Control method, device, and program

Abstract

A control method according to the present invention is performed by a device, wherein: first digital content that has been generated by a first terminal of a first user is acquired (S134); at least one piece of first identification information associated with at least one piece of second digital content that may have been used when the first terminal of the first user generated the first digital content is identified (S135); and the at least one piece of first identification information that has been identified is output (S136).

Description

Control method, device, and program

[0001] The present disclosure relates to a control method, an apparatus, and a program.

[0002] Patent Document 1 discloses a technology for buying and selling NFTs (Non-Fungible Tokens) for proving the uniqueness of digital content or the owner of digital content.

[0003] Patent No. 7129579

[0004] The present disclosure provides a control method and the like that can easily identify candidates for digital content that have been used to generate digital content.

[0005] A control method according to one aspect of the present disclosure is a control method executed by an apparatus, which acquires first digital content generated by a first terminal of a first user, identifies one or more first identification information items associated with one or more second digital content items that may have been used by the first terminal of the first user when generating the first digital content, and outputs the identified one or more first identification information items.

[0006] In addition, an apparatus according to one aspect of the present disclosure includes a processor and a memory, and the processor uses the memory to acquire first digital content generated by a first terminal of a first user, identify one or more first identification information associated with one or more second digital content that may have been used by the first terminal of the first user when generating the first digital content, and output the identified one or more first identification information.

[0007] These comprehensive or specific aspects may be realized as a system, a device, an integrated circuit, a computer program, or a computer-readable recording medium such as a CD-ROM, or may be realized as any combination of a system, a device, an integrated circuit, a computer program, and a recording medium.

[0008] According to the control method and the like of the present disclosure, it is possible to easily identify candidates for digital content that were used to generate the digital content.

[0009] FIG. 1 is a diagram for explaining an overview of a system according to an embodiment. FIG. 2 is a block diagram showing the configuration of a system according to an embodiment. FIG. 3 is a block diagram showing an example of the configuration of a service server according to an embodiment. FIG. 4 is a block diagram showing an example of the configuration of a management server according to an embodiment. FIG. 5 is a sequence diagram showing an example of the process of converting digital content to NFT according to an embodiment. FIG. 6 is a sequence diagram showing an example of details of the first NFT registration phase according to an embodiment. FIG. 7 is a sequence diagram showing an example of details of the Nth NFT registration phase according to an embodiment. FIG. 8 is a diagram showing an example of a UI. FIG. 9 is an explanatory diagram showing the data structure of a blockchain. FIG. 10 is an explanatory diagram showing the data structure of transaction data. FIG. 11 is an explanatory diagram showing transaction data related to the execution of a smart contract. FIG. 12 is an explanatory diagram showing the process related to the execution of a smart contract.

[0010] (Findings that form the basis of the present disclosure) In recent years, various digital contents (content data) have been managed in association with NFTs. By using NFTs, it is possible to ensure the uniqueness of digital content and easily identify the owner of the digital content.

[0011] Incidentally, when considering the buying and selling of virtual digital content placed in the metaverse space, a system is needed that distributes profits from the sale of digital content not only to those involved with the digital content, but also to those involved with other digital content used to generate the digital content. To achieve this system, for example, when new digital content is generated based on other digital content, an NFT associated with the new digital content could include the NFT ID of the NFT associated with the other digital content. In this way, the NFT of the newly generated digital content includes the NFT ID of the NFT of the other digital content, allowing the relationship between the newly generated digital content and the other digital content to be managed by blockchain using the NFT of the newly generated digital content.

[0012] However, when generating an NFT for new digital content, the NFT IDs of the NFTs of other digital content used to generate the new digital content are required. To do this, for example, the creator must declare the other digital content used to generate the new digital content, which requires the creator to take the time and effort to declare.

[0013] Therefore, the present inventors have found a control method that can easily identify candidates for digital content that were used to generate the digital content.

[0014] A control method according to a first aspect of the present disclosure is a control method executed by an apparatus, which acquires first digital content generated by a first terminal of a first user, identifies one or more first identification information items associated with one or more second digital content items that may have been used by the first terminal of the first user when generating the first digital content, and outputs the identified one or more first identification information items.

[0015] Therefore, one or more pieces of first identification information associated with one or more pieces of second digital content that may have been used in generating the first digital content can be used as candidates for the digital content used in generating the first digital content. As a result, for example, by presenting one or more pieces of first identification information to a first user who is the creator of the first digital content, the first user can easily identify the digital content used in generating the first digital content, making it easy to declare the digital content used in generating the first digital content.

[0016] A control method according to a second aspect of the present disclosure is a control method according to the first aspect, wherein the one or more first identification information are identified based on a history of digital content acquired by the first terminal from the device.

[0017] Therefore, it is possible to easily identify one or more pieces of first identification information associated with one or more pieces of second digital content that are highly likely to have been used when generating the first digital content.

[0018] A control method according to a third aspect of the present disclosure is a control method according to the first or second aspect, wherein the first digital content includes one or more second identification information, and the one or more first identification information are identified based on the one or more second identification information included in the first digital content.

[0019] Therefore, it is possible to easily identify one or more pieces of first identification information associated with one or more pieces of second digital content that are highly likely to have been used when generating the first digital content.

[0020] A control method according to a fourth aspect of the present disclosure is a control method according to any one of the first to third aspects, further comprising generating a list including the one or more first identification information for inquiring the first user about one or more third digital contents used in generating the first digital content, and transmitting the list to the first terminal.

[0021] This allows one or more first identification information to be presented as a list to the first user, who is the creator of the first digital content, so that the first user can easily identify from the list the digital content used when generating the first digital content, making it easy to declare the digital content used when generating the first digital content.

[0022] A control method according to a fifth aspect of the present disclosure is a control method according to the fourth aspect, further comprising receiving a response to the list from the first terminal, and identifying one or more third identification information corresponding to the one or more third digital contents in accordance with the response.

[0023] Therefore, the response from the first user can be used as a declaration of the digital content used when generating the first digital content, and one or more third digital contents used when generating the first digital content can be easily identified.

[0024] A control method according to a sixth aspect of the present disclosure is a control method according to the fifth aspect, further comprising generating transaction data including the first digital content and the one or more third identification information, and transmitting the transaction data to a blockchain system, thereby causing the blockchain system to issue an NFT corresponding to the first digital content, wherein the NFT includes the one or more third identification information.

[0025] This makes it easy to generate an NFT that is linked to the first digital content and includes one or more pieces of third identification information associated with one or more pieces of third digital content.

[0026] A control method according to a seventh aspect of the present disclosure is the control method according to the sixth aspect, further comprising obtaining an NFT ID of the NFT from the blockchain system and storing the NFT ID in association with the first digital content.

[0027] Therefore, the first digital content and the NFT ID of the NFT issued in the blockchain system can be stored in association with each other.

[0028] A control method according to an eighth aspect of the present disclosure is a control method according to any one of the fourth to seventh aspects, wherein the one or more first identification information include a fourth identification information and a fifth identification information, the fourth identification information corresponds to a fourth digital content, the fifth identification information corresponds to a fifth digital content, the fourth digital content is more likely to have been used in generating the first digital content than the fifth digital content, and the list further includes information indicating that the fourth digital content is more likely to have been used in generating the first digital content than the fifth digital content.

[0029] This allows a first user who is the creator of the first digital content to be presented with a list including the fourth identification information of the fourth digital content that is likely to have been used and the fifth identification information of the fifth digital content that is less likely to have been used than the fourth digital content, thereby allowing the first user to easily identify from the list the digital content that was used when generating the first digital content and easily declare the digital content that was used when generating the first digital content.

[0030] An apparatus according to a ninth aspect of the present disclosure includes a processor and a memory, wherein the processor uses the memory to acquire first digital content generated by a first terminal of a first user, identify one or more first identification information associated with one or more second digital content that may have been used by the first terminal of the first user when generating the first digital content, and output the identified one or more first identification information.

[0031] Therefore, one or more pieces of first identification information associated with one or more pieces of second digital content that may have been used in generating the first digital content can be used as candidates for the digital content used in generating the first digital content. As a result, for example, by presenting one or more pieces of first identification information to a first user who is the creator of the first digital content, the first user can easily identify the digital content used in generating the first digital content, making it easy to declare the digital content used in generating the first digital content.

[0032] A program according to a tenth aspect of the present disclosure is a program for causing a computer to execute a control method by a device, the program causing a computer to acquire first digital content generated by a first terminal of a first user, identify one or more pieces of first identification information associated with one or more pieces of second digital content that may have been used by the first terminal of the first user when generating the first digital content, and output the identified one or more pieces of first identification information.

[0033] These comprehensive or specific aspects may be realized as a system, a device, an integrated circuit, a computer program, or a computer-readable recording medium such as a CD-ROM, or may be realized as any combination of a system, a device, an integrated circuit, a computer program, and a recording medium.

[0034] Hereinafter, embodiments will be described with reference to the drawings. Note that each of the embodiments described below represents a specific example of the present disclosure. In other words, the numerical values, shapes, materials, components, component arrangements and connection forms, steps, and step orders shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Furthermore, among the components in the following embodiments, components that are not recited in the independent claims that represent the highest concepts are not necessarily required to achieve the objectives of the present disclosure, but are described as components that constitute more preferred embodiments.

[0035] (Embodiment) In this embodiment, a control method that can easily identify candidates for digital content that have been used to generate digital content will be described.

[0036] FIG. 1 is a diagram for explaining an outline of a system according to an embodiment.

[0037] 1 illustrates a transaction on two platforms, including a high-definition service platform 10 and an experience-based commerce service platform 20. In the following figures, the platforms will be referred to as PF.

[0038] The high definition service platform 10 is a platform used for increasing the definition of content represented by content data. A manufacturer 11 provides the high definition service platform 10 with digital data material to be increased in definition.

[0039] The material of the digital data may be, for example, the original data of a three-dimensional object before it is refined. The original data of the three-dimensional object may include information indicating a mesh, texture, material, etc. A mesh is information that defines the shape of a three-dimensional object and is a collection of polygons or vertices. The mesh may include information regarding vertex coordinates, face normals, and UV mapping. A texture is information that defines the appearance or texture of the surface of a three-dimensional object. Textures are used to reproduce the appearance of various materials such as wood, metal, fabric, and leather. A material is information that defines the physical characteristics or optical behavior of a three-dimensional object. Materials include color, reflectivity, transparency, gloss, etc. The material of the digital data is an example of design data (design information). The design data is an example of first content data.

[0040] The creator 12 uses the digital data material provided by the manufacturer 11 and inputs it into a terminal (computer) owned by the creator 12 to enhance the definition of the digital data material. High definition includes processes such as increasing the resolution of the polygons or vertices that define the shape of a three-dimensional object, increasing the resolution of the texture, assigning texture to the added vertices, and increasing the color gradation assigned to the texture. In other words, high definition is a process that increases the amount of information per unit volume in three-dimensional space. Highly detailed three-dimensional objects have an appearance that is closer to that of real objects. Highly detailed three-dimensional objects are stored in the high definition service platform 10.

[0041] The operator 13 of the high definition service platform 10 provides the manufacturer 11 with tools for generating digital data materials, and provides the generator 12 with tools for increasing the definition of the digital data materials. The operator 13 may provide the generator 12 with subsidies to support the generator 12 in the high definition processing.

[0042] The experiential commerce service platform 20 is a platform for buying and selling NFTs corresponding to content data representing three-dimensional objects. For example, the experiential commerce service platform 20 provides a virtual space (metaverse). In the metaverse, the manufacturer 11 can offer a highly detailed three-dimensional object created in the high-definition service platform 10. This allows the consumer 22 to experience the three-dimensional object offered by the manufacturer 11 in the metaverse. For example, the consumer 22 can view the three-dimensional object and hear sounds related to the three-dimensional object during the experience. Furthermore, the consumer 22 can purchase an NFT corresponding to the three-dimensional object that he or she saw or heard while experiencing the metaverse and that is offered for sale in the metaverse.

[0043] It should be noted that the consumer 22 is not limited to experiencing three-dimensional objects, but may also experience two-dimensional video. The two-dimensional video may be a two-dimensional still image or a two-dimensional video. The two-dimensional video may be video captured by a camera or video generated by a human or a computer. The NFT purchased by the consumer 22 may be an NFT corresponding to the two-dimensional video.

[0044] When a consumer 22 purchases an NFT corresponding to a three-dimensional object, the maker 11 pays a fee to the operator 13. The fee is an intermediary fee for the establishment of a sales contract between the maker 11 and the consumer 22 through the experience-based commerce service platform 20. The operator 13 distributes the fee received from the maker 11 to the creator 12 who generated the three-dimensional object corresponding to the NFT traded in the sales contract. This makes it easy to distribute profits earned on the experience-based commerce service platform 20 to creators 12 who are not participating in the experience-based commerce service platform 20.

[0045] The experience-based commerce service platform 20 may be operated by the operator 13 who operates the high-definition service platform 10. The experience-based commerce service platform 20 may also be operated by an operator other than the operator 13 who operates the high-definition service platform 10.

[0046] The manufacturers 11 participating in the high-definition service platform 10 may include the same manufacturers 11 as those participating in the experiential commerce service platform 20. The manufacturers 11 participating in the experiential commerce service platform 20 may also include the same manufacturers 11 as those participating in the high-definition service platform 10.

[0047] Furthermore, the high-definition service platform 10 and the experience-based commerce service platform 20 may be the same platform. That is, the high-definition service platform 10 and the experience-based commerce service platform 20 may be realized on a single platform.

[0048] FIG. 2 is a block diagram showing the configuration of a system according to an embodiment.

[0049] 2, system 1 includes terminals 100a to 100c, a service server 200, and management servers 300a to 300c (also referred to as management servers 300a, etc.). Terminals 100a to 100c, service server 200, and management servers 300a to 300c (also referred to as management servers 300, etc.) may all be connected to one another via a network 400, all may be directly connected to one another so as to be able to communicate, or some may be connected via network 400 and other parts may be directly connected to one another so as to be able to communicate. Network 400 is, for example, the Internet, a mobile phone carrier network, etc., but may be composed of any communication line or network.

[0050] The consumer 22 is a user who experiences the virtual space provided by the service server 200. The manufacturer 11 and the consumer 22 are users who buy and sell three-dimensional objects in the virtual space.

[0051] The service server 200 is a server, which is a computer that manages the virtual space. The service server 200 generates a virtual space and provides it to the user by transmitting VR data representing the virtual space, thereby contributing to the user's experience of the virtual space. The virtual space is, for example, a three-dimensional or two-dimensional virtual space. The virtual space may also be generally referred to as a metaverse. The VR data includes image data of images representing scenes in the virtual space and may also include audio data representing sounds in the virtual space. Objects and avatars may exist in the virtual space. The avatars may be associated with people in the real space.

[0052] The service server 200 allows the consumer 22 to experience a virtual space using, for example, the terminal 100c. The service server 200 transmits VR data to the terminal 100c and receives information (also referred to as position information) regarding the position and attitude of the VR device included in the terminal 100c. The service server 200 is an example of a control device.

[0053] Note that the service server 200 is not limited to providing the virtual space in VR, but may also provide it on a web page. Furthermore, the service server 200 is not limited to providing a virtual space, as long as it can provide a place where users can view NFTs. The service server 200 may also provide a web page where users can view NFTs.

[0054] The service server 200 also enables trading of goods in virtual space. In trading goods, for example, when the goods are transferred from the manufacturer 11 to the consumer 22, crypto assets (also called virtual currency) are transferred from the consumer 22 to the manufacturer 11. The crypto assets are, for example, Bitcoin or Ethereum, and are managed by a distributed ledger. The transfer of goods is managed by a distributed ledger as, for example, the transfer of NFTs.

[0055] The management server 300a is a server that manages the transfer of crypto assets using a distributed ledger. The management server 300a stores the distributed ledger in storage. When the management server 300a receives transaction data indicating the transfer of crypto assets from a VR device or the like, it executes a process of storing the received transaction data in the distributed ledger. The transaction data indicating the transfer of crypto assets includes the addresses in the distributed ledger system of the transfer source and transfer destination of the crypto assets.

[0056] Furthermore, the management server 300a can manage the transfer of an item in a virtual space as a transfer of an NFT using a distributed ledger. When the management server 300a receives transaction data indicating the transfer of an NFT from a VR device or the like, it executes a process of storing the received transaction data in the distributed ledger. The transaction data indicating the transfer of an NFT includes the addresses in the distributed ledger system of the source and destination of the NFT.

[0057] When storing new transaction data in the distributed ledger, the management server 300a stores the new transaction data in the distributed ledger using a method appropriate for the type of distributed ledger. The management server 300a can also send and receive communication data with the other management servers 300b and 300c, and transmits the transaction data to the other management servers 300b and 300c, causing the transaction data to be stored in the distributed ledgers of the other management servers 300b and 300c. When storing the transaction data, a consensus may be reached using a consensus algorithm before the transaction data is stored. The transaction data stored in the distributed ledger is managed to make it difficult to tamper with using characteristics such as hash values ​​(described below).

[0058] For example, if the distributed ledger is a blockchain, the management server 300a generates a block containing new transaction data, and stores the generated block in the distributed ledger after reaching a consensus among the management servers 300a and the like using a consensus algorithm. Note that the distributed ledger method is not limited to the above, and other methods of distributed ledger (e.g., IOTA, hash graph, etc.) can also be adopted.

[0059] The management servers 300b and 300c are similar to the management server 300a, and operate independently of the management server 300a.

[0060] A group of management servers including the management server 300a etc. can also be called a distributed ledger network. While an example will be described in which the distributed ledger network includes three management servers 300a etc., the number of management servers 300a etc. may be four or more.

[0061] The VR device is an information processing device included in each of the terminals 100a to 100c, which presents a virtual space to the user who owns each of the terminals 100a to 100c, and is owned by each user (manufacturer 11, generator 12, consumer 22). The VR device includes a CPU (Central Processing Unit), memory, storage, a display screen, speakers, sensors, etc., and the CPU processes information by executing a predetermined program using the memory. The VR device may also include a GPS (Global Positioning System) receiver that acquires the location of the VR device on Earth. The VR device is worn, for example, on the user's head, and is generally called VR goggles or a VR headset.

[0062] The VR device receives VR data from the service server 200 and uses image data included in the VR data to display an image showing a scene seen in the virtual space on a display screen, thereby presenting the image to the user. The VR device can also use audio data included in the VR data to output sounds heard in the virtual space from a speaker, thereby presenting the sound to the user.

[0063] The VR device also acquires its position information using a sensor (such as a three-axis acceleration sensor or a three-axis angular velocity sensor) and transmits it to the service server 200. The transmitted position information is used by the service server 200 to generate VR data, and the VR data calculated in consideration of the transmitted position information is then transmitted.

[0064] The VR device also transmits information indicating operations performed by the user on the VR device (also referred to as operation information) to the service server 200. The operation information may include, for example, an operation to select an action from a selection of actions in the virtual space (a so-called selection menu, etc.). The transmitted operation information is reflected in the position information of the user (in other words, an avatar corresponding to the user) in the virtual space, and VR data based on the reflected position information, etc. is then transmitted.

[0065] Note that each of the terminals 100a to 100c does not necessarily have to include a VR device. Each of the terminals 100a to 100c may have one or more display devices capable of displaying a location where NFTs provided by the service server 200 can be viewed. The one or more display devices may be, for example, a liquid crystal display, an organic electroluminescence (EL) display, or the like.

[0066] The terminal 100a is an information processing terminal owned by the generator 12 as a user. The terminal 100a includes a CPU, memory, storage, a display screen, etc., and the CPU executes a predetermined program using the memory to perform information processing. The terminal 100a is, for example, a smartphone, a tablet, or a personal computer.

[0067] The terminal 100b is an information processing terminal owned by the manufacturer 11 as a user. The terminal 100c is an information processing terminal owned by the consumer 22 as a user. Each of the terminals 100b and 100c has the same configuration as the terminal 100a.

[0068] The group of devices including the service server 200 and the management server 300a are devices involved in NFT transactions in virtual space, and can also be called an NFT network. Note that "NFT" is not limited to those defined in the Ethereum standard ERC-721, and can be any non-fungible token. A "token" can also be data issued in association with data or a real object.

[0069] FIG. 3 is a block diagram showing an example of the configuration of the service server according to the embodiment.

[0070] 3, service server 200 includes a communication unit 201, a control unit 202, a first PF management unit 203, a second PF management unit 204, and an item management unit 205. Communication unit 201, control unit 202, first PF management unit 203, second PF management unit 204, and item management unit 205 can be realized by a processor (e.g., a CPU (Central Processing Unit)) (not shown) included in service server 200 executing a predetermined program using a memory (not shown). Service server 200 is an example of a control device.

[0071] The communication unit 201 communicates with at least one of the terminals 100a to 100c and the management servers 300a to 300c via the network 400. The communication unit 201 receives information from at least one of the terminals 100a to 100c and the management servers 300a to 300c. The communication unit 201 transmits information to at least one of the terminals 100a to 100c and the management servers 300a to 300c.

[0072] Specifically, the communication unit 201 receives design data to be provided to the generator 12 on the high definition service platform 10 from the terminal 100b of the manufacturer 11. The communication unit 201 transmits the received design data to the terminal 100a of the generator 12.

[0073] The communication unit 201 also receives content data that has been refined based on the design data and a generator ID from the terminal 100a of the generator 12. The generator ID is identification information for identifying the generator 12 and is an example of generator information. The communication unit 201 transmits the received content data to the terminal 100b of the manufacturer 11.

[0074] The communication unit 201 also receives content data for listing on the experiential commerce service platform 20 from the terminal 100b of the manufacturer 11. The communication unit 201 also transmits content data to the terminal 100c of the consumer 22 in response to a request from the terminal 100c of the consumer 22. Specifically, the communication unit 201 transmits VR data for providing the metaverse that the consumer 22 is experiencing through the terminal 100c. The VR data includes content data.

[0075] The communication unit 201 also receives, from the terminal 100c of the consumer 22, the ID of the NFT that the consumer 22 purchased on the experiential commerce service platform 20 and the consumer ID. The communication unit 201 receives, from the terminal 100b of the manufacturer 11, fee information indicating the brokerage fee for the conclusion of a sales contract between the manufacturer 11 and the consumer 22. The sales contract relates to the sale and purchase of NFTs on the experiential commerce service platform 20.

[0076] The communication unit 201 also transmits a registration request to the management servers 300a to 300c to register the NFT to the management servers 300a to 300c, and receives a response to the registration request from the management servers 300a to 300c.

[0077] The control unit 202 executes various processes based on the received information. Specifically, the control unit 202 stores the received information in storage. The control unit 202 also executes a process for converting the received content data or the received design data into an NFT. The NFT conversion process is, for example, a process for causing the communication unit 201 to send an NFT registration request to the management servers 300a to 300c.

[0078] The first PF management unit 203 manages the high definition service platform 10. The first PF management unit 203 provides the high definition service platform 10 to the terminal 100a of the generator 12 and the terminal 100b of the manufacturer 11. The first PF management unit 203 stores design data, high definition content data, etc.

[0079] The second PF management unit 204 manages the experience-based commerce service platform 20. The second PF management unit 204 provides the experience-based commerce service platform 20 to the terminal 100b of the manufacturer 11 and the terminal 100c of the consumer 22. The second PF management unit 204 stores, from among the high-definition content data, content data whose listing has been adopted by the manufacturer 11.

[0080] The item management unit 205 manages real items associated with NFTs. That is, the item management unit 205 stores an NFT ID for identifying an NFT and an item ID for identifying a real item in association with each other. The item management unit 205 may also store an item ID in association with an owner of the item and a location (storage location) of the item in real space.

[0081] FIG. 4 is a block diagram illustrating an example of the configuration of the management server according to the embodiment.

[0082] As shown in FIG. 4, each of the management servers 300a to 300c includes a communication unit 301, a control unit 302, an NFT issuing unit 303, and an NFT management unit 304.

[0083] The communication unit 301 communicates with the service server 200 or the terminal 100b of the manufacturer 11. The communication unit 301 receives an NFT registration request from the service server 200 or the terminal 100b. The communication unit 301 transmits a response to the NFT registration request to the device (the service server 200 or the terminal 100b) that transmitted the NFT registration request.

[0084] The control unit 302 executes various processes based on the received information.

[0085] The NFT issuing unit 303 issues an NFT in response to a request to register the NFT.

[0086] The NFT management unit 304 records the issued NFT in the distributed ledger, which adds a block containing the NFT to the blockchain.

[0087] [System Operation] Next, the operation of the system 1 configured as above will be described.

[0088] FIG. 5 is a sequence diagram showing an example of a process for converting digital content into NFT in the embodiment.

[0089] First, the smart contract issuance phase (smart contract issuance phase) of steps S101 to S104 is executed between the service server 200 and the management server 300a, etc.

[0090] The service server 200 generates a smart contract code (S101). The smart contract code is code that realizes a smart contract for automatically issuing an NFT for transaction data, including data such as digital content, when the transaction data is stored in the blockchain system.

[0091] The service server 200 generates transaction data including the generated smart contract code and transmits the generated transaction data to the management server 300a, etc. (S102).

[0092] The management server 300a, etc. stores the received transaction data in the blockchain managed by the management server 300a, etc., thereby deploying the smart contract represented by the smart contract code included in the transaction data (S103).

[0093] When the deployment of the smart contract is completed, the management server 300a transmits the address on the blockchain where the smart contract is stored to the service server 200 (S104).

[0094] Next, a primary NFT registration phase of steps S105 to S107 is executed between the terminal 100b of the manufacturer 11 as the primary generator, the service server 200, the management server 300a, etc. In the primary NFT registration phase, for example, an NFT of digital content 51 generated without using other digital content is registered.

[0095] The terminal 100b generates the digital content 51 (S105). The digital content 51 is, for example, design data.

[0096] The terminal 100b transmits the digital content 51 to the service server 200 (S106). As a result, the service server 200 acquires the digital content 51 generated by the terminal 100b of the manufacturer 11.

[0097] When the service server 200 acquires the digital content 51, the service server 200 executes the process of converting the digital content 51 into an NFT file with the management server 300a or the like (S107).

[0098] Next, an Nth-order NFT registration phase of steps S108 to S112 is executed between the terminal 100a of the generator 12 as an Nth-order generator (N is a natural number equal to or greater than 2), the service server 200, the management server 300a, etc. In the Nth-order NFT registration phase, for example, an NFT of digital content 52 generated using other digital content such as digital content 51 is registered. Digital content 52 may include a portion of the other digital content, or may include a modified portion of the other digital content. Digital content 52 may include some or all of multiple other digital content.

[0099] The service server 200 transmits data to be used in generating the content to the terminal 100a (S108). Step S108 may be executed in response to a request from the terminal 100a. For example, the creator 12 uses the terminal 100a to access the service server 200 and selects one or more digital contents to be used in generating the digital content to be generated from among the plurality of digital contents stored in the service server 200. The terminal 100a then transmits a request to the service server 200 including information indicating the selected one or more digital contents. The service server 200 may then acquire the request from the terminal 100a. Here, the selected one or more digital contents may include digital content 51 generated without using other digital content, digital content generated using other digital content, or both of these digital contents.

[0100] The terminal 100a generates the digital content 52 (S109). The digital content 52 is, for example, content data in which the design data has been made highly precise.

[0101] The terminal 100a transmits the digital content 52 to the service server 200 (S110).

[0102] Next, an NFT tracing check is performed between the terminal 100a and the service server 200 (S111), and then the process of converting the digital content 52 into NFT is performed between the service server 200 and the management server 300a, etc. (S112).

[0103] FIG. 6 is a sequence diagram showing an example of details of the primary NFT registration phase in the embodiment.

[0104] The terminal 100b generates design data as the digital content 51 (S121). Step S121 corresponds to step S105.

[0105] The terminal 100b transmits the design data to the service server 200 (S122). Step S122 corresponds to step S106.

[0106] When the service server 200 acquires the design data, it determines whether the acquired design data is appropriate (S123). Specifically, the service server 200 determines whether the design data is appropriate as primary NFT content. The appropriateness of the design data may mean that the design data is appropriate as primary NFT content.

[0107] Whether or not a digital content is appropriate as primary NFT content may be determined based on different criteria depending on the attributes (e.g., type) of the digital content. Furthermore, primary NFT content may be determined to be appropriate if it is digital content generated by a pre-approved primary creator. In other words, digital content associated with identification information that identifies a designated primary creator may be determined to be appropriate as primary NFT content.

[0108] The primary NFT content is digital content that is generated without using other digital content. The primary NFT content may be any digital content, such as design data, three-dimensional content, or video content.

[0109] If the service server 200 determines that the design data is appropriate (Yes in S123), it executes step S124, and if it determines that the design data is inappropriate, it ends the processing related to the design data.

[0110] In step S124, the service server 200 transmits transaction data including metadata and a uniform resource identifier (URI) to the management server 300a or the like (S124). The metadata includes, for example, design data (digital content) to be registered in the NFT. The URI indicates the address where the metadata is stored.

[0111] The management server 300a etc. stores the transaction data in the blockchain, executes the smart contract code for issuing the NFT, and issues a new NFT by generating a new NFT ID (S125). The management server 300a etc. may register the NFT in the blockchain by storing the issued NFT ID in the distributed ledger.

[0112] The management server 300a or the like transmits the issued NFT ID to the service server 200 (S126).

[0113] Upon acquiring the NFT ID, the service server 200 may associate the acquired NFT ID with the design data and store the associated data (S127). The service server 200 may associate the two data by adding the NFT ID to the design data as a digital watermark. When a file group including multiple files is NFTized, the service server 200 may add a file. Multiple files may be grouped into a single group using a means such as a folder, and the files included in the group may be NFTized. Multiple files may represent, for example, a single piece of design data. When files are grouped into a folder, the URL of the folder may be NFTized. Furthermore, a single compressed file generated by compressing multiple files may be NFTized. In this way, when multiple files are NFTized, a new file (e.g., a text file) may be generated that records the NFT ID or smart contract address generated by the NFTization. When multiple files are grouped into a folder, the new file may be stored in the folder, or when multiple files are compressed, the new file may be compressed together with the multiple files. In this way, a new file containing an NFT ID may be associated with multiple files.

[0114] Upon acquiring the NFT ID, the service server 200 may notify the terminal 100b of the acquired NFT ID.

[0115] FIG. 7 is a sequence diagram showing an example of details of the Nth NFT registration phase in the embodiment.

[0116] The service server 200 transmits data (digital content) to be used for generating the content to the terminal 100a (S131). Step S131 corresponds to step S108. That is, the terminal 100a downloads (DL) the digital content from the service server 200.

[0117] The service server 200 records the history of the data DL, which is the digital content downloaded (DL) by the terminal 100a (S132).

[0118] The terminal 100a generates the digital content 52 (S133). Step S133 corresponds to step S109.

[0119] The terminal 100a transmits the digital content 52 to the service server 200 (S134). Step S134 corresponds to step S110. As a result, the service server 200 acquires the digital content 52 generated by the terminal 100a of the creator 12. The creator 12 is an example of a first user. The terminal 100a is an example of a first terminal.

[0120] The service server 200 identifies NFT candidates for digital content that may have been used among the one or more existing digital content items (S135). That is, the service server 200 identifies one or more pieces of first identification information associated with one or more existing digital content items that may have been used when the terminal 100a of the creator 12 generated the digital content 52. The one or more pieces of first identification information are information indicating the candidates, and may be, for example, NFT IDs or IDs different from NFT IDs. Furthermore, the one or more pieces of first identification information are not limited to IDs as long as they are information indicating candidates. They may also be titles (character strings) of the digital content items or hash values ​​obtained by hashing the digital content items corresponding to the identification information using a hash function.

[0121] The service server 200 may identify NFT candidates for digital content that may have been used among one or more existing digital content items, for example, based on the history of digital content items acquired by the terminal 100a from the service server 200. The service server 200 may also identify NFT candidates for digital content that may have been used among one or more existing digital content items, for example, based on one or more NFT IDs included in the digital content item 52. In this case, the digital content item 52 may include one or more NFT IDs (one or more pieces of second identification information) of one or more other digital content items used to generate the digital content item 52. For example, the digital content item 52 may include one or more NFT IDs (one or more pieces of second identification information) as digital watermarks.

[0122] The one or more existing digital contents may include primary NFT content or Nth-order NFT content. Nth-order NFT content is digital content generated using at least primary NFT content. For example, secondary NFT content is digital content generated using primary NFT content, and tertiary NFT content is digital content generated using secondary NFT content. In other words, Nth-order NFT content is content generated using (N-1)th-order NFT content. Therefore, since at least secondary NFT content is generated using primary NFT content, (N-1)th-order NFT content can be said to be generated using primary NFT content. NFT content is digital content that is subject to NFT conversion.

[0123] The service server 200 generates a list of the identified NFT candidates and transmits the list of NFT candidates to the terminal 100a (S136). In this manner, the service server 200 outputs one or more pieces of first identification information. The list is a list for inquiring the creator 12 about one or more other digital contents that were used when generating the digital content 52.

[0124] When the terminal 100a acquires the list of NFT candidates, the terminal 100a selects, based on the acquired list, an NFT of the digital content used to generate the digital content 52 (S137). For example, the terminal 100a displays a UI including candidates of digital content used by the creator 12 to generate the digital content 52 based on the list.

[0125] FIG. 8 is a diagram illustrating an example of the UI.

[0126] 8 , the UI includes a file name 501 of the generated digital content 52, a table 502 showing a list of digital content used to generate the digital content 52, and an add button 503 for adding digital content not listed in the table 502 to the list of used digital content. The digital content 52 may be paired with the primary NFT content in advance. In this case, the location of a storage area on the service server 200 for uploading the digital content 52 generated using the primary NFT content may be specified at the time the primary NFT content is downloaded. Note that the digital content 52 is not limited to being paired with the primary NFT content, and may also be paired in advance with NFT content of an earlier generation than the digital content 52.

[0127] Table 502 shows multiple digital content candidates. In table 502, each digital content is shown by a thumbnail, title, description, owner, contract address, and token ID. The token ID is an NFT ID. Furthermore, in the selection column, a check mark indicates that each digital content is content that was actually used by the generator 12 in the digital content 52. In other words, digital content with a check mark is digital content that was selected by the generator 12 as digital content that was actually used in generating the digital content 52, and digital content without a check mark is digital content that was not selected by the generator 12 as digital content that was actually used in generating the digital content 52.

[0128] In this way, the terminal 100a presents the UI 500 and accepts a selection from the generator 12 as the digital content used in the digital content 52. This allows the NFT of the digital content actually used to generate the digital content 52 to be selected.

[0129] The terminal 100a transmits information including the NFT of the selected digital content to the service server 200 (S138). The information including the NFT of the selected digital content includes a response from the creator 12 to the list.

[0130] If the list does not include the NFT of the used digital content, the generator 12 may add the NFT of the used digital content using the add button 503. Also, the list may include a check mark next to the NFT of the digital content that is likely to have been used in advance.

[0131] The digital content that is likely to have been used in advance may be, for example, primary NFT content that has been paired in advance. Note that the digital content that is likely to have been used in advance is not limited to being paired with primary NFT content, but may also be paired in advance with NFT content of an earlier generation than the digital content 52. For example, when the terminal 100a downloads the NFT content that will be used to generate the content from the service server 200, the terminal 100a submits a request to the service server 200 in advance for the downloaded NFT content to generate derivative content based on the NFT content. This request enables the service server 200 to record a user ID identifying the user of the terminal 100a and a content ID (NFT ID) of the NFT content to be downloaded in association with each other. When the user of the terminal 100a uploads content generated by secondary creation to the service server 200, the service server 200 reads out the content ID (NFT ID) of the NFT content that has been recorded in association with the user ID of the user, and displays the read content ID (NFT ID) in the list as checked.

[0132] Furthermore, the digital content that is likely to have been used in advance may be, for example, digital content obtained by inspecting 3D CG. For example, when the user of the terminal 100a uploads content created through derivative work to the service server, the service server scans the uploaded content to check whether it contains information about other NFT content. The scan is performed using a method that corresponds to the method used by the service server 200 to associate the content in step S127, such as a digital watermark or a file containing NFT information. NFT IDs detected by the scan are checked in a list.

[0133] Furthermore, the digital content that is likely to have been used in advance may be, for example, digital content that was downloaded after the design data was downloaded. The service server 200 records the download history of the terminal 100a in chronological order and reads the download history when necessary. If the download history includes paired NFT content or NFT content detected by scanning, the NFT content that was downloaded by the terminal 100a after the user downloaded the NFT content and up to the current content upload is checked and displayed first in the list.

[0134] Furthermore, digital content that is likely to have been used in advance may be, for example, digital content that has not been used when uploading other digital content (digital content that has not been selected). The service server 200 records information about NFTs downloaded by the terminal 100a (e.g., NFT ID) and information about NFTs used (e.g., NFT ID) declared when uploading. If there is an NFT that is not included in the list of used NFTs among the list of NFTs downloaded by the terminal 100a (i.e., there is an NFT that has been downloaded but not used), when the user uploads new content, the NFT is displayed in the list with a check mark next to it.

[0135] Conversely, all digital content candidates in the list may be pre-checked, and the generator 12 may select unused digital content to remove the check mark. In this case, not all digital content may be pre-checked, and only digital content that has been used in other uploads for NFT conversion may be unchecked.

[0136] When the creator 12 selects the digital content to be used using the UI 500, the creator 12 may be limited to selecting the minimum number of digital contents required. In other words, the creator 12 may not be able to proceed to the next step unless a set number of digital contents or more have been selected.

[0137] Upon acquiring the information including the NFT of the selected digital content, the service server 200 transmits the transaction data to the management server 300a or the like (S139). The transaction data is generated by identifying one or more other digital contents that the creator 12 actually used when generating the digital content 52 based on the information. The service server 200 transmits the transaction data including metadata, a uniform resource identifier (URI), and the NFT of the selected digital content to the management server 300a or the like. The metadata includes, for example, the digital content 52 for which the NFT is to be registered. The URI indicates the address where the metadata is stored.

[0138] The management server 300a etc. stores the transaction data in the blockchain, executes the smart contract code for issuing the NFT, and issues a new NFT by generating a new NFT ID (S140). The management server 300a etc. may register the NFT in the blockchain by storing the issued NFT ID in the distributed ledger.

[0139] The management server 300a or the like transmits the issued NFT ID to the service server 200 (S141).

[0140] Upon acquiring the NFT ID, the service server 200 may store the acquired NFT ID in association with the digital content 52 (S142). The service server 200 may associate the two by adding the NFT ID to the digital content 52 as a digital watermark.

[0141] [Effects, etc.] The control method executed by the service server 200 (device) according to this embodiment acquires digital content 52 (first digital content) generated by the terminal 100a (first terminal) of the creator 12 (first user) (S134), identifies one or more NFT IDs (one or more first identification information) associated with one or more other digital contents (one or more second digital contents) that may have been used when the terminal 100a of the creator 12 generated the digital content 52 (S135), and outputs the identified one or more NFT IDs (one or more first identification information).

[0142] Therefore, one or more NFT IDs associated with one or more other digital content that may have been used when generating the digital content 52 can be used as candidates for the digital content used when generating the digital content 52. Thus, by presenting one or more NFT IDs that are candidates for one or more other digital content to the creator 12 of the digital content 52, the creator 12 can easily identify the digital content used when generating the digital content 52, and can easily declare the digital content used when generating the digital content 52.

[0143] In the control method according to the present embodiment, one or more candidate NFT IDs are identified based on the history of digital content acquired by the terminal 100 a from the service server 200 .

[0144] Therefore, it is possible to easily identify one or more NFT IDs associated with one or more other digital contents that are likely to have been used when generating the digital content 52.

[0145] In the control method according to the present embodiment, the digital content 52 includes one or more NFT IDs (one or more pieces of second identification information). The one or more candidate NFT IDs (one or more pieces of first identification information) are identified based on the one or more NFT IDs (one or more pieces of second identification information) included in the digital content 52.

[0146] Therefore, by analyzing the digital content 52, it is possible to easily identify one or more NFT IDs (one or more first identification information) associated with one or more other digital contents that are likely to have been used in generating the digital content 52.

[0147] The control method according to this embodiment further generates a list including one or more NFT IDs (one or more pieces of first identification information) for inquiring the creator 12 about one or more third digital contents used in generating the digital content 52, and transmits the list to the terminal 100a.

[0148] This allows the generator 12 of digital content 52 to be presented with a list of one or more NFT IDs (one or more first identification information), allowing the generator 12 to easily identify from the list the existing digital content that was used when generating digital content 52, making it easy to declare the digital content that was used when generating digital content 52.

[0149] The control method according to this embodiment further includes receiving a response to the list from the terminal 100a, and identifying one or more NFT IDs (one or more pieces of third identification information) corresponding to one or more pieces of third digital content in accordance with the response.

[0150] Therefore, the response from the creator 12 can be used as a declaration of the digital content used in generating the digital content 52, and one or more third digital contents used in generating the digital content 52 can be easily identified.

[0151] The control method of this embodiment further generates transaction data including digital content 52 and one or more NFT IDs (one or more third identification information), and transmits the transaction data to the blockchain system, thereby causing the blockchain system to issue an NFT corresponding to the digital content, where the NFT includes one or more NFT IDs (one or more third identification information).

[0152] Therefore, it is easy to generate an NFT that is associated with digital content 52 and includes one or more NFT IDs (one or more pieces of third identification information) that are associated with one or more third digital contents.

[0153] The control method according to this embodiment further acquires the NFT ID of the NFT corresponding to the digital content 52 from the blockchain system, and stores the NFT ID in association with the digital content 52.

[0154] Therefore, the digital content 52 and the NFT ID of the NFT issued in the blockchain system can be stored in association with each other.

[0155] In the control method according to the present embodiment, the one or more NFT IDs (one or more pieces of first identification information) include a fourth NFT ID (fourth identification information) and a fifth NFT ID (fifth identification information). The fourth NFT ID is associated with fourth digital content, and the fifth NFT ID is associated with fifth digital content. The fourth digital content is more likely to have been used in generating the first digital content than the fifth digital content. The list further includes information indicating that the fourth digital content is more likely to have been used in generating digital content 52 than the fifth digital content.

[0156] This allows the creator 12 of digital content 52 to be presented with a list including the fourth NFT ID of the fourth digital content that is likely to have been used and the fifth NFT ID of the fifth digital content that is less likely to have been used than the fourth digital content. This allows the creator 12 to easily identify from the list the digital content that was used when generating digital content 52, making it easy to declare the digital content that was used when generating digital content 52.

[0157] [Modifications] In the above embodiment, three-dimensional digital content is enhanced in resolution as an example of generating new digital content using other digital content, but two-dimensional digital content may also be enhanced in resolution. Furthermore, in addition to enhancing the resolution of digital content, new digital content may also be generated by cutting out and combining temporal portions of streaming content, or by cutting out and combining spatial portions.

[0158] (Supplementary Note) The following provides a supplementary explanation of the distributed ledger in the above embodiment or modification. Here, a blockchain will be described as an example of a distributed ledger, but the same applies to other distributed ledgers.

[0159] FIG. 9 is an explanatory diagram showing the data structure of a blockchain.

[0160] A blockchain is a chain of blocks, which are the units of record. Each block contains multiple transaction data and the hash value of the immediately preceding block. Specifically, block B2 contains the hash value of the previous block B1. A hash value calculated from the multiple transaction data contained in block B2 and the hash value of block B1 is then included in block B3 as the hash value of block B2. In this way, by connecting blocks in a chain while including the contents of the previous block as a hash value, tampering with the recorded transaction data is effectively prevented.

[0161] If past transaction data were to be changed, the hash value of the block would be different from before the change, and in order to make the altered block appear correct, all subsequent blocks would have to be recreated, which is extremely difficult in reality. This property is used to ensure that blockchains are tamper-resistant.

[0162] FIG. 10 is an explanatory diagram showing the data structure of the transaction data.

[0163] The transaction data shown in Figure 10 includes a transaction body P1 and a digital signature P2. The transaction body P1 is the data body included in the transaction data. The digital signature P2 is a digital signature generated for the hash value of the transaction body P1 using the signature key of the creator of the transaction data. More specifically, it is generated by encrypting the hash value with the private key of the creator of the transaction data. Examples of digital signature methods include ECDSA (Elliptic Curve Digital Signature Algorithm), CRYSTALS-Dilithium, Falcon, and SPHINCS+.

[0164] The transaction data has digital signature P2, making it virtually impossible to tamper with. If the transaction data were to be tampered with, verification using digital signature P2 would fail, revealing that the transaction data had been tampered with. This prevents tampering with the transaction body P1.

[0165] 11 and 12 are explanatory diagrams showing transaction data related to the execution of a smart contract, and processes related to the execution of a smart contract, respectively.

[0166] A series of processes related to the execution of a smart contract using a distributed ledger will be described with reference to Figures 11 and 12.

[0167] In step SB1, the node stores transaction data B11, including contract code B12 that describes the processing of the smart contract, in the distributed ledger B10. For example, the node acquires transaction data B11 by receiving the transaction data B11 from an information processing device via communication or by the node itself generating the transaction data B11, and stores the acquired transaction data B11 in the distributed ledger B10. Step SB1 is performed before executing the smart contract.

[0168] In step SB2, the node stores transaction data B15, including instructions B16 for executing the smart contract, in the distributed ledger B10. For example, the node receives transaction data B15 from an information processing device via communication and stores the received transaction data B15 in the distributed ledger B10.

[0169] In step SB3, in response to the transaction data B15 including the instruction B16 being stored in the distributed ledger B10 in step SB2, the node reads the contract code B12 from the distributed ledger B10 and executes processing based on the contract code B12. The results of the processing may be included in the transaction data and stored in the distributed ledger B10.

[0170] Through the above series of processes, when the distributed ledger system receives transaction data B15 including instructions B16 for executing a smart contract, it automatically (i.e., without manual intervention) executes the processing in accordance with the instructions B16, enabling highly efficient (i.e., high speed or short processing time). Achieving highly efficient processing has the effect of reducing power consumption. Furthermore, since no manual intervention is required, it is possible to prevent human tampering with information, fraud, or human error. Furthermore, since the results of the processing thus executed are stored in the blockchain, it is virtually impossible to tamper with the results of the processing.

[0171] In the above-described embodiments and modifications, each component may be configured with dedicated hardware, or may be realized by executing a software program suitable for each component. Each component may be realized by a program execution unit such as a CPU or processor reading and executing a software program recorded on a recording medium such as a hard disk or semiconductor memory. Here, the software that realizes the information processing device (i.e., the virtual space management server) of the above-described embodiments and modifications is the following program.

[0172] In other words, this program is a program for causing a computer to execute a control method using a device, and causes the computer to acquire first digital content generated by a first terminal of a first user, identify one or more pieces of first identification information associated with one or more pieces of second digital content that may have been used by the first terminal of the first user when generating the first digital content, and output the identified one or more pieces of first identification information.

[0173] While the information processing device (i.e., virtual space management server) according to one or more aspects has been described above based on the embodiments, the present invention is not limited to these embodiments. As long as it does not deviate from the spirit of the present invention, various modifications conceivable by those skilled in the art to the present embodiments, or forms constructed by combining components of different embodiments, may also be included within the scope of one or more aspects.

[0174] The present disclosure can be used as a control method or the like that can easily identify candidates for digital content that have been used to generate digital content.

[0175] 1 System 10 High-definition service platform 11 Manufacturer 12 Generator 13 Operator 20 Experience-based commerce service platform 22 Consumer 100a to 100c Terminal 200 Service server 201, 301 Communication unit 202, 302 Control unit 203 First PF management unit 204 Second PF management unit 205 Goods management unit 300a to 300c Management server 303 NFT issuing unit 304 NFT management unit 400 Network

Claims

1. A control method executed by a device, comprising: acquiring a first digital content generated by a first terminal of a first user; identifying one or more first identification pieces associated with one or more second digital contents that may have been used by the first terminal of the first user when generating the first digital content; and outputting the identified one or more first identification pieces.

2. The control method according to claim 1, wherein the one or more first identification information are identified based on a history of digital content acquired by the first terminal from the device.

3. The control method described in claim 1 or 2, wherein the first digital content includes one or more second identification information, and the one or more first identification information are identified based on the one or more second identification information included in the first digital content.

4. The control method according to claim 1 or 2, further comprising: generating a list including the one or more first identification information for inquiring of the first user about one or more third digital contents used in generating the first digital content; and transmitting the list to the first terminal.

5. The control method according to claim 4, further comprising: receiving a response to the list from the first terminal; and identifying one or more third identification information corresponding to the one or more third digital contents in response to the response.

6. The control method of claim 5, further comprising: generating transaction data including the first digital content and the one or more third identification information; and transmitting the transaction data to a blockchain system, thereby causing the blockchain system to issue an NFT corresponding to the first digital content, wherein the NFT includes the one or more third identification information.

7. The control method according to claim 6, further comprising obtaining an NFT ID of the NFT from the blockchain system, and storing the NFT ID in association with the first digital content.

8. The control method described in claim 4, wherein the one or more first identification information include a fourth identification information and a fifth identification information, the fourth identification information corresponds to a fourth digital content, the fifth identification information corresponds to a fifth digital content, the fourth digital content is more likely to have been used in generating the first digital content than the fifth digital content, and the list further includes information indicating that the fourth digital content is more likely to have been used in generating the first digital content than the fifth digital content.

9. A device comprising: a processor; and a memory, wherein the processor uses the memory to acquire a first digital content generated by a first terminal of a first user; identify one or more first identification pieces associated with one or more second digital contents that may have been used by the first terminal of the first user when generating the first digital content; and output the one or more identified first identification pieces.

10. A program for causing a computer to execute a control method using an apparatus, the program causing a computer to execute the following steps: acquire a first digital content generated by a first terminal of a first user; identify one or more pieces of first identification information associated with one or more pieces of second digital content that may have been used when the first terminal of the first user generated the first digital content; and output the one or more pieces of first identification information that have been identified.

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