WO2023229067A1

WO2023229067A1 - Did-based nft transaction system

Info

Publication number: WO2023229067A1
Application number: PCT/KR2022/007484
Authority: WO
Inventors: 이정륜; 윤태연
Original assignee: 주식회사 블록체인기술연구소
Priority date: 2022-05-26
Filing date: 2022-05-26
Publication date: 2023-11-30
Also published as: KR20230164824A

Abstract

The present invention comprises: a first user node that purchases an NFT and stores original data in a first hub instance of an IDH server, which is related to the first user node; a second user node that wants to purchase the NFT from the first user node; a blockchain node that generates a block having recorded therein metadata of the NFT; and the IDH server that communicates with the first user node to store the original data in the first hub instance, wherein, when trading the NFT, the first user node shares the original data via the IDH server, the second user node downloads the original data via the IDH server and stores the downloaded data in a second hub instance related to the second user node, and the blockchain node changes, by using a contract, an NFT owner item and URL value of a global state of a blockchain from the first user node to the second user node.

Description

DID-based NFT transaction system

The present invention relates to a DID-based NFT transaction system. More specifically, by using DID, a distributed identifier that can prove user identity, and IDH (Identity Data Hub), a DID-based decentralized storage, DID-based NFT can improve the security of original data preservation. It is about the NFT trading system.

Blockchain refers to a data distribution processing technology that distributes and stores all data subject to management by all users participating in the network. It is also called 'Distributed Ledger Technology (DLT)' or 'Public Transaction Ledger' in that the ledger containing transaction information is not held by the transaction subject or a specific institution, but is shared by all network participants. Blockchain is a name given to a chain of blocks containing transaction information. This blockchain is a technology to prevent hacking such as forgery and falsification of transaction details. It sends transaction details to all users participating in the transaction and compares them for each transaction to prevent data forgery.

Blockchain has decentralization as its core concept, moving away from the existing financial system in which all transactions are secured and managed by financial institutions and oriented toward P2P (Peer to Peer) transactions. P2P refers to a communication network that connects personal computers without a server or client, and each connected computer acts as a server and client and shares information. A digital trust relationship is formed through multiple nodes sharing and verifying the same data. This environment makes it possible to implement smart contracts that can conveniently conclude and modify contracts through P2P without an intermediary.

In the existing financial system, financial companies have stored transaction records on a central server, whereas in a blockchain based on the P2P method, transaction information is stored in blocks, linked in turn, and shared by all participants.

In particular, recently, as the importance of digital assets has grown, blockchain-based NFT (Non-Fungible Token) transactions have become active. NFT means non-fungible token, and is a digital certificate that proves the uniqueness of a digital asset by applying blockchain technology that cannot be forged or altered. Types of digital assets may include real estate, intellectual property rights, digital art, biometric data, etc., and the scope for proving uniqueness with NFT is endless.

NFTs are registered as digital assets on the blockchain through the act of issuing (minting) NFTs. NFTs registered on the blockchain can have various attribute values (Id, description, image, url, attribute, etc.) that describe the digital asset. The most important NFT original storage is indicated by URL, and by searching the URL, you can search the digital assets located in the storage.

However, NFT can prove the integrity, uniqueness, and ownership of data through blockchain-based technology, but it cannot guarantee the original preservation of large amounts of data. NFT records the owner information and issuance information of a digital file and the URL of the storage where the original data is stored on the blockchain, and the original data is not stored in the NFT. Because of these characteristics, the original data can be a target for hacking.

NFT itself is impossible to hack because it uses blockchain technology, but there is a risk that hacking of the server where the original data is stored is possible at any time, and a solution to complement this is needed.

The technical problem that the present invention seeks to solve is to provide a DID-based NFT transaction system that can improve security from hacking, etc. for large amounts of original data of NFT.

Another technical problem that the present invention aims to solve is to preserve the original data of the NFT using IDH (Identity Data Hub), a decentralized storage, while verifying the owner of the NFT through an electronic contract (Verifiable Credential) containing an electronic signature. It provides a DID-based NFT transaction system that can provide legitimacy, authenticity, and legal effect to NFT transactions by proving them.

However, the technical problems to be solved by the present invention are not limited to the above problems, and may be expanded in various ways without departing from the technical spirit and scope of the present invention.

The DID-based NFT transaction system according to an embodiment of the present invention to solve the above problem is a DID-based NFT transaction system including a first user node, a second user node, a blockchain node, and an IDH server. , a first user node that purchases the NFT and stores the original data in the first hub instance regarding the first user node of the IDH server, a second user node that wishes to purchase the NFT from the first user node, and the NFT Comprising a blockchain node that generates a block in which metadata is recorded, and an IDH server that communicates with the first user node and stores the original data in the first hub instance, and when trading for the NFT, The first user node shares the original data through the IDH server, the second user node downloads the original data through the IDH server and stores it in a second hub instance related to the second user node, The blockchain node uses a contract to change the NFT owner item and url value of the global state of the blockchain from the first user node to the second user node, and the first user node transfers the NFT to the second user node. Transmit to the second user node.

In some embodiments according to the present invention, the IDH server may control storage and access to the original data using the DID of each user node.

In some embodiments according to the present invention, the blockchain node transfers the owner information and URL value of the metadata recorded in the block using a contract during the NFT transaction from the first user node to the second user node. , and the hash value of the original data does not change.

In some embodiments according to the present invention, the first user node may generate a DID-based verifiable credential to include the transaction process of the NFT and transmit it to the second user node.

In some embodiments according to the present invention, the verifiable credential may include an electronic signature of the first user node and an electronic signature of the second user node.

Other specific details of the invention are included in the detailed description and drawings.

According to the present invention, by storing the original data of NFT in a DID-based decentralized storage, the original data of NFT can be preserved and security from hacking, etc. can be strengthened.

In addition, according to the present invention, legal problems that may arise during NFT transactions can be proven through an electronic contract (Verifiable Credential) containing electronic signatures between contracting parties, thereby accurately proving the owner and promoting legal stability.

In addition, according to the present invention, accurate proof of ownership of digital assets using NFT is possible, contributing to the development and revitalization of the data industry.

However, the effects of the present invention are not limited to the above effects, and may be expanded in various ways without departing from the technical spirit and scope of the present invention.

Figure 1 is a diagram showing a distributed processing system using blockchain to which the technical idea according to the present invention can be applied.

Figures 2 and 3 are block diagrams showing the connection of blocks used in a blockchain system.

Figure 4 is a diagram showing an example of NFT metadata proving that the first user is the owner of the NFT.

Figure 5 is a block diagram showing the configuration and operation procedures of a DID-based NFT transaction system according to an embodiment of the present invention.

Figure 6 is a diagram showing an example of metadata of an NFT proving that the owner item and url value of the NFT have changed from the first user to the second user.

Figure 7 is a configuration diagram of a node computing device according to an embodiment of the present invention.

The advantages and features of the present invention and methods for achieving them will become clear by referring to the embodiments described in detail below along with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and will be implemented in various different forms, but the present embodiments only serve to ensure that the disclosure of the present invention is complete and are within the scope of common knowledge in the technical field to which the present invention pertains. It is provided to fully inform those who have the scope of the invention, and the present invention is only defined by the scope of the claims.

The terminology used herein is for describing embodiments and is not intended to limit the invention. As used herein, singular forms also include plural forms, unless specifically stated otherwise in the context. As used herein, “comprises” and/or “comprising” refers to the presence of one or more other components, steps, operations and/or elements. or does not rule out addition.

Unless otherwise defined, all terms (including technical and scientific terms) used in this specification may be used with meanings that can be commonly understood by those skilled in the art to which the present invention pertains. Additionally, terms defined in commonly used dictionaries are not interpreted ideally or excessively unless clearly specifically defined.

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the attached drawings. The same reference numerals are used for the same components in the drawings, and duplicate descriptions for the same components are omitted.

Below, we will first describe a distributed processing system using blockchain to which the concept of the present invention can be applied.

Referring to Figure 1, a distributed processing system using blockchain is a distributed network system consisting of a plurality of nodes (110 to 170). The nodes 110 to 170 constituting the distributed network 100 may be electronic devices with computing capabilities, such as computers, mobile terminals, and dedicated electronic devices.

In general, the distributed network 100 can store and reference information commonly known to all participating nodes within a connected bundle of blocks called a blockchain. The nodes 110 to 170 are capable of communicating with each other and can be divided into full nodes, which are responsible for storing, managing, and disseminating the blockchain, and light nodes, which can simply participate in transactions. . When a node is mentioned without further explanation in this specification, it often refers to a full node that participates in the decentralized network 100 and performs the operation of creating, storing, or verifying the blockchain, but is not limited to this. .

Each block connected to the blockchain contains transaction details, that is, transactions, within a certain period of time. The nodes can manage transactions by creating, storing, or verifying blockchains according to their respective roles.

Depending on the embodiment, the transaction may represent various types of transactions. In one embodiment, the transaction may correspond to a financial transaction to indicate the ownership status of virtual currency and its changes. In another embodiment, the transaction may correspond to a physical transaction to indicate the ownership status of an item and its changes. In another embodiment, the transaction may correspond to an information sharing process to represent the recording, storage, and transfer of information. Nodes that perform transactions in the distributed network 100 may have a private key and public key pair with a cryptographic relationship.

Referring to FIG. 2, the blockchain 200 is a type of distributed database of one or more sequentially

connected blocks

210, 220, and 230. The blockchain 200 is used to store and manage users' transaction details within the blockchain system, and each node participating in the network of the blockchain system creates a block and connects it to the blockchain 200. Although a limited number of

blocks

210, 220, and 230 are shown in Figure 2, the number of blocks that can be included in the blockchain is not limited thereto.

Each block included in the blockchain 200 may be configured to include a block header 211 and a block body 213. The block header 211 may include the hash value of the previous block 220 to indicate the connection relationship between each block. In the process of verifying whether the blockchain 200 is valid, the connection relationship within the block header 211 is used. The block body 213 may include data stored and managed in the block 210, for example, a transaction list or a transaction chain.

Referring to FIG. 3, the block header 211 may include a hash 2112 of the previous block, a hash 2113 of the current block, and a nonce 2114. Additionally, the block header 211 may include a root 2115 indicating the header of the transaction list within the block.

As described above, the blockchain 200 may include one or more connected blocks. The one or more blocks are connected based on the hash value in the block header 211. The hash value 2112 of the previous block included in the block header 211 is a hash value for the previous block 220 and is the same as the current hash 2213 included in the previous block 220. The one or more blocks are chained by the hash value of the previous block in each block header. Nodes participating in the decentralized network 100 verify the validity of blocks based on the hash value of the previous block included in the one or more blocks, so that a single malicious node cannot forge or alter the contents of an already created block. The action is impossible.

The block body 213 may include a transaction list 2131. The transaction list 2131 is a list of blockchain-based transactions. For example, the transaction list 2131 may include records of financial transactions made in the blockchain-based financial system. The transaction list 2131 may be expressed in the form of a tree. For example, the amount sent by user A to user B is recorded in the form of a list, and the storage length in the block is the length of the transaction included in the current block. It can be increased or decreased based on the number.

Additionally, the block 210 may include other information 2116 other than the information included in the block header 211 and the block body 213.

Nodes participating in the decentralized network 100 have the same blockchain, and the same transaction is stored in the block. Blocks containing the transaction list are shared across the network, so all participants can verify them.

In the present invention, the original data of NFT can be preserved using a DID (distributed identifier) that can prove the identity of the user node and IDH (Identity Data Hub), a DID-based decentralized storage. IDH proposed in the present invention is a DID-based access control storage that stores NFT original data in the logical storage (hub instance) of each user node rather than the central server, and when a transaction is established, the url value included in the NFT metadata You can perform transactions for NFTs by changing the url value of another owner.

NFT is a term that refers to a cryptocurrency in which it is impossible to replace one token with another. It is a technology that proves and protects the ownership of digital assets using blockchain technology that cannot be manipulated in the middle. In other words, by recording owner information about digital files (pictures, music, etc.) as NFTs on the blockchain network, it is possible to permanently prove who owns the original data of the digital file. This can give ownership and scarcity to the digital file itself, unlike digital assets that can be copied infinitely and are therefore worthless.

NFT original data refers to the digital work itself, and metadata includes descriptions and information about the content, such as the genre and title of the digital work and the address where the digital data is stored. The original data is stored in an external storage medium rather than a blockchain network, and the external storage medium is IDH in the present invention. When a transaction is made for NFT original data, a link to the metadata is transmitted rather than the digital work itself, and this code is stored on the blockchain. Therefore, NFT metadata must be stored and managed by individuals.

NFT metadata defines an NFT as a digital asset and includes details about the name of the digital file or the composition of the file. For example, metadata for a video NFT may include the length of the video and the images that make up the individual frames, while metadata for a profile picture (PFP) or digital art NFT may include a specific creation that defines how rare the NFT is. Can contain properties.

In the present invention, it is assumed that the first user node and the second user node know each other's DID, and that the information of the first user node and the information of the second user node are each registered in the IDH.

When an NFT is issued, the metadata of the NFT is recorded on the blockchain, and at this time, the metadata includes the hash value of the NFT original data, the url value where the original data is stored, and owner items. The url value is a value linked to the IDH of the NFT owner, and in this specification, the value described in “huburl” is defined as the url value (see Figure 4). The expression "huburl" can be expressed in any other way as long as it refers to the url value. Through this, the NFT's original data and metadata are not controlled externally, but only authorized users can modify and manage them. Figure 4 shows an example of NFT metadata that proves that the first user is the owner of the NFT.

Before explaining the present invention, the following will first explain the concept of DID and DID document.

DID refers to a unique identifier that can prove your identity by CRUD (Create, Read, Update, Delete) information that can identify an individual without a central agency. DID is a key value that serves as a pointer to the DID document of a blockchain transaction. In particular, DID is an identifier generated based on the user's public key.

A DID document refers to a set of documents required for an individual to authenticate himself and prove his association with a DID. The object of DID's CRUD performance is the DID document, which refers to the information required for verification when using the DID service, and the data set contains properties such as public key and authentication method.

The relationship between DID and DID document is to search DID in the blockchain and create DID document based on transaction contents, and the method of reading DID document based on DID may be different for each blockchain.

The DID-based NFT transaction system according to the present invention operates through an organic relationship between the first user node 310, the second user node 320, the blockchain node 400, and the IDH server 500. do.

Hereinafter, the configuration and operation procedures of the DID-based NFT transaction system according to the present invention will be described with reference to the drawings.

Figure 5 is a block diagram showing the configuration and operation procedures of a DID-based NFT transaction system according to an embodiment of the present invention. Figure 6 is a diagram showing an example of NFT metadata proving that the owner of the NFT has changed from the first user to the second user.

The DID-based NFT transaction system according to an embodiment of the present invention may include a first user node 310, a second user node 320, a blockchain node 400, and an IDH server 500. The operating method for the DID-based NFT transaction system according to the present invention may be an algorithm implemented through an application.

Among the components of the present invention, the first user node 310 may be a terminal device that purchases NFT, stores the original data in its hub instance, and sells the NFT to other users. The first user node 310 may be implemented as a computer capable of accessing a remote server or terminal through a network. Here, the computer may include, for example, a laptop equipped with a navigation system and a web browser, a desktop, a laptop, etc.

In addition, the first user node 310 is, for example, a wireless communication device that guarantees portability and mobility, and includes navigation, personal communication system (PCS), global system for mobile communications (GSM), personal digital cellular (PDC), PHS (Personal Handyphone System), PDA (Personal Digital Assistant), IMT (International Mobile Telecommunication)-2000, CDMA (Code Division Multiple Access)-2000, W-CDMA (W-Code Division Multiple Access), Wibro (Wireless Broadband Internet) ) It may include all types of handheld-based wireless communication devices such as terminals, smartphones, smartpads, and tablet PCs.

The second user node 320 is a terminal device that wishes to purchase NFT from the first user node 310, and like the first user node 310, it will be implemented as a computer that can access a remote server or terminal through a network. You can.

The second user node 320 may include, for example, a laptop equipped with a navigation system or a web browser, a desktop, or a laptop.

In addition, the second user node 320 is, for example, a wireless communication device that guarantees portability and mobility, and includes navigation, personal communication system (PCS), global system for mobile communications (GSM), personal digital cellular (PDC), PHS (Personal Handyphone System), PDA (Personal Digital Assistant), IMT (International Mobile Telecommunication)-2000, CDMA (Code Division Multiple Access)-2000, W-CDMA (W-Code Division Multiple Access), Wibro (Wireless Broadband Internet) ) It may include all types of handheld-based wireless communication devices such as terminals, smartphones, smartpads, and tablet PCs.

The blockchain node 400 is a node that generates a block in which NFT metadata is recorded and may be any node in the blockchain network. In the blockchain node 400, the owner information and url value of the NFT metadata recorded in the block can be changed from the first user node 310 to the second user node 320 through a contract during an NFT transaction, and the original data The hash value of should not be changed.

The IDH server 500 communicates with the first user node 310 and stores the original data of the NFT in the first hub instance of the first user node 310. Here, the hub instance corresponds to logical storage linked to the IDH server 500, and the first user node 310 corresponds to the node that purchased the NFT.

The IDH server 500 can control storage and access to the original data of the NFT using the DID of each user node. For example, the original data of the NFT is stored in the hub instance of the first user node 310. In this case, the original data of the NFT can be accessed using the DID only by the first user node 310 and the original data of the NFT can be shared with other user nodes.

In the present invention, during an NFT transaction, the first user node 310 can share the original data through the IDH server 500, and the second user node 320 can share the original data shared through the IDH server 500. Save it in your second hub instance.

Specifically, the first user node 310 shares the NFT original data stored in the first hub instance through the IDH server 500, and the second user node 320 shares the NFT original data stored through the IDH server 500. The data is downloaded and stored in its second hub instance, and the second user node 320 provides its DID value and the huburl value, which is the location of the NFT original data stored in the second hub instance, through the IDH server 500. 1 Delivered to the user node 310.

Due to the logic difference in the way data is stored and shared in the hub instance through the IDH server 500, the first user node 310 cannot directly transmit NFT original data to the second user node 320, and the IDH server The second user node 320 can store the NFT original data in its second hub instance by sharing it through 500.

In other words, the first user node 310 cannot know the huburl value and the DID value, which are the storage locations of the NFT original data, in relation to the second user node 320, and thus the security regarding the storage of the NFT original data is strengthened. do.

In the present invention, during an NFT transaction, the blockchain node 400 uses a contract to transfer the NFT owner item and URL value of the global state of the blockchain from the first user node 310 to the second user node 320. ), and the NFT is transferred from the first user node 310 to the second user node 320. Figure 6 shows an example of NFT metadata proving that the owner item and url value of the NFT have changed from the first user to the second user.

At this time, the first user node 310 generates a DID-based verifiable credential to include the above processes and transmits it to the second user node 320, and generates the verifiable credential. It can be proven that the owner of the original data of the NFT has changed from the first user node 310 to the second user node 320. This verifiable credential corresponds to an electronic contract, and can give legality, legitimacy, and legal effect to the contract through the electronic signature of the first user node 310 and the second user node 320.

In relation to Verifiable Credential, a Claim is a description of a subject and is expressed as a subject-characteristic-information relationship. Credential is a certificate issued by an issuer and is a set of one or more claims made for one subject. Verifiable Credential is a set of data that includes metadata such as information on whether the issued Credential has been changed, issuer information, and electronic signature.

The computing device 1000 of the node according to an embodiment of the present invention includes a processor 1100 and a memory 1200, and the processor 1100 includes one or more cores, a graphics processing unit, and/or other components and signals. It may include a connection passage (for example, a bus, etc.) for transmitting and receiving.

The processor 1100 according to one embodiment executes one or more instructions stored in the memory 1200, thereby executing the operation of the DID-based NFT transaction system described in relation to FIGS. 4 to 6.

For example, the processor 1100 collects information about data upload/download occurring in one or more nodes by executing one or more instructions stored in memory, records the collected information in a block, and executes the information recorded in the block. Based on the information, relevant information is provided for at least one node.

Meanwhile, the processor 1100 may further include RAM (Random Access Memory) and ROM (Read-Only Memory) that temporarily and/or permanently store internally processed signals (or data). . Additionally, the processor 1100 may be implemented in the form of a system on chip (SoC) including at least one of a graphics processing unit, RAM, and ROM.

The memory 1200 may store programs (one or more instructions) for processing and controlling the processor 1100. Programs stored in the memory 1200 may be divided into a plurality of modules according to their functions.

The operations of the system described in relation to embodiments of the present invention may be implemented directly in hardware, implemented as a software module executed by hardware, or a combination thereof. The software module may be RAM (Random Access Memory), ROM (Read Only Memory), EPROM (Erasable Programmable ROM), EEPROM (Electrically Erasable Programmable ROM), Flash Memory, hard disk, removable disk, CD-ROM, or It may reside on any type of computer-readable recording medium well known in the art to which the present invention pertains.

The components of the present invention may be implemented as a program (or application) and stored in a medium in order to be executed in conjunction with a hardware computer. Components of the invention may be implemented as software programming or software elements, and similarly, embodiments may include various algorithms implemented as combinations of data structures, processes, routines or other programming constructs, such as C, C++, , may be implemented in a programming or scripting language such as Java, assembler, etc. Functional aspects may be implemented as algorithms running on one or more processors.

The above-described embodiments should be understood in all respects as illustrative and not restrictive, and the scope of the present invention will be indicated by the claims below rather than the detailed description above. In addition, the meaning and scope of this claim, as well as all changes and modifications derived from the equivalent concept, should be construed as being included in the scope of the present invention.

Claims

In a DID-based NFT transaction system including a first user node, a second user node, a blockchain node, and an IDH server,

A first user node that purchases NFT and stores the original data in a first hub instance related to the first user node of the IDH server;

A second user node wanting to purchase the NFT from the first user node;

A blockchain node that generates a block in which the metadata of the NFT is recorded; and

An IDH server that communicates with the first user node and stores the original data in the first hub instance,

When trading for the NFT,

The first user node shares the original data through the IDH server, and the second user node downloads the original data through the IDH server and stores it in a second hub instance related to the second user node,

The blockchain node uses a contract to change the NFT owner item and URL value of the global state of the blockchain from the first user node to the second user node,

A DID-based NFT transaction system in which the first user node transmits the NFT to the second user node.
According to clause 1,

The IDH server is a DID-based NFT transaction system that controls storage and access to the original data using the DID of each user node.
According to clause 1,

The blockchain node uses a contract during the NFT transaction to change the owner information and URL value of the metadata recorded in the block from the first user node to the second user node, and hash the original data. A DID-based NFT transaction system that does not change the value.
According to clause 1,

A DID-based NFT transaction system in which the first user node generates a DID-based verifiable credential (Verifiable Credential) to include the transaction process of the NFT and transmits it to the second user node.
According to clause 4,

The verifiable credential (Verifiable Credential) is a DID-based NFT transaction system including the electronic signature of the first user node and the electronic signature of the second user node.