TWI818171B - Multi-party loan consumption system based on blockchain and smart contract and method thereof - Google Patents

Abstract

A multi-party loan consumption system based on blockchain and smart contract and method thereof is disclosed. By providing a buyer host, lending host, seller host, and intermediary host on a blockchain network, wherein the buyer host and the seller host are in a delivery relationship, the buyer host and the lending host are in a loan relationship, and the lending-end host and the seller host are in a payment relationship. When the buyer host makes loan consumption, using at least one smart contract to escrow a plurality of digital currencies and tokens, and the lending host pays the seller host after detecting that the seller host delivers assets to the buyer host, and allows the intermediary host to arbitrate transactions. The mechanism is help to improve the transparency and authenticity of borrowing purpose.

Description

Multi-party lending and consumption system and method based on blockchain and smart contracts

The present invention relates to a loan consumption system and a method thereof, in particular to a multi-party loan consumption system and method based on blockchain and smart contracts.

In recent years, with the popularity and vigorous development of the Internet, various online lending platforms have sprung up. However, how to ensure that loan funds can be earmarked for specific purposes has always been one of the issues that manufacturers are eager to solve.

Generally speaking, traditional online lending refers to direct borrowing between individuals through online lending platforms. Compared with traditional financial institutions, it can significantly save labor costs and management fees, so it can attract users with low handling fees. . However, it is difficult for traditional online lending platforms to track or confirm the flow of loan funds, so they cannot effectively avoid situations where the purpose of the loan does not match the actual purpose. For example, the purpose of the loan is to purchase a computer, but the loan applicant actually obtains the funds. Later, they misappropriated the funds for other purposes, such as purchasing luxury goods, traveling, etc., or even providing the borrowed funds to others. Therefore, when there is no guarantee that the purpose of the loan is consistent with the actual purpose, for the lender, Problems with poor transparency and authenticity of lending purposes may not only affect the financial order, but also present many uncertain risks.

In view of this, some manufacturers have proposed real-time credit reporting technology, which actively detects the flow of funds and repayment sources in the account to determine whether there are any abnormalities after the loan is disbursed. However, this method requires authorization from the loan applicant in order to correctly obtain account information, and judging only based on the flow of funds and the source of repayment still cannot effectively ensure that the purpose of the loan is consistent with the actual purpose, so it still cannot effectively solve the problem of transparency and authenticity of the purpose of the loan. The problem of sexual inadequacy.

To sum up, it can be seen that the previous technology has long had problems with poor transparency and authenticity of lending purposes. Therefore, it is necessary to propose improved technical means to solve this problem.

The invention discloses a multi-party lending and consumption system and method based on blockchain and smart contracts.

First, the present invention discloses a multi-party lending and consumption system based on blockchain and smart contracts, which is applied to a blockchain network composed of multiple node hosts. This system includes: a buyer-side host, a lending-side host, and a seller-side host. and intermediary host. Among them, the buyer-side host serves as one of the node hosts. The buyer-side host is used to allow the debt token to be transferred to the smart contract for custody after the smart contract containing the loan information is successfully published on the blockchain network, and A first hash value is set in the smart contract, where the first hash value is generated by hash calculation of the first unlocking password; the intermediary host serves as one of the node hosts, and the intermediary host is used to allow direct triggering of the execution of the smart contract The delivery function and return function, and set the second hash value in the smart contract that has set the first hash value. The second hash value is generated by hash calculation of the second unlocking password; the seller-side host serves as the node host. One of them, the seller-side host will transfer the asset token to the smart contract for custody after the smart contract is successfully released; and the lending-side host serves as one of the node hosts, and the lending-side host will be used after the smart contract is successfully released. After release, the digital currency or payment token is sent to the smart contract for custody; among them, when the asset token and the digital currency or payment token are both hosted in the smart contract, within the timeout period, the buyer's host is allowed to The first unlocking password is sent to the delivery function of the smart contract or the intermediary host sends the second unlocking password to the delivery function of the smart contract. This delivery function receives the first unlocking password that matches the first hash value or matches the first hash value. When the second unlocking password of the hash value is used, the asset token is transferred to the buyer's host, the digital currency or payment token is transferred to the seller's host, and it is recorded in the loan message as the loan has been executed, or there is custody in the smart contract When the debt token is issued, the debt token is transferred to the lending host. When the execution of the delivery function is completed, the buyer's host calculates the repayment based on the loan information and the debt token held by the lending host, or either of the two. Amount to repay to the lending host.

Next, the present invention also discloses a multi-party lending and consumption system based on blockchain and smart contracts, which is applied to a blockchain network composed of multiple node hosts. This system includes: a buyer-side host, a lending-side host, and a seller-side Host and intermediary host. Among them, the buyer-side host serves as one of the node hosts. The buyer-side host is used to allow the first hash value to be set in the loan-lending relationship smart contract after the loan-lending relationship smart contract is published on the blockchain network. The first hash value is The value is generated by hash calculation of the first unlocking password; the lending host serves as one of the node hosts. The lending host is used to allow the payment relationship to be entered after the payment relationship smart contract is published on the blockchain network. The smart contract sets the first hash value, and transmits the digital currency or payment token to the payment relationship smart contract for custody; the seller-side host serves as one of the node hosts, and the seller-side host is used to publish the delivery relationship smart contract on After the blockchain network, the first hash value is allowed to be set in the delivery relationship smart contract, and the asset token is sent to the delivery relationship smart contract for custody; and the intermediary host serves as the node host. One of them, the intermediary host is used to set a second hash value in the loan relationship smart contract, the payment relationship smart contract or the delivery relationship smart contract that has set the first hash value. This second hash value is unlocked by the second The secret word is generated by hash calculation; among the buyer-side host, the lending-side host and the seller-side host, the two that are not the first to set the first hash value set the first hash value and the second hash value before they have been set. In the loan relationship smart contract, payment relationship smart contract or delivery relationship smart contract of the first hash value and the second hash value, when setting up, the loan relationship smart contract allows the custody of the debt token from the buyer's host, and the delivery relationship wisdom The contract also hosts the asset token from the seller's host, and the payment relationship smart contract also hosts the digital currency or payment token from the lending host; among them, when confirming the execution of the transaction, the buyer's host that first sets the first hash value , the seller-side host or the lending-side host sends the first unlocking secret word to the delivery relationship smart contract, the lending relationship smart contract or the payment relationship smart contract, or the intermediary-side host sends the second unlocking secret word to the delivery relationship smart contract, lending relationship smart contract The contract or the payment relationship smart contract enables the delivery relationship smart contract, the loan relationship smart contract or the payment relationship smart contract to be escrowd when it receives the first unlocking secret word matching the first hash value or the second unlocking secret word matching the second hash value. The asset token, debt token, digital currency or payment token is transmitted to the buyer-side host, lending-side host or seller-side host, and the first unlocking password or the second unlocking password received is disclosed; among them, on the buyer side Among the host, the lending host and the seller's host, the host that is not the first to set the first hash value is allowed to use the detected first unlocking password when detecting the first unlocking password or the second unlocking password. The secret word or the second unlocking secret word is transmitted to a delivery relationship smart contract, a lending relationship smart contract or a payment relationship smart contract that does not disclose the first unlocking secret word or the second unlocking secret word, so that it receives the first unlocking secret word matching the first hash value. Or when the second unlocking password of the second hash value is matched, the managed asset token, debt token, digital currency or payment token is transmitted to the buyer's host or the lending end. The host or the seller's host, and when the detected first unlocking password or the second unlocking password is transmitted to the lending relationship smart contract, allows the loan status of the lending relationship smart contract to be recorded as the loan has been executed.

In addition, the present invention discloses a multi-party lending and consumption method based on blockchain and smart contracts, which is applied to a blockchain network composed of multiple node hosts. The steps include: providing a buyer-side host as one of the node hosts. , the lending host, the seller host and the intermediary host. Among them, the intermediary host allows to directly trigger the delivery function and return function of the smart contract; after the smart contract containing the loan information is successfully published on the blockchain network , the buyer-side host transmits the debt token to the smart contract for custody, and sets the first hash value in the smart contract, where the first hash value is generated by the hash calculation of the first unlocking password, and the intermediary-side host has set The second hash value is set in the smart contract with the first hash value. This second hash value is generated by the hash calculation of the second unlocking password. The seller's host transmits the asset token to the smart contract with the second hash value set. Custody is performed, and the lending host transmits the digital currency or payment token to the smart contract that has set the second hash value for custody; when the debt token, asset token, and digital currency or payment token have all been escrowd in When entering a smart contract, within the timeout period, the buyer-side host is allowed to send the first unlocking secret word to the smart contract's delivery function or the intermediary-side host is allowed to send the second unlocking secret word to the smart contract's delivery function. This delivery function is When receiving the first unlocking password that matches the first hash value or the second unlocking password that matches the second hash value, transfer the asset token to the buyer-side host, transfer the digital currency or payment token to the seller-side host, and transfer The debt token is transferred to the lending host; and after the delivery function is executed, the buyer's host calculates the repayment amount based on the loan information and the debt token held by the lending host in order to repay the lending host .

In addition, the present invention also discloses a multi-party lending and consumption method based on blockchain and smart contracts, which is applied to a blockchain network composed of multiple node hosts. The steps include: providing a buyer-side host, a lending-side host, a seller The end host and the intermediary end host can be used as one of the node hosts respectively; buy The party-side host or the seller-side host publishes the delivery relationship smart contract on the blockchain network, the buyer-side host or the lending-side host publishes the lending relationship smart contract on the blockchain network, and the lending-side host or the seller-side host publishes the smart contract on the block chain. The chain network publishes the payment relationship smart contract; after the delivery relationship smart contract, the loan relationship smart contract and the payment relationship smart contract are all successfully released, the buyer-side host sets the first hash value in the loan relationship smart contract, or by borrowing The outgoing host sets the first hash value in the payment relationship smart contract, or the seller-side host sets the first hash value in the delivery relationship smart contract, where the first hash value is generated by hash calculation of the first unlocking secret word; intermediary The end host sets a second hash value in the loan relationship smart contract, payment relationship smart contract or delivery relationship smart contract that has set the first hash value, and the second hash value is generated by hash calculation of the second unlocking password; in Among the buyer-side host, the lending-side host, and the seller-side host, whichever is not the first to set the first hash value, sets the first hash value and the second hash value to the host that has not yet set the first hash value and the second hash value. Among the lending relationship smart contracts, payment relationship smart contracts or delivery relationship smart contracts, when setting up, the lending relationship smart contract allows the hosting of debt tokens from the buyer-side host, and the delivery relationship smart contract also hosts the debt tokens from the seller-side host. Asset tokens and payment relationship smart contracts also host digital currency or payment tokens from the lending host; when it is determined to execute the transaction, the buyer's host, the seller's host or the lending host that sets the first hash value at the earliest will The first unlocking password is sent to the delivery relationship smart contract, the lending relationship smart contract or the payment relationship smart contract, or the intermediary host sends the second unlocking password to the delivery relationship smart contract, lending relationship smart contract or payment relationship smart contract, so that the delivery relationship When a smart contract, lending relationship smart contract or payment relationship smart contract receives the first unlocking password that matches the first hash value or the second unlocking password that matches the second hash value, it will transfer the managed asset token, debt token, digital The currency or payment token is transmitted to the buyer-side host, the lending-side host or the seller-side host, and the first unlocking password or the second unlocking password received is disclosed; among the buyer-side host, the lending-side host and the seller-side host , not the earliest assumption The two that determine the first hash value allow the detected first unlocking password or the second unlocking password to be transmitted to the undisclosed first unlocking password or the undisclosed first unlocking password or the second unlocking password. The delivery relationship smart contract, loan relationship smart contract or payment relationship smart contract of the second unlocking secret word is such that when it receives the first unlocking secret word matching the first hash value or the second unlocking secret word matching the second hash value, it will be escrowd The asset token, debt token, digital currency or payment token is transmitted to the buyer-end host, lending-end host or seller-end host, and when the first unlocking password or the second unlocking password is detected, it is transmitted to the lending relationship intelligence When contracting, the loan status of the loan relationship smart contract is allowed to be recorded as the loan has been executed.

The system and method disclosed by the present invention are as above. The difference from the prior art is that the present invention provides the buyer-side host, the lending-side host, the seller-side host and the intermediary-side host in the blockchain network, where the buyer-side host and the seller The end host is in a delivery relationship, the buyer-end host and the lending-end host are in a lending relationship, and the lending-end host and the seller-end host are in a payment relationship. Then when the buyer-end host performs loan consumption, a smart contract is used to host the digital currency and tokens. And after detecting that the seller's host delivers assets to the buyer's host, the lending host pays the seller's host and allows the intermediary host to arbitrate the transaction.

Through the above technical means, the present invention can achieve the technical effect of improving the transparency and authenticity of lending purposes.

100,300: Blockchain network

110,310: Buyer-side host

120,320: Lending host

130,330: Seller-side host

140,340: Intermediary host

600: Setting window

611~613: Input block

621~623: Loan and consumption input block

630:Confirm component

Step 210: Provide a buyer-side host, a lending-side host, a seller-side host and an intermediary-side host respectively as one of the node hosts, wherein the intermediary-side host allows to directly trigger the execution of a delivery letter of the smart contract formula and a return function

Step 220: After a smart contract containing a loan message is successfully published on the blockchain network, the buyer-side host is allowed to transmit at least one debt token to the smart contract for custody, and the seller-side host is allowed to send at least one asset The token is sent to the smart contract for custody, and the lending host sends at least one digital currency or at least one payment token to the smart contract for custody

Step 230: When the debt token and the asset token, as well as the digital currency or the payment token are all hosted in the smart contract, allow the buyer-side host, the lending-side host, and the seller One of the end host and the intermediary end host triggers the execution of the delivery function of the smart contract, causing the smart contract to transfer the asset token to the buyer-end host, transfer the digital currency or the payment token to the seller's end host, and Record in the loan message that the loan has been executed, or when the smart contract has the debt token in custody, transfer the debt token to the lending host

Step 240: After the execution of the delivery function is completed, the buyer-side host calculates the repayment amount based on the loan information and the debt token held by the lender-side host, or both, in order to provide the loan to the lender. Host makes repayment

Step 250: When the delivery function is not executed after the timeout period, a return function is triggered by the smart contract, or triggered by the buyer-side host, the lending-side host, the seller-side host or the intermediary-side host Execute the return function to allow the buyer-side host to retrieve the debt tokens in custody, allow the seller-side host to retrieve the asset tokens in custody, and allow the lending-side host to retrieve all the custody tokens. The above-mentioned digital currency or the above-mentioned payment token

Step 410: Provide a buyer-side host, a lending-side host, a seller-side host and an intermediary-side host as one of the node hosts respectively.

Step 420: The buyer-side host or the seller-side host publishes a delivery relationship smart contract on the blockchain network, and the buyer-side host or the lending host publishes a lending relationship smart contract on the blockchain network, The lending host or the seller host publishes a payment relationship smart contract on the blockchain network

Step 430: After the delivery relationship smart contract, the loan relationship smart contract and the payment relationship smart contract are all successfully released, the buyer-side host sets a first hash value in the loan relationship smart contract, or the lending relationship smart contract The end host sets the first hash value in the payment relationship smart contract, or the seller-side host sets the first hash value in the delivery relationship smart contract. Determine the first hash value, wherein the first hash value is generated by hash calculation using a first unlocking password

Step 440: The intermediary host sets a second hash value in the loan relationship smart contract, the payment relationship smart contract or the delivery relationship smart contract that has set the first hash value. The second hash value is determined by a first hash value. Two unlocking passwords are generated by hash calculation.

Step 450: Among the buyer-side host, the lending-side host and the seller-side host, the two that are not the first to set the first hash value set the first hash value and the second hash value to a value that has not yet been set. The first hash value and the second hash value are in the lending relationship smart contract, the payment relationship smart contract or the delivery relationship smart contract, wherein, at the time of setting, the lending relationship smart contract allows hosting from the buyer-side host At least one debt token, the delivery relationship smart contract also hosts at least one asset token from the seller's host, and the payment relationship smart contract also hosts at least one digital currency or at least one payment token from the lender's host

Step 460: When it is determined to execute the transaction, the buyer-side host, the lending-side host or the seller-side host that first sets the first hash value transmits the first unlocking password to the delivery relationship smart contract and the lending relationship. The smart contract or the payment relationship smart contract, or the intermediary host sends the second unlocking password to the delivery relationship smart contract, the loan relationship smart contract or the payment relationship smart contract, so that the delivery relationship smart contract, the loan relationship When the smart contract or the payment relationship smart contract receives the first unlocking password that matches the first hash value or the second unlocking password that matches the second hash value, it will transfer the custody of the asset token and the claim to Tokens and digital goods Coin or at least one payment token is transmitted to the buyer-end host, the lending-end host or the seller-end host, and the received first unlocking password or the second unlocking password is disclosed

Step 470: Among the buyer-side host, the lending-side host and the seller-side host, the one that is not the first to set the first hash value detects the first unlocking password or the second unlocking that is disclosed. When the password is used, the detected first unlocking password or the second unlocking password is allowed to be transmitted to the delivery relationship smart contract, the lending relationship smart contract or the payment that does not disclose the first unlocking password or the second unlocking password. The relationship smart contract allows it to transfer the custody of the asset token and the debt token when it receives the first unlocking password that matches the first hash value or the second unlocking password that matches the second hash value. , the digital currency or the payment token is transmitted to the buyer-side host, the lending-side host or the seller-side host, and when the first unlocking password or the second unlocking password is detected, it is sent to the lending When entering into a smart contract, a loan status of the loan relationship smart contract is allowed to be recorded as the loan has been executed.

Step 480: Set a timeout time in the loan relationship smart contract, the payment relationship smart contract and the delivery relationship smart contract respectively. When the first unlock matching the first hash value is not received within the timeout time, When the password or the second unlocking password matches the second hash value, the seller-side host is allowed to retrieve the asset token in custody, the buyer-side host is allowed to retrieve the debt token in custody, and the lending is allowed. The end host retrieves the hosted digital currency or payment token

Figure 1 is a system block diagram of the first embodiment of the multi-party lending and consumption system based on blockchain and smart contracts of the present invention.

Figure 2 is a method flow chart of the first embodiment of the multi-party lending and consumption method based on blockchain and smart contracts according to the present invention.

Figure 3 is a system block diagram of the second embodiment of the multi-party lending and consumption system based on blockchain and smart contracts of the present invention.

Figures 4A and 4B are method flow charts of the second embodiment of the multi-party lending and consumption method based on blockchain and smart contracts according to the present invention.

Figure 5 is a schematic diagram of applying the present invention for loan consumption.

Figure 6 is a schematic diagram of setting up a smart contract using the present invention.

The embodiments of the present invention will be described in detail below with reference to the drawings and examples, so that the implementation process of how to apply technical means to solve technical problems and achieve technical effects of the present invention can be fully understood and implemented accordingly.

Before describing the multi-party lending and consumption system and method based on blockchain and smart contracts disclosed in the present invention, the terms defined by the present invention are first explained. The "smart contract" and "lending relationship smart contract" mentioned in the present invention ", "Delivery relationship smart contract" and "Payment relationship smart contract" all refer to smart contracts (Smart Contracts) published (Deploy) on the blockchain network. In fact, the smart contract refers to a computer program that drives the execution of instructions based on established conditions and transmitted information. Specifically, the smart contract is programmed through programming languages, such as: Solidity, Serpent, LLL, EtherScript, Sidechain, etc. It can include various functions, events, parameter states, etc. Taking the "Ethereum" environment as an example, its smart contract is compiled to obtain binary encoding and application binary Interface (Application Binary Interface,ABI), In order to broadcast the smart contract to the blockchain network, wait for the miner or validator to put the smart contract on the blockchain and obtain the corresponding address (or contract address). At this point, through the blockchain The transaction completes the release of the smart contract. After that, each node host can execute the corresponding smart contract based on this address, and use different instructions to change the status of the smart contract on the blockchain and detect whether the event is triggered. In addition, the "debt tokens", "payment tokens" and "asset tokens" mentioned above all refer to "Tokens" running on the blockchain network. In actual implementation, these tokens can be implemented through various standards, such as "ERC20", "ERC721", etc. In other words, they are built and run on the blockchain with smart contracts and can be transferred through blockchain transactions. of the pass.

The following diagrams are used to further explain the multi-party lending and consumption system and its method based on blockchain and smart contracts of the present invention. Please refer to "Figure 1" first. "Figure 1" shows the multi-party lending and consumption system and method based on blockchain and smart contracts of the present invention. The system block diagram of the first embodiment of the multi-party lending and consumption system is applied to a blockchain network 100 composed of multiple node hosts. This system includes: a buyer-side host 110, a lending-side host 120, a seller-side host 130 and an intermediary. End host 140. Among them, the buyer-side host 110 serves as one of the node hosts. The buyer-side host 110 is used to allow the debt token to be transferred to the smart contract for processing after the smart contract containing the loan information is successfully published on the blockchain network 100. Hosting. In actual implementation, the node hosts can be computer devices with network functions, such as personal computers, laptops, servers, etc., and are connected to each other through a peer-to-peer (Peer to Peer, P2P) method. To form a blockchain network 100. Therefore, the buyer-side host 110 is a computer device located at the buyer (also known as the lender), and the buyer establishes a lending relationship with the lender (also known as the lender) according to the amount that the buyer should pay for consumption. In addition, the smart contract can be established and published on the blockchain network 100 by any one of the buyer-side host 110, the lending-side host 120, the seller-side host 130, and the intermediary-side host 140. As for determining whether the smart contract is Successful release can be achieved by detecting whether the contract address of its smart contract exists. If it exists, it means that it has been successfully released, otherwise it means that it has not yet been successfully released.

The lending host 120 serves as one of the node hosts. After the smart contract is successfully released, the lending host 120 transmits the digital currency or payment token to the smart contract for custody. In fact, the lending host 120 is a computer device located on the lender's side and can deliver digital currency or tokens to the seller according to the amount of the lending relationship.

The seller-side host 130 serves as one of the node hosts. After the smart contract is successfully released, the seller-side host 130 transmits the asset token to the smart contract for custody. In fact, the seller-side host 130 is a computer device located at the seller, who will deliver the goods/services to be delivered to the buyer.

The intermediary host 140 serves as one of the node hosts. The intermediary host 140 is used to allow direct triggering of execution of the delivery function and return function of the smart contract. In other words, the intermediary host 140 is a computer device located at the intermediary. It serves as a supervisor to conduct arbitration when a transaction dispute occurs. If the arbitration result is "delivery required", the delivery function of the smart contract will be directly executed. Otherwise, the delivery function of the smart contract will be directly executed. , assuming the arbitration result is "cancel transaction", the return function of the smart contract will be executed directly.

As mentioned above, when the asset token and digital currency or payment token are all hosted in the smart contract, one of the buyer-side host 110, the lending-side host 120, the seller-side host 130 and the intermediary-side host 140 is allowed to trigger execution. The delivery function of the smart contract enables the smart contract to transfer the asset token to the buyer's host 110, transfer the digital currency or payment token to the seller's host 130, and record it in the loan message as the loan has been executed, or in the smart contract When there is an escrowd debt token in the contract, the debt token is transferred to the lending host 120. When the execution of the delivery function is completed, the buyer's host 110 The debt token held by the end host 120 or either of the two is used to calculate the repayment amount in order to repay the loan to the lending end host 120.

Please refer to "Figure 2". "Figure 2" is a method flow chart of the first embodiment of the multi-party loan consumption method based on blockchain and smart contracts of the present invention, which is applied to a blockchain composed of multiple node hosts. The steps of the network 100 include: providing a buyer-side host 110, a lending-side host 120, a seller-side host 130 and an intermediary-side host 140 respectively as one of the node hosts. The intermediary-side host 140 allows direct triggering of smart contract execution. The delivery function and return function (step 210); after the smart contract containing the loan information is successfully published on the blockchain network 100, the buyer-side host 110 is allowed to transmit the debt token to the smart contract for custody, and the seller-side The host 130 transmits the asset token to the smart contract for custody, and the lending host 120 transmits the digital currency or payment token to the smart contract for custody (step 220); when the debt token and asset token, and the digital When the currency or payment token has been hosted in the smart contract, one of the buyer-side host 110, the lending-side host 120, the seller-side host 130 and the intermediary-side host 140 is allowed to trigger the execution of the delivery function of the smart contract, so that the smart contract will The asset token is transferred to the buyer-side host 110, the digital currency or payment token is transferred to the seller-side host 130, and is recorded in the loan message as the loan has been executed, or when the smart contract has the debt token in custody, The debt token is transferred to the lending host 120 (step 230); and after the execution of the delivery function is completed, the buyer's host 110 calculates the repayment according to the loan information and the debt token held by the lending host 120 or both. The amount of the loan is determined in order to repay the loan to the lending host 120 (step 240). Through the above steps, the buyer-side host 110, the lending-side host 120, the seller-side host 130 and the intermediary-side host 140 can be provided on the blockchain network 100, where the buyer-side host 110 and the seller-side host 130 are in a delivery relationship. The buyer-side host 110 and the lending-side host 120 are in a lending relationship, and the lending-side host 120 and the seller-side host 130 are in a payment relationship. Then when the buyer-side host 110 performs loan consumption, the smart contract is used to host the digital currency and tokens, and Seller detected After the end host 130 delivers the assets to the buyer end host 110, the lending end host 120 pays the seller end host 130 and allows the intermediary end host 140 to arbitrate the transaction.

In addition, after step 240, when the delivery function is not executed after the timeout period, the smart contract triggers the execution of the return function, or the buyer-side host 110, the lending-side host 120, the seller-side host 130 or the intermediary-side host 140 Trigger the execution of this return function to allow the buyer-side host 110 to retrieve the custody of the debt token, allow the seller-side host 130 to retrieve the custody of the asset token, and allow the lending-side host 120 to retrieve the custody of digital currency or payment Token (step 250).

Next, please refer to "Figure 3". "Figure 3" is a system block diagram of the second embodiment of the multi-party lending and consumption system based on blockchain and smart contracts of the present invention, which is applied to a block composed of multiple node hosts. Link network 300, this system includes: buyer-side host 310, lending-side host 320, seller-side host 330 and intermediary-side host 340. Among them, the buyer-side host 310 serves as one of the node hosts. The buyer-side host 310 is used to allow the first hash value to be set in the loan-lending relationship smart contract after the loan-lending relationship smart contract is published on the blockchain network 300, where The first hash value is generated by performing hash calculation on the first unlocking password. For example, assuming that the first unlocking password is "abc", the first unlocking password can be hashed using a hash function (such as MD5, SHA1, SHA256, etc.) to generate the corresponding first hash value. In actual implementation, the lending relationship smart contract needs to record the used hash function, the lending host address, the amount to be borrowed, the seller's host address, etc., and the lending relationship smart contract can be controlled by the buyer's host 310 or the lending host. The outgoing host 320 is established and published on the blockchain network 300. In addition, in addition to the buyer's host 310 being able to set the first hash value, the lender's host 320 and the seller's host 330 can also be setting the first hash value, but the difference is that the lender's host 320 is paying the relationship smart contract. The first hash value is set in the delivery relationship smart contract, and the seller-side host 330 sets the first hash value in the delivery relationship smart contract. It should be noted in particular that when the buyer-side host 310, the lending-side host 320 and the seller-side host 330 One of the parties becomes the first party to set the first hash value in the smart contract, and after the intermediary host 340 also sets the second hash value in the same smart contract, the other two parties will not set the first hash value and the second hash value. The other two smart contracts follow the same settings. In other words, the first hash value and the second hash value in the three smart contracts will be the same. Further explanation will be given later by taking the buyer-side host 310, the lending-side host 320 and the seller-side host 330 as the first party to set the first hash value respectively as an example.

The lending host 320 serves as one of the node hosts. This lending host 320 is used to allow the payment relationship smart contract to set the first hash value in the payment relationship smart contract after it is published on the blockchain network 300, and convert the digital Currency or payment tokens are sent to the payment relationship smart contract for escrow. In actual implementation, the payment relationship smart contract includes the seller's host address and the amount to be paid, and the payment relationship smart contract can be established by the lending host 320 or the seller's host 330 and published on the blockchain network 300.

The seller-side host 330 serves as one of the node hosts. The seller-side host 330 is used to allow the first hash value to be set in the delivery relationship smart contract after the delivery relationship smart contract is published on the blockchain network 300, and to pass the assets through The certificate is sent to the delivery relationship smart contract for escrow. In actual implementation, the delivery relationship smart contract can be established and published on the blockchain network 300 by the buyer-side host 310 or the seller-side host 330. Assuming that the delivery relationship smart contract is established and published by the seller-side host 330, This delivery relationship smart contract may include the buyer's host address, the asset to be purchased and the amount to be paid. On the contrary, assuming that the delivery relationship smart contract is established and published by the buyer's host 310, the aforementioned delivery relationship smart contract includes The buyer-side host address needs to be changed to the seller-side host address. In other words, if the delivery relationship smart contract is established by the seller, the buyer needs to be specified in it; otherwise, if it is established by the buyer, the seller needs to be specified in it.

The intermediary host 340 serves as one of the node hosts. The intermediary host 340 is used to set the second hash value in the loan relationship smart contract, the payment relationship smart contract or the delivery relationship smart contract that has set the first hash value. The second hash value is generated by hash calculation of the second unlocking password. Assume that the second unlocking password is "123", then the hash function can be used to perform hash calculation on the second unlocking password to generate the corresponding second hash value, and the lending relationship smart contract will also record where the second hash value is passed. Generated by a hash function. In actual implementation, the intermediary host 340 can make the delivery relationship smart contract execute the delivery process and the payment relationship smart contract execute the payment process by providing the second unlocking password. In addition, when the loan relationship smart contract and the delivery relationship smart contract When the contract and the payment relationship smart contract each have a timeout time, for example: the loan relationship smart contract has a first timeout time, the delivery relationship smart contract has a second timeout time, and the payment relationship smart contract has a third timeout time, the intermediary The end host 340 may also not provide the second unlocking password when the buyer's host 310 does not provide the first unlocking password, so that the delivery relationship smart contract cannot receive the first unlocking password and the third unlocking password within the second timeout period. The second unlocking password causes the seller-side host 330 to retrieve the managed asset token, and the payment relationship smart contract cannot receive the first unlocking password and the second unlocking password within the third timeout period, causing the lending-side host 320 to Being able to retrieve custody of digital currency or payment tokens, even when debt tokens have been custody, makes the lending relationship smart contract unable to receive the first unlocking password and the second unlocking password within the first timeout period, causing the buyer to The end host 310 can retrieve the managed debt token from the lending relationship smart contract.

Based on the above, among the buyer-side host 310, the lending-side host 320 and the seller-side host 330, the two that are not the first to set the first hash value will start from the smart contract that has set the first hash value and the second hash value. Obtain the first hash value and the second hash value, and then set the first hash value and the second hash value obtained in the loan relationship smart contract and the payment relationship smart contract where the first hash value and the second hash value have not been set. In the contract or delivery relationship smart contract, when setting up, the lending relationship smart contract allows the custody of debt tokens from the buyer-side host 310, the delivery relationship smart contract also hosts the asset tokens from the seller-side host 330, and the payment relationship smart contract At the same time, the digital currency or payment token from the lending host 320 is hosted. Then, when it is determined to execute the transaction, the buyer-side host 310, the seller-side host 330, or the lending-side host 320 that sets the first hash value at the earliest sends the first unlocking password to the delivery relationship smart contract, the lending relationship smart contract, or the payment relationship. The smart contract, or the intermediary host 340 sends the second unlocking password to the delivery relationship smart contract, the lending relationship smart contract, or the payment relationship smart contract, so that the delivery relationship smart contract, the lending relationship smart contract, or the payment relationship smart contract receives the matching first When the first unlocking password of a hash value or the second unlocking password of the second hash value is matched, the managed asset token, debt token, digital currency or payment token is transmitted to the buyer-side host 310 and the lending-side host 320 Or the seller end host 330, and discloses the received first unlocking password or the second unlocking password. Next, among the buyer-side host 310, the lending-side host 320, and the seller-side host 330, the two that are not the first to set the first hash value detect the first unlocking password or the second unlocking password that is disclosed, Allows the detected first unlocking secret word or second unlocking secret word to be transmitted to a delivery relationship smart contract, lending relationship smart contract or payment relationship smart contract that does not disclose the first unlocking secret word or second unlocking secret word, so that it can receive a matching When the first unlocking password of the first hash value or the second unlocking password of the second hash value matches, the managed asset token, debt token, digital currency or payment token is transmitted to the buyer-end host 310 and the lending-end host 320 or the seller's host 330, and when the detected first unlocking password or the second unlocking password is transmitted to the lending relationship smart contract, the lending status of the lending relationship smart contract is allowed to be recorded as the loan has been executed or the creditor's rights pass will be managed. The certificate is sent to the lending host 320.

The following takes the buyer-side host 310, the lending-side host 320, and the seller-side host 330 as the first party to set the first hash value as an example to further illustrate the multiple parties (i.e., the buyer-side host 310, the lending-side host 320, and the seller-side host). The processing flow between 330 and intermediary 340):

First, for example, the buyer-side host 310 first sets the first hash value in the loan relationship smart contract. The intermediary-side host 340 will set the second hash value in the same smart contract. When the transaction is performed, the buyer-side host 310 will The first unlocking password is sent to the delivery relationship smart contract so that the first unlocking password can be hashed and compared with the first hash value in the delivery relationship smart contract. When the comparison matches, the first hash value will be disclosed in the delivery relationship smart contract. Once the password is unlocked, the managed asset token will be delivered at the same time. When the lending host 320 and the seller host 330 detect the first unlocking password disclosed by the delivery relationship smart contract, the lending host 320 will obtain the first unlocking password and submit it to the lending relationship smart contract for unlocking in order to obtain the loan. The debt token hosted by the relationship smart contract may record the loan status of the loan relationship smart contract as the loan has been executed; the seller's host 330 will obtain this first unlocking password and submit it to the payment relationship smart contract for unlocking, in order to obtain the payment relationship smart contract Custodial digital currency or payment token. The unlocking described here refers to unlocking the hash-locking (Hash-locking), allowing the smart contract to deliver/pay the assets, tokens or digital currencies in its custody to complete the transaction.

Next, for example, the lending host 320 first sets the first hash value in the payment relationship smart contract. The intermediary host 340 will set the second hash value in the payment relationship smart contract. When the transaction is performed, the lending host 340 sets the second hash value in the payment relationship smart contract. 320 will transmit the first unlocking password to the loan relationship smart contract in order to perform a hash operation on the first unlocking password to compare it with the first hash value in the loan relationship smart contract. When the comparison matches, it will be in the loan relationship smart contract. The contract discloses the first unlocking password, and at the same time obtains the debt certificate hosted by the lending relationship smart contract or records the lending status of the lending relationship smart contract as the loan has been executed. When the buyer-side host 310 and the seller-side host 330 detect the first unlocking password disclosed by the lending relationship smart contract At this time, the buyer-side host 310 will obtain the first unlocking password and submit it to the delivery relationship smart contract for unlocking in order to obtain the asset token hosted by the delivery relationship smart contract; the seller-side host 330 will obtain the first unlocking password and submit it to the payment Unlock the relationship smart contract in order to obtain the digital currency or payment token hosted by the payment relationship smart contract.

Finally, for example, the seller-side host 330 first sets the first hash value in the delivery relationship smart contract. The intermediary-side host 340 will set the second hash value in the delivery relationship smart contract. When the transaction is performed, the seller-side host 330 will Send the first unlocking password to the payment relationship smart contract so that the first unlocking password can be hashed and compared with the first hash value in the payment relationship smart contract. When the comparison matches, it will be made public in the payment relationship smart contract. Be the first to unlock the password and at the same time obtain the digital currency or payment token hosted by the smart contract of the payment relationship. When the lending host 320 and the buyer host 310 detect the first unlocking password disclosed by the payment relationship smart contract, the lending host 320 will obtain the first unlocking password and submit it to the lending relationship smart contract for unlocking in order to obtain the loan. The debt token hosted by the relationship smart contract may record the loan status of the loan relationship smart contract as the loan has been executed; the buyer's host 310 will obtain this first unlocking password and submit it to the delivery relationship smart contract for unlocking, in order to obtain the delivery relationship smart contract Custodial asset tokens.

Please refer to "Figure 4A" and "Figure 4B". "Figure 4A" and "Figure 4B" are method flow charts of the second embodiment of the multi-party lending and consumption method based on blockchain and smart contracts of the present invention. When applied to a blockchain network 300 composed of multiple node hosts, the steps include: providing a buyer-side host 310, a lending-side host 320, a seller-side host 330 and an intermediary-side host 340 as one of the node hosts respectively ( Step 410); The buyer-side host 310 or the seller-side host 330 publishes the delivery relationship smart contract on the blockchain network 300, and the buyer-side host 310 or the lending host 320 publishes the lending relationship smart contract on the blockchain network 300. The outgoing host 320 or the seller host 330 publishes the payment relationship on the blockchain network 300 Smart contract (step 420); after the delivery relationship smart contract, the lending relationship smart contract and the payment relationship smart contract are all successfully released, the buyer-side host 310 sets the first hash value in the lending relationship smart contract, or by lending The end host 320 sets the first hash value in the payment relationship smart contract, or the seller end host 330 sets the first hash value in the delivery relationship smart contract, where the first hash value is generated by hash calculation using the first unlocking password ( Step 430); The intermediary host 340 sets a second hash value in the loan relationship smart contract, payment relationship smart contract or delivery relationship smart contract that has set the first hash value, and the second hash value is determined by the second unlocking password. Generated by hash calculation (step 440); among the buyer-side host 310, the lending-side host 320, and the seller-side host 330, the one that is not the first to set the first hash value sets the first hash value and the second hash value. In the lending relationship smart contract, the payment relationship smart contract or the delivery relationship smart contract in which the first hash value and the second hash value have not been set, the lending relationship smart contract allows the custody of claims from the buyer-side host 310 when setting. Token, the smart contract of the delivery relationship also hosts the asset token from the seller's host 330, and the smart contract of the payment relationship also hosts the digital currency or payment token from the lending host 320 (step 450); when it is determined to execute the transaction, The buyer-side host 310, the seller-side host 330, or the lending-side host 320 that sets the first hash value at the earliest sends the first unlocking password to the delivery relationship smart contract, the lending relationship smart contract, or the payment relationship smart contract, or by the intermediary-side host 340 Send the second unlocking password to the delivery relationship smart contract, lending relationship smart contract or payment relationship smart contract, so that the delivery relationship smart contract, lending relationship smart contract or payment relationship smart contract receives the first unlocking password matching the first hash value or When the second unlocking password of the second hash value is matched, the managed asset token, debt token, digital currency or payment token is transmitted to the buyer-side host 310, the lending-side host 320 or the seller-side host 330, and is publicly received The first unlocking password or the second unlocking password is obtained (step 460); among the buyer-side host 310, the lending-side host 320, and the seller-side host 330, the two that are not the first to set the first hash value are detected. Revealed first unlocking secret word or second When unlocking the secret word, the detected first unlocking secret word or second unlocking secret word is allowed to be transmitted to the delivery relationship smart contract, lending relationship smart contract or payment relationship smart contract that does not disclose the first unlocking secret word or second unlocking secret word, so that it can When receiving the first unlocking password that matches the first hash value or the second unlocking password that matches the second hash value, transmit the managed asset token, debt token, digital currency or payment token to the buyer-end host 310, The lending host 320 or the seller host 330, and when the detected first unlocking password or the second unlocking password is transmitted to the lending relationship smart contract, is allowed to record the lending status of the lending relationship smart contract as the loan has been executed ( Step 470). Through the above steps, the buyer-side host 310, the lending-side host 320, the seller-side host 330 and the intermediary-side host 340 can be provided on the blockchain network 300, where the buyer-side host 310 and the seller-side host 330 are in a delivery relationship. The buyer-side host 310 and the lending-side host 320 are in a lending relationship, and the lending-side host 320 and the seller-side host 330 are in a payment relationship. Then when the buyer-side host 310 performs loan consumption, the smart contract is used to host the digital currency and tokens, and After detecting that the seller-side host 330 delivers assets to the buyer-side host 310, the lending-side host 320 pays the seller-side host 330 and allows the intermediary-side host 340 to arbitrate the transaction.

In addition, after step 470, if there is a timeout time set in the lending relationship smart contract, the payment relationship smart contract and the delivery relationship smart contract respectively, when the first hash value matching the first hash value is not received within the timeout time, When the unlocking password or the second unlocking password matches the second hash value, the seller-side host 330 is allowed to retrieve the managed asset token, the buyer-side host 310 is allowed to retrieve the managed debt token, and the lending-side host 320 is allowed to retrieve it. Escrow digital currency or payment token (step 480). In other words, when the matching unlocking password is not received after the timeout period, each smart contract will return the assets, tokens or digital currencies in its custody.

It should be noted that in actual implementation, various hosts described in the present invention can be implemented in various ways, including software, hardware or any combination thereof. For example, in some implementations, Each host can be implemented using software (such as virtual machines, containers, etc.) and hardware, or one of them. In addition, the present invention can also be implemented partially or completely based on hardware, for example, in the system One or more hosts can operate through integrated circuit chips, System on Chip (SoC), Complex Programmable Logic Device (CPLD), Field Programmable Gate Array (FPGA) ) and so on. The invention may be a system, method and/or computer program. The computer program may include a computer-readable storage medium having computer-readable program instructions for causing a processor to implement various aspects of the invention. The computer-readable storage medium may be a tangible device that can hold and store instructions for use by an instruction execution device. equipment. The computer-readable storage medium may be, but is not limited to, an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the above. More specific examples (non-exhaustive list) of computer-readable storage media include: hard disks, random access memory, read-only memory, flash memory, optical disks, floppy disks, and any suitable combination of the above. As used herein, computer-readable storage media is not to be construed as a reference to transient signals per se, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through waveguides or other transmission media (e.g., optical signals through fiber optic cables), or through electrical wires. transmitted electrical signals. In addition, the computer-readable program instructions described herein can be downloaded from a computer-readable storage medium to various computing/processing devices, or downloaded through a network, such as the Internet, a local area network, a wide area network and/or a wireless network to an external computer device or external storage device. Networks may include copper transmission cables, fiber optic transmission, wireless transmission, routers, firewalls, switches, hubs and/or gateways. A network card or network interface in each computing/processing device receives computer-readable program instructions from the network and forwards the computer-readable program instructions for storage on a computer-readable storage medium in each computing/processing device middle. The computer program instructions that perform the operations of the present invention may be combination language instructions, instruction set architecture instructions, machine instructions, machine-related instructions, micro-instructions, firmware instructions, or one or more Source code or object code written in any combination of programming languages, including object-oriented programming languages, such as: Common Lisp, Python, C++, Objective-C, Smalltalk, Delphi, Java, Swift, C# , Perl, Ruby and PHP, etc., as well as conventional procedural (Procedural) programming languages, such as: C language or similar programming languages. The computer program instructions may execute entirely on the computer, partly on the computer, as stand-alone software, partly on the client computer and partly on a remote computer, or entirely on the remote computer or server. execute on.

The following description is given in the form of an embodiment in conjunction with "Figure 5" and "Figure 6". Please refer to "Figure 5" first. "Figure 5" is a schematic diagram of applying the present invention for loan consumption. First, the buyer-side host 110 (may be referred to as the buyer), the intermediary-side host 140 (may be referred to as the intermediary), the seller-side host 130 (may be referred to as the seller), and the lending-side host 120 (may be referred to as the lender) can Considered as a four-party host. Among these four hosts, the buyer-side host 110 and the seller-side host 130 have a delivery relationship, that is, the seller delivers goods/services to the buyer; the buyer-side host 110 and the lending-side host 120 have a loan relationship, that is, the buyer Apply for a loan to the lender; the seller's host 130 and the lender's host 120 have a payment relationship, that is, the lender pays digital currency or payment tokens to the seller, while the intermediary host 140 is independent of the buyer's host 110. A supervisory role other than the seller's host 130 and the lending host 120 to decide whether to deliver or return when arbitration is required. In actual implementation, assuming that a single smart contract is used to implement the first embodiment, and debt tokens are used to record the creditor-debt relationship of loans, the overall loan consumption process is as follows:

1. At the beginning, any one of the four parties can create a smart contract, and specify the other three parties in the smart contract, including the assets to be purchased, the amount to be paid (ie: the amount to be borrowed), the overtime time, etc.

2. According to the instructions of the smart contract, the buyer will trust the debt certificate to the smart contract; the seller will trust the asset certificate to the smart contract; the lender will trust the digital currency or payment certificate to the smart contract.

3. If before the timeout period, the buyer, seller and lender have all custody the digital currency or token (such as debt token, asset token and payment token) corresponding to this transaction in the smart contract. Then, any one of the four parties can execute the delivery function of the smart contract, allowing the smart contract to transfer the digital currency or token it has custody to the corresponding object, for example: transfer the asset token to the buyer, transfer the digital currency or payment token The certificate is transferred to the seller, and the debt certificate is transferred to the lender.

In this way, the subsequent buyer can calculate the repayment amount based on the loan information in the smart contract and the debt certificate held by the lender in order to repay the lender. In particular, if the timeout period exceeds, it means that the transaction has not been completed. Therefore, the buyer is allowed to retrieve the custody of the debt token from the smart contract, the seller is allowed to retrieve the custody asset token from the smart contract, and the loan is allowed. The outgoing party retrieves the escrow digital currency or payment token from the smart contract. In addition, in addition to the above-mentioned use of debt tokens, the loan information in the smart contract can also be recorded as the loan has been executed.

Next, assuming that multiple smart contracts are used to implement the second embodiment, and the buyer is the earliest to set the first hash value, the overall loan consumption process is as follows:

1. The buyer establishes a delivery relationship smart contract, specifies the seller, the assets to be purchased, the amount to be paid, etc., and then publishes it to the blockchain network 100. In actual implementation, the delivery relationship smart contract can also be established by the seller and designate the buyer.

2. The buyer publishes a lending relationship smart contract based on the content of the delivery relationship smart contract, and specifies the lender, the desired loan amount, and the seller. In actual implementation, the lending relationship smart contract can also be established by the lender, and the originally designated lender needs to be changed to the designated buyer.

3. The lender issues a payment relationship smart contract based on the information of the delivery relationship smart contract and the lending relationship smart contract, and specifies the seller and the amount to be paid. The payment relationship smart contract can also be established by the seller, and the originally designated seller needs to be changed to the designated lender (that is, the actual payer).

4. When the above three smart contracts are established, the buyer sets the first hash value and the first timeout time for the lending relationship smart contract; the intermediary sets the second hash value for the lending relationship smart contract; the seller sets the delivery relationship smart contract The first hash value, the second hash value and the second overtime time; the lender sets the first hash value, the second hash value and the third overtime time for the payment relationship smart contract. Afterwards, if anyone provides the first unlocking secret word or the second unlocking secret word to the loan relationship smart contract, the loan relationship smart contract will be recorded as the loan has been executed, and at this time, the creditor's rights and debts are established. In particular, in order for the intermediary to act as a supervisor to avoid transaction disputes (such as disputes over off-chain delivery), it is necessary to set a second hash value corresponding to the second unlocking password in the lending relationship smart contract, as follows First, when a transaction dispute occurs and the buyer is unwilling to provide the first unlocking password, the intermediary can determine whether the transaction should be executed, and when the transaction should be executed, provide the second unlocking password to enforce the transaction.

5. The seller entrusts the asset token to be delivered to the delivery relationship smart contract, and sets the first hash value, the second hash value and the second timeout time in the delivery relationship smart contract; the lender The payment relationship smart contract hosts the digital currency or payment token to be paid, and at the same time sets the first hash value, the second hash value and the third timeout time in the payment relationship smart contract.

6. When confirming the execution of the transaction, the buyer sends the first unlocking password to the delivery relationship smart contract, or the intermediary sends the second unlocking password to the delivery relationship smart contract, so that the delivery relationship smart contract receives the payment within the second timeout period. to the first unlocking password that matches the first hash value or to match the second hash value When the value of the second unlocking password is determined, the asset token in custody is transferred to the buyer, and the received first unlocking password or the second unlocking password is disclosed.

7. When the seller and the lender detect the public first unlocking password or the second unlocking password in the delivery relationship smart contract, the seller will send the detected first unlocking password or second unlocking password to the payment relationship intelligence The contract enables the payment relationship smart contract to transmit the managed digital currency or payment token when it receives the first unlocking password that matches the first hash value or the second unlocking password that matches the second hash value within the third timeout period. to the seller, and the lender transmits the detected first unlocking password or the second unlocking password to the lending relationship smart contract to record the lending status of the lending relationship smart contract as the loan has been executed.

Similarly, subsequent buyers can determine whether they need to repay the lender based on the lending status in the lending relationship smart contract. It should be noted in particular that the delivery relationship smart contract does not receive the first unlocking password that matches the first hash value or the second hash value that matches the second timeout period. When the second password is unlocked, the seller is allowed to retrieve the escrow asset token, and the lender is allowed to retrieve the escrow digital currency or payment token. At this time, the buyer's debt is not established.

As shown in "Figure 6", "Figure 6" is a schematic diagram of setting up a smart contract using the present invention. As mentioned earlier, the smart contract is created and published by one of the buyer-side host 110, the intermediary-side host 140, the seller-side host 130, and the lending-side host 120. The loan message includes the buyer-side host 110, the seller-side host 130, the loan-side host 130, and the lending-side host 120. Among the outgoing host 120 and the intermediary host 140, there are the addresses of the three parties that created and issued this smart contract, as well as the assets to be purchased, the amount to be paid, and the timeout time. In actual implementation, the party that wants to establish a smart contract is the buyer-side host 110. It can open the setting window 600 and enter the specified seller-side host 130 and lending-side host 120 in the input blocks (611~613). and the address of the intermediary host 140. Then, enter the asset you want to purchase, the amount payable and the overtime time in the loan consumption input block (621~623). Finally, click the confirmation component 630 to create and publish the smart contract on the blockchain network. In addition, in the case of multiple smart contracts, the creation and release methods of each smart contract are also similar. The only difference lies in the specified content. For example: the buyer needs to specify the lender to create and release the smart contract, and the borrower needs to borrow money. quantity and seller; if it is created and published by the lender, the originally designated lender needs to be changed to the designated buyer. In addition, the smart contract created and issued by the lender needs to specify the seller and the amount to be paid. If it is created by the seller, the originally designated seller needs to be changed to the designated lender.

In summary, it can be seen that the difference between the present invention and the prior art is that the buyer-side host, the lending-side host, the seller-side host and the intermediary-side host are provided in the blockchain network, where the buyer-side host and the seller-side host are The delivery relationship, the buyer-side host and the lending-side host are in a lending relationship, and the lending-side host and the seller-side host are in a payment relationship. Then when the buyer-side host performs loan consumption, the smart contract is used to host the digital currency and tokens, and during the detection After detecting that the seller's host delivers assets to the buyer's host, the lending host pays the seller's host, and allows the intermediary host to arbitrate the transaction. This technical means can solve the problems existing in the previous technology, and then Achieve the technical effect of improving the transparency and authenticity of lending purposes.

Although the present invention has been disclosed in the foregoing embodiments, they are not intended to limit the present invention. Anyone skilled in the similar art can make some modifications and modifications without departing from the spirit and scope of the present invention. Therefore, the present invention is The scope of patent protection shall be determined by the scope of the patent application attached to this specification.

100:Blockchain network

110: Buyer-side host

120: Lending host

130: Seller-side host

140: Intermediary host

Claims (10)

A multi-party lending and consumption system based on blockchain and smart contracts, applied in a blockchain network composed of multiple node hosts. The system includes: a buyer-side host, as one of the node hosts, the buyer The end host is used to allow at least one debt token to be sent to the smart contract for custody after a smart contract containing a loan message is successfully published on the blockchain network, and set a first priority in the smart contract. A hash value, where the first hash value is generated by hash calculation of a first unlocking password; a lending host, as one of the node hosts, after the smart contract is successfully released, the lending host Transmit at least one digital currency or at least one payment token to the smart contract for custody; a seller-side host, as one of the node hosts, the seller-side host transfers at least one asset after the smart contract is successfully released The token is sent to the smart contract for custody; and an intermediary host, as one of the node hosts, is used to allow direct triggering of a delivery function and a return function of the smart contract, And a second hash value is set in the smart contract that has set the first hash value. The second hash value is generated by hash calculation using a second unlocking password; wherein, when the asset token and the When the digital currency or the payment token has been hosted in the smart contract, the buyer-side host is allowed to send the first unlocking password to the delivery function of the smart contract or the intermediary-side host within a timeout period. transmit the second unlocking password to the delivery function of the smart contract, the When the delivery function receives the first unlocking password matching the first hash value or the second unlocking password matching the second hash value, the delivery function transfers the asset token to the buyer's host, transfers the digital The currency or the payment token is transferred to the seller's host, and is recorded in the loan message as the loan has been executed, or when the smart contract has the debt token in custody, the debt token is transferred to the smart contract. For the lender host, after the execution of the delivery function is completed, the buyer host calculates the repayment amount based on the loan information and the debt token held by the lender host, or both, in order to provide the borrower with Outgoing host for repayment. For example, the multi-party lending and consumption system based on blockchain and smart contract of claim 1, wherein the smart contract is established by one of the buyer-side host, the lending-side host, the seller-side host and the intermediary-side host, and Published, the loan message includes the addresses of three of the buyer-side host, the seller-side host, the lending-side host and the intermediary host that are not responsible for creating and publishing the smart contract, as well as an asset to be purchased, an asset to be purchased, and an The amount payable and the overdue time. For example, in the multi-party lending and consumption system based on blockchain and smart contract in request item 2, the delivery function is not executed and within the timeout period, the buyer-side host is allowed to transmit the first unlocking password to the smart contract. The refund function may allow the intermediary host to transmit the second unlocking password to the refund function of the smart contract. The refund function may receive the first unlocking password matching the first hash value or match the third unlocking password. When the second unlocking password of the hash value is reached, the debt token in custody is returned to the buyer-side host, the asset token in custody is returned to the seller-side host, the digital currency or payment token in custody is returned returned to the lending host, and the When the delivery function is not executed and the timeout period exceeds, the buyer-side host, the seller-side host, the lending-side host and the intermediary-side host directly trigger the execution of the return function of the smart contract to allow the buyer to The end host retrieves the custody of the debt token, allows the seller-end host to retrieve the custody of the asset token, and allows the lending end host to retrieve the custody of the digital currency or the payment token. A multi-party lending and consumption system based on blockchain and smart contracts, applied in a blockchain network composed of multiple node hosts. The system includes: a buyer-side host, as one of the node hosts, the buyer The end host is used to allow a first hash value to be set in the loan relationship smart contract after a loan relationship smart contract is published on the blockchain network, wherein the first hash value is hashed by a first unlocking password Generated by calculation; a lending host, as one of the node hosts, the lending host is used to allow a payment relationship smart contract to be set after the payment relationship smart contract is published on the blockchain network The first hash value, and transmit at least one digital currency or at least one payment token to the payment relationship smart contract for custody; a seller-side host, as one of the node hosts, the seller-side host is used to After a delivery relationship smart contract is published on the blockchain network, it allows the first hash value to be set in the delivery relationship smart contract and transmits at least one asset token to the delivery relationship smart contract for custody; and an intermediary The end host, as one of the node hosts, the intermediary end host is used to set the first hash value in the loan relationship smart contract, the payment A second hash value is set in the relationship smart contract or the delivery relationship smart contract, and the second hash value is generated by a hash calculation using a second unlocking password; wherein, the buyer-side host, the lending-side host and the Among the seller's hosts, the two that are not the first to set the first hash value set the first hash value and the second hash value in the loan relationship intelligence where the first hash value and the second hash value have not been set. In the contract, the payment relationship smart contract or the delivery relationship smart contract, when setting up, the lending relationship smart contract allows hosting of at least one debt token from the buyer's host, and the delivery relationship smart contract also hosts the debt from the seller. At least one asset token from the end host, and the payment relationship smart contract also hosts at least one digital currency or at least one payment token from the lending end host; wherein, when determining to execute the transaction, the earliest hash value is set The buyer-side host, the seller-side host or the lending-side host sends the first unlocking password to the delivery relationship smart contract, the lending relationship smart contract or the payment relationship smart contract, or the intermediary-side host sends the first unlocking password to the delivery relationship smart contract, the lending relationship smart contract or the payment relationship smart contract. The second unlocking password is sent to the delivery relationship smart contract, the loan relationship smart contract or the payment relationship smart contract, so that the delivery relationship smart contract, the loan relationship smart contract or the payment relationship smart contract receives a matching first hash value. When the first unlocking password or the second unlocking password matching the second hash value, the escrowd asset token, the debt token, the digital currency or at least one payment token is transmitted to the buyer The end host, the lending end host, or the seller end host, and discloses the received first unlocking password or the second unlocking password; and Among the buyer-side host, the lending-side host and the seller-side host, the two that are not the first to set the first hash value will detect the first unlocking password or the second unlocking password that is disclosed. when the detected first unlocking password or the second unlocking password is allowed to be transmitted to the delivery relationship smart contract, the lending relationship smart contract or the payment relationship that does not disclose the first unlocking password or the second unlocking password The smart contract allows it to transfer the custody of the asset token, the debt token, The digital currency or the payment token is sent to the buyer-side host, the lender-side host or the seller-side host, and when the first unlocking password or the second unlocking password is detected, it is sent to the lending relationship When using a smart contract, a loan status of the loan relationship smart contract is allowed to be recorded as the loan has been executed. For example, the multi-party lending and consumption system based on blockchain and smart contracts in request item 4, wherein the lending relationship smart contract, the payment relationship smart contract and the delivery relationship smart contract further include a timeout time. If the timeout time is not reached, When the first unlocking password matching the first hash value or the second unlocking password matching the second hash value is received, the seller-side host is allowed to retrieve the managed asset token, and the buyer-side host is allowed to retrieve the asset token. Return the debt token in custody, and allow the lending host to retrieve the digital currency or payment token in custody. A multi-party lending and consumption method based on blockchain and smart contracts is applied to a blockchain network composed of multiple node hosts. The steps include: Provide a buyer-end host, a lending-end host, a seller-end host and an intermediary-end host respectively as one of the node hosts, wherein the intermediary-end host allows to directly trigger the execution of a delivery function of the smart contract and a return function; after a smart contract containing a loan message is successfully published on the blockchain network, the buyer-side host is allowed to transmit at least one debt token to the smart contract for custody, and in the smart contract A first hash value is set in the contract, where the first hash value is generated by a hash calculation of a first unlocking password, and the intermediary sets a second hash value in the smart contract that has set the first hash value. , the second hash value is generated by hash calculation of a second unlocking password, the seller-side host transmits at least one asset token to the smart contract that has set the second hash value for custody, and the lending The end host transmits at least one digital currency or at least one payment token to the smart contract that has set the second hash value for custody; when the asset token and the digital currency or the payment token have all been custody During the smart contract, within a timeout period, the buyer-side host is allowed to send the first unlocking secret word to the delivery function of the smart contract or the intermediary-side host is allowed to send the second unlocking secret word to the smart contract The delivery function, which transfers the asset token to the buyer when receiving the first unlocking password matching the first hash value or the second unlocking password matching the second hash value The end host, transfers the digital currency or the payment token to the seller end host, and records in the loan message that the loan has been executed, or in the existence of the smart contract When the debt token is in custody, the debt token is transferred to the lending host; and after the execution of the delivery function is completed, the buyer host holds the loan information based on the lending information and the lending host. The debt token or either of the two calculates the repayment amount in order to repay the loan host. For example, the multi-party lending and consumption method based on blockchain and smart contracts in request item 6, in which the lending information includes the buyer-side host, the seller-side host, the lending-side host and the intermediary-side host, is not created and published. The addresses of three of the smart contracts, as well as the asset to be purchased, the amount to be paid, and the timeout. For example, the multi-party loan consumption method based on blockchain and smart contract in request item 7, wherein the method further includes the following steps: the delivery function is not executed and within the timeout period, the buyer-side host is allowed to unlock the first The secret word is sent to the refund function of the smart contract or the intermediary host is allowed to send the second unlocking password to the refund function of the smart contract. The refund function receives the third hash value matching the first hash value. When the unlocking password or the second unlocking password matches the second hash value, the debt token in custody is returned to the buyer-side host, and the asset token in custody is returned to the seller-side host, and all the custody tokens are returned. The digital currency or payment token is returned to the lending host; and when the delivery function is not executed after the timeout period, the smart contract triggers the execution of the return function, or the buyer host or the intermediary The end host, the seller end host or the lending end host directly triggers the execution of the return function to allow The buyer-side host retrieves the custody of the debt token, allows the seller-side host to retrieve the custody of the asset token, and allows the lending-side host to retrieve the custody of the digital currency or the payment token . A multi-party lending and consumption method based on blockchain and smart contracts is applied to a blockchain network composed of multiple node hosts. The steps include: providing a buyer-side host, a lending-side host, and a seller-side host. and an intermediary host respectively serving as one of the node hosts; the buyer-side host or the seller-side host publishes a delivery relationship smart contract on the blockchain network, and the buyer-side host or the lending-side host publishes a delivery relationship smart contract on the blockchain network. The blockchain network publishes a loan relationship smart contract, and the lender host or the seller host publishes a payment relationship smart contract on the blockchain network; in the delivery relationship smart contract, the loan relationship smart contract and After the payment relationship smart contract is successfully released, the buyer's host sets a first hash value in the loan relationship smart contract, or the lender's host sets the first hash value in the payment relationship smart contract, Or the seller-side host sets the first hash value in the delivery relationship smart contract, where the first hash value is generated by hash calculation using a first unlocking password; the intermediary-end host sets the first hash value after setting the first hash value A second hash value is set in the lending relationship smart contract, the payment relationship smart contract or the delivery relationship smart contract, and the second hash value is generated by hash calculation using a second unlocking secret word; Among the buyer-side host, the lending-side host and the seller-side host, the two that are not the first to set the first hash value set the first hash value and the second hash value before the first hash value is set. The hash value and the second hash value are in the lending relationship smart contract, the payment relationship smart contract or the delivery relationship smart contract, wherein, when setting, the lending relationship smart contract allows hosting of at least A debt token, the delivery relationship smart contract also hosts at least one asset token from the seller's host, and the payment relationship smart contract also hosts at least one digital currency or at least one payment token from the lender's host; in When it is determined to execute the transaction, the buyer-side host, the lending-side host or the seller-side host that sets the first hash value at the earliest will send the first unlocking password to the delivery relationship smart contract, the lending relationship smart contract or the The payment relationship smart contract, or the intermediary host sends the second unlocking password to the delivery relationship smart contract, the loan relationship smart contract or the payment relationship smart contract, so that the delivery relationship smart contract, the loan relationship smart contract or the payment relationship smart contract When the payment relationship smart contract receives the first unlocking password that matches the first hash value or the second unlocking password that matches the second hash value, it will store the asset token, the debt token, and all the assets in custody. The digital currency or at least one payment token is transmitted to the buyer-side host, the lending-side host or the seller-side host, and the first unlocking password or the second unlocking password received is disclosed; and on the buyer-side host . Among the lending-side host and the seller-side host, the one that is not the first to set the first hash value is allowed to detect the first unlocking password or the second unlocking password that is disclosed. The first unlocking secret word or the The second unlocking secret word is sent to the delivery relationship smart contract, the lending relationship smart contract or the payment relationship smart contract that does not disclose the first unlocking secret word or the second unlocking secret word, so that when it receives the first hash value matching the When the first unlocking password or the second unlocking password matches the second hash value, the escrowd asset token, the debt token, the digital currency or the payment token is transmitted to the buyer. The host, the lending host or the seller host, and when the detected first unlocking password or the second unlocking password is transmitted to the lending relationship smart contract, a loan status of the lending relationship smart contract is allowed to be changed The loan is recorded as executed. For example, the multi-party lending and consumption method based on blockchain and smart contract in request item 9, wherein the method further includes setting a timeout time in the lending relationship smart contract, the payment relationship smart contract and the delivery relationship smart contract, when When the first unlocking password matching the first hash value or the second unlocking password matching the second hash value is not received within the timeout period, the seller-side host is allowed to retrieve the managed asset token. , allowing the buyer-side host to retrieve the custody of the debt token, and allowing the lending-side host to retrieve the custody of the digital currency or the payment token.

Images