Information processing method, information processing system, and computer program

Abstract

The present invention provides an information processing method, an information processing system, and a non-custodial wallet that enable retail settlement using the non-custodial wallet.　This information processing method includes identifying, through an identity verification procedure during the setting of customer identification information of a user and on the basis of associated information in which the address of a non-custodial wallet is associated with the customer identification information of the user, that the non-custodial wallet owned by the user has undergone an identity verification procedure and performing retail settlement using the non-custodial wallet that has undergone the identity verification procedure.

Description

Information processing methods, information processing systems, and computer programs

[0001] This invention relates to an information processing method, an information processing system, and a computer program.

[0002] There are two types of wallets for managing crypto assets: non-custodial wallets (also called self-managed wallets, self-custodial wallets, unmanaged wallets, or non-custodial wallets) and custodial wallets. A custodial wallet is a wallet used by a custodian, and the custodian manages the private key of the custodial wallet. When sending funds from a custodial wallet to another custodial wallet or a non-custodial wallet, the user must first pass authentication set by the custodian before they can perform any operations on their own custodial wallet. In other words, using a custodial wallet requires several operations, and it takes time before the custodial wallet becomes usable. The main reason why custodial wallets cannot be used for retail payments is the long time it takes to become usable. On the other hand, non-custodial wallets are characterized by the fact that the owner is solely responsible for managing the wallet's private key, but the time it takes to become usable is several times faster compared to custodial wallets. While banks and QR code payment companies offer mobile wallets using smartphones, these wallets are not capable of managing crypto assets exchanged on the blockchain.

[0003] Furthermore, existing cashless payment systems used for retail transactions (credit cards, QR codes (registered trademarks), transportation IC cards, prepaid methods, etc.) are plagued by hacking attacks due to the involvement of intermediaries, posing a significant social problem. Generally, payment processing to merchants is slow (for example, payments may only occur once a month), placing a heavy burden on small and medium-sized enterprises. While some intermediaries may allow payments several times a month, they typically charge additional transfer fees. In addition, the presence of intermediaries such as credit card companies results in high merchant fees.

[0004] Patent Document 1 discloses a payment system that photographs the face of a payer with a camera when performing cashless payment, recognizes the facial expression of the face image, and grants a predetermined benefit to the payer based on the recognition result.

[0005] Japanese Unexamined Patent Application Publication No. 2023-170890

[0006] Recommendations from international organizations (FATF: Financial Action Task Force) stipulate that measures such as AML (Anti-Money Laundering) and CFT (Counter Financing of Terrorism) are essential. In Japan, the revised Fund Payment Act, which came into effect in June 2023, has enabled some financial institutions, such as banks, to issue stablecoins (crypto assets pegged to the value of fiat currency), but it is expected that these will primarily be offered through a custodian model. This is because the custodian model allows for the requirement and implementation of strict KYC (Know Your Customer) verification. In the EU, MiCA will also come into effect at the end of 2024, creating a fertile ground for the issuance and circulation of stablecoins. On the other hand, for those who wish to use non-custodial wallets, mandatory KYC registration is often perceived as a violation of privacy, and this is particularly pronounced in EU countries where the GDPR (General Data Protection Regulation) is widely implemented. Furthermore, while the GDPR grants the right to delete registered data, KYC procedures require data retention due to legal requirements, creating a contradiction that is problematic. Additionally, given that the fundamental principles of cryptocurrencies are based on decentralization and anonymity, requiring KYC when using non-custodial wallets is currently difficult. To use a bank ATM as an example, the system of authenticating with a cash card and PIN and then transferring money from the ATM to someone's account is similar to the system of authenticating with a custodian and then transferring cryptocurrency to someone's custodial or non-custodial wallet. However, many non-custodial wallet users feel that requiring KYC registration for non-custodial wallets is equivalent to having their money tracked and managed after withdrawing cash from a bank ATM and putting it in their wallet, including who they gave the money to and how they used it. While non-custodial wallets are certainly suitable for retail payments due to processing time constraints, using them would likely require KYC (Know Your Customer) verification from a FATF (Fact-Assisted Financial Transactions) perspective.

[0007] This invention has been made in view of the above circumstances, and aims to provide an information processing method, an information processing system, and a computer program that enable the use of non-custodial wallets for retail payments.

[0008] The present invention includes multiple means for solving the above problem, but to give one example, the information processing method is an information processing method by a computer that functions as a non-custodial wallet on a user's terminal device, and includes the steps of: providing the address of the non-custodial wallet to a person who performed an identity verification procedure before the start of use of the non-custodial wallet; receiving via a communication network one or more signed authentication pieces of information in which one or more persons who performed the identity verification procedure have applied a first digital signature with a private key managed by the person who performed the identity verification procedure to information that includes at least information indicating the completion of the user's identity verification procedure; and locally generating one or more user authentication data on the user's terminal device, which includes at least a part of the information contained in at least one of the one or more signed authentication pieces of information and further includes one or more pieces of information about the user, and applying a second digital signature with a private key locally managed by the non-custodial wallet to each of the user authentication data pieces. The process includes the steps of generating one or more user authentication information by attaching an electronic signature to the user's signature, storing at least one of the one or more signed authentication information and / or at least one of the one or more user authentication information in a local storage area managed by the user, and transmitting at least one of the one or more signed authentication information or at least one of the one or more user authentication information to the other party's device when sending or settling a payment, wherein the signed authentication information allows verification of the completion of the identity verification procedure by verifying the first electronic signature, the user authentication information allows verification of the legitimacy of the user's management authority over the non-custodial wallet by verifying the second electronic signature, and by using at least one of the information contained in the signed authentication information and the information contained in the user authentication information, it is possible to confirm that the non-custodial wallet has undergone identity verification and that the user is the one who holds the private key of the non-custodial wallet.

[0009] According to the present invention, a non-custodial wallet can be used for retail payments.

[0010] This figure shows an example of the configuration of the information processing system of this embodiment. This figure shows an example of the internal configuration of the buyer terminal device and the seller device. This figure shows an example of the configuration of a non-custodial wallet. This figure shows the difference between a non-custodial wallet and a custodial wallet. This figure shows an example of the configuration using an example of a blockchain block. This figure shows an example of the KYC registration process. This figure shows an example of the VC generation method. This figure shows an example of the retail payment process of this embodiment. This figure shows an example of the screen display of the user's buyer terminal device during retail payment. This figure shows an example of the gas fee compensation process. This figure shows an example of promoting the use of a KYC-registered non-custodial wallet. This figure shows a first example of retail payment processing using multiple crypto assets in the case of this embodiment. This figure shows an example of retail payment processing using multiple crypto assets in the case of a comparative example. This figure shows a comparison between the case of this embodiment and the case of a comparative example. This figure shows a second example of retail payment processing using multiple crypto assets in the case of this embodiment. This figure shows the screen display of the user's buyer terminal device 50 when using multiple different crypto assets. This figure shows a first example of the process of notifying legal heirs of the assets of a non-custodial wallet. This figure shows a second example of the process for notifying legal heirs of assets in a non-custodial wallet. This figure shows an example of a user-specific, dedicated non-custodial wallet. This figure shows an example of the process for deposits and transfers between a bank account and a non-custodial wallet. This figure shows an example of the configuration of a common DID database. This figure shows an example of the display screens of the buyer terminal and seller devices during retail settlement.

[0011] The embodiments of the present invention will be described below with reference to the drawings. Figure 1 is a diagram showing an example of the configuration of the information processing system of this embodiment. The information processing system of this embodiment comprises a user buyer terminal device 50 and a seller device 90. The buyer terminal device 50 corresponds to the user's terminal device, and the seller device 90 corresponds to the payment terminal device on the other side of retail payment from the user's perspective. The seller device 90 is installed, for example, in a store. The buyer terminal device 50 can be configured as, for example, a smartphone, a tablet terminal, etc. Similarly, the seller device 90 can be configured as, for example, a smartphone, a tablet terminal, etc. The buyer terminal device 50 is connected to the seller terminal 90 via a communication network 1. The communication network 1 is connected to an asset management server 200, a corporate server 300, and a blockchain 10 described later.

[0012] Retail payments are settlements between people or businesses, and can be made between the buyer terminal device 50 and the seller device 90 using, for example, QR code (registered trademark) payment. In this case, the buyer terminal device 50 displays a QR code, and the seller device 90 reads the QR code to complete the payment. Alternatively, the seller device 90 can display a QR code, and the buyer terminal device 50 can read the QR code. Furthermore, the payment may be made using NFC (Near Field Communication) functionality installed in both the buyer terminal device 50 and the seller device 90. In this case, either the buyer terminal device 50 or the seller device 90 can act as an NFC card, and the other can act as an NFC reader / writer, but instead of an NFC card, a tag can also be used. In face-to-face retail payments, a non-custodial wallet may use NFC functionality, or a non-custodial wallet may use two-dimensional barcode functionality. Face-to-face payment refers to a payment method performed face-to-face with a store clerk in a physical store.

[0013] The asset provider server 200 is a server managed by a bank, trust company, or money transfer company, while the corporate server 300 is a server managed by a company. In the following description, the asset provider server 200 will be described as a bank server 200 managed by a bank, but it is not limited to a bank server and may be a server managed by a trust company or money transfer company, etc.

[0014] Figure 2 shows an example of the internal configuration of the buyer terminal device 50 and the seller device 90. The buyer terminal device 50 has a non-custodial wallet application 60 (computer program) downloaded and installed. Once the non-custodial wallet application 60 is installed on the buyer terminal device 50 and connected to the blockchain 10, the non-custodial wallet 70 becomes available for use on the buyer terminal device 50. The seller device 90 has either a non-custodial wallet or a custodial wallet 100 installed or is available for use. The wallet 100 (computer program) installed on the seller device 90 can be either a non-custodial wallet or a custodial wallet. As mentioned earlier, a custodial wallet is similar to operating an ATM and is unsuitable for retail payments, but since the recipient in retail payments is not subject to time constraints, it can be used for retail payments. The non-custodial wallet or custodial wallet 100 is collectively referred to as "wallet 100". The non-custodial wallet application 60 (computer program) and wallet 100 (computer program) can read the computer program recorded on the recording medium (e.g., an optically readable disc storage medium such as a CD-ROM) M using a recording medium reading unit (not shown) and store it in the buyer terminal device 50 and the seller device 60.

[0015] Server 80 provides an interface function between the buyer terminal device 50 (non-custodial wallet 70) and the blockchain 10. Server 110 provides an interface function between the seller device 90 (wallet 100) and the blockchain 10. The bank server 200 and the corporate server 300 may also be connected to the blockchain 10.

[0016] Blockchain 10 is a distributed digital ledger that records data by grouping it into blocks and cryptographically linking them. It is a distributed system using a P2P network, where nodes (computers) on the P2P network share the same data (ledger). Blockchain 10 is a technology that manages a ledger through distributed sharing. The servers 80 and 110 shown in Figure 2 can constitute nodes.

[0017] Figure 3 shows an example of the configuration of a non-custodial wallet 70. The non-custodial wallet 70 holds information such as a private key 71, a public key 72, a derived private key 73, an address 74, a transaction number 75, VC (Verifiable Credentials) 76, an asset amount 77, a crypto asset 78, and a DID (Decentralized Identifier) ​​79.

[0018] SSI (Self-Sovereign Identity) is translated as self-sovereign identity and is the underlying concept and philosophy of DID and VC. SSI is a term that refers to "a system that allows individuals to manage their own digital ID," and its purpose is to enable individuals to manage their own identity information without the need for intervention from others.

[0019] In this embodiment, terms such as DID and VC are used as examples of effective technologies to explain implementations based on the concept of SSI, and are not necessarily limited to the strict definitions or implementations of the W3C. For example, in DID, it is common to describe the service endpoint within the DID document, but in this embodiment, a service point is not required.

[0020] DID is generally made public on the blockchain. While the blockchain, being a system without a central authority, seems to satisfy the concepts and philosophy of SSI, it overlooks the fact that it cannot prevent intervention by others. This is because the blockchain is open, accessible to anyone, and its contents can be read. To circumvent this problem, in this embodiment, the DID is recorded and stored in a non-custodial wallet owned by an individual. The reason for using a non-custodial wallet is that it adheres to the philosophy that "the user manages the private key of the wallet that controls all the rights to their own non-custodial wallet," meaning the user must completely manage their own private key, which is consistent with the concepts and philosophy of SSI.

[0021] This section explains DID. Regarding the definition and purpose of DID, it is a new type of identifier being standardized by the W3C, designed to provide verifiable, digitized identities that do not require centralized management. Regarding the structure of DID, it is represented by a URI in the format "did:method:method-specific identifier". For example, "did:example:123456789abcdefghi". Regarding DID documents, each DID has an associated DID document containing information such as public keys, authentication methods, and service endpoints. Regarding the decentralized nature of DID, DIDs do not rely on centralized registration authorities or certification authorities, but are managed using distributed ledger technologies such as blockchain. Regarding the uses of DID, it is used for digital identity management, authentication, digital signatures, and encrypted communication. Regarding the difference between DID and conventional technologies, unlike traditional centralized ID systems, it realizes "self-sovereign identity," where users can completely manage their own IDs.

[0022] The important point here is that a DID itself is merely an identifier and cannot be used for self-proofing by itself. Essential to any identity verification process using a DID is the existence of an associated DID document. The DID document contains the cryptographic verification methods and authentication means necessary for the owner of the DID to prove their identity. In other words, "using a DID to prove who you are" is not strictly accurate; a more technically accurate expression is "using the cryptographic means described in the DID document associated with the DID to prove that you are the legitimate owner of that DID." The DID and the DID document are inseparable; the DID acts as an identifier, and the DID document provides verifiable information associated with that identifier. In this embodiment, a distributed identifier (DID) issued by a bank works together with an associated DID document to enable secure authentication and verification within the system.

[0023] This document explains the reconciliation between the "right to be forgotten" under the GDPR (General Data Protection Regulation) and the technical characteristics of decentralized identifiers (DIDs). Generally, DIDs are either recorded directly on the blockchain or stored in decentralized storage such as IPFS (InterPlanetary File System) via reference information on the blockchain. However, the immutability (the property that information once recorded is virtually impossible to delete) and public nature of blockchains can create a technical contradiction with the "right to be forgotten" as defined by the GDPR.

[0024] In this embodiment, to solve this problem, a method is adopted in which the DID is stored in the user's (owner's) non-custodial wallet. A non-custodial wallet is a wallet in which the user completely manages the private key, granting the user complete control over assets and data. This ensures GDPR compliance.

[0025] The private key 71 is a digital code that users must keep securely, necessary for managing crypto assets on blockchain 10 and signing transactions. The public key 72 is generated unidirectionally from the private key 71 and is used to derive an address for receiving crypto assets (some blockchains use the digital code as is). The derived private key 73 is a child private key generated from the master private key (private key 71) based on the concept of a hierarchical deterministic wallet (HD Wallet), and is used to enhance security and privacy. By generating a new public key 72 and derived private key 73 for each transaction, privacy can be strengthened and asset tracking can be made more difficult. Using these as one-time keys further enhances security. The address derived from the public key 72 is public information necessary when receiving crypto assets and can be securely shared with the transaction partner. This structure allows users to securely store a single private key 71 while generating and using a large number of unique transaction addresses. In this specification, "transaction" refers to retail settlement between a buyer and a seller. Inter-company settlements are also considered retail settlements. In this case, "transaction" refers to a retail settlement between the payer and the invoicer.

[0026] Address 74 is a code assigned to the non-custodial wallet 70 and is information used to identify the non-custodial wallet 70. Address 74 is typically generated from the public key 72.

[0027] Transaction number 75 is information generated for each transaction and can be used when you wish to keep the details of the transaction confidential.

[0028] VC76 is a digital certificate that holds user attribute information in a verifiable format and guarantees its authenticity and integrity with an electronic signature using the private key 71 of the non-custodial wallet 70. In this embodiment, VC76 is created by using DID79 (Decentralized Identifier) ​​as the main component (starting point of trust), adding attribute information (e.g., account information, credit information, etc.) as needed, structuring this information in JSON-LD format, and then electronically signing it with the private key 71 of the non-custodial wallet 70. The contents of VC76 can be selectively disclosed as needed to protect privacy. Furthermore, by hashing part or all of the attribute information, the confidentiality of the information can be ensured while maintaining its originality. The counterparty (verifier) ​​of retail payment can verify the electronic signature attached to VC76 using public-key cryptography to confirm that VC76 was created by a legitimate issuer and that its contents have not been tampered with. In addition, it is possible to verify the identity and authority of the issuer using the DID79 included in VC76. This system allows users to securely manage their personal information and selectively disclose it only when necessary, enabling the operation of digital identities that balance privacy and security.

[0029] In this embodiment, a key feature is that the DID is issued by the bank after being signed with its own private key and stored in the account holder's non-custodial wallet 70. This allows the wallet to function as a highly reliable wallet that has undergone KYC (Know Your Customer) verification. If the DID 79 alone is insufficient as proof of identity (because it is possible to falsify the entire DID), the generation and presentation of the VC 76 becomes effective in this system. Specifically, during retail payments (but not limited to), the VC 76 is generated using the private key 71 of the non-custodial wallet 70 and presented to the other party to prove identity. Specifically, by confirming that a part of the DID information (account information) and a part of the VC information (account information) match, it is possible to prevent the falsification of the DID itself. This is just one example, and the objective can also be achieved by using the non-custodial wallet address of the DID information and the non-custodial wallet address of the VC information. It should also be noted that when using the non-custodial wallet address to prove identity, this information does not need to be included in part of the VC information. The reason is that the sender's wallet address is written into the transaction data generated when performing retail payments and other transactions using blockchain. Furthermore, VC76 utilizes zero-knowledge proof technology to prove attribute information such as "being 20 years of age or older" and "having a trust point of 85 or higher" without disclosing the specific values.

[0030] Asset amount 77 is the amount of cryptocurrency held by the user on blockchain 10. Cryptocurrency 78 indicates the type of cryptocurrency.

[0031] In this embodiment, DID79 is information issued by a bank or the like, and is created by hashing the user's personal information (e.g., account number, name, date of birth, gender, etc.) using a quantum-resistant SHA-3 family hash function and signing it with the private key of the bank or a bank branch. For convenience, symbols will be omitted in the following description. DID includes the DID itself (identifier), the DID document (also called a DID document), and the signature. The identifier of the DID is associated with the DID document. The DID document includes the hashed information, the public key (the key used by the DID owner for authentication and signing), the authentication method (describes the authentication process using the public key), etc., but is characterized by not including the service endpoint (access information to the resource pointed to by the DID). This not only reduces the size, but also reduces potential attack vectors by excluding the service endpoint, reduces the risk of unnecessary information leakage regarding user privacy, and improves communication security. The signature is for the issuer to guarantee its contents, is generated with the issuer's private key, and the public key is used for verification. In this embodiment, the DID can be created by signing related information, such as the address of the non-custodial wallet 70 and the user's bank account number, and the user's personal information, with the private key of the bank or a bank branch. For generating the public key cryptographic pair used at this time, an algorithm for post-quantum computers, such as CRYSTALS-Dilithium listed by NIST, may be used. In the example in Figure 3, the DID issued by the bank is shown to be recorded in the non-custodial wallet 70, but the recording destination of the DID is not limited to the non-custodial wallet 70. For example, the DID may be encrypted and recorded in a predetermined recording location on the internet, or the DID may be encrypted and recorded on the blockchain. The non-custodial wallet 70 contains information to access the aforementioned recording location.

[0032] Security incidents resulting from account hijacking due to viruses infiltrating smartphones or phishing attacks continue unabated in online transactions. Traditional online payment systems often rely on vulnerable authentication methods based on "known information" such as IDs and passwords because authentication using personal items (such as My Number cards or passports) is difficult in online transactions.

[0033] However, identity verification using a KYC-enabled non-custodial wallet can achieve multi-layered security authentication based on blockchain technology, combining "ownership" (only the owner of the non-custodial wallet possesses the private key) and "verification" (bank-signed DID). This DID serves as the starting point of trust, and by sending both the VC and DID to the party to be verified over the internet, it provides an innovative authentication method that the other party can verify.

[0034] For example, when a user logs into an external service such as a securities company, the service issues a challenge to the user. The user's wallet generates a signed response to this challenge using its VC and private key and sends it to the service provider. By verifying this response, the service provider can confirm (1) that the user possesses a legitimate private key, (2) that the user's identity has been verified by a bank, and (3) that the user's name is verified by verifying the DID and VC. In this explanation, a challenge was used, but identity verification is possible without using one. For example, this can be achieved by including a timestamp such as the date in the VC, or because the user's name is written in a signed form within the VC and DID.

[0035] The advantage of this authentication method lies in its robust resistance to phishing scams and theft of authentication information. Even if an attacker obtains the user ID and password, authentication cannot be passed without the private key and VC of the non-custodial wallet. Furthermore, the private key never leaves the device such as a smartphone, making man-in-the-middle attacks difficult. In addition, by using a signed DID from a highly trusted institution such as a bank as the starting point of trust, the risk of impersonation can be significantly reduced. This embodiment significantly reduces the risk of security breaches in financial transactions compared to conventional methods, making it possible to dramatically improve the safety and reliability of online financial services.

[0036] Figure 4 illustrates the differences between non-custodial wallets and custodial wallets. As shown in Figure 4, regarding the management of private keys, in the case of non-custodial wallets, the user must manage them themselves, whereas in the case of custodial wallets, a third party (usually the exchange) manages them. Regarding responsibility for asset management, in the case of non-custodial wallets, the user is entirely responsible, whereas in the case of custodial wallets, the third party is responsible. Regarding security, in the case of non-custodial wallets, it depends on the user's management ability, whereas in the case of custodial wallets, it depends on the security measures of the third party. Regarding convenience, in the case of non-custodial wallets, technical knowledge is required, while custodial wallets are generally easy to use. Regarding transaction approval, in the case of non-custodial wallets, the user approves directly, whereas in the case of custodial wallets, approval is done through a third party. Regarding fund recovery, in the case of non-custodial wallets, recovery in case of loss is difficult, whereas in the case of custodial wallets, support from a third party is possible. Regarding regulatory compliance, non-custodial wallets are often exempt from regulations, while custodial wallets are often required to comply with regulations. Regarding transaction speed, non-custodial wallets are generally faster, while custodial wallets may be slower due to the need for third-party approval. Regarding asset ownership, non-custodial wallets are fully owned by the user, while custodial wallets are managed by a third party.

[0037] Contactless payment apps using virtual credit cards and electronic money on smartphones are becoming widespread. Essential to these payments is an app called a mobile wallet. A mobile wallet stores things like electronic money, virtual credit cards, loyalty cards, membership cards, tickets, and coupons all in one place. However, these mobile wallets cannot record and manage the stored items, such as blockchain-based stablecoins or cryptocurrencies. While installing and using a non-custodial wallet on a smartphone might seem like using a mobile wallet, it's completely different.

[0038] Figure 5 is an example of a blockchain 10 and shows an example of a block structure. Each block in blockchain 10 contains information such as the hash value of the previous block, the hash value of the block itself, transaction data, and a nonce. The transaction data includes information such as the addresses of the sender and receiver, the amount of cryptocurrency transferred, the transaction fee (so-called gas fee), and a timestamp.

[0039] A hash value is a fixed-length value obtained from the original input data through a predetermined operation, and the calculation is performed using the information contained in the previous block as input data.

[0040] Transaction data includes records of transactions that took place during the block period (e.g., transfers of crypto assets).

[0041] A wallet (account) nonce is a numerical value representing the number of transactions for each account, used for ordering transactions and preventing double spending. A block nonce is a value used in the mining process and is adjusted to generate a valid block hash. Nonce is a concept used in some blockchains, such as Ethereum, and is not common to all blockchains. Its main purpose is to ensure security and transaction integrity.

[0042] Next, the processing performed by the information processing system of this embodiment will be described.

[0043] FIG. 6 is a diagram illustrating an example of KYC registration processing. A non-custodial wallet 70 can be determined as having completed KYC registration based on the fact that the account number used by the user who owns the non-custodial wallet 70 has already completed identity verification. The statement that the non-custodial wallet 70 has completed KYC registration is synonymous with the statement that the non-custodial wallet 70 has completed identity verification procedures. When opening a bank account, identity verification procedures are performed, so it is premised that the user who owns the bank account has completed identity verification procedures. In addition, when opening a new account recently, there are cases (so-called eKYC) where identity verification is performed by sending a My Number Card, a driver's license, and a facial photo of the applicant. Going forward, it is expected that information recorded on the IC chip of a My Number Card or the IC chip of a driver's license will be read and used for personal identity verification. On the other hand, when opening a current account, more strict verification measures are implemented.

[0044] One of the issues cited in the use of non-custodial wallets is that the management responsibility for the wallet's private key (which may also include the seed phrase managed by the non-custodial wallet) lies with the individual who uses the non-custodial wallet. As an example in return for KYC registration, the present disclosure describes an example where a bank safely stores the private key of a non-custodial wallet 70. In the non-custodial wallet application, the user is asked to input the personal identification number of their cash card, this input is used as a seed to generate an encryption key in the non-custodial wallet 70, and the private key of the non-custodial wallet 70 is encrypted with the generated encryption key (S11). The non-custodial wallet 70 transmits the address of the non-custodial wallet 70 and the encrypted private key to the bank server 200 (S12).

[0045] The bank server 200 receives the address of the non-custodial wallet 70 and the encrypted private key (S13), and associates the address of the non-custodial wallet 70 with the user's bank account number (S14). By associating the address of the non-custodial wallet 70 with the user's bank account number, the bank server 200 can generate related information that links the address of the non-custodial wallet 70 with the user's bank account number. The related information can be any information that shows that the address of the non-custodial wallet 70 corresponds to the user's bank account number (for example, table format data or link format data). The bank server 200 can store the related information in a predetermined database. In addition to a database, the data may be stored in a secure blockchain (e.g., Arweave: a distributed storage protocol aimed at persistent data storage, where persistent data storage is provided with a single payment), IPFS (InterPlanetary File System), or in the cloud.

[0046] The bank server 200 creates a DID in accordance with the DID specification being standardized by the W3C by signing the associated information, which links the address of the non-custodial wallet 70 with the user's bank account number, with the private key of the bank or a bank branch, and sends it to the non-custodial wallet 70 (S15). It should be noted that the DID (distributed identifier) ​​created here consists of the DID as an identifier and the DID document associated with that identifier, and that the two must work together to perform the function of identity verification.

[0047] As another example of DID creation for the purpose of improving security and saving capacity, taking an example of creation of related information, a DID conforming to the DID specification is created, which includes a result obtained by concatenating the address of the non-custodial wallet 70 and the associated account number as a character string and hashing the concatenated string, which is then signed with the private key of a bank or a branch of the bank. It should be noted that this DID document normally includes a service endpoint, but a feature of the present embodiment is that the service endpoint can also be omitted if unnecessary. This is because deleting this information not only reduces the document size, but also enhances privacy, eliminates dependence on centralized services, improves autonomy and decentralization, and can be an implementation solution that is more in line with the philosophy of blockchain. It also has the effect of reducing potential attack vectors and improving communication security.

[0048] The non-custodial wallet 70 receives the DID, records the received DID in the non-custodial wallet 70 (S17), and ends the process. To ensure consistency with the "right to be forgotten" under the GDPR, the DID is stored in a storage area managed by the non-custodial wallet 70. This allows the user themself to retain full control over deletion and management of data. It should be noted that, from the perspective of a DID (decentralized identifier), the related information is one piece of attribute information (DID document).

[0049] The bank server 200 stores the encrypted private key of the non-custodial wallet 70 in a secure manner (S16), and ends the process. As storage methods, distributed storage and storage on a secure blockchain are contemplated. Furthermore, since the private key is encrypted with an encryption key that uses the personal identification number of the cash card of the holder of the non-custodial wallet 70 as a seed, even if the individual dies suddenly and becomes deceased, the personal identification number of the cash card can be obtained by the bank's system through the conventional mechanism of account freezing and subsequent permission for access to the account by the legal heir, allowing the assets in the non-custodial wallet to be inherited by the legal heir.

[0050] As described above, in a non-custodial wallet 70 owned by a user, the non-custodial wallet 70 becomes a verified non-custodial wallet 70 when the KYC information recorded during the user's bank account opening verification procedure is linked to the non-custodial wallet 70 based on the associated information that links the address of the non-custodial wallet 70 with the user's bank account number. Furthermore, by examining the DID document within the non-custodial wallet 70, it is identified that the non-custodial wallet 70 is linked to a bank account. Regarding bank account numbers, the system for bank account numbers differs from country to country. For example, the Japanese bank account number system is characterized by a triple structure consisting of a 4-digit unified financial institution code (bank code), a 3-digit branch code, and a 7-8 digit account number. This invention refers to bank account numbers used in various countries around the world. In the US ABA system, the 9-digit ABA routing number used under the Federal Reserve consists of a regional code (first 4 digits), a financial institution identifier (next 4 digits), and a checksum (last digit). Account numbers are managed by each bank using a variable length (usually 5 to 17 digits), and accounts are identified in combination with the ABA number. In the EU, the IBAN integrated model conforms to the international standard ISO 13616 and consists of up to 34 alphanumeric characters, a country code (2 characters), a check digit (2 digits), and a domestic bank code system (up to 30 digits). In addition to the relevant information, if additional verification is required, for example, in Japan, it may be necessary to exchange information with the IC chip of the My Number Card, and additional KYC procedures may be added using official identification means in each country (passport or driver's license), and this, combined with the aforementioned relevant information, may be used to perform highly accurate identity verification.

[0051] Furthermore, in the case of a non-custodial wallet 70 owned by a user, the non-custodial wallet 70 may be considered to have undergone identity verification by linking the KYC information recorded during the identity verification procedure when the user set up their customer identification information with the related information that associates the address of the non-custodial wallet 70 with the customer identification information of the user.

[0052] The revised Payment Services Act, which came into effect in 2023, stipulates that only three types of companies (operators) can issue stablecoins: banks, trust companies, and money transfer service providers. Customer identification information is the account number in the case of banks, the contract number or beneficiary ID in the case of trust companies, and the account ID in the case of money transfer service providers (companies). In this specification, a bank account number is used as an example of customer identification information, but customer identification information may also be the contract number, beneficiary ID, or account ID.

[0053] In the case of a trust company, a unique identification number is assigned to each contract, and this identification number functions as a key linking customer (settlor and beneficiary) information with the trust assets. By linking the address of the non-custodial wallet 70 with the contract number, identity verification procedures are performed on a contract-by-contract basis, and the non-custodial wallet 70 can be made identity-verified. In addition, the beneficiary ID functions as a key to identify the right to receive benefits from the trust assets. By linking the address of the non-custodial wallet 70 with the beneficiary ID, identity verification procedures are performed on a beneficiary-by-beneficiary basis, and the non-custodial wallet 70 can be made identity-verified.

[0054] In the case of money transfer businesses, each customer is assigned a unique account ID. This account ID is used for customer identification in remittance or payment services. By linking the address of the non-custodial wallet 70 to the account ID, identity verification is performed, and the non-custodial wallet 70 can be verified.

[0055] In the example above, the bank server 200 generated a DID by embedding information into a DID document that was signed using the private key of the bank or a bank branch (not limited to these two, but any private key based on bank-specific information, which has a corresponding public key and can be used for signature verification) that links the address of the non-custodial wallet 70 with the user's bank account number. However, the method of generating the DID is not limited to this. For example, it could be data that hashes only the account number and signs it with the private key mentioned above, or data that hashs the account holder's name and signs it with the private key mentioned above. What is important is that the non-custodial wallet 70 contains data in which the DID is signed with a bank-related private key. From this fact, it can be asserted that the non-custodial wallet 70 is a KYC-certified non-custodial wallet.

[0056] As another example of the process illustrated in Figure 6, we show a method to reduce the risk of losing the private key while maintaining true non-custodial nature. In this method, cryptographic techniques such as Shamir's secret sharing are used to split the private key of the non-custodial wallet 70 into two parts (split keys K1 and K2). This split makes it impossible to recover the private key without both split keys, so neither can function as a private key on its own.

[0057] After splitting, the first splitting key K1 is encrypted using the method shown in Figure 6 and sent to the bank server 200. The second splitting key K2 is written to the user's IC chip-equipped cash card or My Number card via NFC communication or a contact interface through the non-custodial wallet application. In this writing process, physical security can be ensured by encrypting and storing the second splitting key K2 in the secure element area or a secure area of ​​the cash card.

[0058] When using the private key splitting method, the bank server 200 receives and stores only the first split key K1, so the bank alone cannot recover the private key. This maintains true non-custodial nature. If recovery of the private key is necessary (e.g., when a user reinstalls the wallet), the user has the non-custodial wallet application read an IC chip-equipped cash card or My Number card to obtain the second split key K2, and requests the bank server 200 to send the first split key K1 after user authentication. The non-custodial wallet application, having received both split keys K1 and K2, can combine them to recover the private key.

[0059] This method enhances security because access to the private key requires the involvement of both the bank and the user, while also mitigating the risk of losing the private key while maintaining the principle of "self-management," which is the essence of non-custodial systems.

[0060] Figure 7 shows an example of a method for generating a Virtual Certificate (VC). The generation of the VC shown in Figure 7 can be performed within the non-custodial wallet 70. As shown in Figure 7, the DID is hashed to generate a hash value. The attribute information may include, for example, the user's account information (including account number and bank name), credit information, gender, date of birth, address, and telephone number. The generated hash value is encrypted with the private key of the non-custodial wallet 70 to generate a signature. The VC consists of the hash value and the signature.

[0061] Furthermore, the DID contains information such as the hash value of the non-custodial wallet 70 address signed with the bank's private key, the hash value of the account number signed with the bank's private key, or information on how many years the seller (mainly a company) has been doing business with the bank, as well as information on trustworthiness and credit points. If necessary, a VC can be generated using zero-knowledge proofs on this information, or on the user's input information or recorded input information for the non-custodial wallet 70, recorded in the non-custodial wallet 70, and the recorded VC can be written to the transaction data.

[0062] As described above, by placing the DID and VC in the non-custodial wallet 70 and performing retail payments, the following effects are achieved: (1) Wallet address verification within the DID: By including the hash value of the address of the non-custodial wallet 70, signed with the bank's private key, in the DID, the reliability of the link between the DID and the non-custodial wallet is dramatically improved. This significantly reduces the risk of impersonation and fraudulent wallet use. (2) Encryption integration of bank account information: By including the bank's signature on the hash value of the account number in the DID, the authenticity of the bank account can be guaranteed while protecting privacy. This is an excellent approach that balances the protection of personal information with increasing the reliability of financial transactions. (3) Integration of credit information into the DID: By including information such as the number of years of continuous transactions and credit points in the DID, the reliability of trading partners can be evaluated immediately. This is particularly useful in business-to-business (B2B) transactions for quickly determining the creditworthiness of new trading partners. (4) VC generation using zero-knowledge proofs: The generation of VCs using zero-knowledge proofs from information within the DID and information of holders of the non-custodial wallet 70, and their inclusion in transactions, is an innovative approach that balances privacy protection with flexibility in information disclosure. For example, it becomes possible to prove that "the credit score is above a certain threshold" while not disclosing the specific score, enabling sophisticated information management.

[0063] The effects described above may have the following potential impacts: (1) Improved reliability: Signature verification by banks significantly improves the reliability of the entire system. It becomes possible to integrate the advantages of traditional centralized KYC processes into a decentralized system. (2) More efficient risk management: Real-time verification of trading partners' credit information makes the assessment and management of transaction risks significantly more efficient. This is of particular value in international transactions and transactions with new trading partners. (3) Balancing privacy and compliance: By utilizing zero-knowledge proofs, compliance requirements can be met with the minimum necessary information disclosure. This may function effectively even under strict data protection regulations such as GDPR. (4) Promoting financial inclusion: Individuals and small businesses that were difficult to evaluate under traditional credit rating systems can prove their transaction history and credit information through DID. Alternatively, they can prove their status through DID signed by their employer if they receive a continuous salary from their employer. This may allow more people to access financial services. (5) Creation of new financial products and services: Based on real-time credit information verification, new financial services such as dynamic interest rate setting and immediate lending decisions will become possible. (6) Simplification of cross-border transactions: By basing transactions on the signatures of internationally recognized banks, it will be easier to ensure the reliability of cross-border transactions. This has the potential to promote seamless transactions in the global economy.

[0064] Figure 8 shows an example of retail payment processing in this embodiment. In the retail payment shown in Figure 8, the case using a two-dimensional barcode (hereafter, the term "two-dimensional barcode" will also include QR code®) will be described.

[0065] The non-custodial wallet or custodial wallet 100 (hereinafter simply referred to as "wallet 100") of the seller device 90 displays a two-dimensional barcode (S21). The non-custodial wallet 70 reads the two-dimensional barcode (S22). The non-custodial wallet 70 performs the following processing based on the information it has read. The non-custodial wallet 70 obtains the stablecoin (cryptocurrency pegged to fiat currency), the amount to be sent, and the address of the recipient's wallet (S23). In this case, the user specifies the amount to be sent and the cryptocurrency to be used.

[0066] The non-custodial wallet 70 shares the VC of wallet 100 with the non-custodial wallet 70 (S24). The user's non-custodial wallet 70 verifies that wallet 100 is registered with KYC (S25).

[0067] The non-custodial wallet 70 generates a derived private key and a corresponding public key from the private key of the non-custodial wallet 70 (S26). The generation of the derived private key and its corresponding public key can be achieved using, for example, a hierarchical deterministic algorithm, random number generation, or a method using the wallet address as a seed. The derived private key and public key are generated in advance or each time a transaction occurs, and can be, for example, a one-time valid key or a reusable key. By doing so, the user's purchase privacy is protected by not fixing the wallet address of the user's non-custodial wallet 70. (Because the blockchain is open, anyone can view it and track specific wallet addresses, which could lead to privacy violations, but this method protects against that.)

[0068] Wallet 100 sends the transaction number to the non-custodial wallet 70 (S27). The transaction number only needs to be information that can identify the transaction and does not include personal or attribute information that would identify the seller or buyer, or information that would identify the content of the transaction.

[0069] The non-custodial wallet 70 receives the transaction number (S28) and accepts the user's operation of the payment icon (S29).

[0070] The non-custodial wallet 70 embeds the transaction number, the amount to be sent, and the stablecoin into the transaction data (for example, it can be embedded in a memo field in the blockchain 10), signs the transaction data with the derived private key, and sends it to the address of the seller's wallet 100 (S30), thus ending the process.

[0071] Wallet 100 matches the transaction number in the transaction data and settles the transaction (S31), then terminates the process.

[0072] In the example described above, by preparing at least one temporary or reusable wallet based on the wallet address calculated from the generated public key, and sending crypto assets through that wallet to the address of a verified non-custodial wallet or custodial wallet 100, privacy can be protected and transactions can be made difficult to track.

[0073] As mentioned above, it is easy to set up an environment for retail payments using a non-custodial wallet that has undergone identity verification. "Retail payments using a non-custodial wallet that has undergone identity verification" means that retail payments can be made by embedding transaction data into the transaction data of a non-custodial wallet that has undergone identity verification and sending it to the recipient's wallet address.

[0074] Even when the current account holder is a company or other entity, KYC registration is performed using the account holder's registered name. In addition, there are accounts similar to Japanese current accounts, such as Checking Accounts (USA) and Current Accounts (Europe). In other countries as well, there are occasional cases where fraudulent companies use these accounts, but because current accounts and checking accounts undergo strict KYC (identity verification), fraudulent use is suppressed to a certain extent. On the other hand, conventional cashless systems are constantly plagued by hacking and phishing attacks because intermediaries (such as credit card companies) are involved. Therefore, another objective of this embodiment is to provide an information processing method and information processing system that allows for the safe use of cashless systems, and it is possible to utilize the aforementioned strict KYC procedures.

[0075] According to this embodiment, a non-custodial wallet can be used for retail payments. This is because people using cashless systems, whether using credit cards, QR code payments, or transportation IC cards, have already performed KYC (Know Your Customer) checks before making retail payments. In other words, even people using non-custodial wallets will understand that they do not need to be averse to being checked for KYC checks, at least for retail payments. Furthermore, people who do not want their asset holdings, such as crypto assets, to be tracked (for purposes other than retail payments, for example) can choose not to use the non-custodial wallet of this embodiment.

[0076] Traditionally, wallets for managing cryptocurrencies such as stablecoins have been broadly divided into two types: "custodial" and "non-custodial." In custodial wallets, a third party (such as a cryptocurrency exchange) manages the private key, which presents security risks and single-point-of-failure issues. In fact, large-scale hacking incidents have occurred (e.g., the DMM and ByBit incidents). On the other hand, while non-custodial wallets ensure high security because the user manages the private key themselves, KYC (Know Your Customer) procedures are not adequately implemented, making it difficult to comply with various regulations such as anti-money laundering (AML) and counter-terrorism financing (CFT).

[0077] This regulatory oversight has made it virtually impossible for non-custodial wallets to be used in the retail payment market. In particular, applying non-custodial wallets to retail payments for services provided by banks and financial institutions faces significant technical and institutional barriers, making it difficult for those in the industry to easily conceive of such a solution.

[0078] This embodiment employs an innovative method to simultaneously address these conflicting challenges (security and regulatory compliance), for example, by linking bank account numbers (customer identification information) with non-custodial wallet addresses. This method makes it possible to leverage the strict KYC procedures already implemented by banks while maintaining the advantages of non-custodial wallets where users manage their own private keys.

[0079] Furthermore, the following advantages can be obtained as a remarkable effect of this embodiment: (1) By reusing the bank's KYC process, additional KYC procedures are unnecessary, significantly reducing implementation costs and operational burden. (2) By having the user manage their own private key, regulatory requirements can be met while avoiding the risk of centralized data breaches. (3) Linking bank accounts and wallet addresses improves the detection rate of fraudulent transactions and allows for efficient fulfillment of reporting obligations to regulatory authorities. (4) By realizing direct transactions without the need for intermediaries, merchant fees can be significantly reduced compared to conventional credit card payments. Such technical effects do not arise from the simple idea of ​​combining a non-custodial wallet and KYC, but are innovative and cannot be easily conceived by those skilled in the art, as they are achieved only by employing the specific technical means of linking with bank account numbers.

[0080] Furthermore, it is possible to obtain transaction information identifying the transaction from the counterparty's terminal device in retail payments, generate transaction data including the obtained transaction information and the amount to be sent, and send the generated transaction data to the counterparty's custodial wallet address.

[0081] Furthermore, a derived private key and public key can be generated based on the private key of a non-custodial wallet. After sending the amount required for the transaction to the wallet address generated using the generated public key, the transaction information can be added and sent from the aforementioned wallet address to the wallet 100 owned by the other party. In this way, funds can be sent from the wallet generated with the derived private key to the address of the wallet 100 owned by the other party. The received wallet 100 can then be matched using the transaction information.

[0082] AML countermeasures for blockchain transactions generally involve inspecting transaction data in real time to check for fraud, but this is currently expensive and has not yielded effective results. Furthermore, conventional methods involve detecting fraud retrospectively after a transaction has been made. In contrast, this embodiment uses a non-custodial wallet that has been registered with KYC, enabling transactions to be made only between KYC-registered users, thereby preventing fraudulent transactions.

[0083] In other words, it has the effect of improving the efficiency of AML countermeasures on the chain. Specifically, if the FATF or other organizations require real-time AML inspection on the chain, all blockchain transactions must be inspected in real time using AI and machine learning technology. However, if there is a system that only allows transfers between KYC-certified parties, as in this embodiment, the scope of inspection can be reduced, making a new AML inspection service possible.

[0084] Figure 9 shows an example of the screen display on the user's buyer terminal device 50 during retail payment. First, the user operates the buyer terminal device 50 to launch the non-custodial wallet app and select payment. A screen for selecting the payment method is then displayed, and the payment methods are shown. In the example in Figure 9, "2D barcode payment," "NFC touch payment," and "online payment" are displayed. For example, the user selects "2D barcode payment."

[0085] Next, the user scans the two-dimensional barcode displayed on the seller device 90, confirms that the scanned barcode is displayed, and then operates the payment icon. By scanning the two-dimensional barcode, information such as the seller's name, product name, quantity purchased, unit price, and total purchase amount can be read. The scanned information is displayed on the screen, and the buyer can confirm it. This completes the retail payment.

[0086] Figure 10 shows an example of gas fee reimbursement processing. Gas fees are fees charged when transactions are conducted on the blockchain. In most blockchain systems, the sender pays the gas fees, so the beneficiary does not pay them. A mechanism to correct this is necessary for retail payments. This embodiment describes a method in which the seller reimburses the gas fees paid by the sender (buyer).

[0087] The non-custodial wallet 70 pays the gas fee (S41). Assume that the retail payment is completed between the non-custodial wallet 70 and wallet 100 (S42). Wallet 100 records the points corresponding to the gas fee, or the points corresponding to the gas fee and the purchase amount, associating them with the user (S43). Since a blockchain with low gas fees is used, the usual gas fee is less than 1 yen when converted to Japanese yen. Even if it is less than 1 yen, it is treated as 1 point. If it exceeds 1 point, the amount is rounded up to the nearest whole number and treated as points, and this has already been transmitted to wallet 100 in the transaction data of the retail payment information.

[0088] The non-custodial wallet 70 records gas fees converted into points (S44). Note that the gas fees paid by the sender are usually constant regardless of the purchase amount.

[0089] Wallet 100 converts the receipt for the purchased items (which also contains the point data to be awarded, but includes the points recorded in Wallet 100 + the remittance points (points paid by the remitter as gas fees) in the transaction data, totaling the point amount) into a stablecoin amount, sends this amount to the non-custodial wallet 70 (S45), and terminates the process.

[0090] The non-custodial wallet 70 receives the receipt (S46), confirms that it has received a stablecoin amount that is consistent with the points written on the receipt and the points recorded at the time of the transfer (S47), and terminates the process.

[0091] As mentioned above, when a retail payment is completed using a non-custodial wallet that has undergone identity verification, the receipt (invoice) that is normally exchanged in retail payments is written as digital data to the blockchain transaction data using blockchain technology. This allows the seller to pay the buyer's gas fee when handing over the receipt. Of course, this can be used at the seller's discretion, for example, based on the purchase price or as a discount limited to purchases during a certain period. The gas fee can be replenished in the non-custodial wallet.

[0092] As mentioned above, buyers (consumers) can receive more value than the total amount of gas they paid, which motivates them to use Non-Custodial Wallet 70 for retail payments. There are various ways to compensate for gas costs besides point rewards.

[0093] Figure 11 illustrates an example of promoting the use of KYC-registered non-custodial wallets. As shown in Figure 11, benefits include reduced fees, increased staking rewards, coupons, and early access. The reduced fees involve increasing the points earned by KYC-registered users (for example, by 50%). Staking is a mechanism where users can deposit their crypto assets on the blockchain and receive rewards in return. The increased staking rewards apply, for example, to the non-custodial wallets of KYC-registered users.

[0094] The coupon provision provides users who have registered with KYC with coupons that can be used for their gas bills. Early access grants users who have registered with KYC priority access to the sale of seller products.

[0095] Providing the aforementioned benefits to KYC-registered users will increase their motivation to use KYC-registered non-custodial wallet 70 for retail payments.

[0096] Figure 12 shows a first example of retail payment processing using multiple crypto assets in this embodiment. Below, USDC and USDT will be used as examples of multiple stablecoins. These two are stablecoins whose value is guaranteed to be pegged to the US dollar and are used worldwide. Assume that a retail payment of $70 is to be executed between the non-custodial wallet 70 and wallet 100 (S51).

[0097] Non-custodial wallet 70 is assumed to hold $50 USDC and $60 USDT (S52).

[0098] The non-custodial wallet 70 generates the first transaction data by embedding a common transaction number, USDC 50$, in the memo field and amount field within the transaction, respectively (S53).

[0099] The non-custodial wallet 70 embeds the common transaction number, USDT20$, into the memo field and amount field within the transaction, respectively, and generates second transaction data (S54).

[0100] The non-custodial wallet 70 sends the generated first transaction data and second transaction data to the seller's blockchain address (S55), and then terminates the process.

[0101] Wallet 100 extracts the transaction number from the first transaction data (S56) and the transaction number from the second transaction data (S57). Here, since the extracted transaction numbers are common transaction numbers, the extracted transaction numbers are identical.

[0102] Wallet 100 matches the first transaction with the second transaction based on the extracted common transaction number (S58). Wallet 100 confirms that the $70 transfer has been completed (S59), the settlement is complete (S60), and the process ends.

[0103] As described above, a non-custodial wallet holds multiple crypto assets, generates first transaction data including the transfer amount and common transaction information for the first crypto asset among the multiple crypto assets, generates second transaction data including the transfer amount and the aforementioned common transaction information for the second crypto asset among the multiple crypto assets, and sends the generated first and second transaction data to the address of the non-custodial or custodial wallet owned by the other party. The non-custodial or custodial wallet owned by the other party can match the first and second transaction data based on the common transaction information.

[0104] Figure 13 shows an example of retail payment processing using multiple crypto assets in the case of a comparative example. Conventional non-custodial wallets cannot process transfers using different crypto assets (USDC and USDT) in a single transaction. Therefore, two separate transfers are required for each crypto asset. This shows a case where a retail payment of $70 is executed between non-custodial wallet A and non-custodial wallet B (S71).

[0105] Non-custodial wallet A is assumed to hold $50 USDC and $60 USDT (S72).

[0106] Non-custodial wallet A sends $50 USD by embedding $50 USD in the transaction data and sending it to the address of seller's non-custodial wallet B (S73).

[0107] Non-custodial wallet A sends $20 USD to the seller's non-custodial wallet B by embedding $20 USD in the transaction data and sending it (S74), thus completing the transaction.

[0108] Non-custodial wallet B identifies which transactions are related to the same settlement (S75). If non-custodial wallet B can match the transactions related to the same settlement, it confirms the transfer of $70 (S76), the settlement is completed (S77), and the process ends.

[0109] Figure 14 shows a comparison between this embodiment and a comparative example. As shown in Figure 14, the comparison is made from the perspective of unified management across multiple crypto assets, reduction of the burden on the seller, real-time performance and efficiency, and the balance between privacy protection (especially in retail payments, there are cases where it is necessary to conduct payments that require privacy (hair growth products, diet products, adult-only products, etc.), but since blockchain information is public, anyone can look it up) and convenience. To achieve this, one requirement is to keep the buyer's wallet address unknown. In non-custodial wallet A, a derived private key based on BIP32 / BIP44 is generated using the private key of this wallet, and a hierarchical deterministic wallet (HD wallet) based on this derived private key is prepared on the blockchain, and a mechanism is adopted to send funds from this HD wallet to non-custodial wallet B. In this case, two wallets will be prepared. While BIP32 / BIP44 was presented as a method for creating multiple wallets within non-custodial wallet A, it is also possible to generate multiple wallets from random numbers generated within non-custodial wallet A, or to create multiple public key pairs using the wallet address of non-custodial wallet A as a seed and use these to generate multiple wallets. Since the objective is to protect privacy in retail payments, privacy can be adequately protected by pre-generating two or more wallets within non-custodial wallet A and using them interchangeably as needed. Furthermore, concealment can be achieved by performing the following processing.

[0110] Regarding unified management across multiple cryptocurrencies, in the comparative example, it is necessary to identify which transactions are related to the same settlement. However, since there is no information to use for identification, the seller needs to manually or through a separate system to reconcile the transactions. Manually reconcile multiple transactions is inefficient and time-consuming, negatively impacting the real-time capabilities required for retail settlements. Furthermore, if a large number of transactions occur simultaneously, especially if multiple transfers from the same wallet address occur in different stablecoins within a short time interval, the reconciliation process becomes complicated. In contrast, in this embodiment, a common transaction number is used, making it possible to associate transactions across different cryptocurrencies. The common transaction number is transmitted on-chain via the blockchain from non-custodial wallet B to non-custodial wallet A before the retail settlement begins. The transaction number can be in plain text. On the non-custodial wallet side, instead of using the transaction number in plain text, if the transaction number is ZA12345, a sub-number such as ZA12345001 is added, and the hashed information is written to the memo field of the transaction data for processing. This process hides the transaction number. In the case of blockchains without a memo field, for example, Bitcoin allows the inclusion of up to 80 bytes of data in a transaction using a script called OP_RETURN, so this is used to include the hashed transaction number information. On smart contract platforms such as Ethereum, a custom function is created to include the hashed transaction number information. By adopting this mechanism, matching can be performed efficiently and simply not only from the wallet address of the non-custodial wallet side, but also from the wallet address of a hierarchical deterministic wallet.

[0111] Regarding the reduction of the burden on the seller, in the comparative example, difficult matching work and complex processing are required between multiple transactions of different types of cryptocurrencies. In contrast, in this embodiment, the matching work between multiple transactions of different types of cryptocurrencies can be performed automatically (sharing of how to assign sub-numbers to transaction numbers and which hash function to use is necessary. As a method for assigning sub-numbers, the result using Base64 encoding based on the wallet address of the buyer's non-custodial wallet A may be used. In this method, the seller's non-custodial wallet B can also know this), thus eliminating the need for difficult matching work and complex processing that occurred on the seller's side.

[0112] Regarding real-time performance and efficiency, in the comparative example, difficult matching work and complex processing are required (for example, finding transactions with consecutive nonce information and short transaction time intervals), which increases the working time, thus failing to ensure real-time performance and reducing efficiency. In contrast, in this embodiment, the difficult matching work and complex processing that occurred on the seller's side are eliminated, thus improving real-time performance and efficiency.

[0113] Regarding the balance between privacy protection and convenience, in the comparative example, the buyer's blockchain address and transaction history are visible from the outside. Furthermore, managing transactions on the seller's side is complex, making it difficult to balance privacy protection and convenience. In contrast, in this embodiment, although a common transaction number is visible from the outside, it is hashed, and instead of using the blockchain address of the buyer's non-custodial wallet A directly, the original wallet address of non-custodial wallet A is not used, regardless of whether it is pre-prepared or generated in real time within non-custodial wallet A, making it difficult to determine from the outside. In addition, by adding a sub-number to the transaction number, hashing it, and including it in the transaction data, transaction management becomes easier for the seller (by preparing the hashed data with the sub-number added before performing the matching work), thus achieving a balance between privacy protection and convenience.

[0114] While the example uses two different stablecoins, the method described above can also protect privacy when using the same stablecoin. That is, the amount to be sent can be divided into multiple transactions. (For example, 50 USDC and 20 USDT were used, but it could be 50 USDC and 20 USDC.)

[0115] Figure 15 shows a second example of retail payment processing using multiple crypto assets in this embodiment. Steps S81 to S82 in Figure 15 are the same as steps S51 to S52 shown in Figure 12, and steps S87 to S94 in Figure 15 are the same as steps S53 to S60 shown in Figure 12, so their explanation will be omitted. Steps S83 to S86 will be explained below.

[0116] The non-custodial wallet 70 manages different crypto assets on multiple different blockchains. Specifically, $50 USDC is recorded on the first blockchain (S83). Also, $60 USDT is recorded on the second blockchain (S84).

[0117] The non-custodial wallet 70 extracts $20 USDT from the second blockchain, bridges the blockchains, and records it on the first blockchain (S85). In step S85, in addition to extracting $20 USDT from the second blockchain, $50 USDC may also be extracted from the first blockchain.

[0118] The non-custodial wallet 70 displays the total transfer amount (70 USD), which is the sum of 50 USD and 20 USD (S86), and continues processing from step S87 onwards.

[0119] As described above, the first blockchain among the multiple blockchains connected to the non-custodial wallet records the first crypto asset, the second blockchain among the multiple blockchains records the second crypto asset, the non-custodial wallet can extract the first amount of the first crypto asset from the first blockchain, extract the second amount of the second crypto asset from the second blockchain, and display the sum of the extracted first and second amounts.

[0120] Furthermore, the system generates first transaction data containing the transfer amount of the first cryptocurrency and common transaction information, generates second transaction data containing the transfer amount of the second cryptocurrency and common transaction information, sends the generated first and second transaction data to the custodial wallet address owned by the other party, and the custodial wallet can then match the first and second transaction data based on the common transaction information.

[0121] Figure 16 shows the screen display of the user's buyer terminal device 50 when using multiple different crypto assets. The screen display shown in Figure 16 can be displayed by processing step S86 in Figure 15. The user first operates the buyer terminal device 50 to launch the non-custodial wallet app and select payment, at which point a screen for selecting the payment method will be displayed, and the payment methods will be shown. In the example in Figure 9, "2D barcode payment," "NFC touch payment," and "online payment" are displayed. For example, the user selects "2D barcode payment."

[0122] Next, the user scans the two-dimensional barcode displayed on the seller device 90, confirms that the scanned barcode is displayed, and operates the OK icon. The screen displays "Sending $70" and shows the breakdown of the transfer amount ($70) as $50 USDC and $20 USDT. The user operates the payment icon. This completes the retail payment.

[0123] Figure 17 shows a first example of the process for notifying legal heirs of assets in a non-custodial wallet. Assume that User A owns non-custodial wallet A and non-custodial wallet B. Non-custodial wallet A has waived its confidentiality and is registered with KYC, and is used for daily payments. Non-custodial wallet B maintains its confidentiality (is not registered with KYC) and is used to increase assets. Assume that User A has died.

[0124] If non-custodial wallet B determines that user A has not used non-custodial wallet B for a predetermined period (for example, 3 months) (S101), it sends all assets from non-custodial wallet B to non-custodial wallet A (S102) and terminates the process.

[0125] Non-custodial wallet A receives the assets of non-custodial wallet B (S103), combines the assets of non-custodial wallets A and B (S104), transfers the combined assets to user A's legal heirs (S105), and terminates the process. The private key or seed phrase of non-custodial wallet A may be disclosed to the legal heirs by a bank (or company) registered with KYC after confirming through official documents that user A is deceased.

[0126] As described above, the first non-custodial wallet owned by the user is a non-custodial wallet that has undergone identity verification, while the second non-custodial wallet owned by the user is a non-custodial wallet that has not undergone identity verification. The second non-custodial wallet is configured to generate transaction data to move the crypto assets held in the second non-custodial wallet to the first non-custodial wallet if the user has not used the second non-custodial wallet for a specified period of time, and to send the generated transaction data to the address of the first non-custodial wallet. Alternatively, a smart contract can be used, and this smart contract can be configured to move the crypto assets from the second non-custodial wallet to the first non-custodial wallet.

[0127] This setting (examples of how to set it up: using a smart contract to send funds from the second non-custodial wallet to the first non-custodial wallet, or sending funds directly to the first non-custodial wallet using the second non-custodial wallet's program) allows the first non-custodial wallet to present the user's legal heirs with the combined amount of crypto assets held by the first non-custodial wallet and the crypto assets moved from the second non-custodial wallet.

[0128] The process illustrated in Figure 17 demonstrates that by depositing the private key of KYC-enabled non-custodial wallet A with a bank, the private key can be recovered even if user A, the owner of non-custodial wallet A, passes away. Below, we will explain the case of broadly storing "digital assets" as well. Here, digital assets refer to not only data with monetary value that the deceased stored in digital format, but also information on subscription contracts (including information on cancellation), as well as authentication information for online bank accounts, electronic money, various points and mileage programs, online securities accounts, FX accounts, etc. These have no physical form and are only accessible through the internet or digital devices, and are protected by IDs and passwords, making it difficult for heirs to recognize their existence and content. If you wish to store these digital assets in KYC-enabled non-custodial wallet A of this embodiment, by combining these management functions with the process illustrated in Figure 17, legal heirs will be able to properly inherit the digital assets, including the deceased's crypto assets.

[0129] Figure 18 shows a second example of the process of notifying legal heirs of assets in a non-custodial wallet. Figure 18 shows an example of a digital estate management system using a non-custodial wallet. Assume that user A owns multiple non-KYC non-custodial wallets (e.g., MetaMask, Phantom, etc.) in addition to KYC-certified non-custodial wallet A. These non-KYC non-custodial wallets hold a considerable amount of cryptocurrency for asset building purposes, and if the private key information of these non-KYC non-custodial wallets is lost, access to the assets becomes completely impossible.

[0130] User A's non-custodial wallet A provides a "digital legacy storage" function. User A, during their lifetime, uses this function to input the private key information of another non-custodial wallet (non-KYC non-custodial wallet), thereby allowing non-custodial wallet A to acquire the private key information of the other non-custodial wallet (S201). The acquired information may include not only the private key information but also the seed phrase of the other non-custodial wallet.

[0131] The acquired private key information is encrypted using an arbitrary encryption algorithm such as AES-256, with the private key of non-custodial wallet A as the seed to generate an encryption key within non-custodial wallet A (using PBKDF2, Script, or the common key generation method described in Japanese Patent No. 6863514, etc.), and then encrypted using this key (S202).

[0132] The encrypted private key information is stored in a distributed storage system such as IPFS / Arweave. As a result of storing it in these distributed storage systems, unique address information is generated, and non-custodial wallet A obtains the generated unique address information (S203).

[0133] Non-custodial wallet A registers its unique address information with a smart contract for digital legacy management (S204). This smart contract records the correspondence between the address of non-custodial wallet A and the unique address information obtained as a result of saving. This smart contract is designed to return the unique address information only when authentication is performed using the private key of a legitimate KYC-certified non-custodial wallet.

[0134] If User A dies, the legal heirs shall follow the prescribed legal procedures with the bank to obtain the private key information for KYC-registered non-custodial wallet A (S205).

[0135] The legal heir installs the wallet application on the terminal device and enters the acquired private key information to restore non-custodial wallet B (S206). At this point, the restored non-custodial wallet is not a regular KYC-certified non-custodial wallet. For convenience, it is referred to as non-custodial wallet B to clarify that it is not KYC-certified non-custodial wallet A.

[0136] Non-custodial wallet B connects to the smart contract and, by performing legitimate authentication (authentication using the private key of non-custodial wallet B), retrieves encrypted unique address information recorded in decentralized storage (S207).

[0137] Non-custodial wallet B uses the acquired unique address information to retrieve encrypted private key information of other non-custodial wallets from decentralized storage, generates an encryption key internally within non-custodial wallet B using its own private key as a seed, and uses this to decrypt the private key information of other non-custodial wallets (non-KYC non-custodial wallets) using an arbitrary encryption algorithm such as AES-256 (S208).

[0138] The decrypted information, i.e., the digital legacy, will include seed phrases and other information from other non-custodial wallets, which will be displayed in the non-custodial wallet app. Legal heirs will then be able to use this information to restore other non-custodial wallets and other digital legacy information.

[0139] As described above, by implementing digital estate management functionality in KYC-certified non-custodial wallets, it becomes possible to transfer digital assets, including non-KYC non-custodial wallets, while utilizing inheritance procedures through collaboration with banks. This system not only ensures that the deceased's crypto assets are properly transferred to the heirs, but also eliminates the risk of various digital assets being lost and allows for the appropriate termination of subscription agreements. In short, digital estate management is achieved while ensuring privacy and security by utilizing a system in which digital assets are encrypted and distributed storage is used, smart contracts are employed, and a KYC-registered bank (or company) verifies the death of user A through official documents and discloses the private key of the KYC-certified non-custodial wallet to the legal heirs.

[0140] As another example of the process illustrated in Figure 18, we show a method to reduce the risk of losing the private key while maintaining true non-custodial nature. In this method, cryptographic techniques such as Shamir's secret sharing are used to split the private key of the non-custodial wallet 70 into two parts (split keys K1 and K2). Because of this split, the private key cannot be recovered unless both split keys are present, and therefore, neither can function as a private key on its own.

[0141] The first splitting key K1 is encrypted using the method shown in Figure 6 and sent to the bank server 200. The second splitting key K2 is stored in the non-custodial wallet of the smartphone. For example, an app that is set to activate when the deceased has not used the phone for more than one month, and the legal heir submits the necessary documents to the bank. The Bluetooth® terminal installed in the bank's special room is pre-configured with a 128-bit identifier such as "123e4567-e89b-12d3-a456-426614174000" and is guaranteed to be globally unique. When the legal heir holds the deceased's smartphone over the terminal, Bluetooth communication is established based on the UUID match, and the splitting key K2 can be obtained from the smartphone. After user authentication, the bank server 200 is requested to send the first splitting key K1. A non-custodial wallet application that receives both split keys K1 and K2 can combine them to recover the private key. One example of a method for splitting a private key is the Shamir Secret Sharing method, but this is not the only method. Furthermore, while the explanation describes splitting the private key into two, it is also possible to split it into three or more parts and store each part on a smartphone, a My Number card, and a bank server.

[0142] According to this system, the split key K2 cannot be obtained unless the bank verifies that the person is a legal heir, brings the deceased's smartphone to a special room at the bank, and holds it up to a specific terminal. Therefore, even if the UUID is the same for all customers, no security issues arise. In other words, this method requires physical restrictions and documents proving legal heirship, so it can safely and efficiently recover the private key of the deceased's non-custodial wallet and allow the inheritance of the deceased's digital legacy.

[0143] Figure 19 shows an example of a user-specific, dedicated non-custodial wallet. If the user is a preschooler, the VC used in the non-custodial wallet can be a VC generated within the preschooler's non-custodial wallet by transferring and recording the DID in the parent's non-custodial wallet, and then signing the parent's VC (a VC with the parent's signature). Alternatively, if the user is a preschooler, the VC may be generated within the preschooler's non-custodial wallet based on the remittance record of the user's part-time job from their employer (for example, after a certain period of time). To improve the efficiency and reliability of VC generation, it is preferable that the employer sends remittances from a KYC-enabled wallet, and that the DID and VC are delivered with the employer's signature. Here, "employer" is used, but this includes companies that regularly send wages to the user's non-custodial wallet.

[0144] To verify the address of a preschooler, the non-custodial wallet can confirm that the GPS information was within the same range as the parent's for a certain period of time, during what is presumably the child's sleeping hours. This can enhance the legitimacy of the address data written in the parent's DID (Define ID). The enhanced results may be reflected in the VC. For information regarding the date of birth, the VC issued by the parent takes precedence. That is, if there is a contradiction when the preschooler generates date of birth information in the non-custodial wallet, the parent's VC will be considered correct.

[0145] If the user is an inbound tourist, preferably a non-custodial wallet specifically for inbound tourists is distributed at immigration checkpoints and nearby currency exchange offices. The VC used in this non-custodial wallet is read from passports with built-in IC chips by having a reading function installed in the non-custodial wallet. In the case of passports without built-in IC chips, the necessary information can be obtained from images taken with a smartphone camera, and this information can be used to create the VC. If the user is a private citizen, the VC used in the non-custodial wallet can be a VC issued by a bank or the company where the user works. In this case, the non-custodial wallet may be able to process the VC as needed and present the necessary information upon request.

[0146] Figure 20 shows an example of a deposit and transfer process between a bank account and another account. Steps S111 to S113 show the transfer process from the bank account to the non-custodial wallet 70, and steps S114 to S117 show the deposit process from the non-custodial wallet 70 to the bank account.

[0147] The non-custodial wallet 70 sends a transfer request to the bank server 200, specifying the bank account number (S111). The bank server 200 verifies the user based on the linking information (related information) between the non-custodial wallet 70 address and the bank account number (S112), and sends the stablecoin to the user's non-custodial wallet 70 address (S113).

[0148] The non-custodial wallet 70 sends stablecoins by specifying a bank account number (S114). The bank server 200 verifies the user based on the linking information (related information) between the address of the non-custodial wallet 70 and the bank account number (S115), converts the stablecoins to fiat currency and deposits it into the user's bank account (S116), and then terminates the process.

[0149] Figure 21 shows an example of the configuration of a common DID database. Banks B1, B2, and B3 each issue a DID based on information (related information) linking the non-custodial wallet address of a user who owns a bank account number for that bank with that bank, and record it in a common database. Similarly, companies E1, E2, and E3 each issue a VC based on information (related information) linking the non-custodial wallet address of a user who owns a membership number for that company with that membership number, and record it in a common database.

[0150] In the example in Figure 21, the non-custodial wallet address is "A001," and bank B1 issues a DID, which is written as "A001B1." The codes used here are for convenience only. The same applies to other non-custodial wallet addresses.

[0151] The common database can be used by the group of banks and companies that have provided the DID. This enables the creation of a secure payment system using KYC-registered non-custodial wallets.

[0152] Figure 22 shows an example of the display screens of the buyer terminal device 50 and the seller device 90 during retail payment. The buyer terminal device 50 displays DID information, bank name, and payment icon. The DID information may be the DID itself, or it may be display information formatted for presentation called VP (Verifiable Presentation), which can be uniquely generated from the DID. "A001B1" is displayed as the DID information, and bank B1 is displayed as the bank name.

[0153] The seller's device 90 displays DID information and the bank name. The DID information displays "A001B1," and the bank name displays Bank B1. The seller and buyer can confirm that the displayed VC information and bank name match. This helps prevent accidental transmission or fraudulent attacks targeting the wrong recipient.

[0154] As described above, the user's DID or display information uniquely generated from the DID is displayed on the user's terminal device and presented to the counterparty's terminal device for retail payment. If the counterparty's terminal device can verify the DID or the display information uniquely generated from the DID, the retail payment can be processed. At this time, KYC-related information (for example, information indicating both parties' KYC-completed wallets, or whether the payment amount is low, medium, or high) is encoded and included in the transaction's DATA field.

[0155] The non-custodial wallet of this embodiment can be offered, for example, under a bank's brand name (a so-called white-label business), and each bank can distribute it to its account holders (KYC is registered). Each bank can benefit from the following: (1) The distribution cost of the non-custodial wallet is low, and since current account holders (sellers) can make 1:1 retail payments with buyers (who also possess non-custodial wallets), there is no need for security investment costs and deposits can be made in real time (at a micro level in a certain region, there are cases where buyers use non-custodial wallets from multiple bank brands, but this does not pose any problem for retail payments). (2) Fee income can be expected from deposits from the seller's non-custodial wallet to the current account (including exchanges from stablecoins to yen). (3) The right to deliver advertisements to the non-custodial wallets distributed to buyers and the potential for business income can be expected. (4) In addition to the service of exchanging stablecoins for yen and depositing them into accounts, a business model can be built in which each bank can earn money by providing DeFi services (staking, lending, etc.). (5) A business can be developed that allows for the secure storage of account customers' digital assets. (6) It will be easier to acquire the next generation (children of families who become adults and open new accounts) because a method will be provided for distributing non-custodial wallets for preschool children.

[0156] (Note 1) The information processing method is an information processing method by a computer that functions as a non-custodial wallet on the user's terminal device, comprising the steps of: providing the address of the non-custodial wallet to a person who performed an identity verification procedure prior to the commencement of use of the non-custodial wallet; receiving via a communication network one or more signed authentication pieces of information, each containing at least information indicating the completion of the user's identity verification procedure, and bearing a first digital signature with a private key managed by the person who performed the identity verification procedure; and locally generating one or more user authentication data on the user's terminal device, each including at least a portion of the information contained in at least one of the one or more signed authentication pieces of information and further including one or more pieces of information concerning the user, and affixing a second digital signature with a private key locally managed by the non-custodial wallet to each of the user authentication data pieces. The process includes the steps of generating one or more user authentication information, storing at least one of the one or more signed authentication information and / or at least one of the one or more user authentication information in a local storage area managed by the user, and transmitting at least one of the one or more signed authentication information or at least one of the one or more user authentication information to the other party's device when sending or settling, wherein the signed authentication information allows for verification of the completion of the identity verification procedure by verification of the first electronic signature, the user authentication information allows for verification of the legitimacy of the user's management authority over the non-custodial wallet by verification of the second electronic signature, and by using at least one of the information contained in the signed authentication information and the information contained in the user authentication information, it is possible to verify that the non-custodial wallet has undergone identity verification and that the user is the one who holds the private key of the non-custodial wallet.

[0157] (Note 2) The information processing method, as stated in Note 1, includes any of the following: the person who performed the identity verification procedure is a financial institution, a public institution, or a payment service provider.

[0158] (Note 3) The information processing method, as described in Note 1, allows the generation of user authentication information and the application of the electronic signature to be performed even on the user's terminal device in an offline state, without requiring a network connection to an external server.

[0159] (Note 4) The information processing method further includes the step of providing to the payment or remittance recipient by at least one of the following methods: attaching the user certificate information and the signed authentication information to the payment transaction in a form that can be obtained in association with the payment transaction, or transmitting it via a communication network prior to sending the payment transaction; and executing the payment or remittance by signing the payment transaction with a private key locally managed by the non-custodial wallet and sending it to the network.

[0160] (Note 5) The information processing method, as described in Note 4, involves the other party's device verifying that the non-custodial wallet has undergone identity verification by comparing the address of the non-custodial wallet included in the received signed authentication information or user authentication information with the sender's address.

[0161] (Note 6) The information processing method, as described in Note 4, involves the non-custodial wallet determining on the user's terminal device whether the settlement or remittance amount included in the settlement transaction is equal to or greater than a predetermined amount, and if it is determined that the settlement or remittance amount is equal to or greater than the predetermined amount, it automatically transmits at least one of the user certificate information and the signed authentication information in a format that can be obtained in association with the settlement transaction to at least one of the recipient wallet, the intermediary involved in the processing of the remittance, or the person who performed the identity verification procedure via the communication network, and by verifying the electronic signature included in the transmitted user certificate information and the signed authentication information, it becomes possible to confirm that the identity verification procedure has been completed.

[0162] (Note 7) The information processing method, as described in Note 4, is carried out by storing at least one of the user authentication information and the signed authentication information in the data area of ​​the settlement transaction, in a data area where the recipient of the settlement or remittance can confirm that the non-custodial wallet has undergone identity verification procedures by verifying the electronic signature.

[0163] (Note 8) In the information processing method, in the step in Note 4 in which the non-custodial wallet performs the transfer of crypto assets, the non-custodial wallet provides at least one of the signed authentication information and the user authentication information it holds to the wallet of the recipient of the transfer in association with the transfer, and the non-custodial wallet performs the transfer after verifying that the wallet of the recipient of the transfer has undergone identity verification procedures by cryptographically verifying the electronic signature contained in the information obtained from the wallet of the recipient of the transfer.

[0164] (Note 9) The information processing method, as specified in Note 4 or Note 7, obtains transaction identification information from the terminal device of the counterparty to the settlement or remittance, which does not include personal information identifying the seller or buyer, and generates the settlement transaction including the obtained transaction identification information, the amount to be remitted, and the type of crypto asset to be used.

[0165] (Note 10) The information processing method, as stated in Note 9, is such that the transaction identification information is an identifier generated for each transaction and does not include any personal information or attribute information that identifies the seller or buyer, nor any information that identifies the content of the transaction.

[0166] (Note 11) The information processing method, in any one of Notes 4 to 10, provides at least one of the user authentication information and the signed authentication information to the counterparty in face-to-face payment using short-range wireless communication.

[0167] (Note 12) The information processing method, in any one of Notes 4 to 10, provides the other party with at least one of the user authentication information and the signed authentication information in face-to-face payment using a two-dimensional code.

[0168] (Note 13) The information processing method, in any one of Notes 4 to 12, involves the non-custodial wallet outputting display information generated from at least one of the signed authentication information or user authentication information received from the payment or remittance recipient's wallet to the screen of the terminal device, the wallet operating on the payment or remittance recipient's terminal device outputting display information generated from at least one of the signed authentication information or user authentication information received from the non-custodial wallet to the screen of the terminal device, and the user and the payment or remittance recipient confirming the display information displayed on their respective terminal devices, after which they execute the payment or remittance by operating the non-custodial wallet.

[0169] (Note 14) The information processing method, in any one of Notes 1 to 13, includes the step of generating one or more user authentication data by converting at least a portion of the personal identification information contained in the signed authentication information using a one-way function and storing the converted value in the user authentication data, wherein the conversion is performed locally on the user's terminal device without relying on an external server.

[0170] (Note 15) The information processing method is expressed in a certification format in any one of Notes 1 to 14 such that at least a portion of the information contained in the one or more user authentication data satisfies predetermined conditions without disclosing the specific values ​​of the information.

[0171] (Note 16) The information processing method is as follows: In Note 1, the signed authentication information does not include access information to external resources.

[0172] (Note 17) In the information processing method, as described in Note 1, a key pair generated based on a cryptographic algorithm with quantum resistance is used as the public key cryptographic key pair used to generate the signed authentication information.

[0173] (Note 18) The information processing method, as described in Note 1, involves the non-custodial wallet generating one or more derived private keys and corresponding public keys from the non-custodial wallet's private key, storing the generated one or more derived private keys and public keys in the non-custodial wallet's local storage area, and switching between and using the one or more derived private keys and public keys in retail settlement or remittance.

[0174] (Note 19) The information processing method, as described in Note 1, further includes, in addition to the information electronically signed by the person who performed the identity verification procedure, attribute information signed by a third-party organization having a predetermined relationship with the user using the private key of the said third-party organization, and the attribute information includes at least one of the following: transaction history, credit evaluation, or fund transfer records between the third-party organization and the user.

[0175] (Note 20) The information processing method, in any one of Notes 1 to 19, sends a request to a server managed by the person who performed the identity verification procedure for the transfer of crypto assets from the account to the non-custodial wallet, specifying account identification information that identifies an account managed by the person who performed the identity verification procedure; the server verifies the user based on related information that associates the address of the non-custodial wallet with the account identification information; and if the verification is successful, transfers the crypto assets from the account to the address of the non-custodial wallet.

[0176] (Note 21) The information processing method is as follows: In any one of Notes 1 to 19, the non-custodial wallet specifies account identification information that identifies an account managed by the person who performed the identity verification procedure, and sends the crypto assets along with a transfer request to the account to a server managed by the person who performed the identity verification procedure. The server verifies the user based on related information that associates the address of the non-custodial wallet with the account identification information, and if the verification is successful, converts the received crypto assets into fiat currency and deposits them into the account corresponding to the account identification information.

[0177] (Note 22) The information processing method, in any one of Notes 4 to 13, involves the non-custodial wallet generating a derived private key and a public key corresponding to the derived private key from a locally managed private key, and sending the crypto assets to the wallet address of the payment or remittance recipient via at least one temporary wallet having an address calculated from the public key, thereby making it difficult to track the transaction without fixing the address of the sending wallet.

[0178] (Note 23) The information processing method, in any one of Notes 4 to 13, after the settlement or remittance is completed, receives an electronic transaction record from the counterparty to the settlement or remittance and receives compensation equivalent to the transaction fee for the use of the distributed ledger required for the transaction related to the settlement or remittance.

[0179] (Note 24) The information processing method, as stated in Note 23, includes compensation in the form of digital value equivalent to the added value recorded in the transaction record, in addition to compensation for network usage fees.

[0180] (Note 25) The information processing method is as follows, in any one of Notes 4 to 13, the non-custodial wallet holds multiple crypto assets, generates individual transaction data for each of the multiple crypto assets including an individual transfer amount and common transaction identification information, sends each individual transaction data to the wallet address of the payment or transfer recipient, and the recipient matches each individual transaction data based on the common transaction identification information to complete the payment or transfer.

[0181] (Note 26) The information processing method, as described in Note 25, involves the non-custodial wallet holding multiple types of crypto assets recorded on one or more distributed ledger networks, summing up the amounts of the multiple types of crypto assets held, and using the summed amount for the settlement or remittance.

[0182] (Note 27) The information processing method, in any one of Notes 1 to 26, allows the transfer of digital assets managed by a second non-custodial wallet owned by the user, which has not undergone identity verification procedures, to a non-custodial wallet that has undergone identity verification procedures, provided that the specified conditions are met.

[0183] (Note 28) The information processing method, as described in Note 27, involves summing the digital assets managed by the non-custodial wallet that has undergone identity verification procedures and the transferred digital assets, and then transferring them to the user's heirs.

[0184] (Note 29) The information processing method is as follows, in any one of Notes 1 to 26, the non-custodial wallet that has undergone identity verification procedures encrypts the private key information of another wallet using its own private key, stores the encrypted private key information in distributed storage, registers access information to the distributed storage in a smart contract, and enables an heir who has gone through the prescribed inheritance procedures to recover the private key information of the other wallet through the smart contract.

[0185] (Note 30) The information processing method is an information processing method for the private key of a non-custodial wallet owned by a user, and includes the steps of: the non-custodial wallet divides the private key into a plurality of partial keys; distributes and stores the plurality of partial keys in a plurality of different storage locations; and when the restoration of the private key is necessary, retrieves the plurality of partial keys from each of the plurality of storage locations and combines the retrieved plurality of partial keys to make the private key retrievable, wherein no single storage location can restore the private key on its own.

[0186] (Note 31) The information processing method, as specified in Note 30, includes at least two of the following storage locations: a server managed by the person who performed the identity verification procedure, a terminal device owned by the user, and a portable recording medium owned by the user.

[0187] (Note 32) The information processing method, as described in Note 30 or Note 31, allows the user's heirs to inherit the digital assets held by the user after the user's death by obtaining the multiple partial keys from the multiple storage locations through a prescribed procedure and restoring the private key.

[0188] (Note 33) The information processing method, as described in Note 32, encrypts at least one of the plurality of partial keys using the private key of the non-custodial wallet whose identity has been verified, stores the encrypted partial key in decentralized storage, and registers access information to the decentralized storage in a smart contract, thereby enabling the heir to obtain the partial key through the smart contract.

[0189] (Note 34) The information processing system is an information processing system equipped with a non-custodial wallet for which the user's identity has been verified, and the non-custodial wallet performs one of the above-described information processing methods.

[0190] (Note 35) The information processing system comprises a first terminal device of a user, a second terminal device of the recipient of a payment or remittance by the user, and a server managed by the person who performed the identity verification procedure, wherein the first terminal device comprises a non-custodial wallet that performs any one of the above-described information processing methods, the second terminal device comprises a non-custodial wallet or custodial wallet that has undergone identity verification, the non-custodial wallet or custodial wallet of the second terminal device confirms the completion of the user's identity verification procedure by verifying the electronic signature contained in at least one of the user certificate information or signed authentication information received from the user's non-custodial wallet, the server manages related information that associates the address of the non-custodial wallet with the customer identification information of the user, and verifies the user based on the related information.

[0191] (Note 36) The computer program causes the computer, which functions as a non-custodial wallet owned by the user, to execute one of the aforementioned information processing methods.

[0192] (Note A1) The information processing method is such that a non-custodial wallet owned by a user is identified as having undergone identity verification procedures based on related information that associates the address of the non-custodial wallet with the user's customer identification information, through the identity verification procedures performed when the user's customer identification information is set up, and retail payments are made using the identity-verified non-custodial wallet. More specifically, the information processing method is such that a non-custodial wallet owned by a user is identified as having undergone identity verification procedures based on related information that associates the address of the non-custodial wallet with the user's customer identification information, through the identity verification procedures performed when the user's customer identification information is set up, and the user's identity-verified non-custodial wallet makes retail payments with the other party's non-custodial wallet or custodial wallet.

[0193] (Note A2) The information processing method is as described in Note A1, in face-to-face retail payment, the non-custodial wallet uses NFC functionality.

[0194] (Note A3) The information processing method is as follows: In face-to-face retail payments, the non-custodial wallet uses a two-dimensional barcode function.

[0195] (Appendix A4) The information processing method, in any one of the appendices A1 to A3, includes a bank account number as the customer identification information, accepts the designation of the bank account number and the remittance request, and sends stablecoins from the bank account number to the address of the non-custodial wallet. More specifically, the information processing method includes a bank account number as the customer identification information, the bank server accepts the designation of the bank account number and the remittance request, and the bank server sends stablecoins from the bank account number to the address of the user's verified non-custodial wallet.

[0196] (Appendix A5) The information processing method is as follows: In any one of the appendices A1 to A4, the customer identification information includes a bank account number, the bank server accepts the designation of the bank account number and a deposit request, and deposits stablecoins from the non-custodial wallet to the bank account number. More specifically, the information processing method is as follows: the customer identification information includes a bank account number, the bank server accepts the designation of the bank account number and a deposit request, and the bank server deposits stablecoins from the user's verified non-custodial wallet to the bank account number.

[0197] (Appendix A6) The information processing method records a decentralized identifier issued by the bank in any one of the appendices A1 to A5. More specifically, the information processing method records a decentralized identifier issued by the bank in at least one of the following: the user's verified non-custodial wallet, the retail payment counterparty's non-custodial wallet or custodial wallet, the blockchain, a predetermined database, IPFS, and cloud storage.

[0198] (Appendix A7) The information processing method is attribute information in which all or part of the attribute information of the distributed identifier has been hashed, as described in Appendix A6.

[0199] (Appendix A8) The information processing method, in Appendix A6, uses the distributed identifier containing the attribute information as a starting point of trust, adds the user's attribute information, signs it using the private key of the non-custodial wallet to generate the user authentication information, and enables retail payment by verifying the attribute information contained in the distributed identifier and the attribute information contained in the user authentication information. More specifically, the information processing method enables retail payment by having the user's verified non-custodial wallet use the distributed identifier containing the attribute information as a starting point of trust, adds the user's attribute information, signs it using the private key of the user's verified non-custodial wallet to generate the user authentication information, and having the counterparty's non-custodial wallet or custodial wallet verify the attribute information contained in the distributed identifier and the attribute information contained in the user authentication information.

[0200] (Appendix A9) The information processing method, as described in Appendix A8, displays the decentralized identifier or the display information uniquely generated from the decentralized identifier on the user's terminal device and presents it to the counterparty's terminal device for the retail payment. If the counterparty's terminal device is able to verify the decentralized identifier or the display information, the retail payment is made. More specifically, the information processing method displays the decentralized identifier or the display information uniquely generated from the decentralized identifier on the user's terminal device and presents it to the counterparty's terminal device for the retail payment. If the counterparty's terminal device is able to verify the decentralized identifier or the display information, the retail payment is made.

[0201] (Appendix A10) The information processing method, in any one of the appendices A1 to A9, acquires transaction information identifying the transaction from the counterparty's terminal device for the retail payment, generates transaction data including the acquired transaction information and the amount to be sent, and transmits the generated transaction data to the address of the counterparty's verified non-custodial wallet or custodial wallet. More specifically, the information processing method involves the user's verified non-custodial wallet acquiring transaction information identifying the transaction from the counterparty's terminal device for the retail payment, the user's verified non-custodial wallet generating transaction data including the acquired transaction information and the amount to be sent, and the user's verified non-custodial wallet transmitting the generated transaction data to the address of the counterparty's verified non-custodial wallet or custodial wallet.

[0202] (Appendix A11) The information processing method, in any one of Appendix A1 to A10, generates a derived private key and a public key corresponding to the derived private key based on the private key of the non-custodial wallet, and sends the crypto assets to the verified non-custodial wallet or custodial wallet address via a wallet having a wallet address calculated from the generated public key. More specifically, the information processing method, in which the user's verified non-custodial wallet generates a derived private key and a public key corresponding to the derived private key based on the private key of the user's verified non-custodial wallet, and the user's verified non-custodial wallet sends the crypto assets to the verified non-custodial wallet or custodial wallet address via a wallet having a wallet address calculated from the generated public key.

[0203] (Appendix A12) The information processing method, in any one of the appendices A1 to A11, replenishes the gas fee to the non-custodial wallet when a retail payment using the non-custodial wallet that has undergone identity verification is completed. More specifically, the information processing method, when a retail payment using the non-custodial wallet that has undergone identity verification is completed, replenishes the gas fee to the non-custodial wallet or custodial wallet of the counterparty to the retail payment.

[0204] (Appendix A13) In the information processing method, as described in Appendix A12, when a retail payment using the non-custodial wallet that has undergone identity verification is completed, the non-custodial wallet will compensate for the gas charges equivalent to the amount of points indicated on the receipt received from the non-custodial wallet or custodial wallet that has undergone identity verification owned by the other party, at the time the receipt is received. More specifically, in the information processing method, when a retail payment using the non-custodial wallet that has undergone identity verification is completed, the non-custodial wallet that has undergone identity verification will compensate for the gas charges equivalent to the amount of points indicated on the receipt received from the non-custodial wallet or custodial wallet that has undergone identity verification owned by the other party, at the time the receipt is received.

[0205] (Appendix A14) The information processing method is as follows: In any one of Appendix A1 to A13, the non-custodial wallet holds multiple crypto assets, generates first transaction data including the transfer amount and common transaction information of the first crypto asset among the multiple crypto assets, generates second transaction data including the transfer amount and the common transaction information of the second crypto asset among the multiple crypto assets, sends the generated first transaction data and second transaction data to the address of the identity-verified non-custodial wallet or custodial wallet owned by the counterparty, and the identity-verified non-custodial wallet or custodial wallet of the counterparty matches the first transaction data and the second transaction data based on the common transaction information. More specifically, the information processing method involves the user's verified non-custodial wallet holding multiple crypto assets, generating first transaction data including the transfer amount and common transaction information for a first crypto asset among the multiple crypto assets, generating second transaction data including the transfer amount and common transaction information for a second crypto asset among the multiple crypto assets, sending the generated first and second transaction data to the address of the other party's verified non-custodial wallet or custodial wallet, and the other party's verified non-custodial wallet or custodial wallet matching the first and second transaction data based on the common transaction information.

[0206] (Note A15) The information processing method is as follows: In any one of Notes A1 to A14, the first blockchain among the multiple blockchains connected to the non-custodial wallet records the first crypto asset, the second blockchain among the multiple blockchains records the second crypto asset, the non-custodial wallet extracts the first crypto asset in a first amount from the first blockchain, extracts the second crypto asset in a second amount from the second blockchain, and displays the sum of the extracted first and second amounts. More specifically, the information processing method involves a first blockchain among a plurality of blockchains connected to the user's verified non-custodial wallet recording a first crypto asset, a second blockchain among the plurality of blockchains recording a second crypto asset, the user's verified non-custodial wallet extracting a first amount of the first crypto asset from the first blockchain, the user's verified non-custodial wallet extracting a second amount of the second crypto asset from the second blockchain, and the user's verified non-custodial wallet displaying the sum of the extracted first and second amounts.

[0207] (Appendix A16) The information processing method, in Appendix A15, generates first transaction data including the transfer amount of the first crypto asset and common transaction information, generates second transaction data including the transfer amount of the second crypto asset and the common transaction information, sends the generated first transaction data and second transaction data to the address of the identity-verified non-custodial wallet or custodial wallet owned by the counterparty, and the identity-verified non-custodial wallet or custodial wallet of the counterparty matches the first transaction data and the second transaction data based on the common transaction information. More specifically, the information processing method involves the user's verified non-custodial wallet generating first transaction data including the amount of the first crypto asset to be sent and common transaction information; the user's verified non-custodial wallet generating second transaction data including the amount of the second crypto asset to be sent and the common transaction information; the user's verified non-custodial wallet sending the generated first and second transaction data to the address of the other party's verified non-custodial wallet or custodial wallet; and the other party's verified non-custodial wallet or custodial wallet matching the first and second transaction data based on the common transaction information.

[0208] (Note A17) The information processing method is as follows: In any one of Notes A1 to A16, the first non-custodial wallet owned by the user is a non-custodial wallet that has undergone identity verification procedures, the second non-custodial wallet owned by the user is a non-custodial wallet that has not undergone identity verification procedures, and if the user has not used the second non-custodial wallet for a predetermined period of time, the crypto assets held in the second non-custodial wallet are moved to the first non-custodial wallet. The information processing method also instructs a smart contract to move the crypto assets, and the smart contract moves the crypto assets held in the second non-custodial wallet to the first non-custodial wallet.

[0209] (Appendix A18) The information processing method, as described in Appendix A17, is to present to the user's legal heir the crypto assets obtained by summing the crypto assets held by the first non-custodial wallet and the crypto assets moved from the second non-custodial wallet.

[0210] (Note A19) The information processing system comprises a first terminal device of the user and a second terminal device of the counterparty for the user's retail payment. The first terminal device is equipped with a non-custodial wallet owned by the user, and the second terminal device is equipped with a non-custodial wallet or custodial wallet owned by the counterparty that has undergone identity verification. Based on related information that associates the address of the non-custodial wallet with the user's customer identification information, the non-custodial wallet is identified as having undergone identity verification through the identity verification procedure performed when the user's customer identification information was set up, and retail payment is made between the first terminal device and the second terminal device using the identity-verified non-custodial wallet.

[0211] (Note A20) A non-custodial wallet is identified as having undergone identity verification procedures based on related information that associates the address of the non-custodial wallet owned by the user with the user's customer identification information, through the identity verification procedures performed when the user sets up their customer identification information.

[0212] (Note A21) The information processing method is an information processing method using a non-custodial wallet installed on a user's terminal device, wherein the certification authority digitally signs the address of the non-custodial wallet provided to the certification authority and the user's identity verification related information already held by the certification authority with the certification authority's private key to generate signed verifiable authentication information, distributes the generated signed verifiable authentication information to the non-custodial wallet, the non-custodial wallet stores the distributed signed verifiable authentication information, and performs settlement or transfer using the non-custodial wallet that has undergone identity verification and holds the signed verifiable authentication information.

[0213] (Appendix A22) The information processing method, as described in Appendix A21, verifies the signature of the signed verifiable authentication information using the public key corresponding to the private key of the certification authority.

[0214] (Note A23) The information processing method is as follows, in Note A21 or Note A22, the non-custodial wallet uses NFC functionality in the settlement.

[0215] (Appendix A24) The information processing method is as follows, in Appendix A23, in the settlement, the non-custodial wallet uses a machine-readable information display function other than the NFC function.

[0216] (Appendix A25) The information processing method is as follows: In any one of the appendices A21 to A24, the identity verification related information includes a bank account number, the bank account number is specified and a transfer request is received, and the crypto assets are transferred from the bank account number to the address of the non-custodial wallet.

[0217] (Appendix A26) The information processing method is as follows: In any one of the appendices A21 to A24, the identity verification related information includes a bank account number, the bank account number is specified and a deposit request is received, and crypto assets are deposited from the non-custodial wallet to the bank account number.

[0218] (Appendix A27) The information processing method includes recording the signed and verifiable authentication information issued by the bank as the authentication authority in any one of the appendices A21 to A26.

[0219] (Appendix A28) The information processing method is, as described in Appendix A27, attribute information which is all or part of the attribute information of the signed verifiable authentication information hashed.

[0220] (Appendix A29) The information processing method, as described in Appendix A28, uses the signed verifiable authentication information including the attribute information as the starting point of trust, adds the user's attribute information, signs it using the private key of the non-custodial wallet to generate the user certificate information, and enables the payment or transfer by verifying the attribute information included in the signed verifiable authentication information and the attribute information included in the user certificate information.

[0221] (Appendix A30) The information processing method, as described in Appendix A29, displays the signed verifiable authentication information or display information uniquely generated from the signed verifiable authentication information on the user's terminal device and presents it to the terminal device of the counterparty to the payment. If the counterparty's terminal device is able to verify the signed verifiable authentication information or display information, the payment is made.

[0222] (Appendix A31) The information processing method, in any one of Appendix A21 to Appendix A30, obtains transaction information identifying the transaction from the terminal device of the counterparty to the settlement, generates transaction data including the obtained transaction information and the amount to be sent, and sends the generated transaction data to the address of the counterparty's verified non-custodial wallet or custodial wallet.

[0223] (Appendix A32) The information processing method, in any one of Appendix A21 to Appendix A31, generates a derived private key and a public key corresponding to the derived private key based on the private key of the non-custodial wallet, and sends the crypto assets to the address of the verified non-custodial wallet or custodial wallet via a wallet having a wallet address calculated from the generated public key.

[0224] (Appendix A33) In the information processing method, if a settlement using the non-custodial wallet for which the identity verification procedure has been completed is completed in any one of the appendices A21 to A32, the digital value equivalent to the incentive included in the transaction certificate information is replenished in the non-custodial wallet based on the transaction certificate information recorded as transaction data on the blockchain received from the counterparty.

[0225] (Appendix A34) The information processing method, in any one of Appendix A21 to A33, is as follows: The non-custodial wallet holds multiple crypto assets, generates first transaction data including the transfer amount and common transaction information of the first crypto asset among the multiple crypto assets, generates second transaction data including the transfer amount and the common transaction information of the second crypto asset among the multiple crypto assets, sends the generated first transaction data and second transaction data to the address of the identity-verified non-custodial wallet or custodial wallet owned by the counterparty, and the identity-verified non-custodial wallet or custodial wallet of the counterparty matches the first transaction data and the second transaction data based on the common transaction information.

[0226] (Appendix A35) The information processing method is as follows: In any one of the appendices A21 to A25, the first blockchain among the multiple blockchains connected to the non-custodial wallet records the first crypto asset, the second blockchain among the multiple blockchains records the second crypto asset, the non-custodial wallet extracts the first crypto asset in a first amount from the first blockchain, extracts the second crypto asset in a second amount from the second blockchain, and displays the sum of the extracted first and second amounts.

[0227] (Appendix A36) The information processing method, in Appendix A35, generates first transaction data including the transfer amount of the first crypto asset and common transaction information, generates second transaction data including the transfer amount of the second crypto asset and the common transaction information, sends the generated first transaction data and second transaction data to the address of the identity-verified non-custodial wallet or custodial wallet owned by the counterparty, and the identity-verified non-custodial wallet or custodial wallet of the counterparty matches the first transaction data and the second transaction data based on the common transaction information.

[0228] (Note A37) The information processing method is as follows, in any one of Notes A21 to A36, the first non-custodial wallet owned by the user is a non-custodial wallet that has undergone identity verification procedures, the second non-custodial wallet owned by the user is a non-custodial wallet that has not undergone identity verification procedures, and if the user has not used the second non-custodial wallet for a predetermined period of time, the crypto assets held in the second non-custodial wallet are moved to the first non-custodial wallet.

[0229] (Appendix A38) The information processing method, as described in Appendix A37, is that the first non-custodial wallet notifies the user of the total amount of crypto assets, which is the sum of the crypto assets held by the first non-custodial wallet and the crypto assets moved from the second non-custodial wallet.

[0230] (Note A39) The information processing system is an information processing system that includes a user terminal device and uses a non-custodial wallet installed in the terminal device, wherein the certification authority generates signed verifiable authentication information by digitally signing the address of the non-custodial wallet provided to the certification authority and the user's identity verification related information already held by the certification authority with the certification authority's private key, distributes the generated signed verifiable authentication information to the non-custodial wallet, the non-custodial wallet stores the distributed signed verifiable authentication information, and performs settlement or transfer using the non-custodial wallet that has undergone identity verification and holds the signed verifiable authentication information.

[0231] The matters described in each embodiment can be combined with each other. Furthermore, the independent and dependent claims described in the claims can be combined with each other in any combination, regardless of the form of reference. In addition, the claims use a form in which claims referencing two or more other claims (multi-claim form), but are not limited to this. A form in which multi-claims referencing at least one multi-claim (multi-multi-claim) may also be used.

[0232] 1 Communication network 10 Blockchain 50 Buyer terminal device 70 Non-custodial wallet 100 Non-custodial wallet or custodial wallet 90 Seller device 200 Asset dealer server 300 Corporate server

Claims

1. A computer-based information processing method that functions as a non-custodial wallet on a user's terminal device, comprising the steps of: providing the address of the non-custodial wallet to a person who has performed an identity verification procedure prior to the commencement of use of the non-custodial wallet; receiving, via a communication network, one or more signed authentication information, in which one or more persons who have performed the identity verification procedure have applied a first digital signature with a private key managed by the person who performed the identity verification procedure to information that includes at least information indicating the completion of the user's identity verification procedure; generating one or more user authentication information locally on the user's terminal device, which includes at least a portion of the information contained in at least one of the one or more signed authentication information, and further includes one or more pieces of information concerning the user; and applying a second digital signature with a private key locally managed by the non-custodial wallet to each piece of user authentication information to generate one or more user authentication information; and storing at least one of the one or more signed authentication information and / or at least one of the one or more user authentication information in a local storage area managed by the user. An information processing method comprising the step of transmitting at least one of the one or more signed authentication pieces of information or at least one of the one or more user authentication pieces of information to the recipient's device when sending or settling money, wherein the signed authentication piece of information allows for the completion of the identity verification procedure by verification of the first electronic signature, the user authentication piece of information allows for the legitimacy of the user's management authority over the non-custodial wallet by verification of the second electronic signature, and by using at least one of the information contained in the signed authentication piece of information and the information contained in the user authentication piece of information, it is possible to confirm that the non-custodial wallet has undergone identity verification and that the user is the person who holds the private key of the non-custodial wallet.

2. The information processing method according to claim 1, wherein the person who performed the identity verification procedure includes a financial institution, a public institution, or a payment service provider.

3. The information processing method according to claim 1, wherein the generation of user authentication information and the application of the electronic signature can be performed even on the user's terminal device in an offline state without requiring a network connection to an external server.

4. The information processing method according to claim 1, further comprising the step of providing at least one of the user certificate information and the signed authentication information to the payment or remittance recipient by at least one of the following methods: attaching it in a form that can be obtained in association with the payment transaction, or transmitting it via a communication network prior to the transmission of the payment transaction; and executing the payment or remittance by signing the payment transaction with a private key locally managed by the non-custodial wallet and transmitting it to the network.

5. The information processing method according to claim 4, wherein the other party's device verifies that the non-custodial wallet has undergone identity verification by comparing the address of the non-custodial wallet contained in the received signed authentication information or user authentication information with the sender's address.

6. The information processing method according to claim 4, wherein the non-custodial wallet determines on the user's terminal device whether the settlement or remittance amount included in the settlement transaction is equal to or greater than a predetermined amount, and if it is determined that the settlement or remittance amount is equal to or greater than the predetermined amount, it automatically transmits at least one of the user authentication information and the signed authentication information in a format that can be obtained in association with the settlement transaction to at least one of the recipient wallet, the intermediary involved in the processing related to the remittance, or the person who performed the identity verification procedure via a communication network, and it is possible to confirm that the identity verification procedure has been completed by verifying the electronic signature included in the transmitted user authentication information and the signed authentication information.

7. The information processing method according to claim 4, wherein the provision is performed by storing at least one of the user authentication information and the signed authentication information in the data area of ​​the settlement transaction, in which the recipient of the settlement or remittance can confirm that the non-custodial wallet has undergone identity verification by verifying the electronic signature.

8. The information processing method according to claim 4, wherein in the step of the non-custodial wallet performing a crypto asset transfer, the non-custodial wallet provides at least one of the signed authentication information and the user authentication information it holds to the wallet of the recipient of the transfer in association with the transfer, and the non-custodial wallet performs the transfer after verifying that the wallet of the recipient of the transfer has undergone identity verification by cryptographically verifying the electronic signature contained in the information obtained from the wallet of the recipient of the transfer.

9. The information processing method according to claim 4 or 7, comprising: obtaining transaction identification information from the terminal device of the counterparty to the settlement or remittance, which does not include personal information identifying the seller or buyer; and generating the settlement transaction including the obtained transaction identification information, the amount to be remitted, and the type of crypto asset to be used.

10. The information processing method according to claim 9, wherein the transaction identification information is an identifier generated for each transaction and does not include personal information or attribute information that identifies the seller or buyer, nor information that identifies the content of the transaction.

11. The information processing method according to any one of claims 4 to 10, wherein, in face-to-face payment, the provision of at least one of the user authentication information and the signed authentication information to the counterparty is performed using short-range wireless communication.

12. The information processing method according to any one of claims 4 to 10, wherein, in face-to-face payment, the provision of at least one of the user authentication information and the signed authentication information to the counterparty is performed using a two-dimensional code.

13. The information processing method according to any one of claims 4 to 12, wherein the non-custodial wallet outputs display information generated from at least one of the signed authentication information or user authentication information received from the payment or remittance recipient's wallet to the screen of the terminal device, a wallet operating on the payment or remittance recipient's terminal device outputs display information generated from at least one of the signed authentication information or user authentication information received from the non-custodial wallet to the screen of the terminal device, and after the user and the payment or remittance recipient confirm the display information displayed on their respective terminal devices, they perform a payment or remittance by operating on the non-custodial wallet.

14. The information processing method according to any one of claims 1 to 13, wherein the step of generating one or more user authentication data includes storing in the user authentication data a converted value obtained by converting at least a portion of the personal identification information contained in the signed authentication information using a one-way function, and the conversion is performed locally on the user's terminal device without relying on an external server.

15. The information processing method according to any one of claims 1 to 14, wherein at least a portion of the information contained in the one or more user authentication data is expressed in a certification format that allows a verifier to confirm that certain conditions are met without disclosing the specific values ​​of the information.

16. The information processing method according to claim 1, wherein the signed authentication information does not include information on access to external resources.

17. The information processing method according to claim 1, wherein a key pair generated based on a cryptographic algorithm having quantum resistance is used as the public key cryptographic key pair used to generate the signed authentication information.

18. The information processing method according to claim 1, wherein the non-custodial wallet generates one or more derived private keys and corresponding public keys from the private key of the non-custodial wallet, stores the generated one or more derived private keys and public keys in the local storage area of ​​the non-custodial wallet, and switches between using the one or more derived private keys and public keys in retail settlement or remittance.

19. The information processing method according to claim 1, wherein the signed authentication information further includes, in addition to the information electronically signed by the person who performed the identity verification procedure, attribute information signed by a third-party organization having a predetermined relationship with the user using the private key of the third-party organization, and the attribute information includes at least one of the following: transaction history, credit evaluation, or fund transfer records between the third-party organization and the user.

20. The information processing method according to any one of claims 1 to 19, wherein the non-custodial wallet sends a request to a server managed by the person who performed the identity verification procedure for the transfer of crypto assets from the account to the non-custodial wallet, specifying account identification information that identifies an account managed by the person who performed the identity verification procedure; the server verifies the user based on related information that associates the address of the non-custodial wallet with the account identification information; and if the verification is successful, transfers the crypto assets from the account to the address of the non-custodial wallet.

21. The information processing method according to any one of claims 1 to 19, wherein the non-custodial wallet specifies account identification information that identifies an account managed by the person who performed the identity verification procedure, and sends the crypto assets along with a transfer request to the account to a server managed by the person who performed the identity verification procedure; the server verifies the user based on related information that associates the address of the non-custodial wallet with the account identification information; and if the verification is successful, converts the received crypto assets into fiat currency and deposits it into the account corresponding to the account identification information.

22. The information processing method according to any one of claims 4 to 13, wherein the non-custodial wallet generates a derived private key and a public key corresponding to the derived private key from a private key managed locally, and sends the crypto assets to the address of the recipient's wallet by passing them through at least one temporary wallet having an address calculated from the public key, thereby making it difficult to track the transaction without fixing the address of the sending wallet.

23. The information processing method according to any one of claims 4 to 13, wherein, after the settlement or remittance is completed, the method receives an electronic transaction record from the counterparty to the settlement or remittance and receives compensation equivalent to the transaction fee for the use of a distributed ledger required for the transaction relating to the settlement or remittance.

24. The information processing method according to claim 23, wherein the compensation includes, in addition to compensation for network usage fees, compensation with digital value equivalent to the added value recorded in the transaction record.

25. The information processing method according to any one of claims 4 to 13, wherein the non-custodial wallet holds multiple crypto assets, generates individual transaction data for each of the multiple crypto assets including an individual transfer amount and common transaction identification information, sends each individual transaction data to the wallet address of the payment or transfer recipient, and the recipient matches each individual transaction data based on the common transaction identification information to complete the payment or transfer.

26. The information processing method according to claim 25, wherein the non-custodial wallet holds multiple types of crypto assets recorded on one or more distributed ledger networks, the total amount of the multiple types of crypto assets held is totaled, and the total amount is used for the settlement or remittance.

27. The information processing method according to any one of claims 1 to 26, wherein, if a second non-custodial wallet owned by the user and which has not undergone identity verification procedures is met, the digital assets managed by the second non-custodial wallet can be transferred to the non-custodial wallet which has undergone identity verification procedures.

28. The information processing method according to claim 27, comprising summing the digital assets managed by the non-custodial wallet that has undergone identity verification procedures and the transferred digital assets, and inheriting them to the user's heirs.

29. The information processing method according to any one of claims 1 to 26, wherein the non-custodial wallet that has undergone identity verification procedures encrypts the private key information of another wallet using its own private key, stores the encrypted private key information in decentralized storage, registers access information to the decentralized storage in a smart contract, and enables an heir who has gone through a predetermined inheritance procedure to restore the private key information of the other wallet through the smart contract.

30. A method for processing information on a private key of a non-custodial wallet owned by a user, comprising the steps of: dividing the private key of the non-custodial wallet into a plurality of partial keys; distributing and storing the plurality of partial keys in a plurality of different storage locations; and, when the restoration of the private key is necessary, obtaining the plurality of partial keys from each of the plurality of storage locations and combining the obtained plurality of partial keys to make the private key recoverable, wherein no single storage location can restore the private key on its own.

31. The information processing method according to claim 30, wherein the plurality of storage locations include at least two of the following: a server managed by the person who performed the identity verification procedure, a terminal device owned by the user, and a portable recording medium owned by the user.

32. The information processing method according to claim 30 or 31, wherein, after the death of the user, the user's heirs obtain the multiple partial keys from the multiple storage locations through a prescribed procedure and restore the private key, thereby enabling them to inherit the digital assets held by the user.

33. The information processing method according to claim 32, wherein at least one of the plurality of partial keys is encrypted using the private key of the non-custodial wallet whose identity has been verified, the encrypted partial key is stored in decentralized storage, and access information to the decentralized storage is registered in a smart contract, thereby enabling the heir to obtain the partial key through the smart contract.

34. An information processing system comprising a non-custodial wallet for which user identity verification procedures have been completed, wherein the non-custodial wallet performs the information processing method described in any one of claims 1 to 33.

35. An information processing system comprising a first terminal device of a user, a second terminal device of the recipient of a payment or remittance by the user, and a server managed by the person who performed the identity verification procedure, wherein the first terminal device comprises a non-custodial wallet that executes the information processing method described in any one of claims 1 to 33, the second terminal device comprises a non-custodial wallet or custodial wallet for which the identity verification procedure has been completed, the non-custodial wallet or custodial wallet of the second terminal device confirms the completion of the user's identity verification procedure by verifying the electronic signature contained in at least one of the user certificate information or signed authentication information received from the user's non-custodial wallet, and the server manages related information associating the address of the non-custodial wallet with the user's customer identification information, and verifies the user based on the related information.

36. A computer program that causes a computer that functions as a non-custodial wallet owned by a user to execute the information processing method described in any one of claims 1 to 33.

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