User device and operating method thereof

Abstract

A user device according to embodiments of the present disclosure may comprise: a communication circuit that communicates with a blockchain network; and a processor that receives, from the blockchain network, a link of metadata before a dynamic non-fungible token (DNFT) is changed and a first hash value calculated on the basis of a previous hash value and the link of the metadata before the change, calculates a second hash value by using the link of the metadata before the change, compares the first hash value with the second hash value, and determines, on the basis of a result of the comparison, whether the metadata of the DNFT has been manipulated.

Description

User devices and their operation methods

[0001] The present disclosure relates to a method for detecting manipulation of metadata of a dynamic non-fungible token.

[0002] A non-fungible token (NFT) is a virtual token that uses blockchain technology to prove ownership of an asset.

[0003] NFTs can be mapped with metadata. Metadata may include one or more of the following: the asset's attributes, the asset's owner's address, or the asset's price. Metadata may also include general information about the asset.

[0004] Currently, the metadata that NFTs can express is limited.

[0005] While NFT refers to an immutable token, recent use cases often show that metadata that actually contains the value information of the NFT is updated.

[0006] A dynamic NFT (DNFT) is an NFT whose metadata can be changed.

[0007] In other words, a dynamic NFT is an NFT whose metadata can be updated depending on external conditions.

[0008] However, the question arises as to whether arbitrarily changing the metadata of NFTs is in line with the purpose of NFTs as digital assets in terms of reliability.

[0009] Additionally, there are still reliability issues with dNFTs due to the possibility of manipulation by the Updater that updates the metadata (falsely displaying the metadata link before the change).

[0010] The purpose of this disclosure is to ensure the reliability of dNFT by allowing viewers to track / search the previous change history and contents even if dNFT metadata is changed.

[0011] The purpose of this disclosure is to detect manipulation of metadata of DNFT.

[0012] A user device according to an embodiment of the present disclosure may include a communication circuit for communicating with a blockchain network, and a processor for receiving a first hash value calculated based on a link of metadata before change of a dynamic non-fungible token (DNFT) from the blockchain network and a link of a previous hash value and the metadata before change, calculating a second hash value using the link of the metadata before change, comparing the first hash value with the second hash value, and determining whether metadata of the DNFT has been manipulated based on a result of the comparison.

[0013] A method of operating a user device according to an embodiment of the present disclosure may include receiving a first hash value calculated based on a link of metadata before change of a dynamic non-fungible token (DNFT) from a blockchain network and a previous hash value and a link of the metadata before change, calculating a second hash value using the link of the metadata before change, comparing the first hash value with the second hash value, and determining whether the metadata of the DNFT has been manipulated based on a result of the comparison.

[0014] According to an embodiment of the present disclosure, the change history of a DNFT can be tracked and the integrity of the change history of a DNFT can be verified using only the metadata of the DNFT, without a block explorer or a query on the blockchain.

[0015] FIG. 1 is a block diagram illustrating a configuration of a user device according to an embodiment of the present disclosure.

[0016] FIG. 2 is a block diagram illustrating the configuration of a management server according to one embodiment of the present disclosure.

[0017] FIG. 3 is a ladder diagram for explaining an operation method of a blockchain system according to an embodiment of the present disclosure.

[0018] Fig. 4a is a diagram showing a process of changing unmanipulated metadata of DNFT, and Figs. 4b to 4d are diagrams showing examples of manipulated metadata of DNFT.

[0019] FIG. 5 is a diagram illustrating an actual example of a viewer of a user device verifying the integrity of metadata of a DNFT according to an embodiment of the present disclosure.

[0020] Hereinafter, embodiments related to the present invention will be described in more detail with reference to the drawings. The suffixes "module" and "part" used in the following description for components are assigned or used interchangeably solely for the convenience of writing the specification, and do not in themselves have distinct meanings or roles.

[0021] A user device according to an embodiment of the present invention may be, for example, an intelligent user device that adds a computer-assisted function to a broadcast reception function.

[0022] User devices can be equipped with more convenient interfaces such as manual input devices, touch screens, or spatial remote controls, while remaining faithful to broadcast reception functions and adding Internet functions.

[0023] The user device can connect to the Internet and a computer with wired or wireless Internet capabilities, and can also perform functions such as email, web browsing, banking, or gaming.

[0024] The user device described in the present disclosure can perform various user-friendly functions because various applications can be freely added or deleted, for example, on a general-purpose OS kernel.

[0025] The user device can be any of a smartphone, smart pad, laptop, PC, network TV, smart TV, LED TV, or OLED TV.

[0026] FIG. 1 is a block diagram illustrating a configuration of a user device according to an embodiment of the present disclosure.

[0027] The user device (10) may be implemented as a fixed or mobile device, such as a projector, a mobile phone, a smart phone, a desktop computer, a laptop, a digital broadcasting terminal, a PDA (personal digital assistant), a PMP (portable multimedia player), a navigation device, a tablet PC, a wearable device, a set-top box (STB), a DMB receiver, a radio, a desktop computer, a TV, etc.

[0028] Referring to FIG. 1, the user device (10) may include a communication circuit (110), an input interface (120), a memory (130), a display (140), and a processor (190).

[0029] The communication circuit (110) can transmit and receive data with external devices such as other user devices or servers using wired or wireless communication technology.

[0030] The communication circuit (110) can perform communication using any one of the communication standards of GSM (Global System for Mobile communication), CDMA (Code Division Multi Access), LTE (Long Term Evolution), 5G, WLAN (Wireless LAN), Wi-Fi (Wireless-Fidelity), Bluetooth (Bluetooth TM), RFID (Radio Frequency Identification), Infrared Data Association (IrDA), ZigBee, and NFC (Near Field Communication).

[0031] The input interface (120) may include a camera for inputting a video signal, a microphone for receiving an audio signal, a user input unit for receiving information from a user, etc.

[0032] Here, the camera or microphone is treated as a sensor, and the signal obtained from the camera or microphone can be called sensing data or sensor information.

[0033] The memory (130) can store various software and data related to the operation of the user device (10).

[0034] The display (140) can display a video signal received from the outside.

[0035] The processor (190) can control the overall operation of the user device (10).

[0036] When connection of an external device is required to perform an operation of the user device (10), the processor (190) can generate a control signal for controlling the external device and transmit the generated control signal to the external device.

[0037] The processor (190) can control at least some of the components of the user device (10) to run an application program stored in the memory (130).

[0038] The processor (190) can operate two or more of the components included in the user device (10) in combination to drive the application program.

[0039] FIG. 2 is a block diagram illustrating the configuration of a blockchain node according to an embodiment of the present disclosure.

[0040] A blockchain node (20) is a component of a blockchain network that can verify transactions and record them in the verified blockchain network.

[0041] A blockchain network may include multiple blockchain nodes.

[0042] A blockchain node (20) may be a user device (10) such as a server or edge device.

[0043] Referring to FIG. 2, a blockchain node (20) may include a communication interface (210), a database (230), and a controller (290).

[0044] The communication interface (210) can perform Internet communication with a user device (10) or an update request device (30).

[0045] The database (230) can store data received from a user device (10) or an update request device (30).

[0046] The communication interface (210) may have a communication circuit for Internet communication.

[0047] The controller (290) can control the overall operation of the blockchain node (20).

[0048] FIG. 3 is a ladder diagram for explaining an operation method of a blockchain system according to an embodiment of the present disclosure.

[0049] Referring to FIG. 3, the blockchain system may include a user device (10), a blockchain network (50), an update request device (30), and a distributed file system (InterPlanetary File System, IPFS, 40).

[0050] The update request device (30) may include the same components as the user device (10).

[0051] A blockchain network (50) may include one or more blockchain nodes.

[0052] The update request device (30) generates updated metadata of DNFT and uploads the generated metadata to IPFS (40) (S301).

[0053] IPFS (40) may be a system that stores files by dividing them across multiple nodes.

[0054] IPFS (40) stores the metadata of the uploaded DNFT in distributed nodes (S303).

[0055] IPFS (40) can divide the metadata of the uploaded DNFT into data blocks and store each data block in distributed nodes.

[0056] The update request device (30) transmits an update request for updating the metadata of DNFT to the blockchain network (50) (S305).

[0057] The update request device (30) can transmit an update request to the blockchain network (50) so that the metadata of the DNFT uploaded to IPFS (40) is updated on the blockchain network (50).

[0058] The blockchain network (50) calculates a first hash value based on the previous metadata link in response to an update request and writes the first hash value to the first contract (S307).

[0059] The blockchain network (50) can calculate the first hash value using the previous hash value and the previous metadata link (the link before the metadata was changed).

[0060] For example, the blockchain network (50) can generate a first hash value by combining a previous hash value and a previous metadata link.

[0061] The blockchain network (50) can calculate the cumulative hash value of the metadata links of the existing DNFT and obtain the calculated cumulative hash value as the first hash value.

[0062] The blockchain network (50) can calculate the cumulative hash value through the following [Mathematical Formula 1].

[0063] [Mathematical Formula 1]

[0064]

[0065] The operator can be an operator representing a string attach combination.

[0066] Hash represents a hash function, which can be a function that follows the Secure Hash Algorithm-256 (SHA-256).

[0067] SHA-256 may be a cryptographic hash algorithm that produces a 256-bit condensed message from an arbitrary length message.

[0068] can be the value stored in the contract when the metadata of DNFT is changed for the Nth time.

[0069] A contract may be a smart contract in which code is automatically executed and the contract content is executed when specific contract conditions are met in a blockchain network (50).

[0070] Upon occurrence of a contract, a contract address can be generated through the blockchain network (50).

[0071] When the metadata is changed for the Nth time, it can be a link indicating the storage address of the metadata before the change. The metadata link can indicate the address of IPFS where the metadata of DNFT is stored.

[0072] In one embodiment, the first hash value (S1) may be null.

[0073] In another embodiment, the first hash value (S1) may be the address of a personal wallet of the user device (10).

[0074] In another embodiment, the first hash value (S1) may be a contract address generated at the time of issuance of DNFT.

[0075] The blockchain network (50) can record the accumulated hash value of metadata links before a request for metadata update in a variable included in the contract.

[0076] The blockchain network (50) can record the accumulated hash value in the contract address.

[0077] After that, the blockchain network (50) updates the DNFT using the update information received from the update request device (30) (S309).

[0078] The processor (190) of the user device (10) can request the most recent metadata link (N-1th metadata link) and the first hash value of DNFT to the blockchain network (50) through the communication circuit (110) (S313).

[0079] The processor (190) of the user device (10) can receive the most recent metadata link (N-1th metadata link) and the first hash value of DNFT from the blockchain network (50) in response to the request (S315).

[0080] The processor (190) can read a first hash value representing the most recent metadata link and cumulative hash value of DNFT from the blockchain network (50).

[0081] A decentralized application (Dapp) may be installed on the user device (10).

[0082] The processor (190) can execute a decentralized application to perform step S315 and subsequent steps.

[0083] A decentralized application may be an application that operates on a blockchain network (50).

[0084] The processor (190) of the user device (10) can calculate a second hash value using the most recent metadata link received (S317).

[0085] In one embodiment, the processor (190) may calculate the second hash value using the most recent metadata link (the N-1th metadata link) and the N-1th hash value.

[0086] That is, the processor (190) can calculate a second hash value representing the cumulative hash value through [Mathematical Formula 2].

[0087] [Equation 2]

[0088]

[0089] The operator can be an operator representing a string attach combination.

[0090] Hash can be a hash function that follows the Secure Hash Algorithm-256 (SHA-256).

[0091] can be the Nth cumulative hash value.

[0092] may be a link indicating the storage address of the metadata before the above change.

[0093] In one embodiment, the first hash value ( ) can be null.

[0094] In another embodiment, the first hash value ( ) may be the address of the personal wallet of the user device (10).

[0095] In another embodiment, the first hash value ( ) may be the contract address generated at the time of issuance of DNFT.

[0096] The processor (190) of the user device (10) compares the first hash value and the second hash value (S319), and as a result of the comparison, can determine whether the first hash value and the second hash value match (S321).

[0097] The processor (190) of the user device (10) can determine that the metadata of the DNFT has not been manipulated if the first hash value and the second hash value match (S323).

[0098] The processor (190) may output a first notification indicating that the metadata of the DNFT has not been manipulated if the first hash value and the second hash value match.

[0099] For example, the processor (190) may display a first notification on the display (140) indicating that the metadata of the DNFT has not been manipulated if the first hash value and the second hash value match.

[0100] The processor (190) of the user device (10) can determine that the metadata of the DNFT has been manipulated if the first hash value and the second hash value do not match (S325).

[0101] If the first hash value and the second hash value do not match, the processor (190) may output a second notification indicating that the metadata of the DNFT has been manipulated.

[0102] For example, if the first hash value and the second hash value do not match, the processor (190) may display a second notification on the display (140) indicating that the metadata of the DNFT has been manipulated.

[0103] In this way, according to an embodiment of the present disclosure, the change history of a DNFT can be tracked and the integrity of the change history of the DNFT can be verified using only the metadata of the DNFT, without a block explorer or a query on the blockchain.

[0104] Fig. 4a is a diagram showing a process of changing unmanipulated metadata of DNFT, and Figs. 4b to 4d are diagrams showing examples of manipulated metadata of DNFT.

[0105] In the following, we assume that DNFT is an NFT issued for the purpose of proving ownership of a home appliance.

[0106] Referring to FIG. 4a, the metadata of the DNFT may include a metadata link indicating additional information of the DNFT and a storage address of the metadata.

[0107] DNFT metadata can be stored in IPFS (40).

[0108] DNFT can be issued by a smart contract generated in a blockchain network (50). The blockchain platform used by the blockchain network (50) may be Ethereum, but this is merely an example.

[0109] Additional information of a DNFT may include one or more of the DNFT's name, issuance information, owner information, attribute information, and history information.

[0110] A metadata link can point to the address where the metadata was stored before it was changed.

[0111] Referring to FIG. 4a, the first metadata (400_1) of the DNFT may include first additional information (400_1a) and a first metadata link (400_1b).

[0112] The first additional information (400_1a) may include a management event of the home appliance and the date on which the management event occurred.

[0113] A maintenance event can represent any one of the following events: inspection, repair, or replacement of parts of an appliance.

[0114] The first metadata link (400_1b) may be recorded as empty, as the DNFT has not been updated previously.

[0115] The Nth metadata (400_N) of the DNFT may include Nth additional information (400_Na) and Nth metadata link (400_Nb).

[0116] Additional information N (400_Na) may include a management event of the home appliance and the date on which the management event occurred.

[0117] A maintenance event can represent any one of the following events: inspection, repair, or replacement of parts of an appliance.

[0118] The Nth metadata link (400_Nb) may include the storage address of the N-1th updated metadata.

[0119] Figure 4b shows the metadata link before the change to hide the manipulation of metadata by the updater. <empty>This is when updating with metadata recorded in .

[0120] The updater may be a user of the update requesting device (30).

[0121] Referring to FIG. 4b, the Nth metadata link (400Nb) included in the Nth metadata (400_N) by the updater <empty>It shows that it is recorded as .

[0122] Figure 4c shows a case where the updater updates metadata to an address that skips several metadata links before the change to hide manipulation of the metadata.

[0123] Referring to FIG. 4c, it is shown that the Nth metadata link (400Nb) included in the Nth metadata (400_N) by the updater is recorded to indicate the Nth metadata (400_(N-2)) that skips the previously updated N-1 metadata (400_(N-1)).

[0124] FIG. 4d is a case where the updater updates the metadata (410) by changing the link of the metadata before the change to the link of the metadata (400_N) of the other DNFT to add the metadata change history of the other DNFT to its own change history.

[0125] A user device (10) according to an embodiment of the present disclosure can determine whether the change history of metadata has been manipulated as in FIGS. 4b to 4d through the embodiment of FIG. 3.

[0126] FIG. 5 is a diagram illustrating an actual example of a viewer of a user device verifying the integrity of metadata of a DNFT according to an embodiment of the present disclosure.

[0127] 1. The updater records and uploads DNFT metadata (400_N) to IPFS (40).

[0128] 2. The updater transmits an update request to the blockchain network (50) to update the metadata (400_N) of DNFT on the blockchain network (50).

[0129] 3. The blockchain network (50) can calculate the first hash value (cumulative hash value) using the following [Mathematical Formula 1] in response to an update request, and record the calculated first hash value (cumulative hash value) in the contract.

[0130] [Mathematical Formula 1]

[0131]

[0132] 4. The blockchain network (50) can update the metadata of DNFT from the N-1 metadata (400-(N-1)) to the N-th metadata (400_N).

[0133] 5. The user device (10) used by the viewer can read the N-1 metadata link (400_Nb) indicating the address where the first hash value (cumulative hash value) and the metadata (400-(N-1)) of the previous DNFT are stored through the installed Dapp.

[0134] 6. The user device (10) can calculate the second hash value using the N-1 metadata link (400_Nb).

[0135] 7. The user device (10) can return a comparison result between the first hash value and the second hash value.

[0136] The viewer can determine that the DNFT metadata has been manipulated if the first hash value and the second hash value are different through the comparison result.

[0137] In this way, according to an embodiment of the present disclosure, the change history of a DNFT can be tracked and the integrity of the change history of the DNFT can be verified using only the metadata of the DNFT, without a block explorer or a query on the blockchain.

[0138] According to one embodiment of the present disclosure, the above-described method can be implemented as a processor-readable code on a medium in which a program is recorded.

[0139] Examples of processor-readable media include ROM, RAM, CD-ROM, magnetic tape, floppy disks, and optical data storage devices.< / empty> < / empty>

Claims

1. On the user device, A communication circuit that communicates with a blockchain network; and A processor that receives a first hash value calculated based on a link of metadata before change of a Dynamic Non-Fungible Token (DNFT) from the blockchain network and a previous hash value and a link of the metadata before change, calculates a second hash value using the link of the metadata before change, compares the first hash value with the second hash value, and determines whether the metadata of the DNFT has been manipulated based on the comparison result. User device.

2. In paragraph 1, The above processor If the first hash value and the second hash value are not the same, it is determined that the metadata of the DNFT has been manipulated, If the first hash value and the second hash value are the same, it is determined that the metadata of the DNFT has not been manipulated. User device.

3. In paragraph 1, The above processor If the first hash value and the second hash value are not the same, output a first notification indicating that the metadata of the DNFT has been manipulated; If the first hash value and the second hash value are the same, a second notification is output indicating that the metadata of the DNFT has not been manipulated. User device.

4. In paragraph 1, The above processor The second hash value is calculated using the following [Mathematical Formula 1]. [Mathematical Formula 1] The operator is an operator representing a string attach combination, and Hash is a hash function that follows the Secure Hash Algorithm-256 (SHA-256). is the Nth cumulative hash value, is a link indicating the storage address of the metadata before the above change. User device.

5. In paragraph 1, The above processor Requesting the link of the metadata before the change of the DNF and the first hash value from the blockchain network User device.

6. In paragraph 5, The above processor Requesting the link of the metadata before the change of the DNF and the first hash value to the blockchain network through a decentralized application installed on the user device. User device.

7. In paragraph 1, The above metadata of the above DNFT Contains additional information about the above DNFT and a link to the metadata before the change. User device.

8. In the method of operation of the user device, A step of receiving a link of metadata before change of a dynamic non-fungible token (DNFT) from a blockchain network and a first hash value calculated based on the link of the metadata before change and a previous hash value; A step of calculating a second hash value using a link of the metadata before the change; A step of comparing the first hash value and the second hash value; and A step of determining whether the metadata of the DNFT has been manipulated based on the comparison result is included. How the user device operates.

9. In paragraph 8, The above judging steps are If the first hash value and the second hash value are not the same, a step of determining that the metadata of the DNFT has been manipulated; and A step of determining that the metadata of the DNFT has not been manipulated when the first hash value and the second hash value are the same. How the user device operates.

10. In paragraph 8, If the first hash value and the second hash value are not the same, a step of outputting a first notification indicating that the metadata of the DNFT has been manipulated; and If the first hash value and the second hash value are the same, further comprising a step of outputting a second notification indicating that the metadata of the DNFT has not been manipulated. How the user device operates.

11. In paragraph 8, The step of calculating the second hash value is A step of calculating the second hash value through the following [Mathematical Formula 1] is included. [Mathematical Formula 1] The operator is an operator representing a string attach combination, and Hash is a hash function that follows the Secure Hash Algorithm-256 (SHA-256). is the Nth cumulative hash value, is a link indicating the storage address of the metadata before the above change. How the user device operates.

12. In paragraph 8, Further comprising a step of requesting a link of the metadata before the change of the DNF and the first hash value to the blockchain network. How the user device operates.

13. In paragraph 12, The steps requested above are A step of requesting a link of the metadata before the change of the DNF and the first hash value to the blockchain network through a decentralized application installed on the user device. How the user device operates.

14. In paragraph 8, The above metadata of the above DNFT Contains additional information about the above DNFT and a link to the metadata before the change. How the user device operates.

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