Non-fungible token record management system, non-fungible token record management method, and non-fungible token record management program

Abstract

A non-fungible token record management system is provided that manages the contents of records in a distributed ledger associated with non-fungible tokens. [Solution] The non-fungible token record management system comprises: an object information generation unit 2 that generates object information relating to an object associated with a non-fungible token; a first transaction generation unit 4 that generates a first transaction to be stored in a block in a closed distributed ledger, which is a distributed ledger in which only specific persons can participate in the record processing; a closed ledger information acquisition unit 7 that acquires closed ledger information, which is information stored in the closed ledger; an open ledger information acquisition unit 8 that acquires open ledger information, which is information stored in an open distributed ledger, which is a distributed ledger in which an unspecified number of people can participate in the record processing; a ledger information comparison unit 9 that compares the closed ledger information and the open ledger information; and an additional information generation unit 10 that generates additional information, which is information to be added to the open distributed ledger to have the same content as the closed ledger information.

Description

[Technical Field]

[0001] The present invention relates to a technology for managing the recorded contents in a distributed ledger associated with non-fungible tokens. [Background technology]

[0002] In recent years, technologies have been proposed that link digital content, such as digital art, to non-fungible tokens (NFTs) and manage content transaction histories and rights transfers and changes on public blockchains accessible to an unspecified number of users. Transaction histories and other information are managed using a distributed ledger on the public blockchain, and the authenticity of newly entered digital information is determined by majority vote among an unspecified number of nodes. This ensures the accuracy of the information written to the ledger and accurately manages the transaction history, rights assignment, transfer, and changes of non-fungible tokens (and associated digital content). Such public blockchains allow for the creation of programs that operate automatically according to pre-specified rules (so-called "smart contracts"). This allows for the creation of frameworks that would be difficult to achieve with traditional transactions, such as a system in which a portion of the transaction price is returned to the copyright owner each time a non-fungible token associated with copyrighted digital content is traded.

[0003] Patent Document 1 discloses technology related to a transaction management blockchain that sets up and manages NFTs for ownership and usage rights of digital copyrighted works. Patent Document 2 discloses technology related to a transaction management system using NFTs, which extends the scope of management to tangible artworks. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-189475 [Patent Document 2] Patent No. 7033352 Summary of the Invention [Problem to be solved by the invention]

[0005] However, because public blockchains allow an unspecified number of people to participate, there is a concern that a malicious participant could, for example, determine incorrect electronic information as true during a majority vote and record untrue transaction histories (a so-called "51% attack"). Furthermore, because public blockchains already have a set protocol, there is a problem with limited flexibility in designing management systems. For example, even if certain conditions are imposed on the transfer of digital content or tangible objects linked to non-fungible tokens (e.g., the transferee must have certain qualifications), if the legitimate owner provides electronic information (and a digital signature encrypted with the owner's private key) indicating that the content has been transferred to the transferee, the transaction will be approved and recorded in the distributed ledger, even if the transferee does not have the required qualifications, as long as the electronic information is correct.

[0006] This invention has been made in view of the above-mentioned problems, and aims to provide a record management system for non-fungible tokens that ensures design flexibility and security. [Means for solving the problem]

[0007] To achieve the above objective, the non-fungible token record management system according to claim 1 is a non-fungible token record management system that manages the contents of a distributed ledger having a correspondence with a non-fungible token associated with a specific object, and is characterized by comprising: object information generation means for generating object information which is information relating to an object associated with a non-fungible token; first information output means for outputting the object information generated by the object information generation means to a closed distributed ledger which is a distributed ledger having a correspondence with the non-fungible token and in which only predetermined specific persons can participate in the record processing; additional information generation means for generating additional information which is information output to an open distributed ledger which is a distributed ledger having a correspondence with the non-fungible token and in which an unspecified person can participate in the record processing, and which matches the contents of the open distributed ledger with the contents of the closed distributed ledger including the object information output by the first information output means; and second information output means for outputting the additional information generated by the additional information generation means to the open distributed ledger.

[0008] Furthermore, in order to achieve the above objective, the non-fungible token record management system according to claim 2 is a closed ledger information acquisition means that acquires closed ledger information which is all or part of the recorded contents of the closed distributed ledger, including the object information output by the first information output means; open ledger information acquisition means that acquires open ledger information which is all or part of the recorded contents of the open distributed ledger, and within the range of information corresponding to the closed ledger information; and the closed ledger information acquired by the closed ledger information acquisition means The system further comprises an information comparison means for comparing the content with the content of the open system ledger information acquired by the open system ledger information acquisition means, wherein the additional information generation means generates information corresponding to the missing portion as additional information when the information comparison means determines that the open system ledger information has a portion that is insufficient compared to the closed system ledger information, and generates information that eliminates or cancels out the excess portion as additional information when the information comparison means determines that the open system ledger information has a portion that is in excess compared to the closed system information.

[0009] Furthermore, in order to achieve the above object, the non-fungible token record management system according to claim 3 is characterized in that, in the above invention, it further comprises an open system ledger information monitoring means that continuously monitors changes in the record contents of the open system distributed ledger, the open system ledger information acquisition means and the closed system ledger information acquisition means acquire the open system ledger information and the closed system ledger information, respectively, when the open system ledger information monitoring means detects a change in the record contents of the open system distributed ledger, the information comparison means compares the acquired open system ledger information and the closed system ledger information, and the additional information generation means, when the information comparison means determines that the contents of the open system ledger information and the contents of the closed system ledger information differ, further generates the additional information so that the record contents of the open system distributed ledger match the record contents of the closed system distributed ledger.

[0010] Furthermore, in order to achieve the above object, the non-fungible token record management method according to claim 4 is a non-fungible token record management method for managing the record contents of a distributed ledger that has a correspondence relationship with a non-fungible token associated with a specific object, and is characterized by comprising: an object information generation step for generating object information, which is information about an object associated with the non-fungible token; a first information output step for outputting the object information generated in the object information generation step to a closed-system distributed ledger that has a correspondence relationship with the non-fungible token and is a distributed ledger that only predetermined specific persons can be involved in the record processing; an additional information generation step for generating additional information, which is information that is output to an open-system distributed ledger that has a correspondence relationship with the non-fungible token and is a distributed ledger that unspecified persons can be involved in the record processing, and which matches the record contents of the open-system distributed ledger with the record contents of the closed-system distributed ledger including the object information output by the first information output step; and a second information output step for outputting the additional information generated in the additional information generation step to the open-system distributed ledger.

[0011] Furthermore, in order to achieve the above objective, the non-fungible token record management method according to claim 5 is a closed ledger information acquisition step in which closed ledger information is obtained which is all or part of the record contents of the closed distributed ledger, including the object information output by the first information output means; open ledger information acquisition step which is open ledger information, which is all or part of the record contents of the open distributed ledger, and within the scope of information corresponding to the closed ledger information; and the contents of the closed ledger information acquired in the closed ledger information acquisition step and the The method further includes an information comparison step of comparing the contents of the open system ledger information acquired in the open system ledger information acquisition step with the contents of the open system ledger information, wherein in the additional information generation step, if the information comparison step determines that the open system ledger information has a portion that is insufficient compared to the closed system ledger information, information corresponding to the insufficient portion is generated as the additional information, and if the information comparison step determines that the open system ledger information has a portion that is in excess compared to the closed system information, information that eliminates or cancels out the excess portion is generated as the additional information.

[0012] Furthermore, in order to achieve the above-mentioned object, a non-fungible token record management program according to claim 6 is a non-fungible token record management program that causes a computer to manage the record contents of a distributed ledger that has a correspondence relationship with a non-fungible token associated with a specific object, and is characterized in that it causes the computer to execute an object information generation function that generates object information, which is information about an object associated with a non-fungible token; a first information output function that outputs the object information generated by the object information generation function to a closed-system distributed ledger that has a correspondence relationship with the non-fungible token and is a distributed ledger that only predetermined specific persons can be involved in the record processing; an additional information generation function that generates additional information, which is information that is output to an open-system distributed ledger that has a correspondence relationship with the non-fungible token and is a distributed ledger that unspecified persons can be involved in the record processing, and that matches the record contents of the open-system distributed ledger with the record contents of the closed-system distributed ledger including the object information output by the first information output function; and a second information output function that outputs the additional information generated by the additional information generation function to the open-system distributed ledger. [Effects of the Invention]

[0013] The present invention has the effect of enabling the construction of a record management system for non-fungible tokens that ensures freedom of design and security. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a schematic diagram illustrating a configuration of a non-fungible token record management system according to a first embodiment. [Figure 2] 1 is a flowchart showing the processing contents of the non-fungible token record management system according to the first embodiment. [Figure 3] FIG. 10 is a schematic diagram illustrating a configuration of a non-fungible token record management system according to a second embodiment. [Figure 4] FIG. 10 is a schematic diagram illustrating the configuration of a non-fungible token record management system according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] The embodiments of the present invention will be described in detail below with reference to the drawings. The following embodiments describe the most appropriate examples of the present invention, and naturally, the content of the present invention should not be limited to the specific examples shown in these embodiments. It goes without saying that any configuration other than the specific configurations shown in the embodiments that produces similar functions and effects is also included in the technical scope of the present invention.

[0016] (Embodiment 1) First, a description will be given of a non-fungible token record management system according to the first embodiment. As shown in Fig. 1, the non-fungible token record management system according to the first embodiment includes a token generation unit 1 that generates a non-fungible token associated with an object of a transaction or the like, an object information generation unit 2 that generates object information that is information on an object associated with the non-fungible token, an information verification unit 3 that verifies the appropriateness of the generated object information, a first transaction generation unit 4 that generates a first transaction that is associated with the non-fungible token generated by the token generation unit 1 and is stored in a block in a closed-system distributed ledger that is a distributed ledger in which only specific people can participate in the recording process, based on the object information verified by the information verification unit as being correct information, a first electronic signature generation unit 5 that generates a first electronic signature that is an electronic signature for proving that the content of the first transaction follows proper procedures, a first information output unit 6 that outputs the generated first transaction and the first electronic signature to the closed-system distributed ledger, and a first information output unit 7 that reads closed-system ledger information that is information stored in the closed ledger. an open ledger information acquisition unit 8 that acquires open ledger information, which is information associated with the token generated by the token generation unit 1 and stored in an open distributed ledger, which is a distributed ledger in which unspecified people can be involved in the recording process; a ledger information comparison unit 9 that compares the closed ledger information with the open ledger information; an additional information generation unit 10 that generates additional information, which is information to be added to the open distributed ledger to make the content of the open distributed ledger identical to the content of the closed ledger information, based on the comparison result by the ledger information comparison unit 9; a second transaction generation unit 11 that generates a second transaction, which is a transaction to be stored in the open distributed ledger, based on the additional information; a second electronic signature generation unit 12 that generates a second electronic signature, which is an electronic signature to prove that the content of the second transaction has been made in accordance with proper procedures; a second information output unit 13 that outputs the generated second transaction and second electronic signature to the open distributed ledger; and a private key storage unit 14 that stores the private key used in the second electronic signature generation unit 12.

[0017] The token generation unit 1 is for generating a non-fungible token corresponding to an object. A "non-fungible token" refers to a so-called NFT (Non-Fungible Token), that is, a token that has unique data and is therefore non-substitutable for other tokens, and is issued, for example, based on ERC721, a standard of Ethereum (registered trademark). The non-fungible token in this embodiment 1 is issued based on ERC721 or other predetermined standards, and is configured such that the transaction history of the object, information about the owner, and information on the establishment, transfer, and change of rights such as the right to use the object are recorded in a distributed ledger on a blockchain corresponding to the non-fungible token.

[0018] "Blockchain" is a technology that utilizes cryptographic techniques to synchronize data between multiple computers that make up a distributed network. Specifically, each block is composed of a collection of information about tokens, such as agreed-upon transaction records, and information for connecting to other blocks (information from the previous block), and a blockchain is formed by linking multiple blocks together. Even if data is tampered with on one computer, the correct data is selected by majority vote among the other computers, making data destruction and tampering extremely difficult. Blockchains are classified into public blockchains, which do not restrict participants in majority votes, i.e., any person can participate in recording in the distributed ledger; consortium blockchains, which allow only one or more specific people to participate in majority votes, i.e., only predetermined specific people can participate in recording in the distributed ledger; and private blockchains. The former is a concept included in the open distributed ledger of this invention, and the latter is a concept included in the closed distributed ledger of this invention. The non-fungible token in this embodiment has a correspondence relationship established between the open distributed ledger and the closed distributed ledger.

[0019] A specific form of linking a non-fungible token with an object is to associate the identifier of the non-fungible token with the identification information of the object. In principle, the correspondence between the object and the non-fungible token is one to one, but multiple non-fungible tokens may be set for one object depending on the situation.

[0020] Furthermore, in the first embodiment, the blocks constituting the distributed ledger corresponding to the generated non-fungible tokens will record transaction records relating to the transfer of the ownership of the non-fungible token (including cases where the transfer is made to match the ownership / ownership name of the object), as well as preferably information relating to the transfer of the ownership / ownership name of the object, the establishment of rights such as usage rights granted for the object, the transfer of the right holder who holds the rights, changes to the content of the rights, etc. However, it is also possible to configure the block to record information other than the above, or to record only part of the content listed above.

[0021] Note that non-fungible tokens may be generated by the token generator 1 itself, or may be generated by an external system that is directly or indirectly connected to the token generator 1 by issuing a predetermined command to the external system. The specific format of the non-fungible token is not limited to one that complies with ERC721, the Ethereum (registered trademark) standard, and any format may be used as long as it has non-fungible properties and information such as transaction history can be stored in an open distributed ledger or a closed distributed ledger.

[0022] The object information generation unit 2 is for generating object information to be included in the first transaction output to the closed distributed ledger. Specifically, the object information generation unit 2 generates object information that preferably includes a transaction history of the object corresponding to the non-fungible token (a history of name changes of the owner / holder), the content of the rights established for the object, a history of transfers of the rights (a history of name changes of the rights holder, etc.), information on the content, transfer, changes, etc. of the rights, etc. However, the content of the object information may include all of the above elements, or may include only some of them as a simpler configuration, or may include elements other than the above elements, such as information on the non-fungible token associated with the object.

[0023] The information verification unit 3 is for verifying whether the object information generated by the object information generation unit 2 conforms to predetermined standards in the system including the closed distributed ledger that is the output destination. Specifically, the closed distributed ledger in this embodiment 1 can be set up on a consortium blockchain where correct data is selected by majority vote of a specific group of people, or on a private blockchain where correct data is selected by majority vote of a specific single person or one or more people appointed by that single person, and can be designed differently from public blockchains where an unspecified number of people can participate, and accordingly, unique standards may be imposed on the content of the information recorded on the distributed ledger. In this embodiment 1, the information verification unit 3 verifies whether the object information generated by the object information generation unit 2 meets these standards, and if it is determined that the standards are met, it outputs the object information to the first transaction generation unit 4. On the other hand, if it is determined that the standards are not met, it does not output the object information, or modifies it to meet the constraints and outputs it to the first transaction generation unit 4. Examples of unique criteria regarding the content of information include conditions that impose age and qualification restrictions on the transferee of ownership or holding rights to non-fungible tokens and / or related objects, objective conditions such as restrictions on the content of the rights to be established (e.g., exclusive usage rights cannot be established), and procedural conditions such as content verification by specific individuals involved in majority voting and completion of approval procedures. Other types of conditions may also be used.

[0024] The first transaction generation unit 4 is for generating the first transaction to be stored in a block within a closed distributed ledger. Specifically, the first transaction generation unit 4 generates the first transaction, which is information about the contents of the object information, such as information regarding a change in the name of the holder of a non-fungible token, or information regarding the content of the usage rights of the object associated with the non-fungible token.

[0025] The first electronic signature generation unit 5 generates a first electronic signature, which is data that certifies the authenticity of information included in the first transaction. Specifically, the first electronic signature generation unit 5 has the function of generating a hash value of the first transaction generated by the first transaction generation unit 4 and encrypting the hash value with a private key to generate a first electronic signature. Note that a "hash value" is a fixed-length value obtained by applying a specific calculation procedure to original data. Because the calculation procedure is irreversible, it is considered impossible to restore the original data from the hash value. Furthermore, a "private key" is a sequence of numbers used in encryption processing that can be decrypted using a corresponding "public key." Note that in the first embodiment, the first transaction generation unit 4 and the first electronic signature generation unit 5 are configured to generate the transaction and electronic signature themselves, but this is not a limitation. The first transaction generation unit 4 and the first electronic signature generation unit 5 may simply have the function of instructing an external device to generate the first transaction and the first electronic signature.

[0026] The first information output unit 6 is for outputting the first transaction generated by the first transaction generation unit 4 and the first digital signature generated by the first digital signature generation unit 5 to a closed distributed ledger associated with a non-fungible token. The first information output unit 6 functions as one aspect of the first information output means in the claims, and in this embodiment, it is configured to directly output the first transaction and the first digital signature, but it may also be configured to merely instruct other components (including those provided outside the system) to output. In this embodiment 1, the first information output unit 6 is directly or indirectly connected to the network on which the closed distributed ledger is installed, and is configured to output predetermined data to the closed distributed ledger. Regarding the data output from the first information output unit 6, a hash value of the first transaction is generated, and the hash value and the data obtained by decrypting the first digital signature with a public key are compared. If the two values ​​are different, it is determined that it is not a legitimate transaction and registration to the closed distributed ledger is rejected. If the two values ​​match, it is determined to be a legitimate transaction, and the information composed of the transaction is stored in a block that constitutes the closed distributed ledger.

[0027] The Closed Ledger Information Acquisition Unit 7 is for acquiring all or part of the information recorded in the closed distributed ledger that corresponds to the non-fungible token generated by the Token Generation Unit 1. Specifically, the Closed Ledger Information Acquisition Unit 7 has the function of accessing the closed distributed ledger that corresponds to the non-fungible token and acquiring the information recorded regarding the non-fungible token and the object associated with it. The information to be acquired may be all the information recorded in the closed distributed ledger, or it may be only a part of the information, such as only information newly added since the last information acquisition, only information added during a certain period, or only information in a certain field (for example, the transaction history of the object).

[0028] The open ledger information acquisition unit 8 is for acquiring information recorded in an open distributed ledger that corresponds to the non-fungible token generated by the token generation unit 1. Specifically, the open ledger information acquisition unit 8 has a function of accessing the open distributed ledger that corresponds to the non-fungible token and acquiring information recorded regarding the non-fungible token and the object associated therewith. The content of the acquired information may be all or part of the information recorded in the open distributed ledger, but in relation to the information comparison process in the ledger information comparison unit 9 described below, it is preferable that the information be of the same range as the information acquired by the closed ledger information acquisition unit 7.

[0029] The ledger information comparison unit 9 is for comparing the information acquired by the closed system ledger information acquisition unit 7 and the open system ledger information acquisition unit 8, respectively, and extracting the differences. Specifically, the ledger information comparison unit 9 has a function of extracting the difference value between the information acquired by the closed system ledger information acquisition unit 7 and the information acquired by the open system ledger information acquisition unit 7 (information that is included in the former but not in the latter, or information that is included in the latter but not in the former), and outputting it to the additional information generation unit 10. In the first embodiment, it is assumed that when the first transaction and the first digital signature are output from the first information output unit 6 and a change occurs in the recorded content of the closed system distributed ledger, the closed system ledger information acquisition unit 7 and the open system ledger information acquisition unit 8 and the ledger information comparison unit 9 perform information acquisition and information comparison processing.

[0030] The additional information generation unit 10 generates additional information, which is information that matches the recorded content of the open-system distributed ledger with the recorded content of the closed-system distributed ledger including the object information output from the first information output unit 6, based on the comparison result by the ledger information comparison unit 9. Specifically, if the comparison result by the ledger information comparison unit 9 indicates that there is a deficiency in the information recorded in the open-system distributed ledger relative to the closed-system distributed ledger, the additional information generation unit 10 generates information corresponding to the deficiency as additional information. Also, if the comparison result by the ledger information comparison unit 9 indicates that there is an excess portion in the information recorded in the open-system distributed ledger relative to the closed-system distributed ledger, the additional information generation unit 10 generates information that eliminates the excess portion (for example, information that instructs the open-system distributed ledger to delete the excess portion) or information that negates the excess portion (for example, information that assumes the existence of the excess portion and subsequently corrects the excess portion).

[0031] The second transaction generation unit 11 is for generating second transactions to be stored in blocks in the open distributed ledger. Specifically, the second transaction generation unit 11 has a function of generating second transactions including the additional information generated by the additional information generation unit 10.

[0032] Second electronic signature generation unit 12 is for generating a second electronic signature, which is data that proves that the information included in the second transaction is authentic. Specifically, second electronic signature generation unit 12 has a function of generating a hash value of the second transaction generated by second transaction generation unit 11 and encrypting the hash value with a private key stored in private key storage unit 14, which will be described later, to generate a second electronic signature. Note that in the first embodiment, second transaction generation unit 11 and second electronic signature generation unit 12 are configured to generate the transaction and electronic signature themselves, but this is not a limitation. Second transaction generation unit 11 and second electronic signature generation unit 12 may also have a function of simply instructing an external device to generate the second transaction and second electronic signature.

[0033] The second information output unit 13 is configured to provide and output the second transaction generated by the second transaction generation unit 11 and the second electronic signature generated by the second electronic signature generation unit 12 to an open distributed ledger associated with the non-fungible token. Like the first information output unit 6, the second information output unit 13 may be configured to directly output the second transaction and the second electronic signature, or may be configured to simply instruct other components to output them. Regarding the data output by the second information output unit 13, a hash value of the second transaction is generated, and the hash value is compared with data obtained by decrypting the second electronic signature using a public key. If the two values ​​differ, the transaction is determined to be an invalid transaction and its registration in the open distributed ledger is rejected. However, if the two values ​​match, the transaction is determined to be valid, and the information constituted by the transaction is stored in a block constituting the open distributed ledger.

[0034] The private key storage unit 14 is for storing a private key used when generating a second electronic signature in the second electronic signature generation unit 12. Generally, the private key used when creating an electronic signature is held by the holder of the non-fungible token, but the private key storage unit 14 in the first embodiment independently stores the private key on behalf of the holder of the non-fungible token, or stores a copy having the same function as the private key held by the holder of the non-fungible token.

[0035] Next, the processing content of the non-fungible token record management system according to the first embodiment will be described with reference to the flowchart in Fig. 2. First, the transaction record generation unit 2 generates object information, which is information about an object (step S101), and the information verification unit 3 verifies whether the generated object information conforms to the criteria defined by the system including the closed distributed ledger (step S102). If it is determined that the object information does not conform to the criteria (step S102, No), the process returns to step S101 and object information is generated again (this process may be performed by the object information generation unit 2 or the information verification unit 3 itself). If it is determined that the object information conforms to the criteria (step S102, Yes), a first transaction and a first digital signature are generated based on the object information and output to the closed distributed ledger (step S103).

[0036] Thereafter, the closed system ledger information acquisition unit 7 and the open system ledger information acquisition unit 8 acquire the information recorded in each distributed ledger, and the ledger information comparison unit 9 compares the two to determine whether there are any differences (step S104). If there are no differences (step S104, No), the processing ends. If there are differences (step S104, Yes), the additional information generation unit 10 generates additional information consisting of the content to be recorded in the open system distributed ledger so that the recorded content of the open system distributed ledger matches the recorded content of the closed system distributed ledger (step S105), and a second transaction and a second digital signature are generated based on the additional information and output to the open system distributed ledger (step S106), and all processing ends.

[0037] Next, the advantages of the non-fungible token record management system according to the first embodiment will be described. First, the non-fungible token record management system according to the first embodiment has a correspondence relationship with both a closed distributed ledger and an open distributed ledger for a single token (and the object associated therewith), and employs a configuration in which information regarding the transfer of ownership and holding authority of the non-fungible token and / or the corresponding object, as well as the establishment, transfer, and modification of rights, is recorded in both ledgers. Because the closed distributed ledger is configured to involve only specific individuals, it allows for unique institutional design, unlike open distributed ledgers such as public blockchains that allow the participation of an unspecified number of people. On the other hand, because the closed distributed ledger is a closed network in which only specific individuals can participate, information such as the transaction history of the non-fungible token and / or the corresponding object cannot be widely disclosed to the public. Therefore, in this first embodiment, a token management system with increased freedom in system design, etc. is realized by storing the first transaction including the object information in a closed distributed ledger, and by synchronizing the contents of the open distributed ledger, which allows the participation of an unspecified number of people, with the contents of the closed distributed ledger, the object information can be made widely available to the public.

[0038] Furthermore, the non-fungible token record management system according to the first embodiment employs a configuration in which the ledger information comparison unit 9 compares the information recorded in the closed-system distributed ledger with the information recorded in the open-system distributed ledger, and if there are any differences, generates additional information to be recorded in the open-system distributed ledger so that the content of the information recorded in the open-system distributed ledger matches the content of the information recorded in the closed-system distributed ledger. Adopting such a configuration has the advantage that when object information is added to the closed-system distributed ledger, it can be quickly reflected in the open-system distributed ledger. Furthermore, even if false information is recorded by a malicious unspecified person who determines false information to be true by majority vote (a so-called "51% attack"), the existence of false information can be confirmed by comparison by the ledger information comparison unit 9, and additional information can be generated and output to match the recorded content of the closed-system distributed ledger, thereby eliminating or canceling the false information. By adopting this configuration, the non-fungible token record management system according to this embodiment 1 not only improves the degree of freedom in system design but also has the advantage of improving security by suppressing the inclusion of false information. Furthermore, even if multiple distributed ledgers, such as closed and open distributed ledgers, are associated with a single non-fungible token, there is no confusion among users (e.g., holders of non-fungible tokens and those who acquire them). For example, by building each system using the Ethereum Virtual Machine (EVM), a software environment that executes smart contracts on the Ethereum blockchain, users can use the systems without being aware of the differences between closed and open distributed ledgers. Because the EVM is compatible with both closed and open distributed ledgers, for example, in a system that uses multiple distributed ledgers, users can access all systems using a single public address.

[0039] (Embodiment 2) Next, a non-fungible token recording management system according to Embodiment 2 will be described. In Embodiment 2, components that have the same name and reference numerals as those in Embodiment 1 will perform the same functions as those in Embodiment 1 unless otherwise specified.

[0040] Fig. 3 is a schematic diagram showing the configuration of a non-fungible token record management system according to embodiment 2. As shown in Fig. 3, the non-fungible token record management system according to embodiment 2 includes, in addition to the configuration of embodiment 1, an open system ledger information monitoring unit 16 that continuously monitors changes in the recorded content of the open distributed ledger, and a monitoring result notification unit 19 that outputs the monitoring result to a closed system ledger information acquisition unit 17 and an open system ledger information acquisition unit 18 when a change in the recorded content is detected.

[0041] The open system ledger information monitoring unit 16 is for continuously monitoring changes in the recorded content of the open system distributed ledger associated with the non-fungible token generated by the token generation unit 1. In the second embodiment, the open system ledger information monitoring unit 16 has a function of continuously monitoring whether or not there is a change in the recorded content of the open system distributed ledger, regardless of whether or not there is information output by the second information output unit 13. By newly providing the open system ledger information monitoring unit 16, it is possible to detect whether or not there is an irregular information rewrite to the open system distributed ledger, that is, the addition of information other than the information output by the second information output unit 13. It is desirable that the open system ledger information monitoring unit 16 monitors continuously, but it may also be configured to check for changes in the recorded content of the open system distributed ledger at regular time intervals.

[0042] The monitoring result notification unit 19 notifies the closed system ledger information acquisition unit 17 and the open system ledger information acquisition unit 18 of the monitoring results of the open system ledger information monitoring unit 16. Specifically, when the open system ledger information monitoring unit 16 detects that a change has occurred in the record contents of the open system distributed ledger, the monitoring result notification unit 19 notifies the closed system ledger information acquisition unit 17, etc., of this fact. Upon receiving the notification from the monitoring result notification unit 19, the closed system ledger information acquisition unit 17 and the open system ledger information acquisition unit 18 perform processing to acquire the closed system ledger information and the open system ledger information, which are information recorded in the closed system distributed ledger and the open system distributed ledger, respectively, and output the acquired information to the ledger information comparison unit 9. The ledger information comparison unit 9 performs a comparison process based on the input information, and the additional information generation unit 10 generates additional information based on the comparison result obtained by the ledger information comparison unit 9 so that the record contents of the open system distributed ledger where a change has occurred match the record contents of the closed system distributed ledger. As in the first embodiment, the generated additional information is generated by the second transaction generation unit 11 and the second electronic signature generation unit 12 and output from the second information output unit 13 to the open distributed ledger, and as a result, the recorded contents of the open distributed ledger are revised to match the recorded contents of the closed distributed ledger.

[0043] Next, the advantages of the non-fungible token record management system according to the second embodiment will be described. The non-fungible token record management system according to the second embodiment includes an open ledger information monitoring unit 16 that continuously monitors changes in the recorded contents of the open distributed ledger. By adopting such a configuration, the non-fungible token record management system according to the second embodiment has the advantage that, since an unspecified number of people can be involved, even if false information is recorded based on malicious intent, the fact can be quickly grasped, and additional information can be generated to ensure that the recorded contents are correct, thereby realizing a more highly secure system.

[0044] Furthermore, even when a first transaction based on object information is output to the closed system distributed ledger, updating the contents of the closed system distributed ledger, and additional information corresponding to the updated contents is generated and output to the open system distributed ledger in response, the open system ledger information monitoring unit 16 determines whether or not a change has occurred in the contents recorded in the open system distributed ledger (in this case, it is appropriate for a change to occur), and if a change has occurred, the closed system ledger information acquisition unit 17 and the open system ledger information acquisition unit 18 acquire the recorded contents of each distributed ledgers, and the ledger information comparison unit 9 determines whether they are different or the same. This makes it possible to determine whether appropriate additional information corresponding to the content of the object information for the closed distributed ledger has been generated and output (for example, if appropriate additional information has been generated, the determination result of the ledger information comparison unit 9 will be "no discrepancy"). In the unlikely event that there is an error in the additional information, new additional information that resolves the error so that it matches the content of the closed distributed ledger can be created and output, thereby improving the accuracy of the content of the open distributed ledger.

[0045] (Embodiment 3) Next, a non-fungible token recording management system according to Embodiment 3 will be described. In Embodiment 3, as well as in Embodiments 1 and 2, components that have the same names and reference numerals will, in principle, perform the same functions as the components of Embodiments 1 and 2.

[0046] Fig. 4 is a schematic diagram showing the configuration of a non-fungible token record management system according to embodiment 3. As shown in Fig. 4, the non-fungible token record management system according to embodiment 3 includes, in addition to the configuration of embodiment 1, a generation process recording unit 21 that records the processing details from generation to output of information for the closed system distributed ledger, a closed system ledger information monitoring unit 22 that continuously monitors changes in the recorded content of the closed system distributed ledger, and a generation process verification unit 23 that, when a change in the recorded content is detected, verifies the processing details from generation to output of information corresponding to the change in the recorded content.

[0047] The generation processing record unit 21 is for recording the generation and output process of the first transaction and the first digital signature that are output to a closed distributed ledger associated with the non-fungible token generated by the token generation unit 1. Specifically, the generation processing record unit 21 has the function of recording details such as the specific processing when generating object information in the object information generation unit 24, the verification processing of object information in the information verification unit 3, the specific processing when generating the first transaction in the first transaction generation unit 4, and the specific processing when generating the first digital signature in the first digital signature generation unit 5. The content recorded in the generation processing record unit 21 may be only a part of what is described above, or it may be unique processing content that corresponds to unique constraints different from those of an open distributed ledger, such as the items and content of information to be recorded in the ledger or the information generation procedure.

[0048] The Closed System Ledger Information Monitoring Unit 22 is for continuously monitoring changes in the recorded content of the Closed System Distributed Ledger associated with the non-fungible tokens generated by the Token Generation Unit 1. In this embodiment 3, the Closed System Ledger Information Monitoring Unit 22 has the function of continuously monitoring whether or not there are changes in the recorded content of the Closed System Distributed Ledger, regardless of whether or not information is output by the First Information Output Unit 6. It is desirable that the monitoring frequency of the Closed System Ledger Information Monitoring Unit 22 be constant, but it is also possible to configure it to check whether or not there are changes in the recorded content of the Closed System Distributed Ledger at regular time intervals.

[0049] When the closed-system ledger information monitoring unit 22 detects a change in the recorded content of the closed-system distributed ledger, the generation process verification unit 23 verifies whether the information generation and output process of the changed part was performed in accordance with predetermined standards. Specifically, the generation process verification unit 23 extracts the content of the information generation and output process corresponding to the changed part of the recorded content from the generation process recording unit 21 and verifies whether the information generation and output process content complies with predetermined processing standards, whether it satisfies qualifications and other requirements, and other standards established in the system including the closed-system distributed ledger. The generation process verification unit 23 may also perform verification based not only on the information extracted from the generation process recording unit 21 but also on other information such as public information. If the generation process verification unit 23 determines as a result of the verification process that the information generation protocol has not been complied with (for example, the transferee does not meet predetermined qualification requirements (e.g., age 20 or older)), it instructs the object information generation unit 24 to generate object information with content that cancels the changed part. The object information generation unit 24 generates new object information based on the instruction, and the first transaction generation unit 4 and the first electronic signature generation unit 5 generate a first transaction and a first electronic signature based on the object information, which are output by the first information output unit 6, thereby changing the record content of the closed system distributed ledger to one in which the changed portion is resolved or negated. If the changed portion is also reflected in the record content of the open system distributed ledger, the information acquisition unit 17 and the open system ledger information acquisition unit 18 detect the fact that the changed portion is reflected, and the additional information generation unit 10 generates additional information that resolves or negates the changed portion, and the second transaction generation unit 11 and the second electronic signature generation unit 12 generate a second transaction and a second electronic signature, which are output by the second information output unit 13 to the open system distributed ledger, thereby changing the record content of the open system distributed ledger to one in which the changed portion is resolved or negated.

[0050] Next, the advantages of the non-fungible token record management system according to the third embodiment will be described. The non-fungible token record management system according to the third embodiment includes a closed-system ledger information monitoring unit 22 that continuously monitors changes in the record contents of the closed-system distributed ledger, and a generation process verification unit 23 that, when it is determined that a change in the record contents has occurred, verifies whether the information generation and output related to the change has been generated and output in accordance with standards. Unlike an open-system distributed ledger, where the accuracy of the record contents can be determined based on the record contents of the closed-system distributed ledger, in a closed-system distributed ledger, even if a change occurs in the record contents, it is not easy to determine whether the change is an appropriate change or an inappropriate change caused by unauthorized access or the like. Therefore, in the third embodiment, when a change in the record contents of the closed-system distributed ledger is discovered, it is determined whether the information generation and output process related to the changed portion has been performed in accordance with standards. If it is determined that the change has not been performed in accordance with standards, the changed portion is deemed to be inappropriate, and new object information is generated to resolve or cancel the change, thereby correcting the record contents of the closed-system distributed ledger. By adopting such a configuration, the non-fungible token record management system according to the third embodiment can accurately detect, for example, cases in which changes in the record contents occur due to unauthorized access from outside, as well as cases in which fraud has been committed by certain individuals who have access to the closed distributed ledger, and has the advantage of being able to quickly resolve inappropriate conditions and maintain the record contents of the closed distributed ledger in an appropriate state, thereby realizing a safer system. [Industrial Applicability]

[0051] The present invention can be used as a technology for managing the recorded content in a distributed ledger associated with non-fungible tokens. [Explanation of symbols]

[0052] 1 Token generation part 2, 24 Object information generation unit 3. Information Verification Department 4. First Transaction Generation Unit 5 1st electronic signature generation section 6. First information output unit 7, 17 Closed System Ledger Information Acquisition Department 8, 18 Open ledger information acquisition unit 9. Ledger Information Comparison Department 10 Additional information generation section 11 Second Transaction Generation Unit 12 Second electronic signature generation section 13 Second information output unit 14 Private key storage 16 Open ledger information monitoring department 19 Monitoring result notification section 21 Generation processing recording unit 22 Closed System Ledger Information Monitoring Department 23 Generation process verification unit

Claims

1. A non-fungible token record management system that manages records in a distributed ledger that have a correspondence relationship with non-fungible tokens associated with specific objects, an object information generating means for generating object information that is information about an object associated with a non-fungible token; a first information output means for outputting the object information generated by the object information generation means to a closed distributed ledger that corresponds to the non-fungible token and is a distributed ledger in which only predetermined specific persons can participate in recording processing; additional information generation means for generating additional information, which is information output to an open distributed ledger that has a correspondence relationship with the non-fungible token and is a distributed ledger in which unspecified people can participate in recording processing, and which matches the recorded content of the open distributed ledger with the recorded content of the closed distributed ledger including the object information output by the first information output means; a second information output means for outputting the additional information generated by the additional information generation means to the open distributed ledger; A non-fungible token record management system comprising:

2. a closed system ledger information acquisition means for acquiring closed system ledger information, which is information on all or part of the recorded contents of the closed system distributed ledger including the object information output by the first information output means; An open ledger information acquisition means for acquiring open ledger information, which is information on all or part of the recorded contents of the open distributed ledger, and which is information within a range corresponding to the closed ledger information; an information comparison means for comparing the content of the closed system ledger information acquired by the closed system ledger information acquisition means with the content of the open system ledger information acquired by the open system ledger information acquisition means; Furthermore, The non-fungible token record management system described in claim 1, characterized in that the additional information generation means generates information corresponding to the unexpected portion as the additional information when the information comparison means determines that the open system ledger information has a deficient portion compared to the closed system ledger information, and generates information that eliminates or cancels the surplus portion as the additional information when the information comparison means determines that the open system ledger information has a surplus portion compared to the closed system information.

3. Further, an open ledger information monitoring means for continuously monitoring changes in the recorded content of the open distributed ledger is provided, the open system ledger information acquisition means and the closed system ledger information acquisition means acquire the open system ledger information and the closed system ledger information, respectively, when the open system ledger information monitoring means detects a change in the recorded content of the open system distributed ledger; The information comparison means compares the acquired open system ledger information with the acquired closed system ledger information, The non-fungible token record management system according to claim 2, characterized in that, when the information comparison means determines that the contents of the open system ledger information and the closed system ledger information differ, the additional information generation means further generates the additional information so that the recorded contents of the open system distributed ledger match the recorded contents of the closed system distributed ledger.

4. A method for managing records of non-fungible tokens in a distributed ledger that has a correspondence relationship with non-fungible tokens associated with specific objects, comprising: an object information generation step of generating object information that is information about an object associated with the non-fungible token; a first information output step of outputting the object information generated in the object information generation step to a closed distributed ledger that has a correspondence relationship with the non-fungible token and is a distributed ledger in which only predetermined specific persons can be involved in recording processing; an additional information generation step of generating additional information, which is information output to an open-system distributed ledger that has a correspondence relationship with the non-fungible token and is a distributed ledger in which unspecified people can participate in recording processing, and which matches the recorded content of the open-system distributed ledger with the recorded content of the closed-system distributed ledger including the object information output by the first information output step; a second information output step of outputting the additional information generated in the additional information generation step to the open distributed ledger; A method for managing records of non-fungible tokens, comprising:

5. a closed system ledger information acquisition step of acquiring closed system ledger information, which is information on all or part of the recorded contents of the closed system distributed ledger including the object information output by the first information output means; an open system ledger information acquisition step of acquiring open system ledger information, which is information on all or part of the recorded contents of the open system distributed ledger, and which is information within a range corresponding to the closed system ledger information; an information comparison step of comparing the content of the closed system ledger information acquired in the closed system ledger information acquisition step with the content of the open system ledger information acquired in the open system ledger information acquisition step; further comprising A non-fungible token recording and management method as described in claim 4, characterized in that in the additional information generation step, if the information comparison step determines that the open system ledger information has a deficient portion compared to the closed system ledger information, information corresponding to the unanticipated portion is generated as the additional information, and if the information comparison step determines that the open system ledger information has a surplus portion compared to the closed system information, information that eliminates or cancels the surplus portion is generated as the additional information.

6. A non-fungible token record management program that causes a computer to manage record contents of a distributed ledger that have a correspondence relationship with a non-fungible token associated with a specific object, to the computer, an object information generation function that generates object information, which is information about an object associated with a non-fungible token; a first information output function that outputs the object information generated by the object information generation function to a closed distributed ledger that has a correspondence relationship with the non-fungible token and is a distributed ledger in which only predetermined specific persons can be involved in recording processing; an additional information generation function that generates additional information, which is information that corresponds to the non-fungible token and is output to an open distributed ledger, which is a distributed ledger in which unspecified people can participate in recording processing, and which matches the recorded content of the open distributed ledger with the recorded content of the closed distributed ledger including the object information output by the first information output function; a second information output function that outputs the additional information generated by the additional information generation function to the open distributed ledger; A non-fungible token record management program that executes the above.

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