the repayment date. Also, user B who wants to be a lender accesses the mediation server 300 via the terminal 140 and registers a contract condition proposal for lending with the mediation server 300. The contract condition proposal can include, for example, the loanable amount, the interest, and the repayment date. The NFT information 71A of the NFT 71 to be used as collateral may be registered in the mediation server 300.

[0080] The mediation server 300 has a function of displaying the NFT information 71A of the NFT 71 (guarantee NFT) possessed by user A who wants to be a borrower. The mediation server 300 obtains the NFT information 71A from the management server 100 via the network if necessary. The mediation server 300 causes the user terminal to display the NFT information 71A in order to enable other users to refer to the NFT information 71A.

[0081] The intermediary server 300 has, for example, a bulletin board function. The bulletin board is used for users to determine the contract terms with each other and can be referenced and written by users. The contract terms agreed upon between user A who becomes the borrower and user B who becomes the lender are registered in the intermediary server 300. The agreed contract terms can include, for example, data indicating the borrower, the lender, the borrowing amount, the interest, and the repayment date. The contract terms may include an identifier for uniquely identifying each contract.

[0082] The intermediary server 300 transmits the contract terms registered based on the agreement to the smart contract 20 on the blockchain 10. The smart contract 20 performs a process (see FIG. 1) of fulfilling the borrowing and lending between user A who becomes the borrower and user B who becomes the lender according to the received contract terms. Note that the registered contract terms are also transmitted to the management server 100.

[0083] Note that the management server 100 can acquire necessary information among the information possessed by the intermediary server 300 and the smart contract 20 via the network. Also, the intermediary server 300 can acquire necessary information among the information possessed by the management server 100 and the smart contract 20 via the network. Further, the smart contract 20 can acquire necessary information among the information possessed by the intermediary server 300 and the management server 100.

[0084] The smart contract 20 is implemented on the blockchain 10 so as to automatically execute a protocol according to the received contract terms. Note that the smart contract 20 according to the embodiment is implemented on the blockchain 10 by an administrator.

[0085] The smart contract 20 is configured by implementing a computer program 20A in a computer network (computer system) that constitutes the blockchain 10. The computer program 20A is executed in the computer network (computer system) that constitutes the blockchain 10. The computer program 20A has program code that defines the operation as a smart contract 20. When the computer program 20A is executed in the computer network (computer system) that constitutes the blockchain 10, the operation of the smart contract is performed. The smart contract 20 is stored at an address (contract address) in the blockchain 10.

[0086] Returning to FIG. 1, the mediation server 300 transmits the contract conditions agreed upon between user A who is the borrower and user B who is the lender to the smart contract 20 (step S41). The smart contract 20 receives the contract conditions transmitted from the mediation server 300 (step S21).

[0087] User A, who is the borrower, performs an operation of transmitting to the smart contract 20 in the wallet application 130A (terminal 130) to deposit the NFT 71 (collateral NFT; first digital asset; first non-fungible token) serving as collateral in accordance with the contract conditions (step S11). When this operation is performed, the collateral NFT 71 is transmitted from user A to the smart contract 20. The smart contract 20 receives the transmitted collateral NFT 71 (step S22). That is, as shown in FIG. 3, the collateral NFT 71 is transmitted from the address 30 (account) of user A to the smart contract 20. As a result, the smart contract 20 holds the NFT 71 as collateral from user A.

[0088] When the collateral NFT71 is sent to the smart contract 20, the certificate NFTs 72 and 73 are generated. The generation of the certificate NFTs 72 and 73 may be performed by the management server 100, may be performed by the smart contract 20, or may be performed by the cooperation of the management server 100 and the smart contract 20. Also, the generation timing of the certificate NFTs 72 and 73 is not particularly limited. The generation of the certificate NFTs 72 and 73 may be before the collateral NFT71 is sent to the smart contract 20, or may be after the collateral NFT71 is sent to the smart contract 20. The generation of the certificate NFTs 72 and 73 will be described later.

[0089] The certificate NFTs 72 and 73 are generated in association with the collateral NFT71. Therefore, each computer constituting the smart contract 20 and the computer system according to the embodiment can identify the certificate NFT72 associated with the collateral NFT71 and can identify the certificate NFT73 associated with the collateral NFT71. Also, each computer constituting the smart contract 20 and the computer system according to the embodiment can identify the collateral NFT71 associated with the certificate NFT72 and can identify the collateral NFT71 associated with the certificate NFT73.

[0090] Also, the certificate NFTs 72 and 73 are generated in association with each other. Therefore, each computer constituting the smart contract 20 and the computer system according to the embodiment can identify the certificate NFT73 associated with the certificate NFT72 and can identify the certificate NFT72 associated with the certificate NFT73.

[0091] The certificate NFT72 is generated in association with at least one of the borrowing and the lending. Therefore, each computer constituting the smart contract 20 and the computer system according to the embodiment can identify the certificate NFT72 associated with the borrowing or the lending and can identify the borrowing or the lending associated with the certificate NFT72.

[0092] The certificate NFT73 is generated in association with at least one of the borrowing and lending amounts. Therefore, each computer constituting the smart contract 20 and the computer system according to the embodiment can identify the certificate NFT73 associated with the borrowing or lending amount, and can also identify the borrowing or lending amount associated with the certificate NFT73.

[0093] The correspondence data indicating each of the above correspondences may be stored in the certificate NFTs 72 and 73, may be stored in the management server 100, or may be stored in the smart contract 20. The correspondence data may be stored in multiple locations. The correspondence data is referred to when returning the deposited digital assets (collateral NFT71, lending amount 81).

[0094] The lender, user B, performs an operation of sending the fungible token that becomes the lending amount 81 (principal) to user A to the smart contract 20 in accordance with the contract conditions in the wallet application 140A (terminal 140) (step S31). When this operation is performed, the lending amount 81 is sent from user B to the smart contract 20. The smart contract 20 receives the sent lending amount 81 (step S23). That is, as shown in FIG. 4, the lending amount 81 is sent from the address 40 (account) of user B to the smart contract 20. As a result, the smart contract 20 holds the lending amount 81 to user A deposited from user B.

[0095] Note that the reception of the lending amount from user B may be performed before the reception of the collateral NFT71 from user A.

[0096] When the smart contract 20 receives both the collateral NFT 71 and the loan amount 81, it sends the loan amount 81 to user A, who is the borrower, as a loan (principal) by user A (step S24). User A receives the sent loan amount 81A (step S12). That is, as shown in FIG. 5, the loan amount 81A is sent from the smart contract 20 to the address 30 of user A. Thereby, user A is in a state of having received the loan amount 81A.

[0097] However, in the embodiment, the loan amount 81A sent to user A is not the entire loan amount (principal), but a part of the loan amount. The other part of the loan amount is collected by the administrator as the first fee 81B. The smart contract 20 sends the first fee 81B to the administrator (step S25). The administrator receives the sent first fee 81B (step S42). That is, as shown in FIG. 5, the first fee 81B is sent from the smart contract 20 to the address 50 of the administrator. Thereby, the administrator obtains the first fee 81B. Note that the entire loan amount may be sent to user A.

[0098] When the smart contract 20 receives the collateral NFT 71, it sends an NFT 72 (deposit certificate NFT; borrowing certificate NFT; second non-fungible token) having the role of a deposit certificate of the collateral NFT 71 to user A (step S26). Note that the sending of the deposit certificate NFT 72 may be performed by the smart contract 20 simultaneously with or after the reception of the collateral NFT 71, and may also be performed before the sending of the loan amount to user A. User A receives the sent deposit certificate NFT 72 (step S13). That is, as shown in FIG. 6, the deposit certificate NFT 72 is sent from the smart contract 20 to the address 30 of user A. Thereby, user A is in a state of having received the deposit certificate NFT 72. In the embodiment, when user A receives the loan amount 81A and the deposit certificate NFT 72, the borrowing is completed.

[0099] User A can prove that they are the rightful owner (owner of the deposit certificate NFT72) who can have the collateral NFT71 returned by repaying the borrowed money with the deposit certificate NFT72. In other words, User A can prove that they are the rightful owner (owner of the deposit certificate NFT72) of the right to retrieve the collateral NFT71 by repaying the borrowed money with the deposit certificate NFT72. Similar to other NFTs, the deposit certificate NFT72 can be transferred (ownership change) to others on the blockchain 10. Therefore, by sending (changing ownership) the deposit certificate NFT72 to others, the right to retrieve the collateral NFT71 by repaying the borrowed money can be transferred to others.

[0100] When the smart contract 20 receives the loan amount 81, it sends an NFT73 (loan certificate NFT; the third non-fungible token) that serves as a loan certificate to User B (step S27). The loan certificate NFT73 is also a deposit certificate indicating that the smart contract 20 has received the loan amount. Note that the transmission of the loan certificate NFT73 may be performed simultaneously with the receipt of the loan amount 81 by the smart contract 20, after the receipt of the loan amount 81, or after the borrowed money is sent to User A. User B receives the sent loan certificate NFT73 (step S32). That is, as shown in FIG. 6, the loan certificate NFT73 is sent from the smart contract 20 to the address of User B. As a result, User B is in a state of having received the loan certificate NFT73. In the embodiment, the loan is completed when User B sends the loan amount 81 and receives the loan certificate NFT73.

[0101] User B can prove that they are the rightful owner (owner of the loan certificate NFT73) who can have the loan amount 81 returned by the loan certificate NFT73. In other words, User B can prove that they are the rightful owner of the right to receive repayment of the loan amount by the loan certificate NFT73.

[0102] In addition, User B can prove that they are the rightful owner of the right to obtain the collateral NFT71 if User A fails to repay the loan with the loan certificate NFT73. Similar to other NFTs, the loan certificate NFT73 can be transferred (ownership change) to others on the blockchain 10. Therefore, by sending (changing ownership) the loan certificate NFT73 to others, the right to receive repayment of the loan and the right to obtain the collateral NFT71 if the repayment is not made can be transferred to others.

[0103] Figure 7 shows the procedure for loan repayment processing. As also shown in Figure 8, User A, who is the borrower, performs a repayment operation in the wallet application 130A (terminal 130) (step S111). The repayment operation can be performed before the repayment due date. The repayment operation is received by the management server 100 (step S141). The management server 100 that has received the repayment operation sends the repayment amount to the terminal 130 of User A (step S142). The repayment amount is, for example, the sum of the loan (principal) and the interest up to the repayment date. The terminal 130 receives the repayment amount (step S112). Thereby, User A can grasp the repayment amount.

[0104] User A sends fungible tokens amounting to the repayment amount 91 to the smart contract 20 in order to receive the return of the collateral NFT71 (step S113). The smart contract 20 receives the sent repayment amount 91 (step S121). That is, as shown in Figure 8, the repayment amount 91 is sent from the address 30 of User A to the smart contract 20. Thereby, the smart contract 20 is in a state of holding the repayment amount 91.

[0105] In addition, when the fungible tokens amounting to the repayment amount 91 are sent to the smart contract 20, the deposit certificate NFT72 may also be sent from the address of User A to the smart contract 20.

[0106] When the smart contract 20 receives the repayment 91, it sends the deposited collateral NFT 71 (step S122). The smart contract 20 identifies the collateral NFT 71 corresponding to the repayment 91 and sends the identified collateral NFT 71. The smart contract 20 identifies the NFT 71 corresponding to the repayment 91 based on, for example, the deposit certificate NFT 72 sent together with the repayment 91. The collateral NFT 71 corresponding to the repayment 91 may be notified to the smart contract 20 by a user operation.

[0107] Also, prior to sending the collateral NFT 71, the smart contract 20 identifies the destination of the collateral NFT 71. The destination of the collateral NFT 71 is the owner account of the deposit certificate NFT 72. The smart contract 20 identifies the owner account of the deposit certificate NFT 72 by referring to the blockchain 10. Also, the smart contract 20 may identify the sender of the received deposit certificate NFT 72 as the owner account of the deposit certificate NFT 72.

[0108] If the owner of the deposit certificate NFT 72 is User A, the smart contract 20 sends the collateral NFT 71 to the account of User A. Thus, in the embodiment, the collateral NFT 71 is returned to the owner of the deposit certificate NFT 72 associated with the collateral NFT 71. Also, in the embodiment, the smart contract 20 returns the collateral NFT 71 to the sender of the deposit certificate NFT 72. In the embodiment, it is advantageous that the smart contract 20 does not need to save or manage the return destination of the collateral NFT 71.

[0109] User A receives the sent collateral NFT 71 (step S114). That is, as shown in FIG. 9, the collateral NFT 71 is sent from the smart contract 20 to the address 30 of User A. Thereby, User A is in a state of receiving the return of the collateral NFT 71.

[0110] In the embodiment, the smart contract 20 receiving the repayment amount 91 is the return condition of the collateral NFT 71. When the smart contract 20 receives the repayment amount 91, it determines that the return condition of the collateral NFT 71 is satisfied and returns the collateral NFT 71. Note that the return condition of the collateral NFT 71 may be that the smart contract 20 receives the certificate NFT 72. Also, the return condition of the collateral NFT 71 may be that the smart contract 20 receives the repayment amount 91 and the certificate NFT 72.

[0111] The smart contract 20 invalidates (BANs) the certificate NFT 72 simultaneously with or after transmitting the collateral NFT 71 (step S123). The invalidation is to make the NFT 72 non-tradable on the blockchain 10. Making the NFT 72 non-tradable on the blockchain 10 may be to make the NFT 72 disappear on the blockchain 10. Making the NFT 72 non-tradable on the blockchain 10 may be that the smart contract 20 continues to hold the NFT 72. If the smart contract 20 does not hold the NFT 72 to be invalidated, the NFT 72 may be forcibly transmitted to the smart contract 20.

[0112] Also, making the NFT 72 non-tradable on the blockchain 10 may be that the smart contract 20 transmits the NFT 72 to an address (account) that no user can trade.

[0113] When the smart contract 20 receives the repayment amount 91 for the loan amount 81 from the borrower, user A, it identifies the transmission destination of the repayment amount 91 and transmits the repayment amount 91A to the identified transmission destination (for example, borrower B) (step S124). The smart contract 20 identifies the owner account of the loan certificate NFT 73 corresponding to the repayment amount 91 (loan amount 81) as the transmission destination of the repayment amount 91A. The smart contract 20 can identify, for example, the loan certificate NFT 73 corresponding to the repayment amount 91 (loan amount 81) and identify the owner of the loan certificate NFT 73 as the transmission destination of the repayment amount 91. The owner of the loan certificate NFT 73 can be identified by referring to the blockchain 10. The smart contract 20 may identify the loan certificate NFT 73 associated with the deposit certificate NFT 72 transmitted to the smart contract 20 together with the repayment amount 91 and identify the owner of the loan certificate NFT 73 as the transmission destination of the repayment amount 91. The smart contract 20 may identify the loan certificate NFT 73 associated with the transmitted collateral NFT 71 and identify the owner of the loan certificate NFT 73 as the transmission destination of the repayment amount 91. The loan certificate NFT 73 corresponding to the repayment amount 91 (loan amount 81) may be notified to the smart contract 20 by a user operation.

[0114] If the owner of the loan certificate NFT 73 is user B, the smart contract 20 transmits the repayment amount 91A (the amount of money corresponding to the loan amount 81) to the account of user B. In this way, in the embodiment, the loan amount 81 by user B is returned to the owner of the loan certificate NFT 73 associated with the loan amount 81. Also, in the embodiment, the smart contract 20 returns the loan amount 81 to the owner of the loan certificate NFT 73 corresponding to the deposit certificate NFT 72 or the owner of the loan certificate NFT 73 corresponding to the collateral NFT 71. In the embodiment, it is advantageous that the smart contract 20 does not need to store or manage the repayment destination of the loan amount 81.

[0115] User B receives the repaid amount 91A that has been sent (step S131). That is, as shown in FIG. 10, the repaid amount 91A is sent from the smart contract 20 to the address 40 of User B. As a result, User B is in a state of having received the repayment of the loan. That is, User B is in a state of having received the repayment of the loan amount 81.

[0116] However, in the embodiment, the repaid amount 91A sent to User B is not the entire repaid amount but a part of the repaid amount. The other part of the repaid amount is collected by the administrator as the second fee 91B. The smart contract 20 sends the second fee 91B to the administrator (step S125). The administrator receives the sent second fee 91B (step S143). That is, as shown in FIG. 10, the second fee 91B is sent from the smart contract 20 to the address 50 of the administrator. As a result, the administrator obtains the second fee. Note that the entire repaid amount may be sent to User B.

[0117] In order for User B, who is the owner of the loan certificate NFT73, to receive the repaid amount 91A, it may be a condition that the loan certificate NFT73 is sent from User B's account to the smart contract 20. That is, the loan certificate NFT73 may be sent from User B's account to the smart contract 20 simultaneously with or before the smart contract 20 sends the repaid amount 91A.

[0118] In the embodiment, the smart contract 20 receiving the repaid amount 91 is a condition for the repayment of the loan amount 81. When the smart contract 20 receives the repaid amount 91, it determines that the repayment condition of the loan amount 81 is satisfied and repays the loan amount 81. Note that the repayment condition of the loan amount 81 may be that the smart contract 20 receives the certificate NFT73. Also, the repayment condition of the loan amount 81 may be that the smart contract 20 receives the repaid amount 91 and the certificate NFT73.

[0119] Smart contract 20 invalidates (BANs) the loan certificate NFT 73 simultaneously with or after the transmission of the repayment amount 91A (step S126). The invalidation method is the same as that of NFT 72.

[0120] Thus, the repayment process is completed.

[0121] In the embodiment, the person who repays the borrowed money is not limited to the borrower, user A, but may be the owner (first owner) of the deposit certificate NFT 72. That is, the owner of the deposit certificate NFT 72 has the obligation to repay the borrowed money. When the deposit certificate NFT 72 is transferred (owner change) from the borrower to another person free of charge or for a fee, the other person who is the transferee of the deposit certificate NFT 72 becomes the new owner (first owner) of the deposit certificate NFT 72. In the embodiment, the smart contract 20 may be configured to accept repayment only from the owner of the deposit certificate NFT 72.

[0122] As shown in FIG. 11, the borrower, user A, can form an agreement to sell (transfer) the deposit certificate NFT 72 to user C in the NFT market 400. The NFT market 400 is, for example, a website for NFT transactions. In this case, the deposit certificate NFT 72 is transmitted from the address 30 (account) of user A to the address 31 (account) of user C. Thereby, user C becomes the new owner (first owner) of the deposit certificate NFT 72.

[0123] User C can obtain the collateral NFT 71 by repaying the borrowed money as the owner of the deposit certificate NFT 72 on behalf of user A according to the repayment process procedure shown in FIG. 7. Note that the repayment of the borrowed money is also possible for the person who has received the deposit certificate NFT 72 from user C.

[0124] In an embodiment, the person who receives the repayment of the loan is not limited to the lender, user B, but may be the owner (second owner) of the loan certificate NFT73. That is, the owner of the loan certificate NFT73 has the right to receive the repayment of the loan and the right to acquire the collateral NFT71 when the repayment is not made. When the loan certificate NFT73 is transferred (ownership change) from the lender to another person, either gratuitously or for consideration, the transferee of the loan certificate NFT73 becomes the new owner (second owner) of the loan certificate NFT73.

[0125] As shown in FIG. 12, the lender, user B, can form an agreement to sell (transfer) the loan certificate NFT73 to user D in the NFT market 400. The NFT market 400 is, for example, a website for NFT transactions. In this case, the loan certificate NFT73 is transmitted from the address 40 (account) of user B to the address 41 (account) of user D. Thereby, user D becomes the new owner (second owner) of the loan certificate NFT73.

[0126] User D can receive the repayment amount as the owner of the loan certificate NFT73 on behalf of user B according to the repayment processing procedure shown in FIG. 7. Also, when the repayment is not made, user D can receive the collateral NFT71 as described later. Note that the receipt of the repayment amount and the receipt of the collateral NFT71 are also possible for the person who has received the loan certificate NFT73 from user D.

[0127] FIG. 13 shows the non-repayment processing (processing during the collateral flow). The non-repayment processing is executed when the repayment is not made by the repayment due date. In the non-repayment processing, the collateral NFT71 held by the smart contract 20 is transmitted to the lender, user B (the second owner of the loan certificate NFT73).

[0128] First, when the management server 100 detects that the repayment due date in the contract terms has passed, that is, the non - fulfillment of repayment, it sends a notice that the repayment due date has passed to user B (the second owner of the loan certificate NFT73), who is the lender (step S241). Note that the management server 100 can grasp the current second owner of the loan certificate NFT73 by performing a process of referring to the owner of the loan certificate NFT73 in the blockchain 10.

[0129] User B, who has received the notice that the repayment due date has passed, can grasp that the collateral NFT71 has become available for acquisition. In order to exercise the right to acquire the collateral NFT71, the fungible token, which is the third - party fee, is sent to the smart contract 20 (step S231). The third - party fee is the fee that should be paid to the administrator for acquiring the collateral NFT71.

[0130] When the smart contract 20 receives the third - party fee (step S221), it sends the collateral NFT71 to user B. That is, the collateral NFT71 is sent from the smart contract to the address of user B.

[0131] User B receives the collateral NFT71 sent from the smart contract 20 (step S232). As a result, instead of receiving repayment, user B can acquire the collateral NFT71.

[0132] Also, when the third - party fee is sent to the smart contract 20, the certificate NFT73 may also be sent to the smart contract 20.

[0133] In the embodiment, when the repayment due date in the contract conditions has passed and the third commission has been received, the smart contract 20 determines that the third commission has been received after the repayment due date and the quality flow condition is satisfied, and sends the collateral NFT 71 to the address of user B. Note that the quality flow condition may be that the repayment due date in the contract conditions has passed. Also, the quality flow condition may be that the third commission has been received. Also, the quality flow condition may be that the certificate NFT 73 has been received. The quality flow condition may be that the third commission and the certificate NFT 73 have been received. Also, the quality flow condition may be that the owner of the certificate NFT 72 has waived the collateral NFT 71. The quality flow condition may be that the owner of the certificate NFT 72 has waived the collateral NFT 71 and the third commission and the certificate NFT 73 have been received.

[0134] When the smart contract 20 receives the third commission (step S221), it sends the third commission to the administrator (step S223). The administrator receives the third commission (step S242).

[0135] The smart contract 20 invalidates (BANs) the deposit certificate NFT 72 and the loan certificate NFT 73 simultaneously with or after the transmission of the collateral NFT 71 (step S224). The method of invalidation is as described above.

[0136] Thus, the non-repayment processing is completed.

[0137] FIG. 14 shows how the deposit certificate NFT 72 and the loan certificate NFT 73 are generated (NFT generation process). In the NFT generation process, the deposit certificate NFT 72 and the loan certificate NFT 73 may be generated simultaneously or at different timings. The NFT generation process is executed, for example, triggered by receiving a digital asset such as the collateral NFT 71. For example, when the smart contract 70 receives a digital asset such as the collateral NFT 71, the NFT generation process is executed triggered by that reception.

[0138] In an embodiment, the deposit certificate NFT72 (second non-fungible token) and the loan certificate NFT73 (third non-fungible token) are issued by the management server 100 as an example. In this way, the management server 100 is used for the generation process of NFTs. Also, the management server 100 according to the embodiment is used in the method of depositing and returning digital assets. Further, the management server 100 according to the embodiment is used in the method of managing borrowing and lending. The management server 100 includes a processor that operates to issue the second non-fungible token 72 and the third non-fungible token 73 from the data 71A related to the first non-fungible token 71 and transmit the second non-fungible token 72 and the third non-fungible token 73 to the smart contract 20. That is, the management server 100 issues the certificate NFTs 72, 73 associated with the collateral NFT71. Also, the management server 100 issues the certificate NFTs 72, 73 associated with at least one of the borrowed amount and the loan amount. The issued NFTs 72, 73 are transmitted by the transmission process of the smart contract 20.

[0139] The management server 100 determines the information (data) added to the generated NFTs 72, 73 according to the collateral NFT or the loan amount as the digital asset. For example, the management server 100 uses the NFT information 71A (data related to the first non-fungible token) to issue the deposit certificate NFT72 and the loan certificate NFT73. The NFT information 71A includes, for example, an image of the collateral NFT71. In order to add the image of the collateral NFT71 to the NFTs 72, 73, the image of the collateral NFT71 is acquired in the NFT generation process. The image is acquired from, for example, the aforementioned issuer server 200. An image stored inside the management server 100 may be acquired. Note that the NFT information may include an identifier of the NFT.

[0140] In an embodiment, the management server 100 issues a deposit certificate NFT 72 and a loan certificate NFT 73 using the contract condition data 71B as well. The management server 100 obtains the contract condition data 71B from, for example, the mediation server 300. The contract condition data 71B includes, for example, the NFT_ID (identifier of the NFT) of the collateral NFT 71, the borrowing date (loan date), the repayment due date, the interest, the borrowing amount (loan amount), and the total repayment amount.

[0141] When the management server 100 obtains the contract condition data 71B from the mediation server 300, it combines the NFT information 71A of the collateral NFT 71 and the contract condition data 71B to generate a deposit certificate NFT 72 associated with the collateral NFT 71. The generated deposit certificate NFT 72 has information regarding the collateral NFT 71 and the contract conditions. That is, the deposit certificate NFT 72 has data regarding the digital asset collateral NFT 71. Therefore, a third party referring to the deposit certificate NFT 72 can grasp the information regarding the collateral NFT 71 and the contract conditions. As a result, smooth trading of the deposit certificate NFT 72 becomes possible.

[0142] Also, when the management server 100 obtains the contract condition data 71B from the mediation server 300, it combines the NFT information 71A of the collateral NFT 71 and the contract condition data 71B to generate a loan certificate NFT 73 associated with the collateral NFT 71 or the loan amount. That is, the loan certificate NFT 73 has data regarding the collateral NFT 71 as a digital asset. Also, the loan certificate NFT 73 has data regarding the loan amount as a digital asset.

[0143] The generated loan certificate NFT 73 indicates information regarding the collateral NFT 71 and the contract conditions (including data regarding the loan amount). Therefore, a third party referring to the loan certificate NFT 73 can grasp the information regarding the collateral NFT 71 and the contract conditions. As a result, smooth trading of the loan certificate NFT 73 becomes possible.

[0144] The management server 100 transmits the generated deposit certificate NFT 72 and loan certificate NFT 73 to the smart contract 20. The smart contract 20 transmits the received deposit certificate NFT 72 to the borrower (the sender of the collateral NFT 71) (step S26 in FIG. 1). The smart contract 20 transmits the received loan certificate NFT 73 to the lender (the sender of the loan amount) (step S27 in FIG. 1).

[0145] Note that the certificate NFTs 72 and 73 may be generated by the smart contract 20 or other computers constituting the computer system according to the embodiment. The generation process of the NFTs 72 and 73 may be generated by a smart contract for generating NFTs different from the smart contract 20.

[0146] The present invention is not limited to the above embodiment, and various modifications are possible.

[0147] <3. Supplementary Note>

[0148] The above embodiment also discloses "a method for managing borrowing and lending, a method for managing borrowing, a method for managing lending, and a smart contract". The outline is as follows.

[0149] <3.1. Outline of a method for managing borrowing and lending, a method for managing borrowing, a method for managing lending, and a smart contract>

[0150] The inventors of the present invention obtained the idea of managing borrowing and lending by a smart contract. Since the execution history of the smart contract is recorded on the blockchain, using the smart contract can ensure the transparency of the contract.

[0151] Therefore, it is desired to provide a technical means for managing borrowing or lending by a smart contract.

[0152] (1) The method according to the embodiment is a method for managing borrowing and lending by a smart contract operating on a blockchain. The method may include the smart contract receiving a first non-fungible token owned by the borrower of the borrowed money as collateral for repayment of the borrowed money. Thereby, the smart contract holds the first non-fungible token as collateral.

[0153] The method may include the smart contract sending a second non-fungible token as a deposit certificate of the first non-fungible token to the borrower. Thereby, instead of depositing the collateral with the smart contract, the borrower obtains a second non-fungible token as a deposit certificate.

[0154] The method may include the smart contract sending a third non-fungible token as a deposit certificate of the loan amount to the lender of the loan amount that has become the borrowed money. Thereby, the lender obtains a third non-fungible token as a deposit certificate of the loan amount.

[0155] According to the method according to the embodiment, management of borrowing and lending using the first non-fungible token, the second non-fungible token, and the third non-fungible token is realized.

[0156] (2) The method may include the smart contract receiving the loan amount from the lender. Thereby, the smart contract holds the loan amount.

[0157] The method may include the smart contract sending the loan amount to the borrower as the borrowed money. Thereby, instead of depositing the collateral with the smart contract, the borrower obtains the borrowed money.

[0158] (3) The method may further include the smart contract sending a portion of the borrowed funds to an administrator, who is a third party other than the borrower and the lender, as a first fee. Thereby, the administrator obtains a fee.

[0159] (4) The method may further include that when the smart contract receives the repayment for the borrowed funds from the first owner of the second non-fungible token, the smart contract sends the first non-fungible token to the first owner and invalidates the second non-fungible token. When the borrowed funds are repaid, the first non-fungible token as collateral is returned, and the second non-fungible token as a certificate of deposit of the collateral becomes invalid.

[0160] (5) The first owner is preferably the borrower or the transferee of the second non-fungible token. The borrower or the transferee can repay the borrowed funds.

[0161] (6) The method may further include that when the smart contract receives the repayment for the borrowed funds from the first owner of the second non-fungible token, the smart contract sends the repayment to the second owner of the third non-fungible token and invalidates the third non-fungible token. When the repayment is made, the third non-fungible token as a certificate of deposit of the loan becomes invalid. When a non-fungible token becomes invalid, subsequent transactions (owner changes) in the blockchain become impossible.

[0162] (7) The second owner is preferably the lender or the transferee of the third non-fungible token. The lender or the transferee can receive the repayment.

[0163] (8) The method may further include the smart contract sending a portion of the repayment to an administrator, who is a third party other than the borrower and the lender, as a second fee. Thereby, the administrator obtains a fee.

[0164] (9) If the repayment of the loan is in default, the smart contract may further include the smart contract sending the first non-fungible token to the second owner of the third non-fungible token. The default of repayment may be, for example, the expiration of the repayment date. The default of repayment includes a declaration by the owner of the second non-fungible token not to make the repayment.

[0165] (10) If the repayment of the loan is in default and the smart contract receives a third fee from the second owner of the third non-fungible token, the smart contract may send the first non-fungible token to the second owner of the third non-fungible token and send part or all of the third fee to an administrator who is a third party other than the borrower and the lender. Thereby, the administrator obtains a fee.

[0166] (11) If the repayment of the loan is in default, the smart contract may send the first non-fungible token to the second owner of the third non-fungible token and invalidate the third non-fungible token. Thereby, the second owner obtains the first non-fungible token as collateral, and the third non-fungible token as a deposit certificate for the loan becomes invalid.

[0167] (12) If the repayment of the loan is in default, the smart contract may further include invalidating the second non-fungible token. Thereby, the second non-fungible token as a deposit certificate for collateral becomes invalid.

[0168] (13) The method can further include: a server that can access the smart contract issues the second non-fungible token and the third non-fungible token from data regarding the first non-fungible token, and the server transmits the second non-fungible token and the third non-fungible token to the smart contract. In this case, the server can issue the second non-fungible token and the third non-fungible token.

[0169] (14) Preferably, the borrowing and lending amounts are fungible tokens. In this case, it is easy to handle borrowing and lending amounts in the blockchain.

[0170] Note that in this specification and the claims, the order of description of each step constituting the method does not limit the order in which each step is executed. That is, the method includes those with an execution order different from the order of description of each step constituting the method.

[0171] (15) The method according to the embodiment is a method for managing borrowing by a smart contract operating on a blockchain, the method including: the smart contract receiving a first non-fungible token owned by a borrower of the borrowing amount as collateral for repayment of the borrowing amount, and the smart contract transmitting a second non-fungible token as a deposit certificate of the first non-fungible token to the borrower.

[0172] (16) The method according to the embodiment is a method for managing lending by a smart contract operating on a blockchain, the method including: the smart contract receiving a lending amount from a lender, and the smart contract transmitting a non-fungible token as a deposit certificate of the lending amount to the lender.

[0173] (17) The smart contract according to the embodiment is a smart contract implemented on a blockchain composed of a computer network, which receives a first non-fungible token owned by the borrower of the loan as collateral for the repayment of the loan, and transmits a second non-fungible token as a deposit certificate of the first non-fungible token to the borrower. It is preferably configured to execute an operation including the above.

[0174] (18) The smart contract according to the embodiment is a smart contract implemented on a blockchain composed of a computer network, which receives a loan from a lender and transmits a non-fungible token as a deposit certificate of the loan to the lender. It is preferably configured to execute an operation including the above.

Explanation of Signs

[0175] 10: Blockchain 20: Smart Contract 20A: Computer Program 30: Address of User A 31: Address of User C 40: Address of User B 41: Address of User D 50: Address of Administrator 71: First Non-fungible Token (Collateral NFT) 71A: NFT Information 71B: Contract Condition Data 72: Second Non-fungible Token (Deposit Certificate NFT of Collateral NFT) 73: Third Non-fungible Token (Loan Certificate NFT; Deposit Certificate NFT of Loan) 81: Loan 81A: Borrowed Money 81B: First Fee 91: Repayment 91A: Repayment 91B: Second Fee 100: Management Server 130: Terminal 130A: Wallet application 140: Terminal 140A: Wallet application 200: Issuer server 300: Intermediary server 400: NFT market A: User B: User C: User D: User

Claims

1. 1. A computer system implemented method for depositing and returning a first tradeable digital asset, comprising: receiving, by the computer system, the first digital asset transmitted from the user's account to deposit the first digital asset from the user; generating, by the computer system, a second non-fungible token associated with the first digital asset, the second non-fungible token having an owner recorded in a blockchain; transmitting, by the computer system, the second generated non-fungible token to the account of the user; When the computer system determines that a return condition for the first digital asset has been satisfied, transmitting the first digital asset by the computer system to an owner account of the second non-fungible token associated with the first digital asset for return of the first digital asset. Be prepared to method.

2. the blockchain is configured to record the owner account of the second non-fungible token; The computer system is configured to identify the owner account of the second non-fungible token associated with the first digital asset by referencing the blockchain. The method of claim 1.

3. The second non-fungible token generated by the computer system has data related to the first digital asset. The method according to claim 1 or claim 2.

4. The first digital asset is a first non-fungible token whose transaction is recorded on the blockchain. The method according to any one of claims 1 to 3.

5. Holding the first digital asset from the user means that the computer system holds the first non-fungible token as collateral for repayment of a loan borrowed by the user. The method according to claim 4.

6. The first digital asset is a first fungible token whose transaction is recorded on the blockchain. The method according to any one of claims 1 to 3.

7. Holding the first digital asset from the user means that the computer system holds the first fungible token as a loan from the user. The method according to claim 6.

8. 1. A method implemented by a computer system, comprising: receiving, by the computer system, a first non-fungible token transmitted from an account of a first user as security for repayment of a loan borrowed by the first user; receiving, by the computer system, a loan transmitted from an account of a second user to deposit the loan by the second user; generating, by the computer system, a second non-fungible token associated with the first non-fungible token, the second non-fungible token having an owner recorded in a blockchain, and a third non-fungible token associated with the loan, the third non-fungible token having an owner recorded in the blockchain; transmitting the generated second non-fungible token to the account of the first user by the computer system as a receipt for the first non-fungible token; transmitting the generated third non-fungible token by the computer system to the second user's account as a receipt for the loan; transmitting, by the computer system, the first non-fungible token to an owner account of the second non-fungible token associated with the first non-fungible token for returning the first non-fungible token when the computer system determines that a return condition for the first non-fungible token has been satisfied; when the computer system determines that a condition for returning the loan has been satisfied, transmitting the loan by the computer system to an owner account of the third non-fungible token associated with the loan for returning the loan; Be prepared to method.

9. 1. A computer system configured to execute a process for depositing and returning a first tradeable digital asset, comprising: The process comprises: receiving, by the computer system, the first digital asset transmitted from the user's account to deposit the first digital asset from the user; generating, by the computer system, a second non-fungible token associated with the first digital asset, the second non-fungible token having an owner recorded in a blockchain; transmitting, by the computer system, the second generated non-fungible token to the account of the user; When the computer system determines that a return condition for the first digital asset has been satisfied, transmitting the first digital asset by the computer system to an owner account of the second non-fungible token associated with the first digital asset for return of the first digital asset. Be prepared to Computer system.

10. A computer system configured to perform a process comprising: The process comprises: receiving, by the computer system, a first non-fungible token transmitted from an account of a first user as security for repayment of a loan borrowed by the first user; receiving, by the computer system, a loan transmitted from an account of a second user to deposit the loan by the second user; generating, by the computer system, a second non-fungible token associated with the first non-fungible token, the second non-fungible token having an owner recorded in a blockchain, and a third non-fungible token associated with the loan, the third non-fungible token having an owner recorded in the blockchain; transmitting the generated second non-fungible token to the account of the first user by the computer system as a receipt for the first non-fungible token; transmitting the generated third non-fungible token by the computer system to the second user's account as a receipt for the loan; transmitting, by the computer system, the first non-fungible token to an owner account of the second non-fungible token associated with the first non-fungible token for returning the first non-fungible token when the computer system determines that a return condition for the first non-fungible token has been satisfied; when the computer system determines that a condition for returning the loan has been satisfied, transmitting the loan by the computer system to an owner account of the third non-fungible token associated with the loan for returning the loan; Be prepared to Computer system.

11. A computer system generates a non-fungible token corresponding to the received digital asset; The computer system identifies the owner of the non-fungible token as a destination of the digital asset. How to prepare for this.

12. A computer system configured to perform a process comprising: The process comprises: Generate a non-fungible token that corresponds to the received digital asset; Identifying the owner of the non-fungible token as a destination of the digital asset. Be prepared to Computer system.

13. configured to perform a generating process and a transmitting process upon receiving the digital asset from a source over a computer network; The generating process includes generating a non-fungible token for transmission to the source, the non-fungible token having an owner recorded in a blockchain; The transmission process includes transmitting the non-fungible token generated by the generation process to the transmission source. Computer system.

14. The generating process includes obtaining data to be added to the non-fungible token; The non-fungible token generated in the generation process has the acquired data.

14. The computer system of claim 13.

15. The data includes an image to be attached to the non-fungible token.

15. The computer system of claim 14.

16. The data includes data regarding non-fungible tokens as the digital assets. A computer system according to claim 14 or claim 15.

17. The data is determined in response to the received digital asset. A computer system according to any one of claims 14 to 16.

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