JP6224283B1 - Escrow settlement method and system by smart contract - Google Patents

Abstract

In an escrow settlement at an EC site or the like, each work of a service provider is independent, and it cannot necessarily be said that the safety and reliability are high. Further, in the case of escrow settlement by smart contract, the purchaser needs to use virtual currency which is an asset on BC. A series of processes in escrow settlement is constructed and executed using a smart contract without using a virtual currency, thereby performing a transaction that ensures safety and reliability. [Selection] Figure 3

Description

  The present invention relates to an escrow settlement method and system using a smart contract. More specifically, the present invention relates to a method and a system capable of performing a transaction that ensures safety and reliability by constructing and executing a series of processes in escrow settlement using a smart contract.

  In escrow settlement, a third party mediates settlement between a seller and a buyer in order to ensure safety in commercial transactions. When performing escrow payments on the Internet, such as at EC malls, merchandise sellers register their products for sale via an EC site provided by a third party as a service provider. ("Purchaser") makes a payment procedure using a credit card or the like along with an application for product purchase. Upon confirming the payment from the purchaser (confirmation work), the service provider delivers the product to the purchaser (delivery work) and pays the seller (payment work).

  On the other hand, blockchain (hereinafter referred to as “BC”), which makes it difficult to tamper with transaction data by ensuring the reliability of transactions with a third party, has been increasingly used in commercial transactions due to its high security. ing. In particular, smart contracts that are attracting attention as an application technology of BC are programs that program a series of processes and automatically execute the series of processes without delay when a specific condition is satisfied (this program on BC) It is difficult to tamper with because it is published and managed).

  However, in the escrow settlement on the EC site, each work of the service provider is independent, and it cannot necessarily be said that the safety and reliability are high. For example, even if the purchaser deposits money, there are problems such as delays and forgetting for each work of the service provider, goods not reaching the purchaser, or payment to the seller not being made correctly. May occur. In addition, it cannot be said that the goods or charges are not stolen by the service provider.

  Therefore, there is a possibility that the safety and reliability of the transaction can be ensured by constructing a series of processes of escrow settlement using a smart contract. For example, the smart contract is configured to automatically execute the delivery process and the payment process with a purchaser's payment as a specific condition and satisfying this condition as a trigger. In this case, there is no room for a third party to intervene between the purchaser's payment and the delivery process and payment process.

  However, in the case of escrow settlement using such a smart contract, the purchaser needs to use virtual currency (for example, bitcoin) which is an asset on the BC. From the service provider's point of view, it is difficult to establish a service when there is no virtual currency exchange company. Furthermore, unless the virtual currency has the same value and guarantee as the real currency, after all, the payment is made in legal currency, and you have to use the virtual currency only to use the smart contract. It can be assumed that it will become.

  The present invention has been made in view of such problems, and its purpose is to ensure safety and reliability by constructing and executing a series of processes in escrow settlement using a smart contract. Is to make a deal. Furthermore, it is to realize the escrow settlement by such smart contract without using virtual currency, thereby reducing the labor of the purchaser.

In order to achieve such an object, the present invention is a computer in a system that executes escrow settlement by smart contract, wherein the computer is a first computer,
Receive payment instruction data for the item you wish to purchase from the second computer,
Based on at least the payment instruction data and the account data of the purchase requester of the desired purchase item, it is determined whether or not payment of the price to the seller of the desired purchase item is possible,
When it is determined that the payment can be made, the third computer storing the smart contract is notified that the payment is possible, and the smart contract is notified that the payment is possible. Is received, the third computer is caused to execute a settlement process for the desired product for purchase, and the settlement process includes at least instructions for a payment process and a delivery process for the desired product for purchase,
Receiving settlement data of the purchase desired product from the third computer;
The payment processing from the purchase applicant to the seller is executed based on the payment data.

  Further, in the first computer described in the preceding paragraph, receiving the payment data of the purchase desired product from the third computer as the payment processing instruction is an application program interface on the first computer. (API) is performed by being called from the smart contract.

  Furthermore, the first computer described in the preceding two paragraphs is further configured to notify the third computer of the execution result of the payment process, and if the execution result indicates that the execution result has failed, the smart contract is The third computer is not allowed to execute the delivery processing instruction.

Then, the first computer described in the preceding three paragraphs receives from the third computer an instruction to cancel the payment process transmitted when the delivery process fails.
It is further configured to execute a cancellation process of the payment process in response to receiving the cancellation instruction.

  In addition, the first computer described in the preceding four paragraphs is further configured to withdraw the price in advance from the purchaser's account data when it is determined that the price can be deposited. And

In another embodiment, the present invention is a method executed by a first computer in a system for executing escrow settlement by smart contract, wherein the method includes:
The first computer receiving payment instruction data for a desired product from the second computer;
The first computer determines whether or not payment of a price to the seller of the purchase desired product is possible based on at least the payment instruction data and the account data of the purchase requester of the purchase desired product. When,
When it is determined that the payment can be made, the first computer notifies the third computer in which the smart contract is stored that the payment is possible, and the smart contract Receives the notification that payment is possible, and causes the third computer to execute a settlement process for the purchase desired product, and the settlement process includes at least a payment process for the purchase desired product and Steps including instructions for delivery processing; and
The first computer receiving payment data of the desired product for purchase from the third computer;
The first computer includes the step of executing the payment processing from the purchase applicant to the seller based on the payment data.

Furthermore, in yet another embodiment, the present invention provides a computer program that is executed by a first computer in a system that executes escrow settlement using a smart contract, and the computer program is executed by the first computer.
Receiving payment instruction data of a purchase desired product from the second computer;
Determining whether payment to the seller of the purchase desired product is possible based on at least the payment instruction data and the account data of the purchase requester of the purchase desired product;
A step of notifying a third computer storing the smart contract that it is possible to deposit when it is determined that the payment can be made, and the smart contract can be deposited; Receiving the notification to the effect, causes the third computer to execute a settlement process for the desired purchase product, and the settlement process includes at least instructions for a payment process and a delivery process for the desired purchase product. Steps,
Receiving settlement data of the desired product for purchase from the third computer;
The first computer is caused to execute the step of executing the payment processing from the purchase applicant to the seller based on the payment data.

In another embodiment, the present invention is a computer in a system for executing escrow settlement by smart contract, wherein the computer is a first computer, the smart contract is stored, and the smart contract is stored in the smart contract. ,
The second computer receives a notification that payment of the price of the product desired for purchase to the seller is possible, and the second computer receives payment instruction data for the product desired for purchase from the third computer. In response to the receipt, it is determined whether or not payment of the price to the seller of the purchase desired product is possible based on at least the payment instruction data and the account data of the purchase requester of the purchase desired product. , We ’ll notify you if we ’ve determined that you can deposit the money,
Upon receipt of the notification that the deposit is possible, the settlement data of the purchase desired product is created,
In order to cause the second computer to execute a settlement process for the desired product for purchase, the generated settlement data is transmitted to the second computer, and the settlement process includes at least a payment process and delivery of the desired product for purchase. Including processing instructions,
Receiving the execution result of the settlement process from the second computer;
Determining whether the payment process was successful;
When it is determined that the payment process is successful, the delivery process is executed.

  As described above, according to the present invention, a series of processes in escrow settlement can be established and executed using a smart contract, thereby making it possible to conduct a transaction that ensures safety and reliability. Furthermore, the escrow settlement by such smart contract can be realized without using the virtual currency, and the labor of the purchaser can be reduced.

1 is a diagram illustrating an overall configuration of a system according to an embodiment of the present invention. It is a figure which shows the structure of the financial institution server of the system which concerns on one Embodiment of this invention. It is a flowchart which shows the escrow settlement process which concerns on one Embodiment of this invention. It is a figure which shows the product data managed on the smart contract which concerns on one Embodiment of this invention. It is a figure which shows the data stored in the payment instruction data storage part which concerns on one Embodiment of this invention. It is a figure which shows the data stored in the account data storage part which concerns on one Embodiment of this invention. It is a figure which shows the data stored in the payment possible notification data storage part which concerns on one Embodiment of this invention. It is a figure which shows the data stored in the payment data storage part which concerns on one Embodiment of this invention.

  Hereinafter, a system according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a diagram showing an overall configuration of a system according to an embodiment of the present invention. In FIG. 1, a financial institution server 100 managed by a financial institution is installed in a data center or the like. The EC site server 104 is a computer managed by an operating company that provides EC site services such as an EC mall (hereinafter referred to as “service provider”). The EC site server 104 is configured to communicate with a purchaser terminal 101 and a seller terminal 102 used by a purchaser and a seller who use the EC site, respectively, via a network 103 (for example, the Internet). Note that the EC site server 104 is not necessary in the case of an interpersonal transaction between a purchaser and a seller without using a service provider. The financial institution server 100 is also configured to communicate with the purchaser terminal 101 and the like via the network 103.

  The EC site server 104 is managed by a service provider and provides an EC site service. The EC site server 104 stores a smart contract 105 for performing escrow settlement. The smart contract 105 is a program that runs on a BC user terminal participating in a blockchain network (hereinafter referred to as “BC-NW”), and does not necessarily need to run on the EC site server 104 (in particular, (Individual transactions between buyers and sellers not via service providers, and EC sites where there are no service providers are also assumed). That is, the EC site server 104 is not an essential component in the present invention, and need not be a server computer. However, when providing a stable EC site service, it is better to use a server computer managed by the service provider. In the embodiment described in detail below, the smart contract 105 on the EC site server 104 is executed. It is described assuming that EC site service is provided.

  The purchaser terminal 101 and the seller terminal 102 are terminals used by the purchaser and seller who use the EC site, respectively, and participate in the BC-NW. Therefore, although not shown in FIG. 1, the smart contract 105 can be operated on the purchaser terminal 101 and the seller terminal 102. The seller registers an item for sale on the EC site provided by the EC site server 104 via the seller terminal 102. However, in another embodiment, the purchaser terminal 101 and / or the seller terminal 102 do not have to participate in the BC-NW (at least the data of the commodity registered for sale is linked on the smart contract 105. Just fine). The purchaser browses each product exhibited on the EC site via the purchaser terminal 101. When there is a product desired to be purchased, the purchaser instructs the financial institution server 100 to pay the desired product via the purchaser terminal 101.

  The financial institution server 100 is managed by a financial institution and does not participate in the BC-NW. When the financial institution server 100 receives a payment instruction for the desired product from the purchaser terminal 101, the financial institution server 100 checks the purchaser's account and determines whether or not payment to the seller is possible. When it is determined that payment is possible, the financial institution server 100 notifies the smart contract 105 to that effect, and causes payment processing (payment processing and delivery processing) to be executed. Payment processing (transfer of funds from the purchaser's account to the seller's account) in the settlement process is performed by the financial institution server 100. Therefore, the smart contract 105 calls an application program interface (API) for payment processing on the financial institution server 100, and the financial institution server 100 returns (notifies) the execution result to the smart contract 105 after executing the payment processing.

  Next, the configuration of the financial institution server 100 will be described in detail. FIG. 2 is a diagram showing a configuration of a financial institution server in the system according to the embodiment of the present invention. In FIG. 2, a single server computing system is assumed. However, in another embodiment, each processing unit is configured to be distributed to a plurality of server computers. It can also be configured. The financial institution server 100 includes a CPU 110, a RAM 111, an input device 112, an output device 113, a communication control device 114, and a storage device 116 that are connected to each other via a system bus 115. The storage device 116 is configured by a nonvolatile storage medium (ROM, HDD, or the like), and includes a program storage area that stores a software program and a data storage area that stores data handled by the software program. Each processing unit in the program storage area described later is actually an independent software program, its routine, component, and the like, and is stored in the storage device 116. Each processing unit is called from the storage device 116 by the CPU 110 at the time of execution and is expanded in the work area of the RAM 111, so that each function can be performed while appropriately accessing a database or the like.

  The software programs stored in the program storage area in the storage device 116 of FIG. 2 include a deposit acceptance / rejection determination processing unit 120 and a payment processing unit 121 if only those related to the present invention are listed. These processing units are executed by the CPU 110.

  The data storage areas in the storage device 116 in FIG. 2 are only those related to the present invention, and the payment instruction data storage unit 130, the account data storage unit 131, the depositable notification data storage unit 132, and the settlement data storage unit 133 are listed. Is provided. Both are fixed storage areas secured in the storage device 116.

  Next, the function of each processing unit stored in the storage device 116 in FIG. 2 will be described. 2 receives payment instruction data indicating a payment instruction for the desired product from the purchaser terminal 101, and stores it in the payment instruction data storage unit 130. Further, the deposit acceptance / rejection determination processing unit 120 searches the purchaser's account data stored in the account data storage unit 131 based on the received payment instruction data, and determines whether or not the purchaser can deposit to the seller. judge. When it is determined that the deposit is possible, the deposit acceptance / rejection determination processing unit 120 creates depositable notification data indicating that the deposit is possible and stores the depositable notification data in the depositable notification data storage unit 132. Further, the deposit acceptance / rejection determination processing unit 120 transmits the created deposit acceptance notification data to the smart contract 105. The smart contract 105 that has received the depositable notification data creates payment data and instructs the payment processing unit 121 of the financial institution server 100 to execute the payment processing (executes an API for payment processing on the financial institution server 100). ).

  The payment processing unit 121 in FIG. 2 receives payment data for instructing execution of payment processing from the smart contract 105 and stores it in the payment data storage unit 133. Further, the payment processing unit 121 executes fund transfer (payment processing) from the purchaser's account data stored in the account data storage unit 131 to the seller's account data based on the received payment data. Further, the payment processing unit 121 notifies the smart contract 105 of the execution result of the payment processing. The smart contract 105 that has received the execution result executes the delivery process when the payment process is successful.

  Next, data stored in each storage unit of the storage device 116 in FIG. 2 will be described. The payment instruction data storage unit 130 in FIG. 2 stores data relating to payment instructions for desired products for purchase. FIG. 5 is a diagram showing payment instruction data stored in the payment instruction data storage unit 130 according to an embodiment of the present invention.

  The payment instruction data in FIG. 5 includes a “product ID” that uniquely indicates a desired product to be purchased, a “purchaser address” that uniquely indicates a purchaser on the BC, and a “purchaser account” that uniquely indicates the purchaser's account. Etc. can be stored.

  The payment instruction data in FIG. 5 is transaction data created via the purchaser terminal 101 by the purchaser who has browsed the EC site. The “product ID” in FIG. 5 is the “product ID” in the product data (FIG. 4) on the smart contract 105 to be described later, whereby the payment instruction data and the product data can be associated with each other. In the example of FIG. 5, the “buyer account” is set to a value obtained by combining “financial institution code”, “branch code”, “account type”, and “account number” of account data (FIG. 6) described later. This uniquely identifies the buyer's account.

  The account data storage unit 131 in FIG. 2 stores contract customer account data in financial institutions. Contract customers in the present embodiment include service providers in addition to purchasers and sellers who use EC sites. This is because a fee may be paid to the service provider's account. FIG. 6 is a diagram showing account data stored in the account data storage unit 131 according to an embodiment of the present invention.

  The account data in FIG. 6 includes a “financial institution code” that uniquely indicates the financial institution that provides the contract account, a “financial institution name” that indicates the name, and a “branch code” that uniquely indicates the branch of the financial institution. "Branch name" indicating the name, "Account type" indicating the account type (subject) of the contract account, "Account number" indicating the account number of the contract account, "Account name" indicating the account name of the contract account, and The “deposit amount” indicating the current deposit amount of the contract account can be stored.

  The account data in FIG. 6 is master data registered by a financial institution when a contract customer opens an account. The contract account is uniquely identified by “financial institution code”, “branch code”, “account type”, and “account number”. In the “account type”, a numerical value indicating the account type (for example, 1: normal deposit, 2: current account,...) Can be set. Further, although the account data in FIG. 6 is described assuming a real account, in another embodiment, the present invention can be realized by a virtual account.

  The depositable notification data storage unit 132 in FIG. 2 stores data relating to purchase desired products that can be deposited from the purchaser to the seller. FIG. 7 is a diagram showing deposit-possible notification data stored in the deposit-possible notification data storage unit 132 according to an embodiment of the present invention.

  In the depositable notification data in FIG. 7, “product ID” that uniquely indicates a purchase desired product that can be deposited, “purchaser address” that uniquely indicates a purchaser on the BC, and the account of the purchaser that is uniquely “ A “buyer account”, a “merchant address” that uniquely identifies the merchant on the BC, a “merchant account” that uniquely identifies the merchant's account, and a “product price” that indicates the price and commission of the product desired to purchase “Fees” can be stored.

  7 is transaction data created by the financial institution server 100 when it is determined that payment to the seller is possible. The “product ID” in the product data (FIG. 4), which will be described later, can also be set in the “product ID” in FIG. 7, and the depositable notification data can be associated with the product data on the smart contract 105. “Purchaser account” and “Seller account” are the same as “Purchaser account” in the payment instruction data (FIG. 5). The “fee” is paid to the service provider when the service provider exists. For this reason, the determination of whether or not payment is possible when a fee to the service provider is generated determines whether or not the total amount of “product price” + “fee” is within the deposit amount of the “purchaser account”.

  The payment data storage unit 133 in FIG. 2 stores data relating to payment of a purchase desired product determined to be depositable. FIG. 8 is a diagram showing payment data stored in the payment data storage unit 133 according to an embodiment of the present invention.

  The payment data in FIG. 8 includes a “product ID” that uniquely indicates a purchase desired product to be settled, a “purchaser account” that uniquely indicates an account of the purchaser, the seller, and the service provider, and a “seller account”. ”,“ Provider account ”, and“ product price ”and“ fee ”indicating the price and fee of the product to be settled, respectively, can be stored.

  The settlement data in FIG. 8 is transaction data created by the smart contract 105 when receiving a payment available notification for the desired product for purchase. The “purchaser account”, “seller account”, and “provider account” are the same as the “purchaser account” in the payment instruction data (FIG. 5). Through the payment process based on the settlement data, the total amount of “product price” + “fee” is withdrawn from the buyer account, the “product price” amount is “seller account” and the “fee” amount is “provider account” ”To each.

  Next, product data linked on the smart contract 105 will be described. The merchandise data is data relating to merchandise registered for sale by the seller on the EC site. FIG. 4 is a diagram showing product data on the smart contract according to an embodiment of the present invention.

  The product data in FIG. 4 includes a “product ID” that uniquely indicates a product registered for exhibition, a “product name” that indicates the name of the product, a “seller address” that uniquely indicates the seller who has exhibited on the BC, It is possible to store a “product price” indicating the price of the sold product and a “merchant account” uniquely indicating the seller's account.

  The product data in FIG. 4 is master data created in the smart contract 105 every time a seller registers an item for sale via the seller terminal 102. The “merchant account” in FIG. 4 is the same as the “purchaser account” in the payment instruction data (FIG. 5). By storing the “merchant account” and the “merchant address” in association with each other, the merchant on the BC and the account in the financial institution can be linked. However, the “contractor account” is not linked on the smart contract 105, and mapping data (not shown) between the “seller account” and the “seller address” can be stored on the financial institution server 100. . In this case, the “merchant account” is not included in the product data in FIG.

  Next, an escrow settlement process according to an embodiment of the present invention will be described along the flow with reference to the flowchart of FIG. 3 and the data of FIGS. 4-8. FIG. 3 is a flowchart showing an escrow settlement process according to an embodiment of the present invention. In this process, the seller registers the product for sale on the EC site, the purchase applicant who wishes to purchase the exhibited product instructs the financial institution to make a payment, and determines whether the seller can receive the payment. Thereafter, settlement processing (payment processing and delivery processing) is performed by the smart contract.

  First, the seller registers the product data (FIG. 4) of the product to be displayed on the EC site via the seller terminal 102, and the smart contract 105 receives the product data (step S300). The seller terminal 102 participates in the BC-NW, and the exchange between the seller terminal 102 and the smart contract 105 is performed on the BC-NW. However, in another embodiment, the seller terminal 102 does not have to participate in the BC-NW (even in this case, for example, the data of the commodity registered for exhibition via the EC site server 104). Are linked on the smart contract 105). The merchandise data can include not only the data of the merchandise to be registered for sale, but also the merchant address indicating the merchant on the BC and the account data of the merchant to which the price of the merchandise is deposited. Thereby, the seller on BC and the account in a financial institution can be linked | related. Note that the product data in FIG. 4 indicates a product group registered by various sellers. Therefore, the product data received in step S300 is at least merchant data.

  Next, the purchaser accesses the EC site via the purchaser terminal 101 and browses the group of products registered for exhibition. When a product desired to be purchased is found, the purchaser instructs the financial institution to pay the purchase desired product via the purchaser terminal 101. Thereafter, the deposit acceptance / rejection determination processing unit 120 of the financial institution server 100 receives the payment instruction data (FIG. 5) (step S301) and stores it in the payment instruction data storage unit 130 (step S302). The exchange between the purchaser terminal 101 and the deposit acceptance / rejection determination processing unit 120 is performed via the EC site displayed on the output device (screen) of the purchaser terminal 101 using the payment instruction data as a parameter or argument as a deposit acceptance / rejection determination processing unit 120. Is done by passing to In another embodiment, payment instruction data may be transmitted to the deposit acceptance / rejection determination processing unit 120 via the smart contract 105. In this case, the smart contract 105 transmits the product data (FIG. 4) together with the received payment instruction data to the depositing permission / inhibition determination processing unit 120, so that the product data in step S303 to be described later can be acquired simultaneously with step S301. it can.

  Upon receipt of the payment instruction data (FIG. 5), the deposit acceptance / rejection determination processing unit 120 acquires the product data (FIG. 4) on the smart contract 105 using the “product ID” in the payment instruction data as a search key (step S303). .

  Next, the deposit acceptance / rejection determination processing unit 120, based on the payment instruction data received in step S301 (FIG. 5) and the merchandise data acquired in step S303 (FIG. 4), purchaser account data (FIG. 6). To determine whether or not payment to the seller is possible (step S304). Specifically, using the “purchaser account” in the payment instruction data (FIG. 5) as a search key, the account data (FIG. 6) stored in the account data storage unit 131 is searched, and the “deposit amount” of the purchaser account is searched. To get. The acquired deposit amount is compared with the “product price” in the product data (FIG. 4). If the deposit amount is equal to or greater than the product price, it is determined that the deposit is possible. At this time, if it is necessary to consider various fees (for example, fees for service providers and financial institutions), it is determined whether or not the deposit amount is equal to or higher than the product price + the fee.

  If it is determined in step S304 that payment is not possible, the process proceeds to a No route in step S305, and the payment availability determination processing unit 120 notifies the purchaser that payment is not possible (step S308). Specifically, for example, notification on the EC site, e-mail notification to an address designated by the purchaser, and the like can be considered. After step S308, this process ends.

  On the other hand, if it is determined in step S304 that depositing is possible, the process proceeds to a Yes route in step S305, and the depositing possibility determination processing unit 120 creates depositable notification data (FIG. 7) for notifying the smart contract 105. And stored in the depositable notification data storage unit 132 (step S306). If payment is possible, the price of the product (including the fee) can be withdrawn from the deposit amount in the purchaser account in advance, and the price can be secured at the financial institution. This is to prevent the withdrawal by another transaction from the time when it is determined that the deposit is possible until the payment process is performed, and the deposit is impossible.

  Next, the deposit acceptance / rejection determination processing unit 120 notifies the smart contract 105 that the deposit is possible by transmitting the deposit enable notification data (FIG. 7) created in step S306 (step S307). The payment available notification data includes the price of the product determined to be available for payment and the account data of the purchaser and seller.

  When the smart contract 105 receives the depositable notification data (step S309), the smart contract 105 creates settlement data (FIG. 8) for executing the payment process based on the depositable notification data (step S310). The payment data includes service provider account data in the case of paying the service provider in addition to the price of the product to be processed for payment and the account data of the purchaser and seller.

  Next, the smart contract 105 instructs the payment processing unit 121 to execute the payment process by transmitting the payment data (FIG. 8) created in step S310 (step S311). Specifically, for example, the smart contract 105 calls an API for payment processing on the financial institution server 100.

  Next, the payment processing unit 121 receives the payment data (step S312) and stores it in the payment data storage unit 133 (step S313).

  Next, the payment processing unit 121 executes payment processing on the account data (FIG. 6) stored in the account data storage unit 131 based on the received settlement data (FIG. 8) (step S314). Specifically, the total amount of “product price” + “fee” in the payment data is deducted from the “deposit amount” in the account data linked to the “buyer account” in the payment data, and the amount of “product price” is The amounts of “merchant account” and “fee” are credited to the “provider account”, respectively. When the purchaser account, the seller account, or the provider account is related to a different financial institution, funds are transferred between the accounts of different financial institutions via Densai Net or the like. In addition, as described in the explanation of step S306, when the product price (including the fee) is previously withdrawn from the deposit amount of the purchaser account, the withdrawal is not performed again in this step.

  Next, the payment processing unit 121 notifies the execution result of the payment processing to the smart contract 105 (step S315). Specifically, the execution result is returned to the smart contract 105 as the return value of the API called in step S311.

  When the smart contract 105 receives the execution result (step S316), the smart contract 105 determines whether the payment process is successful based on the received execution result (step S317). If it is determined that the payment process has failed, the process proceeds to the No route in step S318, and the smart contract 105 executes an error process (step S321). The error processing here is, for example, error notification to an administrator terminal (not shown). After step S321, this process ends.

  On the other hand, if it is determined that the payment process is successful, the process proceeds to a Yes route in step S318, and the smart contract 105 executes a delivery process (step S319). The delivery process is, for example, an instruction for shipping products to the shipping company. When the delivery process fails, the process proceeds to the No route in step S320, and the smart contract 105 executes an error process (step S321). The error processing here is an instruction to cancel the payment processing to the payment processing unit 121 in addition to the error notification to the administrator terminal. When the payment processing unit 121 receives the cancellation instruction, as a cancellation process of the payment process, for example, the price is withdrawn from the seller's account, and the financial institution holds the price. As a result, the delivery process can be retried, and after the delivery process is successful, payment can be made again to the seller's account. In another embodiment, the delivery process can be executed before the payment process, and the payment process can be executed when the delivery process is successful.

  If the delivery process in step S319 is successful, the process proceeds to the Yes route in step S320, and the process ends. At this time, the smart contract 105 can also notify the purchaser that the product has been shipped (for example, notification on the EC site or email notification to the buyer-specified address).

  As described above, according to the present invention, it is possible to perform a transaction that ensures safety and reliability by constructing and executing a series of processes in escrow settlement using a smart contract. Furthermore, the escrow settlement by such smart contract can be realized without using the virtual currency, and the labor of the purchaser can be reduced.

Claims (8)

A computer in a system for executing an escrow settlement by smart contract, wherein the computer is a first computer,
Receive payment instruction data for the item you wish to purchase from the second computer,
Based on at least the payment instruction data and the account data of the purchase requester of the desired purchase item, it is determined whether or not payment of the price to the seller of the desired purchase item is possible,
When it is determined that the payment can be made, the third computer storing the smart contract is notified that the payment is possible, and the smart contract is notified that the payment is possible. Is received, the third computer is caused to execute a settlement process for the desired product for purchase, and the settlement process includes at least instructions for a payment process and a delivery process for the desired product for purchase,
Receiving settlement data of the purchase desired product from the third computer;
A computer configured to execute the payment processing from the purchase applicant to the seller based on the payment data.   As the payment processing instruction, receiving the settlement data of the purchase desired product from the third computer is performed by calling an application program interface (API) on the first computer from the smart contract. The computer according to claim 1, wherein the computer is a computer.   The smart contract is further configured to notify the third computer of the execution result of the payment process, and the smart contract executes the delivery process instruction to the third computer when the execution result indicates failure. The computer according to claim 1, wherein the computer is not allowed to be executed. Receiving from the third computer an instruction to cancel the payment process transmitted when the delivery process fails;
4. The computer according to claim 1, further configured to execute a cancellation process of the payment process in response to receiving the cancellation instruction. 5.   5. The computer according to claim 1, further configured to deduct the price in advance from the account data of the purchase applicant when it is determined that the price can be deposited. . A method performed by a first computer in a system for performing escrow settlement by smart contract, the method comprising:
The first computer receiving payment instruction data for a desired product from the second computer;
The first computer determines whether or not payment of a price to the seller of the purchase desired product is possible based on at least the payment instruction data and the account data of the purchase requester of the purchase desired product. When,
When it is determined that the payment can be made, the first computer notifies the third computer in which the smart contract is stored that the payment is possible, and the smart contract Receives the notification that payment is possible, and causes the third computer to execute a settlement process for the purchase desired product, and the settlement process includes at least a payment process for the purchase desired product and Steps including instructions for delivery processing; and
The first computer receiving payment data of the desired product for purchase from the third computer;
The first computer comprises the step of executing the payment process from the purchase requester to the seller based on the payment data. A computer program to be executed by a first computer in a system for executing escrow settlement by smart contract, wherein the computer program is executed by the first computer,
Receiving payment instruction data of a purchase desired product from the second computer;
Determining whether payment to the seller of the purchase desired product is possible based on at least the payment instruction data and the account data of the purchase requester of the purchase desired product;
A step of notifying a third computer storing the smart contract that it is possible to deposit when it is determined that the payment can be made, and the smart contract can be deposited; Receiving the notification to the effect, causes the third computer to execute a settlement process for the desired purchase product, and the settlement process includes at least instructions for a payment process and a delivery process for the desired purchase product. Steps,
Receiving settlement data of the desired product for purchase from the third computer;
A computer program for causing the first computer to execute the step of executing the payment process from the purchase applicant to the seller based on the payment data. A computer in a system for executing an escrow settlement by smart contract, wherein the computer is a first computer, the smart contract is stored in the smart contract,
The second computer receives a notification that payment of the price of the product desired for purchase to the seller is possible, and the second computer receives payment instruction data for the product desired for purchase from the third computer. In response to the receipt, it is determined whether or not payment of the price to the seller of the purchase desired product is possible based on at least the payment instruction data and the account data of the purchase requester of the purchase desired product. , We ’ll notify you if we ’ve determined that you can deposit the money,
Upon receipt of the notification that the deposit is possible, the settlement data of the purchase desired product is created,
In order to cause the second computer to execute a settlement process for the desired product for purchase, the generated settlement data is transmitted to the second computer, and the settlement process includes at least a payment process and delivery of the desired product for purchase. Including processing instructions,
Receiving the execution result of the settlement process from the second computer;
Determining whether the payment process was successful;
A computer configured to execute the delivery process when it is determined that the payment process is successful.