Digital currency operation system and operation method thereof

Abstract

An electronic apparatus may: acquire a token identifier corresponding to an offline-transition request; and transmit, to an operation server by means of a private key included in a predetermined offline-transition key pair, which is an asymmetric key for offline-transition, pre-offline digital currency including the token identifier, quantitative information of digital currency to be issued by offline-transition, and a public key of a predetermined blockchain key pair or a token signature signed for a value derived from the public key. The electronic apparatus may receive, from the operation server, offline digital currency including an authority signature that has been signed by an offline-transition authority key for pre-offline digital currency. The electronic apparatus may update offline digital currency information of a corresponding account on the basis of the offline digital currency. The authority signature may be generated by the operation server on the basis of verification of the predetermined offline-transition key pair, validation of the token identifier, balance of the online digital currency, and signature verification by the token signature.

Description

Digital currency operating system and its operating method

[0001] The present disclosure relates to a digital currency operating system and its operating method that support offline or online digital currency.

[0002] Digital assets, which are intangible assets, may include digital currency (hereinafter referred to as "digital currency"). Digital currency is a general term for currency that stores monetary value in digital form, rather than in physical form, and can be used as a means of payment. Digital currency may include virtual currency, electronic currency, digital private currency, or digital legal tender.

[0003] The virtual currency mentioned above may be a digital currency whose scope of use is limited to local organizations, such as a community or a specific company. The virtual currency may correspond to, for example, internet or mobile coupons. The electronic currency may be an electronic payment method that stores monetary value in the form of electronic symbols, or digital information, on a card with an integrated circuit (IC) chip or on an electronic device connected to a network, and then uses it for payment.

[0004] The aforementioned digital currency, in order to be used as a means of payment, relies on a network environment that guarantees digital accessibility. Therefore, it may be difficult to use the aforementioned digital currency as a means of payment in network environments where digital accessibility is not guaranteed.

[0005] The above information may be provided as background art to aid in understanding the present disclosure. No claim or determination is made as to whether any of the above-described matters constitute prior art related to the present disclosure.

[0006] According to one embodiment of the present disclosure, an operating method of an electronic device may include: obtaining a token identifier corresponding to an offline request; transmitting, to an operating server, pre-offline digital currency including a token signature in which the token identifier, quantitative information of digital currency to be issued by offline activation, and a public key of a predetermined blockchain key pair or a value derived from the public key are signed by a private key included in a predetermined offline key pair, which is an asymmetric key for offline activation; receiving, from the operating server, offline digital currency including an authorization signature in which the pre-offline digital currency is signed by an offline activation authorization key; and updating offline digital currency information of a corresponding account based on the offline digital currency. The authorization signature may be generated by the operating server based on verification of the predetermined offline key pair, validity verification of the token identifier, a balance of online digital currency, and signature verification by the token signature.

[0007] According to one embodiment of the present disclosure, an electronic device includes a communication circuit, a memory including one or more storage media storing instructions, and at least one processor including a processing circuit, wherein when the instructions are individually or collectively executed by the at least one processor, the electronic device is operable to obtain a token identifier corresponding to an offline request, transmit to an operation server a pre-offline digital currency including a token signature signed by a private key included in a predetermined offline key pair which is an asymmetric key for offline, the token identifier, quantitative information of digital currency to be issued by offline, and a public key of a predetermined blockchain key pair or a value derived from the public key, and receive from the operation server an offline digital currency including an authorization signature signed by an offline authorization key for the pre-offline digital currency, and update offline digital currency information of a corresponding account based on the offline digital currency. The above authority signature may be generated by the operation server based on verification of the above-described offline key pair, validation of the token identifier, balance of the online digital currency, and signature verification by the token signature.

[0008] According to one embodiment of the present disclosure, a method of operating an operation server may include receiving pre-offline digital currency including a token identifier, quantitative information of digital currency to be issued by offline activation, and a token signature signed by a public key of a predetermined blockchain key pair or a value derived from the public key by a private key included in a predetermined offline key pair which is an asymmetric key for offline activation from an electronic device, an operation of generating an authorization signature signed by an offline activation authorization key for the pre-offline digital currency, and an operation of transmitting the offline digital currency including the authorization signature to the electronic device.

[0009] According to one embodiment of the present disclosure, an operation server comprises at least one processor comprising a communication circuit, a memory comprising one or more storage media storing instructions, and a processing circuit, wherein when the instructions are individually or collectively executed by the at least one processor, the operation server is operable to receive, from an electronic device, a pre-offline digital currency comprising a token identifier, quantitative information of digital currency to be issued by offline-ization, and a token signature signed by a public key of a predetermined blockchain key pair or a value derived from the public key by a private key included in a predetermined offline key pair which is an asymmetric key for offline-ization, and generate an authorization signature signed by an offline-ization authorization key for the pre-offline digital currency, and transmit the offline digital currency comprising the authorization signature to the electronic device.

[0010] In connection with the description of the drawings, the same or similar reference numerals may be used for the same or similar components.

[0011] FIG. 1 is a configuration diagram of a digital currency operating system according to one embodiment of the present disclosure.

[0012] FIG. 2 is a state transition diagram for performing offline or online operations in a digital currency operating system according to one embodiment of the present disclosure.

[0013] FIG. 3 is a flowchart illustrating an operation for performing offline and / or online processing of legal cryptocurrency in a digital currency operating system according to one embodiment of the present disclosure.

[0014] FIG. 4 is a signal flow diagram for performing offline operation in a digital currency operation system according to one embodiment of the present disclosure.

[0015] FIG. 5 is a signal flow diagram for performing online operation in a digital currency operation system according to one embodiment of the present disclosure.

[0016] FIG. 6 is a block diagram of a processor for performing offline and / or online operation in an electronic device according to the disclosure of the present invention.

[0017] FIG. 7 is a configuration diagram of a processor for performing offline and / or online operation in an operating server according to the disclosure of the present invention.

[0018] FIG. 8A is an exemplary diagram of a user interface for requesting offline operation in an electronic device, according to one embodiment of the present disclosure.

[0019] FIG. 8b is an exemplary diagram of a user interface for offline operation in an electronic device, according to one embodiment of the present disclosure.

[0020] FIG. 9A is an exemplary diagram of a user interface for requesting online registration in an electronic device, according to one embodiment of the present disclosure.

[0021] FIG. 9b is an exemplary diagram of a user interface for online connection in an electronic device, according to one embodiment of the present disclosure.

[0022] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings so that those skilled in the art can easily implement the present disclosure. However, the present disclosure may be implemented in various different forms and is not limited to the embodiments described herein. In connection with the description of the drawings, the same or similar reference numerals may be used for identical or similar components. Furthermore, in the drawings and related descriptions, descriptions of well-known functions and configurations may be omitted for clarity and conciseness.

[0023] In an embodiment of the present disclosure, a digital currency operating system and an operating method thereof that support offline or online digital currency operation to adaptively process offline or online transactions based on a network environment can be provided.

[0024] According to an embodiment of the present disclosure, by utilizing smart contract technology without independent operation on individual terminals, operations to support offline or online operation are programmed, thereby improving the reliability of operation results.

[0025] The technical problems to be achieved in the present disclosure are not limited to the technical problems mentioned above, and other technical problems not mentioned above can be derived from the exemplary embodiments of the present disclosure by a person having ordinary knowledge in the relevant technical field.

[0026] The effects that can be achieved by the exemplary embodiments of the present disclosure can be clearly derived and understood by those skilled in the art to which the exemplary embodiments of the present disclosure pertain, from the following description. In other words, unintended effects resulting from the implementation of the exemplary embodiments of the present disclosure can also be derived by those skilled in the art from the exemplary embodiments of the present disclosure.

[0027] Figure 1 is a configuration diagram of a digital currency operating system (10) according to one embodiment of the present disclosure.

[0028] Referring to FIG. 1, a digital currency operating system (10) may include at least one electronic device (110, 130) or operating server (120) that provides use of digital currency, such as digital transaction (hereinafter referred to as “transaction”) or distribution of digital currency in a network environment.

[0029] The above network environment can support a communication function that connects a plurality of nodes with a transmission medium to exchange signals, information, or data between them. The above network environment can provide a platform for supporting a communication function between a plurality of nodes using a network (100) as a transmission medium. The transmission medium can be based on long-distance communication. The long-distance communication can use a communication protocol such as a legacy cellular, 5G, next-generation communication, the Internet, or a computer network (e.g., a local area network (LAN) or a wide area network (WAN)) as a standard.

[0030] The above multiple nodes may include hosts that can execute applications (or apps) (e.g., a wallet app for a personal account) in response to specific events (e.g., a request for a digital currency transaction, a digital currency going offline, or a digital currency going online). The digital currency (or cryptocurrency) may be used as a means of payment for purchasing or renting goods or using services. The amount (or quantity unit) used for purchasing goods or using services may be deducted from the remaining amount (or quantity) of digital currency held.

[0031] For example, the digital currency may be digital fiat currency. The digital fiat currency may correspond to a digital asset issued and / or controlled by a trusted institution, such as a central bank or government. The digital fiat currency may be issued by the institution using a distributed ledger based on blockchain technology. For example, the digital fiat currency may be a central bank digital currency (CBDC) issued by a central bank of each country. The digital fiat currency not only has relatively low manufacturing costs compared to cash, but can also be distributed quickly and prevent illegal transactions. The CBDC may be included in a stable coin, which reduces volatility by pegging it to a specific currency or commodity. The digital fiat currency is similar to digital private currencies (e.g., Bitcoin, Ethereum, or Ripple) in that it is stored electronically using blockchain technology. However, because it is guaranteed by a specific institution (e.g., a central bank), it may be relatively more stable than the digital private currencies. The above blockchain technology is a distributed data storage technology that does not store transaction records on a server, but rather links all users who participated in the transaction in the form of a chain and records them on multiple recording media (e.g., distributed ledgers).

[0032] The CBDC described above may be a digital payment instrument with the same unit of account as common legal tender, as a direct liability of the central bank. Depending on the issuing entity or user, the CBDC may include wholesale CBDC, which financial institutions, including commercial banks, hold in their central bank accounts and use. The CBDC may also include retail or universal CBDC, which the general public, including households and / or businesses, may hold in their accounts with the central bank or a private payment service provider (PSP) or carry in token form on their mobile devices and use like cash.

[0033] The wholesale CBDC not only provides large-sum payment settlement capabilities to financial intermediaries, including commercial banks holding reserves at the central bank, through a permissioned blockchain or distributed ledger network (100), but also enables new financial services. For example, the wholesale CBDC may have programmability, as it can implement smart contracts that automatically execute transactions when set conditions are met. The wholesale CBDC may facilitate transaction composability, as it can combine multiple functions and execute them together. The wholesale CBDC may also operate across borders through a multi-CBDC platform that includes central banks and currencies from various countries around the world.

[0034] The aforementioned retail / universal CBDC could closely complement a retail fast payment system (FPS). Most routine operations and consumer-facing services related to the aforementioned retail / universal CBDC could be performed by commercial banks and non-bank PSPs. In contrast, the central bank could focus on core operations such as ensuring currency stability, providing flexible liquidity, and overseeing the overall security of the payment and settlement system.

[0035] The CBDC implementation method can be divided into wholesale and retail methods. Central banks of each country may adopt either the wholesale or retail method. Regardless of the method adopted, the CBDC can be considered a new means of transaction that can replace currency. Therefore, offline functions that enable cash-like transactions even in offline situations where the network (100) connection is unstable or disconnected are necessary. In the following disclosure, we propose an offline digital currency implementation method based on the premise of a retail CBDC, in which a "token-based" implementation facilitates user anonymity. That is, each user holds their own blockchain key pair (BCK: block chain key) and operates as a node. However, the proposal in this disclosure is not necessarily specific to retail CBDC and can be applied to wholesale CBDC as well.

[0036] The at least one electronic device (110, 130) may include a first electronic device (110) in an online state that can access the operation server (120) via a network (100). The first electronic device (110) may operate in an online state, for example, if long-distance communication is possible. The at least one electronic device (110, 130) may include a second electronic device (130) in an offline state that cannot access the operation server (120) via the network (100). The second electronic device (130) may operate in an offline state, for example, if long-distance communication is not possible. The first electronic device (110) may switch to an offline state in a shadow area where long-distance communication is not possible.

[0037] The at least one electronic device (110, 130) may record the quantity of digital currency (hereinafter referred to as “online digital currency” or “coin”) to be used in an online state and / or the quantity of digital currency (hereinafter referred to as “offline digital currency” or “token”) to be used in an offline state in an embedded chip. The embedded chip may be various, such as, for example, a trusted execution environment (TEE), an embedded secure element (eSE), a secure element (SE) IC, a subscriber identification module (SIM) card, or an embedded subscriber identification module (eSIM).

[0038] The first electronic device (110) can execute a wallet app for a personal account that manages online digital currency, and perform transaction operations (hereinafter referred to as "online transaction operations") using online digital currency through the executed wallet app. The online transaction operations may include, for example, operations for paying for goods with digital currency based on a network (100) (e.g., based on long-distance communication) or transferring digital currency to another account.

[0039] The first electronic device (110) can perform an offline operation via the wallet app executed online. For example, the first electronic device (110) can perform an offline operation to exchange online digital currency for offline digital currency.

[0040] The first electronic device (110) can execute a wallet app of a personal account in an offline state and perform a transaction operation (hereinafter referred to as an “offline transaction operation”) using offline digital currency managed by the executed wallet app. The offline transaction operation may include, for example, an operation for paying digital currency for purchasing an item from the second electronic device (130) based on short-range communication, or for transferring digital currency to a user account of the second electronic device (130). The short-range communication may use a communication protocol such as NFC (near field communication), UWB (ultra-wideband), Bluetooth, WiFi (wireless fidelity) direct, or IrDA (infrared data association) as a standard.

[0041] The first electronic device (110) can perform an online operation via the executed wallet app while online. For example, the first electronic device (110) can perform an online operation to exchange offline digital currency in a unit of quantity changed due to an offline transaction operation for online digital currency. The unit of quantity of the offline digital currency due to the offline transaction operation may increase or decrease. If the offline transaction did not occur, the unit of quantity of the offline digital currency may not change.

[0042] The first and / or second electronic devices (110, 130) may include a user terminal (e.g., a smart phone, a mobile phone, or a tablet device) that can be carried by a user, a computer device, a portable multimedia device, a portable medical device, a camera, a wearable device, or a home appliance. The electronic devices in this document are not limited to the aforementioned devices. The first and / or second electronic devices (110, 130) may have application programs installed to provide various functions. The first and / or second electronic devices (110, 130) may execute the installed application programs in response to a user's operation. The first and / or second electronic devices (110, 130) may display information according to the execution of the application programs through a display.

[0043] For example, an electronic device (110, 130) that performs operations for offline transactions, online transactions, offlineization, and / or onlineization may include an IC card or smart card having an embedded or attached IC chip. Information for offline transactions, online transactions, offlineization, and / or onlineization may be recorded on the IC chip. The IC chip may function as a physical digital wallet supporting digital transactions. The IC card or smart card may support offline transactions based on a tag attached to a device such as an RFID (radio frequency identification) reader, for example.

[0044] The above-mentioned operating server (120) may be a management institution that manages offline digital currency, such as a government or central bank, or may be a server operated by a separate institution delegated authority from the management institution. The operating server (120) may perform operations according to offline and / or online operation. The operating server (120) may have the authority to issue an offline tokenization key pair (OTK) for each individual account. The offline tokenization key pair may be an asymmetric key including a private key and a public key. The operating server (120) may issue the offline key pair in a manner similar to the manner in which a certificate authority (CA) issues keys and / or certificates to individuals. The private key constituting the offline key pair may be used, for example, by the first electronic device (110) to sign predetermined information for an offline operation request. The predetermined information may include a token identifier and / or a public key constituting a blockchain key pair. The above-described information may include a token identifier and / or a value derived from a public key constituting a blockchain key pair. A token signature (TS) for the offline request may be generated by signing the token identifier, quantitative information of the digital currency to be issued by offline transaction, and / or a public key (or a value derived from the public key) constituting the blockchain key pair using a private key constituting the offline key pair. The operation server (120) may register an offline tokenization key pair (OTK) by mapping it to a blockchain key pair (BCK: block chain key) for each account and / or individual.

[0045] below shows an example of registering an offline tokenization key pair (OTK) by mapping it to a blockchain key pair (BCK: block chain key).

[0046] Blockchain key or address Offline key BCK_A's public key OTA_A's public key BCK_B's public key OTA_B's public key BCK_C's public key OTA_C's public key BCK_D's public key OTA_D's public key

[0047] The mapping table of the above shows an example of mapping the public key of a blockchain key pair (BCK: block chain key) and the public key of an offline tokenization key pair (OTK: offline tokenization key). However, depending on the implementation example, a value derived from the public key, a blockchain address of the blockchain key pair (BCK: block chain key) may be applied, or in the case of an offline tokenization key pair (OTK: offline tokenization key), a value derived from the public key or a certificate may be mapped as information that can correspond one-to-one. The value derived from the public key may be, for example, a hash value of the public key. The operation server (120) can confirm the mapping of the address on the blockchain for the corresponding account and / or individual with the public key of the offline key pair.

[0048] The above-mentioned operation server (120) holds an account on the blockchain and can uniquely call an offline smart contract to perform an offline operation. When distributing a smart contract based on blockchain technology, the operation server (120) can determine an address that can call and execute the corresponding smart contract. If the request of the first electronic device (110) is valid, the operation server (120) can issue offline digital currency, i.e., a token. The operation server (120) can, for example, protect the key for issuing an offline key pair and / or the key for issuing offline digital currency (hereinafter referred to as an “offline authorization key pair”) in a secure device such as a hardware security module (HSM).

[0049] The above-described operation server (120) may support online transaction operations, such as operations for paying with digital currency for purchasing goods or using services or transferring digital currency to another account, in response to an online transaction request from a first electronic device (110) that is online. The above-described operation server (120) may support an offline operation to issue offline digital currency from the online digital currency of the corresponding account in response to an offline request from the online first electronic device (110). The above-described operation server (120) may support an online operation to update the remaining amount of offline digital currency of the corresponding account in response to an online request from the online first electronic device (110) and to issue offline digital currency corresponding to part or all of the remaining amount in online digital currency.

[0050] In the digital currency operating system (10), transactions between individuals who own addresses and key pairs (private key and public key pairs) on the blockchain can be recorded in a distributed ledger. In the digital currency operating system (10), generating a key pair (e.g., an offline key pair and / or a blockchain key pair) and a unique address for each individual on the blockchain for each account and / or individual can be referred to as “account creation” or “wallet creation.” Once the key pair (e.g., an offline key pair and / or a blockchain key pair) is generated, an electronic device (110, 130) included in the digital currency operating system (10) can use the key pair to generate a transaction on the blockchain to send or receive online digital currency with another person.

[0051] FIG. 2 is a state transition diagram for performing an offline or online operation in a digital currency operating system (e.g., the digital currency operating system (10) of FIG. 1) according to one embodiment of the present disclosure.

[0052] Referring to FIG. 2, the digital currency operating system (10) can perform digital transactions using digital currency in an online state (210) (operation 213). The online state (210) may be, for example, a state in which digital transactions are possible via a network (e.g., the network (100) of FIG. 1).

[0053] In one example, the digital currency operating system (10) can perform an online transaction using online digital currency in an online state (210) (operation 213). For example, the digital currency operating system (10) can perform an online transaction to transfer online digital currency between nodes by generating a transaction on the blockchain. The transaction can occur in response to a transaction request, such as a purchase of an item, use of a service, or a transfer.

[0054] In one example, the digital currency operating system (10) can perform an offline transaction using offline digital currency in an online state (210) (operation 213). For example, even in the online state (210), an electronic device (e.g., the first electronic device (110) of FIG. 1) holding offline digital currency can establish a direct communication link with another electronic device (e.g., the second electronic device (130) of FIG. 1) and perform an offline transaction through the direct communication link. As an example, an electronic device in the online state (210) holding offline digital currency can provide a user interface that allows the user to select a type of digital transaction on a wallet app. If an offline transaction is selected through the user interface, the electronic device can perform an offline transaction using offline digital currency. If an online transaction is selected through the user interface, the electronic device can perform an online transaction using online digital currency.

[0055] The digital currency operating system (10) can perform offline conversion in an online state (210) (operation 211). The offline conversion may be an operation of converting online digital currency into offline digital currency. When an offline conversion request for a conversion amount (e.g., amount) of one or more token units (or currency units) for offline conversion is triggered, the digital currency operating system (10) can perform offline conversion for each combination of the token unit and the conversion amount using a token identifier (token ID) corresponding to the offline conversion request. Offline conversion for each combination of the token unit and the conversion amount may be performed independently. Offline conversion for each combination of the token unit and the conversion amount may be performed sequentially. Offline conversion for each combination of the token unit and the conversion amount may be performed in parallel or in batches.

[0056] For example, tokens corresponding to the offline digital currency can be classified into token A (or 1 offline token) corresponding to a unit token, token B (or 5 offline tokens) having a token unit corresponding to five unit tokens, token C (or 10 offline tokens) having a token unit corresponding to ten unit tokens, or token D (or 30 offline tokens) having a token unit corresponding to thirty unit tokens. In this case, the token unit can be 1, 5, 10, or 30. Accordingly, one token B with a token unit of 5 has a quantity corresponding to five tokens A with a token unit of 1, one token C with a token unit of 10 has a quantity corresponding to two tokens B or a quantity corresponding to ten tokens A, and one token D with a token unit of 30 has a quantity corresponding to three tokens C, a quantity corresponding to six tokens B, or a quantity corresponding to thirty tokens A. The above conversion quantity may correspond to the number of tokens to be issued per unit through offline.

[0057] For example, when an offline request is made to issue five tokens A, one token B, and two tokens C, the digital currency operating system (10) may perform an offline operation to issue eight tokens in response to the offline request. That is, the digital currency operating system (10) may perform five offline operations to issue five tokens A, one offline operation to issue one token B, and two offline operations to issue two tokens C. The offline operations to issue the eight tokens may be performed independently. The offline operations to issue the eight tokens may be performed sequentially. The offline operations to issue the eight tokens may be performed in parallel or in batches. Some operations among the offline operations to issue the eight tokens may be performed independently, and the remaining operations may be performed in parallel or in batches.

[0058] When the above eight offline operations are completed, the digital currency operating system (10) can finally issue five tokens A, one token B, and two tokens C in response to one offline request to which one token identifier (token ID) is assigned.

[0059] The above digital currency operating system (10) can transition to an offline state (220) when an offline transition event occurs (215) in an online state (210) and perform an offline transaction operation using offline digital currency (operation 221). The offline transition event can occur when access to the network (100) is blocked or when access to the network (100) is blocked on its own. For example, the offline transaction operation can be performed by an electronic device (e.g., the first electronic device (110) of FIG. 1) holding offline digital currency establishing a direct communication link with another electronic device (e.g., the second electronic device (130) of FIG. 1) and performing an offline transaction through the direct communication link.

[0060] The digital currency operating system (10) may transition from an offline state (220) to an online state (210) and perform online conversion (operation 217) when an online conversion event occurs (223). The online conversion event may occur when access to the network (100) is resumed or when access to the network (100) is allowed on its own. The online conversion may be an operation for converting offline digital currency into online digital currency. When an online conversion request for a conversion quantity (e.g., amount) of one or more token units (or currency units) for online conversion is triggered, the digital currency operating system (10) may perform online conversion for each combination of the token unit and the conversion quantity. The online conversion operation for each combination of the token unit and the conversion quantity may be performed independently. The online conversion operation for each combination of the token unit and the conversion quantity may be performed sequentially. The online operation for each combination of the token unit and the conversion quantity may be performed in parallel or in batches. Some of the online operation for each combination of the token unit and the conversion quantity may be performed independently, and the remaining operations may be performed in parallel or in batches.

[0061] For example, when a request for online is made for three tokens A (1 offline token), one token B (5 offline tokens), and one token C (10 offline tokens), the digital currency operating system (10) can perform an online operation to issue the five tokens as online digital currency in response to the online request. That is, the digital currency operating system (10) can perform three online operations to issue three coins A (1 online coin), one online operation to issue one coin B (5 online coins), and one online operation to issue one token C (10 online coins). When the five online operations are completed, the digital currency operating system (10) can finally issue three coins A, one coin B, and one coin C.

[0062] FIG. 3 is a flowchart illustrating an operation for performing offline and / or online processing for legal cryptocurrency in a digital currency operating system (e.g., the digital currency operating system (10) of FIG. 1) according to one embodiment of the present disclosure.

[0063] In the following examples, the operations may be performed sequentially, but are not necessarily sequential. For example, the order of the operations may be changed, and at least two operations may be performed in parallel.

[0064] Referring to FIG. 3, the digital currency operating system (10) may, in operation 310, perform offline conversion of legal cryptocurrency (or online digital currency or coin). The offline conversion may be an operation of converting online digital currency into offline digital currency.

[0065] More specifically, the digital currency operating system (10) may, when an offline request for the conversion quantity (e.g., amount) of one or more token units (or currency units) for offline conversion is triggered, perform offline conversion for each combination of the token unit and the conversion quantity using a token identifier (token ID) corresponding to the offline request. The offline conversion operation for each combination of the token unit and the conversion quantity may be performed independently. The offline conversion operation for each combination of the token unit and the conversion quantity may be performed sequentially. The offline conversion operation for each combination of the token unit and the conversion quantity may be performed in parallel or in batches. Some operations among the offline conversion operations for each combination of the token unit and the conversion quantity may be performed independently, and the remaining operations may be performed in parallel or in batches.

[0066] The offline digital currency tokens can be obtained by going offline. The tokens obtainable by going offline can have different token units. For example, the offline digital currency can include Token A (or 1 offline token), which is a unit token. The offline digital currency can include Token B (or 5 offline tokens), which has a token unit corresponding to five unit tokens. The offline digital currency can include Token C (or 10 offline tokens), which has a token unit corresponding to ten unit tokens. The offline digital currency can include Token D (or 30 offline tokens), which has a token unit corresponding to thirty unit tokens. That is, the token unit can be 1, 5, 10, or 30.

[0067] The digital currency operating system (10) may, for example, sequentially or in parallel perform offline operations corresponding to eight times, which is the number of total combinations, when an offline request for five tokens A, one token B, and two tokens C occurs. The digital currency operating system (10) may issue five tokens A by performing five offline operations. The digital currency operating system (10) may issue one token B by performing one offline operation. The digital currency operating system (10) may issue two tokens C by performing two offline operations. When the above-described eight offline operations are completed, the digital currency operating system (10) may finally issue five tokens A, one token B, and two tokens C in response to one offline request to which one token identifier (token ID) is assigned.

[0068] The digital currency operating system (10) may call an offline tokenization smart contract to create a smart contract corresponding to the requested token identifier. The digital currency operating system (10) may issue a new address for the smart contract when creating the smart contract. The offline tokenization smart contract may verify the requested content according to the program, check the balance at the address (or smart contract address) on the blockchain corresponding to the corresponding online account, and lock the checked balance to prevent transactions of the amount requested to be offline. The digital currency operating system (10) may create a smart contract corresponding to the offline digital currency containing conditions that can reactivate transactions of the corresponding amount, and distribute the address of the created smart contract on the blockchain. In this case, the address of the smart contract may be shared by nodes constituting the blockchain. For example, the operating server (120) may distribute the address of the smart contract on the blockchain when transmitting an offline digital currency token to the electronic device (110). The above-mentioned operation server (120) may also transmit the address of a newly issued smart contract for obtaining the offline digital currency token together with the offline digital currency token to the electronic device (110) that requested the offline operation.

[0069] The digital currency operating system (10) can perform an online transaction operation using online digital currency and / or an offline transaction operation using offline digital currency (operation 320). For example, the digital currency operating system (10) can support an offline transaction operation in which an electronic device (e.g., the first electronic device (110) of FIG. 1) holding offline digital currency establishes a direct communication link with another electronic device (e.g., the second electronic device (130) of FIG. 1) and performs an offline transaction through the direct communication link. For example, the digital currency operating system (10) can support an online transaction operation in which an electronic device (e.g., the first electronic device (110) of FIG. 1) holding online digital currency establishes a communication link with another electronic device (e.g., the second electronic device (130) of FIG. 1) online and performs an online transaction through the communication link.

[0070] For example, the digital currency operating system (10) can perform an offline transaction in which a first electronic device (110) and a second electronic device (130) exchange offline digital currency tokens in an offline situation. For example, when a token, which is an offline digital currency corresponding to a certain amount, is to be transferred to a second electronic device (130), the first electronic device (110) can execute a wallet app, which is its own account, and select tokens corresponding to a single token or a combination of multiple token units to reach the certain amount on the executed wallet app. The first electronic device (110) can transmit the selected tokens to the second electronic device (130). In response to an offline request, the first electronic device (110) can provide the address of the smart contract transmitted by the operating server (120) to the second electronic device (130).

[0071] The first electronic device (110), for example, when it wants to transfer an amount X, can select one token whose token unit is X. The first electronic device (110), for example, when it wants to transfer an amount X, can select X unit tokens. When the selection of tokens corresponding to the amount X to be transferred is completed, the first electronic device (110) can establish a direct communication link with the second electronic device (130) and transfer the selected token to a wallet according to the account of the second electronic device (130) through the established direct communication link.

[0072] As described above, offline transactions can be performed even in offline situations where both the wallets of the first electronic device (110) and the second electronic device (130) are disconnected from the network (100). However, offline transactions can also be performed online, if necessary. Since these offline transactions occur between devices (wallets) without connection to the network (100), transaction details are not only unknown but also untraceable. Therefore, tokens transmitted from the first electronic device (110) to the second electronic device (130) may be distributed to multiple accounts through one or more offline transactions. The electronic devices corresponding to these multiple accounts can then onlineize the tokens acquired through offline transactions.

[0073] According to one example, the digital currency operating system (10) can perform an online transaction in which a first electronic device (110) and a second electronic device (130) exchange coins, which are online digital currency, in an online situation. For example, when a user wants to transfer coins, which are online digital currency, to a second electronic device (130), the first electronic device (110) can execute a wallet app, which is its own account, and select the quantity of coins corresponding to the quantity on the executed wallet app. When the quantity of coins to be transferred is selected, the first electronic device (110) can establish a communication link with the second electronic device (130) online, and can transfer the selected quantity of coins to a wallet according to the account of the second electronic device (130) through the established communication link.

[0074] For example, the digital currency operating system (10) can perform an offline transaction in which a first electronic device (110) and a second electronic device (130) exchange tokens, which are offline digital currencies, in an online situation. For example, when a token, which is an offline digital currency corresponding to a certain amount, is to be transferred to a second electronic device (130), the first electronic device (110) can execute a wallet app, which is its own account, and select a quantity of tokens corresponding to the certain amount on the executed wallet app. When the first electronic device (110) selects the quantity of tokens to be transferred, it can establish a direct communication link with the second electronic device (130), and transfer the selected quantity of tokens to a wallet according to the account of the second electronic device (130) through the established direct communication link.

[0075] The digital currency operating system (10) may, in operation 330, perform online conversion for a predetermined offline digital currency, i.e., remaining tokens, in an online state. When a request for online conversion for one or more token units (or currency units) of a conversion quantity (e.g., amount) for online conversion is triggered, the digital currency operating system (10) may independently perform online conversion for each combination of the token unit and the conversion quantity. The online conversion operation for each combination of the token unit and the conversion quantity may be performed independently. The online conversion operation for each combination of the token unit and the conversion quantity may be performed sequentially. The online conversion operation for each combination of the token unit and the conversion quantity may be performed in parallel or in batches. Some operations among the online conversion operations for each combination of the token unit and the conversion quantity may be performed independently, and the remaining operations may be performed in parallel or in batches.

[0076] For example, when a request for online is made for three tokens A (1 offline token), one token B (5 offline tokens), and one token C (10 offline tokens), the digital currency operating system (10) can perform an online operation to issue the five tokens as online digital currency in response to the online request. That is, the digital currency operating system (10) can perform three online operations to issue three coins A (1 online coin), one online operation to issue one coin B (5 online coins), and one online operation to issue one token C (10 online coins). When the five online operations are completed, the digital currency operating system (10) can finally issue three coins A, one coin B, and one coin C.

[0077] The specific operations according to the online operation of legal cryptocurrency performed in the above digital currency operation system (10) will be described in detail below with reference to FIG. 5.

[0078] FIG. 4 is a signal flow diagram for performing offline operation in a digital currency operating system (e.g., the digital currency operating system (10) of FIG. 1) according to one embodiment of the present disclosure.

[0079] In the following examples, the operations may be performed sequentially, but are not necessarily sequential. For example, the order of the operations may be changed, and at least two operations may be performed in parallel.

[0080] Referring to FIG. 4, the electronic device (110) can monitor whether an offline request occurs in operation 411. The form of a wallet for managing digital currency can be implemented in various ways depending on the type of the electronic device (110). The electronic device (110) can be, for example, a smartphone, a smartwatch, or an IC card. Among the examples of the electronic device (110), a smartwatch or an IC card, which have relatively limited user interfaces due to the size of their displays, can access the wallet app of the smartphone through a communication link established based on a direct communication method (e.g., BLE (Bluetooth Low Energy), NFC (Near Field Communication), UWB (Ultra Wide Band)) with a smartphone, which has relatively unrestricted displays. In this case, the user can trigger an offline request using the wallet information displayed on the smartphone's display.

[0081] For example, the electronic device (110) may execute a wallet app and, through the execution screen of the wallet app, output the online or blockchain address and the balance of the online digital currency held by the corresponding account and / or individual. If the electronic device (110) selects an offline menu on the execution screen of the wallet app, the electronic device (110) may request offline conversion of part or all of the online digital currency balance. The electronic device (110) may determine the conversion amount of the token to be offlined. The conversion amount of the token to be offlined may be input by the user on the execution screen of the wallet app. The conversion amount of the token to be offlined may be input by selecting the token unit and / or the conversion amount. The conversion amount may be the number of tokens having the corresponding token unit.

[0082] The electronic device (110), for example, when an offline request for a conversion quantity (e.g., amount) of one or more token units (or currency units) for offline conversion is triggered, may perform offline conversion for each combination of the token unit and the conversion quantity using a token identifier (token ID) corresponding to the offline request. The offline conversion operation for each combination of the token unit and the conversion quantity may be performed independently. The offline conversion operation for each combination of the token unit and the conversion quantity may be performed sequentially. The offline conversion operation for each combination of the token unit and the conversion quantity may be performed in parallel or in batches. Some operations among the offline conversion operations for each combination of the token unit and the conversion quantity may be performed independently, and the remaining operations may be performed in parallel or in batches.

[0083] For example, tokens corresponding to the offline digital currency can be classified into token A (or 1 offline token) corresponding to a unit token, token B (or 5 offline tokens) having a token unit corresponding to five unit tokens, token C (or 10 offline tokens) having a token unit corresponding to ten unit tokens, or token D (or 30 offline tokens) having a token unit corresponding to thirty unit tokens. In this case, the token unit can be 1, 5, 10, or 30. Accordingly, one token B with a token unit of 5 has a quantity corresponding to five tokens A with a token unit of 1, one token C with a token unit of 10 has a quantity corresponding to two tokens B or a quantity corresponding to ten tokens A, and one token D with a token unit of 30 has a quantity corresponding to three tokens C, a quantity corresponding to six tokens B, or a quantity corresponding to thirty tokens A. The above conversion quantity may correspond to the number of tokens to be issued per unit through offline.

[0084] When the offline request occurs, the electronic device (110) may generate a token identifier (token ID) in operation 413. The token identifier may be used to generate a pre-offline digital currency (TBS (to be signed) offline token). As an example, the electronic device (110) may randomly generate a token identifier. To this end, the electronic device (110) may prepare a generation formula for randomly generating a token identifier. The electronic device (110) may send a query to a specific smart contract provided by the operation server (120) to receive a valid token identifier. The electronic device (110) may verify whether a token identifier randomly generated in a user wallet is valid by sending a query to a predetermined smart contract provided by the operation server (120). The electronic device (110) may use a token identifier verified by the predetermined smart contract. The above electronic device (110) can verify the validity of a token identifier randomly generated based on the details of the distributed ledger in the user wallet.

[0085] The electronic device (110) may generate tokenization information in operation 415. The electronic device (110) may generate tokenization information using, for example, a pre-offline digital currency (TBS (to be signed) offline token). The electronic device (110) may include the tokenization information in an offline request message and transmit it to the operation server (120) in operation 417. For example, the electronic device (110) may use an offline tokenization key pair (OTK) assigned to the user for a signature included in the pre-offline digital currency (TBS (to be signed) offline token). The user may also be issued an offline tokenization key pair (OTK: offline tokenization key) and a blockchain key pair (BCK: block chain key) when a wallet is issued. The offline key pair and / or the blockchain key pair may have the form of an asymmetric key including a private key and a public key. The electronic device (110) can transmit an offline request message including the pre-offline digital currency (TBS (to be signed) offline token) to the operation server (120).

[0086] below defines an example of an offline request message.

[0087] TBSofflineToken for (public key of BCK_A)OTK public key: 0408090a0b0c0d0e0f… . (public key of OTK_A)tokenSignature(TS): Sign(key=private key of OTK_A, message=(TokenID, X, BCK_A))}

[0088] In the above , the offline request message may include a token identifier (token ID) as a pre-offline digital currency (TBS offline token), quantitative information of the digital currency to be issued by offline conversion, a token unit (or currency unit) (X) to be issued by performing offline conversion, a public key of a blockchain key pair (BCK: block chain key), a public key of an offline tokenization key pair (OTK: offline tokenization key), or a token signature (TS: token signature). The token signature may be generated by signing a token identifier (token ID), token information for offline conversion, and a public key (or a value derived from the public key) of a blockchain key pair (BCK: block chain key) by a private key of an offline tokenization key pair (OTK: offline tokenization key). The token information for offline conversion may include quantitative information of the digital currency to be issued by offline conversion. The token information for offline operation may include, for example, information about a token unit (or currency unit) (X) to be obtained through offline operation. The token information for offline operation may include, for example, information about the quantity of tokens to be obtained through offline operation. The operation server (120) may receive pre-offline digital currencies (TBS offline tokens) from the electronic device (110) in operation 417. The received pre-offline digital currencies (TBS offline tokens) may have the same token identifier. The operation server (120) may verify an offline tokenization key pair (OTK) of the received pre-offline digital currencies (TBS offline tokens) (operation 419).The electronic device (110) can, for example, check whether the mapping between the offline tokenization key (OTK) transmitted from the electronic device (110) for the offline request and the blockchain key (BCK) is correct by checking the issuance history of the offline tokenization key pair (OTK), and the blockchain key pair (BCK). If a certificate for the offline tokenization key (OTK) exists, the operation server (120) can verify the offline tokenization key pair (OTK) using the certificate (operation 419). This may vary depending on the issuance method of the offline tokenization key pair (OTK).

[0089] The operation server (120) may validate the token identifier (operation 421). If the token identifier used in the pre-offline digital currency (TBS offline token) has been used previously or has a history of overlapping use with a previously used token identifier, the operation server (120) may reject the offline request. The operation server (120) may also reject the offline request if the balance registered in the address opened by the user on the blockchain is insufficient to issue tokens in the quantity requested for offline request. The electronic device (110) may verify the signature of the token signature (TS) included in the pre-offline digital currency (TBS offline token).

[0090] If all of the above-described verification conditions are met, the operating server (120) can perform offline migration to generate the desired offline digital currency token. However, if any of the above-described verification conditions are not met, the operating server (120) may reject the offline migration request.

[0091] The above-described operation server (120) can generate an authority signature (AS) if all verification conditions are satisfied (operation 423). For example, if all verification conditions are satisfied, the operation server (120) can request generation of an authority signature (AS) for all of the pre-offline digital currencies (TBS offline tokens) through a key management system, such as an associated HSM. The key management system, such as the HSM, can generate an authority signature (AS) for all of the pre-offline digital currencies (TBS offline tokens) using an offline tokenization authority key (OTAK) in response to the request of the operation server (120).

[0092] The above operation server (120) can receive an authority signature (AS) from the key management system and generate a signed token, which is an offline digital currency signed using the received authority signature (AS) (operation 425).

[0093] below defines an example of a signed token, which is a signed offline digital currency to be included in an offline response message.

[0094] OfflineToken for X{TBSofflineToken for XauthoritySignature(AS): Sign(key=private key of OTAK, message=TBSOfflineToken for

[0095] In the above , the offline response message may include a signed offline digital currency (offline token), a pre-offline digital currency (TBS offline token), and an authority signature (AS). The authority signature (AS) may be generated by signing the pre-offline digital currency (TBS offline token) with a private key of an offline tokenization authority key (OTAK). The operation server (120) may request the creation of a smart contract corresponding to a specific offline digital currency. The operation server (120) may call the offline tokenization smart contract (430) to request the creation of a smart contract corresponding to the requested token identifier (operation 431).

[0096] The offline tokenization smart contract (430) may verify the requested information according to the program, check the balance at the address on the blockchain corresponding to the online account, and lock the confirmed balance to prevent transactions of the amount requested to be offline. Furthermore, a smart contract corresponding to offline digital currency containing conditions for reactivating transactions of the amount may be generated, and the address of the generated smart contract may be distributed on the blockchain (operation 433). The address of the distributed smart contract may be shared with nodes constituting the blockchain. The offline tokenization smart contract (430) may transmit the verification results obtained for the offline conversion results to the operation server (120) (operation 435).

[0097] The above-mentioned operating server (120) may transmit an offline response message containing the signed token, which is the generated signed offline digital currency, to the electronic device (110) (operation 427). The operating server (120) may transmit the address of the smart contract together with the signed token to the electronic device (110).

[0098] The electronic device (110) can receive signed offline digital currencies (offline Tokens) transmitted from the operating server (120). The electronic device (110) can store the received signed offline digital currencies (offline Tokens) in a secure area provided within the wallet of the eSE, TZ, or SE IC (operation 429). The electronic device (110) can use the signed offline digital currencies (offline Tokens) stored in the secure area during offline transactions.

[0099] The electronic device (110) may include the address of the smart contract generated and distributed by the offline tokenization smart contract in the information of the signed offline digital currency. This is to make it relatively easier to find the smart contract to be called when the signed offline digital currency is later made online.

[0100] FIG. 5 is a signal flow diagram for performing online operation in a digital currency operation system (e.g., the digital currency operation system (10) of FIG. 1) according to one embodiment of the present disclosure.

[0101] In the following examples, the operations may be performed sequentially, but are not necessarily sequential. For example, the order of the operations may be changed, and at least two operations may be performed in parallel.

[0102] Referring to FIG. 5, an electronic device (e.g., the first electronic device (110) of FIG. 1) may monitor, in operation 511, whether an online request has occurred. The electronic device (110) may identify that an online request has occurred, for example, by triggering an online request for a conversion quantity (e.g., an amount) of one or more token units (or currency units) for online transaction.

[0103] When the request for online storage occurs, the electronic device (110) may transmit the request for online storage to an operating server (e.g., the operating server (120) of FIG. 1) in operation 513. For example, the electronic device (110) may transmit an online storage request message to the operating server (120) for the online storage request. The electronic device (110) may request online storage by calling a corresponding smart contract in the operating server (120) in response to a transaction according to the online storage request. The online storage request may be made for each token identifier. The online storage request message may be signed using a private key constituting a blockchain key pair assigned to each account and / or individual. The online storage request may also be made for each quantity unit having the same token identifier.

[0104] When the operation server (120) receives a request to make the electronic device (110) online, it can call a smart contract (530) of a token identifier corresponding to the request to make the device online in operation 515. The operation server (120) can use the address of the smart contract (530) to be called to call the smart contract (530). The address of the smart contract can be generated and distributed by the operation server (120) when issuing an offline digital currency token through offline issuance.

[0105] The above-mentioned operation server (120) may request online verification from the called smart contract (530) at operation 517. The called smart contract (530) may perform verification on the signed token to be onlined, included in the onlined request message, at operation 531. The called smart contract (530) may perform onlined verification based on the verification result at operation 531, thereby updating information regarding online digital currency. The smart contract (530) may be programmed to perform transactions according to predetermined conditions.

[0106] In one example, a smart contract (530) corresponding to the token identifier may verify the received offline token according to the predetermined conditions, and if the predetermined conditions are not satisfied, may reject the online tokenization request (operation 533). For example, the smart contract (530) may verify the token identifier of the received offline token (operation 531). The smart contract (530) may verify the account and / or requester who requested the online tokenization (operation 531). The account and / or requester may be verified through verification of a blockchain key pair. The smart contract (530) may verify the token signature and / or authority signature included in the received token (operation 531). The above smart contract (530) can check whether the token signature and / or the authority signature were requested for online processing in advance or whether there is a history of online processing already being performed based on the previous online processing history.

[0107] The above smart contract (530) unlocks the use of coins at an address corresponding to the blockchain key pair (BCK_A) recorded in a token that has passed verification for all conditions on the blockchain, and can generate a remittance transaction of coins according to the online transaction to an address corresponding to the blockchain key pair (BCK_B) assigned to the account and / or user that requested the online transaction (operation 531). The blockchain key pair (BCK_A) recorded in the token may be a blockchain key pair assigned to the account and / or user that requested the offline transaction of the corresponding token.

[0108] The operation server (120) may, in operation 519, transmit an online processing response message including the result of performing the online processing to the electronic device (110). The electronic device (110) may receive the online processing response message and, based on the result of the online processing included in the online processing response message, confirm that the number of coins, which are online digital currencies, in its wallet through online processing has increased (operation 521). The electronic device (110) may, based on the result of the online processing included in the online processing response message, confirm that the number of tokens, which are offline digital currencies, in its wallet through online processing has decreased (operation 521).

[0109] FIG. 6 is a block diagram of a processor for performing offline and / or online operation in an electronic device (e.g., the first electronic device (110) of FIG. 1) according to the disclosure of the present invention.

[0110] Referring to FIG. 6, an electronic device (110) may have a personal account (or wallet) (610) for managing digital currency. The electronic device (110) may activate the personal account (or wallet) (610) by executing a wallet app of the personal account. An offline tokenization key (OTK) (611) or a block chain key (BCK) (613) may be stored in the personal account (610). For example, the personal account (610) may include a cryptographic account for storing the offline tokenization key (OTK) (611) or the block chain key (BCK) (613).

[0111] The personal account (610) may be invoked and executed by an online operation processor (620) or an offline operation processor (630). The online operation processor (620) may perform online transactions using stored online digital currency. The online transactions performed by the online operation processor (620) using the online digital currency may be performed by a transfer module (621) or a payment module (623). The online operation processor (620) may include an offline module (625) that performs offline conversion to convert online digital currency coins into offline digital currency tokens. The offline operation processor (630) may perform offline transactions using stored offline digital currency. The offline transactions performed by the offline operation processor (630) using the offline digital currency may be performed by a transfer module (631) or a payment module (633). The above offline operation processor (630) may include an online module (635) that performs online conversion for converting offline digital currency, token, into online digital currency, coin.

[0112] FIG. 7 is a configuration diagram of a processor for performing offline and / or online operation in an operating server (e.g., operating server (120) of FIG. 1) according to the disclosure of the present invention.

[0113] Referring to FIG. 7, the operation server (120) may include a key management process (710) or a smart contract (720). The smart contract (720) may include an offline tokenization smart contract (721) or a smart contract for offline tokens (723). The smart contract for token identifiers (723) may be generated by the offline smart contract (721) for each token identifier.

[0114] The above offline smart contract (721) can issue a smart contract (a smart contract for a specific offline CBDC token, described below) containing conditions that lock a certain amount of online digital currency transactions for a specific account when a command satisfies a condition, and unlock the online digital currency. Only accounts with offline tokenization authority can call the above offline smart contract (721).

[0115] The smart contract (723) for the token identifier may exist for each token identifier of the offline digital currency issued by the offline tokenization authority (723_0, 723_1, 723_2……, 723_n-1). The smart contract (723) for the token identifier may be programmed to perform online conversion, which converts offline digital currency back into online digital currency, according to conditions. For example, the smart contract (723) for the token identifier may, when an input that satisfies a specific condition is received, unlock the transaction of the online digital currency amount specified in the input among the total online digital currency locked at the address of the online digital currency of the blockchain account that initially performed the offline conversion after validation. After unlocking the transaction, the smart contract (723) for the token identifier may be programmed to transfer the digital currency to the address of the online digital currency of the blockchain account that called the online conversion request.

[0116] FIG. 8A is an exemplary diagram of a user interface requesting offline operation in an electronic device (e.g., the first electronic device (110) of FIG. 1 ), according to one embodiment of the present disclosure.

[0117] Referring to FIG. 8A, the electronic device (110) may execute a wallet app of a personal account managing online digital currency and display an execution screen (820) of the wallet app on the display (810). The execution screen (820) of the wallet app may be, for example, a screen related to an online account (or wallet). In the execution screen (820) of the wallet app, the screen (830) related to the online account may include an address (831) generated corresponding to one's account on the blockchain (e.g., Oxabcdef) and a balance (833) of coins (e.g., 100 coins) or function buttons. The above function buttons may include a function button for requesting confirmation of transaction history of online digital currency, a function button for requesting transfer, a function button for requesting payment, a function button for requesting payment, a function button for requesting payment, or a function button for requesting offline, a function button for requesting payment, an ...

[0118] FIG. 8b is an exemplary diagram of a user interface for offline operation in an electronic device (e.g., the first electronic device (110) of FIG. 1) according to one embodiment of the present disclosure.

[0119] Referring to FIG. 8B, when a function button requesting offline operation (e.g., offline (839) of FIG. 8A) is selected, the electronic device (110) may display a screen (840) for offline token generation on the display (810). The offline token generation screen (840) may include a setting screen (850) for inputting the conversion amount to be issued per token unit (or currency unit). The setting screen (850) may include, for example, items (851, 852, 853, 854, 855) for inputting the conversion amount to be issued per token unit by the offline operation. The items (851, 852, 853, 854, 855) for entering the conversion amount per token unit may include, for example, an item (851) for entering the conversion amount a of 1 offline token, an item (852) for entering the conversion amount b of 5 offline tokens, an item (853) for entering the conversion amount c of 10 offline tokens, an item (854) for entering the conversion amount d of 30 offline tokens, or an item (855) for entering the conversion amount f of an arbitrary token unit e. The conversion amounts a, b, c, d, or f may be positive integers including 0. The setting screen (850) may include, for example, an item (856) for displaying the total token amount summed up based on the conversion amount per token unit entered. The above setting screen (850) may include an 'offline request (857)' function button for requesting offline operation for items (851, 852, 853, 854, 855) that can input the conversion amount per token unit.

[0120] For example, when the offline request (857) is selected, the electronic device (110) may perform offline processing for each combination of the token unit and the conversion quantity using a token identifier (token ID) corresponding to the offline request. The offline processing operation for each combination of the token unit and the conversion quantity may be performed independently. The offline processing operation for each combination of the token unit and the conversion quantity may be performed sequentially. The offline processing operation for each combination of the token unit and the conversion quantity may be performed in parallel or in batches. Some operations among the offline processing operations for each combination of the token unit and the conversion quantity may be performed independently, and the remaining operations may be performed in parallel or in batches.

[0121] For example, the electronic device (110) may perform an offline operation to issue a predetermined number (a+b+c+d+f) of tokens in response to the offline request. The electronic device (110) may perform the offline operation to issue a predetermined number (a+b+c+d+f) of tokens in response to the offline request sequentially, in parallel, or may perform some of the offline operations sequentially and some of the operations in parallel. The electronic device (110) may perform an offline operation a to issue a number of 1 offline token. The electronic device (110) may perform an offline operation b to issue b number of 5 offline tokens. The electronic device (110) may perform an offline operation c to issue c number of 10 offline tokens. The electronic device (110) may perform an offline operation d to issue d number of 30 offline tokens. The above electronic device (110) can perform f offline operations to issue f e offline tokens.

[0122] When the above predetermined number of offline operations (a+b+c+d+f) is completed, the electronic device (110) can finally receive a predetermined number of tokens (a+b+c+d+f) in response to one offline request to which one token identifier (token ID) is assigned.

[0123] FIG. 9A is an exemplary diagram of a user interface requesting online access in an electronic device (e.g., the first electronic device (110) of FIG. 1), according to one embodiment of the present disclosure.

[0124] Referring to FIG. 9A, the electronic device (110) may execute a wallet app of a personal account managing offline digital currency and display an execution screen (920) of the wallet app on the display (910). The execution screen (920) of the wallet app may be, for example, a screen regarding an offline account (or wallet). In the execution screen (920) of the wallet app, the screen (930) regarding the offline account may include an address (931) (e.g., Oxabcdef) generated in correspondence with one's account on the blockchain, a balance (933) of an offline digital currency token (e.g., 15 tokens), or function buttons. The above function buttons may include a function button 'View Details (935)' that can request confirmation of offline digital currency transaction history, a function button 'Transfer (937)' that can request transfer, a function button 'Payment (938)' that can request payment, or a function button 'Online (939)' that can request online.

[0125] FIG. 9b is an exemplary diagram of a user interface for online connection in an electronic device (e.g., the first electronic device (110) of FIG. 1) according to one embodiment of the present disclosure.

[0126] Referring to FIG. 9B, when a function button requesting online conversion (e.g., online (939) of FIG. 9A) is selected, the electronic device (110) may display a screen (940) for generating online tokens on the display (910). The online token generation screen (940) may include a setting screen (950) for inputting the conversion amount for conversion into coins per token unit (or currency unit). The setting screen (950) may include, for example, items (951, 952, 953, 954, 955) for inputting the conversion amount for each token unit to be converted into coins by the online conversion operation. The items (951, 952, 953, 954, 955) for entering the conversion amount per token unit may include, for example, an item (951) for entering the conversion amount a of 1 offline token, an item (952) for entering the conversion amount b of 5 offline tokens, an item (953) for entering the conversion amount c of 10 offline tokens, an item (954) for entering the conversion amount d of 30 offline tokens, or an item (955) that can be selected to convert all remaining tokens in bulk. The conversion amounts a, b, c, or d may be positive integers including 0. The setting screen (950) may include, for example, an item (956) for displaying the total token amount added up based on the conversion amount per token unit entered. The above setting screen (950) may include a function button, 'Online request (957),' for requesting offline conversion for items (951, 952, 953, 954, 955) that can input the conversion amount per token unit.

[0127] For example, when the online request (957) is selected, the electronic device (110) can perform online processing for each combination of the token unit and the conversion quantity. The online processing operation for each combination of the token unit and the conversion quantity can be performed independently. The online processing operation for each combination of the token unit and the conversion quantity can be performed sequentially. The online processing operation for each combination of the token unit and the conversion quantity can be performed in parallel or in batches. Some operations among the online processing operations for each combination of the token unit and the conversion quantity can be performed independently, and the remaining operations can be performed in parallel or in batches.

[0128] For example, the electronic device (110) may perform an online operation to convert a predetermined number (a+b+c+d) of tokens into coins in response to the online operation request. The electronic device (110) may perform the online operation to convert the predetermined number (a+b+c+d) of tokens into coins sequentially, in parallel, or some of the online operations may be performed sequentially and some of the online operations may be performed in parallel in response to the online operation request. The electronic device (110) may perform an online operation a to convert a number of 1 offline tokens into coins. The electronic device (110) may perform an online operation b to convert b number of 5 offline tokens into coins. The electronic device (110) may perform an online operation c to convert c number of 10 offline tokens into coins. The electronic device (110) may perform an online operation d to convert d number of 30 offline tokens into coins. The electronic device (110) may perform online conversion for converting each of the remaining one or more tokens into coins if an item (957) requesting online conversion for all remaining tokens is selected.

[0129] In one example, an operating method of an electronic device may include an operation of obtaining a token identifier (token ID) corresponding to an offlineization request. As an example, the operating method may include an operation of transmitting, to an operating server, a pre-offline digital currency (TBS (to be signed) offline token) including a token signature (TS) signed by a private key included in a predetermined offline tokenization key pair (OTK), which is an asymmetric key for offlineization, the token identifier, quantitative information of digital currency to be issued by offlineization, and a public key of a predetermined block chain key pair (BCK) or a value derived from the public key. As an example, the operating method may include an operation of receiving, from the operating server, an offline digital currency (token) including an authority signature (AS) signed by an offline tokenization authority key (OTAK) for the pre-offline digital currency. As an example, the operating method may include updating offline digital currency information of a corresponding account based on the offline digital currency. As an example, the authorization signature may be generated by the operating server based on verification of the predetermined offline key pair, validation of the token identifier, balance of the online digital currency, and signature verification using the token signature.

[0130] As an example, the operation of obtaining the token identifier may include an operation of randomly generating a candidate token identifier, an operation of requesting the operation server to verify the validity of the candidate token identifier, and an operation of determining the candidate token identifier as the token identifier based on the result of the verification of the validity of the candidate token identifier by the operation server.

[0131] As an example, the operation of obtaining the token identifier may include an operation of randomly generating a candidate token identifier, an operation of verifying the validity of the candidate token identifier based on the details of a distributed ledger, and an operation of determining the candidate token identifier as the token identifier based on the result of the verification of the validity of the candidate token identifier.

[0132] As an example, the method of operation may include an operation of obtaining the predetermined offline key pair and the predetermined blockchain key pair in response to a request for creation of the corresponding account.

[0133] As an example, the method of operation may include an operation of obtaining quantitative information capable of predicting the amount of offline digital currency to be issued by the offline transaction for the offline transaction request.

[0134] As an example, the above method of operation may include an operation of outputting an offline result based on the updated offline digital currency information.

[0135] As an example, the operating method may include an operation of establishing a direct communication link with a counterpart electronic device in a situation where connection to a blockchain network is blocked, an operation of transmitting some or all of the offline digital currency stored in the corresponding account to the counterpart electronic device through the direct communication link in response to an offline transaction request, an operation of updating offline digital currency information of the corresponding account based on the transmitted offline digital currency, and an operation of releasing the direct communication link.

[0136] As an example, the operating method may include an operation of establishing a direct communication link with a counterpart electronic device in a situation where connection to a blockchain network is blocked, an operation of receiving a predetermined offline digital currency from the counterpart electronic device through the direct communication link in response to an offline transaction request, an operation of updating offline digital currency information of the corresponding account based on the predetermined offline digital currency, and an operation of releasing the direct communication link.

[0137] As an example, the method of operation may include an operation of receiving a request for online conversion of some or all of the offline digital currency stored in the corresponding account, and an operation of transmitting the target offline digital currency for online conversion to the operating server in response to the online conversion request.

[0138] As an example, the target offline digital currency may be generated so that the operating server can obtain at least one of the token identifier, the predetermined blockchain key pair, the token signature, or the authority signature.

[0139] As an example, the operating method may include an operation of receiving an online processing result from the operating server and an operation of outputting online digital currency information in an account updated based on the online processing result.

[0140] According to an example, an operating method of an operating server may include receiving a pre-offline digital currency (TBS (to be signed) Offline Token) including a token identifier, quantitative information of a digital currency to be issued by offline tokenization, and a token signature (TS) signed by a public key of a pre-offline key pair (BCK: block chain key) or a value derived from the public key by a private key included in a predetermined offline tokenization key pair (OTK: offline tokenization key) which is an asymmetric key for offline tokenization from an electronic device. As an example, the operating method may include generating an authority signature (AS: authority signature) signed by an offline tokenization authority key (OTAK) for the pre-offline digital currency. As an example, the operating method may include transmitting an offline digital currency (Offline Token) including the authority signature to the electronic device.

[0141] As an example, the operating method may include an operation of verifying the predetermined offline key pair, an operation of checking the validity of the token identifier, an operation of checking the balance of online digital currency, an operation of verifying a signature by the token signature, and an operation of requesting generation of the authority signature by considering at least one result of verification of the predetermined offline key pair, verification of the validity of the token identifier, balance of online digital currency, or verification of a signature by the token signature.

[0142] As an example, the method of operation may include an operation of locking the use of online digital currency corresponding to the offline digital currency issued by the offline transaction in the corresponding account by calling a smart contract corresponding to the token identifier in response to a request for generation of the authorization signature.

[0143] As an example, the method of operation may include an operation of registering the predetermined offline key pair corresponding to the predetermined blockchain key pair.

[0144] The terminology used in this disclosure is merely used to describe specific embodiments and is not intended to limit the present disclosure. For example, a singular element should be understood to include plural elements unless the context clearly indicates only a singular element. As used herein, phrases such as “A or B,” “at least one of A and B,” “at least one of A or B,” “A, B, or C,” “at least one of A, B, and C,” and “at least one of A, B, or C” can each include any one of the items listed together in the corresponding phrase, or all possible combinations thereof. It should be understood that the term “and / or” as used herein encompasses any and all possible combinations of one or more of the listed items. The terms "include," "have," "comprise," and the like used in this disclosure are intended to specify only the presence of a feature, component, part, or combination thereof described in this disclosure, and the use of these terms does not exclude the possibility of the presence or addition of one or more other features, components, parts, or combinations thereof. The expressions "first," "second," and the like used in this disclosure can modify various components regardless of order and / or importance, and are only used to distinguish one component from another, without limiting the components.

[0145] The expression "configured to" used in the present disclosure can be appropriately used interchangeably with, for example, "suitable for," "capable of," "designed to," "modified to," "made to," or "capable of." The term "configured to" may not necessarily mean only something "specially designed" in terms of hardware. Instead, in some situations, the expression "a device configured to" may mean that the device is "capable of" doing something together with other devices or components. For example, the phrase "a device configured (or set) to perform A, B, and C" may mean a dedicated device for performing the corresponding operations, or a general-purpose device that can perform various operations including the corresponding operations.

[0146] Meanwhile, the terms 'upper side', 'lower side', and 'front-rear direction' used in the present disclosure are defined based on the drawing, and the shape and position of each component are not limited by these terms.

[0147] Although the foregoing description in this disclosure has focused on specific embodiments, it should be understood that this disclosure is not limited to such specific embodiments, but rather encompasses various modifications, equivalents, and / or alternatives of the various embodiments.

Claims

1. In the method of operating an electronic device, An action to obtain a token identifier (token ID) corresponding to an offline request; An operation of transmitting a pre-offline digital currency (TBS (to be signed) offline token) including a token identifier, quantitative information of digital currency to be issued by offline tokenization, and a token signature (TS) signed by a public key of a predetermined blockchain key pair (BCK: block chain key) or a value derived from the public key by a private key included in a predetermined offline tokenization key pair (OTK: offline tokenization key), which is an asymmetric key for offline tokenization, to an operating server; An operation of receiving offline digital currency (token) including an authority signature (AS) signed by an offline tokenization authority key (OTAK) for the pre-offline digital currency from the above operating server; and Including an operation of updating offline digital currency information of a corresponding account based on the above offline digital currency, The above authority signature is generated by the operation server based on verification of the above-described offline key pair, validation of the token identifier, balance of online digital currency, and signature verification by the token signature.

2. In paragraph 1, The action of obtaining the above token identifier is: The action of randomly generating a candidate token ID; An action of requesting validation of the candidate token identifier to the above operating server; and A method comprising an action of determining the candidate token identifier as the token identifier based on the result of validation of the candidate token identifier by the operating server.

3. In paragraph 1, The action of obtaining the above token identifier is: The action of randomly generating candidate token identifiers; An action to verify the validity of the candidate token identifier based on the history of the distributed ledger; and A method comprising an action of determining the candidate token identifier as the token identifier based on the result of the validation of the candidate token identifier.

4. In any one of paragraphs 1 to 3, A method comprising an operation of obtaining the predetermined offline key pair and the predetermined blockchain key pair in response to a request for creation of the corresponding account.

5. In any one of paragraphs 1 to 3, A method comprising an operation of obtaining quantitative information capable of predicting the amount of offline digital currency to be issued by the offline transaction, for the offline transaction request.

6. In any one of paragraphs 1 to 5, The act of establishing a direct communication link with an opposing electronic device in a situation where the connection to the blockchain network is blocked; An action of transmitting some or all of the offline digital currency stored in the corresponding account to the counterpart electronic device via the direct communication link in response to an offline transaction request; An operation of updating offline digital currency information of the corresponding account based on the offline digital currency transmitted above; and A method comprising the action of releasing the direct communication link.

7. In any one of paragraphs 1 to 5, The act of establishing a direct communication link with an opposing electronic device in a situation where the connection to the blockchain network is blocked; An action of receiving a predetermined offline digital currency from the counterpart electronic device via the direct communication link in response to an offline transaction request; An operation of updating offline digital currency information of the corresponding account based on the received predetermined offline digital currency; and A method comprising the action of releasing the direct communication link.

8. In any one of paragraphs 1 to 7, An action to receive a request to online some or all of the offline digital currency stored in the above corresponding account; An action of transmitting the target offline digital currency for online conversion to the operating server in response to the above online conversion request; An operation of receiving an online processing result from the above operating server; and An action to output online digital currency information within an updated account based on the above online processing results. Including, but not limited to, A method wherein the target offline digital currency is generated so that the operating server can obtain at least one of the token identifier, the predetermined blockchain key pair, the token signature, or the authority signature.

9. Regarding the operation method of the operating server, An operation of receiving a pre-offline digital currency (TBS (to be signed) Offline Token) including a token identifier, quantitative information of digital currency to be issued by offline tokenization, and a token signature (TS) signed by a public key of a predetermined blockchain key pair (BCK: block chain key) or a value derived from the public key by a private key included in a predetermined offline tokenization key pair (OTK: offline tokenization key) which is an asymmetric key for offline tokenization from an electronic device; An operation of generating an authority signature (AS) signed by an offline tokenization authority key (OTAK) for the pre-offline digital currency; and A method comprising the action of transmitting an offline digital currency (Offline Token) including the above authority signature to the electronic device.

10. In paragraph 9, An operation for verifying the above-described offline key pair; An action to validate the above token identifier; The action of checking the balance of online digital currency; An operation of verifying a signature by the above token signature; and A method comprising an operation of requesting generation of the authorization signature by considering at least one result of verification of the predetermined offline key pair, validation of the token identifier, balance of the online digital currency, or signature verification by the token signature.

11. In paragraph 10, A method comprising an action of locking the use of online digital currency corresponding to the offline digital currency issued by the offline transaction in the corresponding account by calling a smart contract corresponding to the token identifier in response to a request for generation of the above authorization signature.

12. In any one of paragraphs 9 to 11, A method comprising an operation of registering the predetermined offline key pair corresponding to the predetermined blockchain key pair.

13. In any one of paragraphs 9 to 12, An operation of sharing the above token identifier and receiving the pre-offline digital currency (TBS (to be signed) Offline Token) by unit amount for the offline operation, A method wherein the above-described received pre-offline digital currency (TBS (to be signed) Offline Token) is signed by the above-described authority signature.

14. In paragraph 10, A method comprising the action of rejecting an offline request for the pre-offline digital currency (TBS (to be signed) Offline Token) if at least one of verification of the predetermined offline key pair, validation of the token identifier, balance of the online digital currency or signature verification by the token signature fails.

15. In any one of paragraphs 9 to 14, An action of receiving offline digital currency for online conversion from said electronic device by requesting online conversion of some or all of the offline digital currency stored in the corresponding account; and The action of transmitting the online processing result to the above electronic device Including, but not limited to, The above target offline digital currency is generated so that the operating server can obtain at least one of the token identifier, the predetermined blockchain key pair, the token signature, or the authority signature, The above offline digital currency (Offline Token) is a legal digital currency.

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