JP2002150195A - Electronic payment system, electronic payment method - Google Patents

Abstract

(57) [Summary] [Problem] To perform payment settlement securely and securely on a network without using a credit card. A user downloads a dedicated encryption program from a payment server to a user terminal. When a purchase order for a product is made in the seller server 12, the product name, the purchase price, and the like are input to the encryption program to generate an encryption code. The generated encryption code is transmitted from the user terminal 14 to the settlement server 10 and the seller server 12.
Send to each. The seller server 12 transfers the transmitted encryption code to the settlement server 10. Only when the encryption code from the user terminal 14 and the encryption code from the seller server 12 match, the settlement server 10 performs a process of withdrawing the money from the buyer's account and depositing the money into the seller's account. .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a system and a method for performing payment for a sales transaction on a network.

[0002]

2. Description of the Related Art In recent years, a number of merchandise sales sites such as so-called electronic stores and electronic malls have been constructed on the Internet, and it is common to purchase goods on the Internet. In addition, many auction sites are being found on the Internet, and interpersonal trading on the Internet is becoming widespread. When merchandise transactions are performed on such an online store site or an auction site, payment methods generally include a payment method using a credit card for payment through a bank transfer and a payment method using cash on delivery.

[0003]

However, in settlement by credit card, the purchaser must enter a credit card number and personal information, and many people are concerned about security. On the other hand, the settlement by bank transfer requires a transfer to the bank every time the purchase is made, which is complicated, and also requires a transfer fee. Furthermore, settlement by cash on delivery of goods often requires payment of a premium to a delivery company, which is costly.

SUMMARY OF THE INVENTION [0004] The present invention has been made to solve the above-mentioned problems associated with the conventional settlement method, and aims to securely and securely perform payment on a network without using a credit card. It is an object of the present invention to provide an electronic payment system and an electronic payment method that can perform the following.

[0005]

In order to achieve the above object, an invention set forth in claim 1 is an electronic payment system for performing payment for a sales transaction performed on a network, The following means (1) to (6) are provided. (1) Database means in which a user ID, an encryption / decryption key, and an account ID of a payment account are recorded for each user. (2) First receiving means for receiving, from a user terminal of a user who is a purchaser involved in the sales transaction, a first encrypted code and a user ID of the user. The first encryption code is obtained by encrypting sales data including a purchase price related to the sales transaction with an encryption key corresponding to the encryption / decryption key of the user.

(3) Second receiving means for receiving a second encrypted code from a computer of a seller involved in the sales transaction. (4) decryption means for decrypting the received first encrypted code using a decryption key recorded in the database in association with the user ID received together with the first encrypted code. (5) determining means for determining whether or not the received first encrypted code has a predetermined correspondence with the received second encrypted code. (6) Only when the received first encryption code and the received second encryption code have the predetermined correspondence, the purchase price included in the data decrypted by the decryption means is reduced. The corresponding amount is associated with the received user ID, and the account I recorded in the database.
Execution means for executing a settlement process for debiting the account specified in D.

According to a second aspect of the present invention, in the electronic settlement system according to the first aspect, the second receiving means transmits the sales transaction together with the second encrypted code from the seller's computer. And a second determining unit for determining whether the purchase price included in the data decrypted by the decryption unit matches the received sales price, and further comprising the execution unit Is
Only when it is determined that the received first encryption code and the received second encryption code have the predetermined correspondence and the purchase price and the sale price match, the The payment processing is performed.

According to a third aspect of the present invention, in the electronic settlement system according to the first or second aspect, the sales data further includes a product related to the sales transaction and a sales transaction date, and Means for recording the purchase data including the product, the sales transaction date, and the purchase price included in the decrypted trade data in the database in association with the received user ID, and in response to a request from the user accessing from the user terminal. Accordingly, the apparatus further comprises means for reading out the purchase data recorded in association with the user ID of the user from the database and transmitting the purchase data to the user terminal.

Further, according to the invention described in claim 4, the settlement of the price for the sales transaction performed on the network is performed by:
An electronic payment method performed using an electronic payment system including a server computer connected to the network, wherein a database included in the electronic payment system includes:
For each user, a user ID, an encryption / decryption key, and an account ID of an account for payment are recorded, and at a user terminal of a user who is a purchaser involved in the sales transaction, a transaction including a purchase price related to the sales transaction is performed. The data is encrypted with an encryption key corresponding to the decryption key of the user to generate a first encryption code, and the generated first encryption code is transmitted to the settlement server together with the user ID of the user. And transmitting a second encryption code having a predetermined correspondence relationship with the first encryption code to a computer of a seller involved in the sales transaction, and transmitting the second encryption code from the user terminal at the computer of the seller. The second encrypted code transmitted to the electronic payment system, and the second encrypted code transmitted from the user terminal is transmitted to the electronic payment system. Is decrypted using an encryption / decryption key recorded in the database in association with the user ID received together with the first encryption code, and the first encryption code transmitted from the user terminal. It is determined whether the encrypted code and the second encrypted code transmitted from the seller's computer have the predetermined correspondence relationship, and the first encrypted code and the second encrypted code are determined. When the code has the predetermined correspondence,
Executing a process for withdrawing the amount corresponding to the purchase price included in the data decrypted by the decryption means from the account specified by the account ID recorded in the database in association with the user ID. And

The invention described in claim 5 relates to an electronic settlement system used in the electronic settlement method according to claim 4.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an overall configuration diagram of a network showing an embodiment of the present invention. As shown in FIG. 1, in the present embodiment, a settlement server 10, a seller server 12,
And a user terminal (for example, a personal computer or a portable information processing terminal such as a mobile phone or a PDA) 1
4 are interconnected via the Internet 16. In addition, the settlement server 10 has a settlement bank (a contract with the operating company of the settlement server 10) indicating that a settlement process such as opening an account, debiting an account, and performing a debit transfer should be performed in accordance with an instruction from the settlement server 10. A host computer 18 for managing an account of the financial institution (concluded financial institution) is connected via a dedicated line 19. When the operating company of the settlement server 10 is a financial institution, the operating company itself can be a settlement bank.

Payment server 10 and seller server 1
2 are both mass storage devices (for example, hard disks)
And a computer interface having a communication interface and the like, and functions as a WWW server by performing data communication with the user terminal 14 accessed from the Internet 16 according to a protocol such as HTTP.

The seller server 12 is a WWW of an electronic store.
It functions as a server, and the user can place an order to purchase a desired product from the electronic store by accessing the seller server 12 from the user terminal 14. In the present embodiment, the payment for the purchase order made in the seller server 12 is performed by debiting the purchaser's account established in the settlement bank via the settlement server 10.

As shown in FIG. 1, the settlement server 10 includes a customer database 20, a seller database 22, and a code recording database 24.

FIG. 2 shows a data structure of the customer database 20. As shown in FIG. 2, the customer database 20 stores a user ID, a password, personal information (address, name, mail address, etc.), an encryption / decryption key, for a user who has opened an account at a settlement bank (hereinafter referred to as a registered user). , An account number, a current account balance, and purchase information (information indicating a purchase history including a purchase date, a purchased product name, a purchase quantity, a purchase amount, an account balance after purchase, etc.) are recorded in association with each other. As will be described later, the encryption / decryption code is used to decrypt the encryption code transmitted from the user terminal 14.

FIG. 3 shows the data structure of the seller database 22. As shown in FIG. 3, the seller database 22
The seller ID, the account number of the deposit account, and the contact information for the seller server 12 of the online shopping site (hereinafter referred to as a contract site) that has concluded a contract for performing settlement via the settlement server 10 Email addresses are recorded in relation to each other. In this embodiment, it is assumed that the seller's deposit account is also opened at the settlement bank, but the deposit account may be opened at another financial institution. Database 22
Record the financial institution code along with the account number.

The code recording database 24 includes:
As described later, the encryption code (seller code) transmitted from the seller server 12 and the user terminal 1
4 Encrypted code (purchaser code) sent from
Is recorded.

Hereinafter, the contents of the processing in this embodiment will be described. When the user terminal 14 accesses the payment server 10, a menu screen shown in FIG. 4 is transmitted from the payment server 10 to the user terminal 14. FIG.
As shown in the figure, menu items such as "open account", "view purchase history", "send purchase code", "change password", and "software download" are displayed on the menu screen. Further, a link (for example, a banner advertisement) to each contract site is displayed on this menu screen, and the user can directly jump to a desired contract site from the menu screen.

A user who wants to open a new account at the settlement bank selects the "open account" menu on the menu screen shown in FIG. Then, the settlement server 10
Transmits to the user terminal 14 an account opening application screen including input fields for personal information such as a user's address, name, telephone number, and mail address. When the personal information input to the account opening application screen at the user terminal 14 is returned to the settlement server 10, the settlement server 10 issues a user ID and a password unique to the user who is the applicant, and sends it to the user terminal 14. At the same time, the host computer 18
The instruction information to the effect that a new account in the name of the applicant should be opened is transmitted to the applicant. When the host computer 18 completes the account opening process according to the instruction information, it notifies the settlement server 10 of the account number of the opened account. The settlement server 10 that has received the notification transmits a notification screen for notifying the user ID, the password, and the account number to the user terminal 14 and stores the user I
Record D, password, personal information, account number, and current account balance (0 yen). In order to confirm the identity of the user, a copy of the user's identification card may be sent to the operating company of the settlement server 10 or the settlement bank, and after confirming the identity, an account may be opened. .

A user who has opened an account at the settlement bank (ie, a registered user) can freely change the password by selecting the "change password" menu on the menu screen.

The registered user can download an encryption program for generating an encryption code required for payment using the payment server 10 by selecting a “soft download” menu on the menu screen. This encryption program uses a purchase order date, a product name, and a purchase price of a product as input data, and encrypts the input data with an encryption key embedded in the program to generate an encryption code. However, the input data to the encryption program is not limited to these, and the input data may include the purchase quantity, the site name of the purchase order destination, and the like.

In this embodiment, the encryption is performed by the common key method using the same key as the encryption key and the decryption key. However, the encryption key and the decryption key may be different. Various known encryption algorithms can be used for the encryption process.

When the "software download" menu is selected on the menu screen, the settlement server 10 requests the user terminal 14 to input a user ID and a password, authenticates the user, and then applies a unique password to the user. Generate an encryption key for. Then, the generated encryption key is embedded in the encryption program and transmitted to the user terminal 14, and this encryption key is associated with the user ID of the user as an encryption / decryption key and stored in the customer database 20.
To record. The download of the encryption program may be automatically performed at the time of applying for an account opening.

Next, a description will be given of the flow of processing from the time when a registered user accesses the seller server 12 to place a purchase order for a product until the payment settlement is completed via the settlement server 10. It is assumed that the registered user deposits an appropriate amount of funds in his or her account of the settlement bank in advance.
When the payment is made to the account of the settlement bank, the deposit amount and the account number are notified from the host computer 18 to the settlement server 10. The settlement server 10 specifies the user ID corresponding to the notified account number, and
In, the deposit amount is added to the current account balance associated with the user ID.

The registered user accesses the seller server 12 from the user terminal 14 and places an order to purchase a product.
Launch the encryption program and enter the purchase order date, product name, and purchase price. The encryption program generates an encryption code from these input data using an encryption key embedded in the program.

The registered user sends the transaction number relating to the purchase order at the seller server 12 (this transaction number is notified from the seller server 12 at the time of the purchase order) and the above-mentioned encryption code to the seller server 12. Send. Specifically, for example, when a purchase order operation is performed on the user terminal 14 that has accessed the seller server 12, the user ID
An input screen for inputting the encryption code is transmitted from the seller server 12 to the user terminal 14. At this time, the encryption program is activated to generate an encryption code, and by inputting the user ID, transaction number, and encryption code on the input screen, these data are transmitted to the seller server 12. .

At the same time, the registered user sends the generated encryption code to the settlement server 10 together with the user ID. Specifically, for example, when the user accesses the payment server 10 from the user terminal 14 and selects the “send purchase code” menu on the menu screen, an input screen for inputting an encryption code is displayed from the payment server 10 to the user terminal 14.
Will be sent to By inputting the user ID and the encryption code on this input screen, the user ID and the encryption code are transmitted to the settlement server 10.

The transmission of the encrypted code and the like from the user terminal 14 to the seller server 12 and the settlement server 10 may be performed by electronic mail or other means. In addition, by providing the encryption program with a communication function, or by configuring the encryption program as a plug-in program to an existing browser program, accessing the seller server 12 and performing a purchase order, Generate encryption code and settle payment server 1
A series of processes up to transmission of the encryption code to 0 and the seller server 12 may be automatically performed.

When the transaction number and the encryption code are transmitted from the user terminal 14, the seller server 12 obtains the sales price in the sales transaction specified by the transaction number by referring to the sales data or the like. . And
The acquired selling price and the transmitted encryption code are transmitted to the settlement server 10 together with the own seller ID.

When the user ID and the encryption code are transmitted from the user terminal 14, the settlement server 10 uses the encryption code as a purchaser-side code and associates the code with the user ID as shown in FIG. The information is recorded in the recording database 24. When the seller ID, the selling price, and the encryption code are transmitted from the seller server 12, as shown in FIG. 6, the encryption code is used as the seller-side code, and the seller ID is added to the seller ID together with the sales price. The relation is recorded in the code recording database 24. Then, at an appropriate timing (for example, once a day), the payment processing is executed based on the recorded contents of the code recording database 24.

Hereinafter, the contents of the price settlement processing will be described with reference to the flowcharts shown in FIGS. As shown in FIG. 7, first, in step 100,
The index i is initialized to “1”.

Next, in step 102, referring to the code recording database 24, it is determined whether or not the purchaser code Pj that matches the i-th seller code Si is recorded. As a result, if the purchaser-side code Pj that matches the seller-side code Si is recorded, the process of step 104 is executed. On the other hand, if it is not recorded, the index i is incremented in step 106 shown in FIG. 8, and in the subsequent step 108, it is confirmed that the i-th seller side code Si is recorded, The processing of 102 is executed.

In step 104, the user ID associated with the purchaser-side code Pj (that is, the user ID of the purchaser) is read from the code recording database 24, and
From the customer database 20, the decryption key Cj associated with this user ID is read. Then, in the following step 110, the purchase order date, the product name, and the purchase price are decrypted from the purchaser side code Pj using the decryption key Cj.

In step 112, referring to the code recording database, it is determined whether or not the sales price associated with the seller code Si matches the decrypted purchase price. As a result, if they do not match, the purchase price notified by the buyer and the sales price notified by the seller do not match, and in step 114, it is determined that the sales transaction is not established due to the price mismatch. The user terminal 14 and the seller server 12 are notified by e-mail or the like. Then, step 11 shown in FIG.
At 5, after the purchaser side code Pj and the seller side code Si are deleted from the code record database 24,
The process of step 106 is performed. On the other hand, if the decrypted purchase price matches the sales price associated with the seller-side code Pj, the process of step 116 is executed next.

In step 116, the customer database 2
With reference to 0, the account number and current account balance associated with the purchaser's user ID are read.

In step 118, the above-mentioned step 116
Is the settlement amount, that is, the purchase price (the settlement server 1) decrypted from the purchaser-side code Pj.
In the case where a fee is collected from the purchaser side at 0, it is determined whether it is equal to or more than the purchase price plus the fee). As a result, if the current account balance is less than the settlement amount, the process of step 120 is executed, while if the current account balance is equal to or more than the settlement amount, the process of step 122 is executed.

In step 120, the user terminal 14 of the purchaser (ie, the sender of the purchaser side code Pj) and the seller server 12 of the seller (ie, the sender of the seller side code Si) store the buyer's balance shortage. Is notified by e-mail, for example, that the payment cannot be made, in step 116, the purchaser-side code Pj and the seller-side code Si are deleted.

In step 122, the account number (seller-side account number) associated with the seller ID is read out with reference to the seller database 22.

In step 124, the settlement amount is deducted from the account of the purchaser account number read out in step 116 to the host computer 18, and the amount obtained by subtracting the commission from the debited amount is read from the seller account read out in step 122. Transfer instruction information to the effect that money should be paid to the account of the number is transmitted. The host computer 18 executes a transfer process, for example, on a predetermined date (for example, at the end of every month) based on the transmitted remittance instruction information. Please note that the fee deducted from the amount debited from the buyer's account,
Payment is made to the account of the operating company of the settlement server 10. When the process of step 124 is completed, the process of step 126 shown in FIG. 8 is executed.

In step 126, the seller server 12
Information to the effect that payment for the merchandise transaction with the transaction number decrypted in step 110 is surely made from the buyer's account will be transmitted to the customer. The operator of the seller server 12 can prevent troubles such as unpaid money by sending out the product after receiving this information.

In step 128, the customer database 2
At 0, the settlement amount is deducted from the current account balance associated with the purchaser's user ID, and the purchase order date, product name, and purchase price decrypted in step 110, and the settlement amount are subtracted. Is recorded as purchase information.

When the processing in step 128 is completed, the seller-side code Si and the purchaser-side code Pi are deleted from the code recording database 24 in step 115 described above. Incremented and step 1
At 08, it is confirmed that the i-th seller-side code has been recorded in the code recording database 24, and then the process of step 102 shown in FIG. 7 is executed again.

Next, the processing when the purchaser browses the purchase history will be described. A registered user who wishes to view the purchase history accesses the settlement server 10 from the user terminal 14, and selects the "view purchase history" menu on the menu screen described above. In response, the settlement server 10 transmits an input screen for inputting a user ID and a password to the user terminal 14. Then, after performing authentication based on the user ID and password returned from the user terminal 14, the purchase information and the current account balance recorded in association with the user ID are read out from the customer database 20, and this purchase is performed. Generates a purchase history list screen displaying a list of information and generates a user terminal 1
Send to 4. Thereby, the registered user can confirm the transition of his / her purchase history and account balance on the screen of the user terminal 14. That is, the registered user can use the settlement server 10 instead of the purchase record memo and the passbook.

As described above, according to the system of the present embodiment, in the settlement server 10, the encryption code (purchase side code) transmitted from the purchaser and the encryption code transmitted from the seller. Only when the (seller-side code) matches each other, the price is withdrawn from the buyer's account, so that a secure and reliable payment can be made after confirming the establishment of the sales transaction. Also, if the purchase price notified by the buyer and the sales price notified by the seller do not match, the settlement will not be performed and the sales transaction will not be completed, so the settlement will be performed at an improper price different from the price at the time of the purchase order. This can be prevented.

Further, since the encryption code is generated by the purchaser by the encryption program, it is not necessary to use the purchaser's credit card number, and the purchaser does not feel security insecurity and can safely settle the price. It can be performed. Further, since the input of the credit card number is not required, a user who does not have a credit card can make a payment on the Internet using the payment server 10 of the present embodiment. That is,
According to the present embodiment, the number of users who make payments on the Internet is significantly expanded, and it becomes possible to promote activation of commercial transactions using the Internet.

In the present embodiment, the encryption program is configured to be encrypted with an encryption key unique to each registered user, and the encryption key is stored in the customer database 20 in association with each user ID. Is recorded, and the settlement server 10 decrypts the purchaser-side code transmitted from each registered user with an encryption key unique to the user who is the sender. For this reason, even if another person pretends to be the purchaser and transmits the purchaser's code, the payment server 10 cannot decrypt the purchaser's code, so that the subsequent payment processing does not proceed. As described above, the system according to the present embodiment has high security even when another person impersonates the purchaser and transmits the encryption code.

Further, if the balance of the account provided at the settlement bank is insufficient, the payment is not performed, so that even if an unexpected event occurs, the purchaser can exceed the balance of the account. You can have a sense of security that you will not receive it.

On the other hand, the seller can also confirm that the payment from the purchaser is reliable, and then can send out the merchandise, so that there is an advantage in that troubles such as no payment from the purchaser can be prevented.

The registered user can jump to the seller site, request purchase price settlement (transmission of the purchaser side code), view purchase history, A series of procedures related to product purchase and settlement such as password change can be performed. That is, the settlement server 10 has a function of a portal site for electronic settlement, and can realize a WEB site that is highly convenient for users who purchase products on the Internet.

In the above-described embodiment, the seller server 12 functions as a WEB server of the electronic store, and the settlement server 10 performs the payment for the purchase and sale at the electronic store. However, the present invention is not limited to this, and can also be applied to the case where payment for individual transactions such as auctions on the Internet is performed. That is, for the seller in the auction, the seller ID and the deposit account number are registered in the seller database 22 in the same manner as the contract site in the above embodiment, and the successful bidder (buyer) of the auction is executed by the encryption program. The generated encryption code is transmitted to the payment server 10 and the user terminal 14 of the seller, and the seller transmits the encrypted code to the payment server 10. Payment processing can be performed.

Also, in the above embodiment, the encryption code (purchaser code) transmitted from the user terminal 14 of the purchaser to the settlement server 10 and the encryption code (seller code) transmitted to the seller server 12 ) Coincide with each other, but the present invention is not limited to this, and the two encrypted codes may have a certain correspondence relationship. That is, for example, a code obtained by converting an encrypted code generated as a purchaser-side code according to a predetermined rule may be transmitted to the seller server 12 as a seller-side code. In this case, the payment server may determine whether or not both codes have the corresponding relationship, instead of determining whether or not the purchaser's code and the seller's code match.

[0052]

According to the first, fourth, and fifth aspects of the present invention, the first encryption code transmitted from the purchaser and the second encryption code transmitted from the seller. Only when there is a predetermined correspondence between the customer and the purchaser, the payment will be withdrawn from the buyer's account. Can be realized.

According to the second aspect of the present invention, if the purchase price notified by the purchaser does not match the sales price notified by the seller, the payment is not performed, and the sales transaction is not performed. Is not established, it is possible to prevent payment from being made at an unfair price different from the price at the time of the purchase order.

According to the third aspect of the present invention, the purchaser can browse his / her purchase history.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a network according to an embodiment of the present invention.

FIG. 2 is a diagram showing a data configuration of a customer database.

FIG. 3 is a diagram showing a data configuration of a seller database.

FIG. 4 is a diagram showing a menu screen transmitted from a settlement server.

FIG. 5 is a diagram showing an example of recording data (purchaser side) in a code recording database.

FIG. 6 is a diagram showing an example of recording data (seller side) in a code recording database.

FIG. 7 is a flowchart (part 1) illustrating the content of a payment settlement process executed by the settlement server.

FIG. 8 is a flowchart (part 2) illustrating the content of the payment settlement process executed by the settlement server.

[Explanation of symbols]

 Reference Signs List 10 settlement server 12 seller server 14 user terminal 16 internet 20 customer database 22 seller database 24 code record database

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G06F 17/60 512 G06F 17/60 512 H04L 9/08 H04L 9/00 601B 9/32 673A 675D

Claims (5)

[Claims] 1. An electronic payment system for performing payment for a sales transaction performed on a network, comprising the following means (1) to (6). (1) Database means in which a user ID, an encryption / decryption key, and an account ID of a payment account are recorded for each user. (2) First receiving means for receiving, from a user terminal of a user who is a purchaser involved in the sales transaction, a first encrypted code and a user ID of the user. The first encryption code is obtained by encrypting sales data including a purchase price related to the sales transaction with an encryption key corresponding to the encryption / decryption key of the user. (3) Second receiving means for receiving a second encrypted code from a computer of a seller involved in the sales transaction. (4) decryption means for decrypting the received first encrypted code using a decryption key recorded in the database in association with the user ID received together with the first encrypted code. (5) determining means for determining whether or not the received first encrypted code has a predetermined correspondence with the received second encrypted code. (6) Only when the received first encryption code and the received second encryption code have the predetermined correspondence, the purchase price included in the data decrypted by the decryption means is reduced. The corresponding amount is associated with the received user ID, and the account I recorded in the database.
Execution means for executing a settlement process for debiting the account specified in D. 2. The electronic settlement system according to claim 1, wherein the second receiving unit receives a selling price related to the trading transaction together with the second encrypted code from the seller's computer, and the decrypting unit. And a second determining unit that determines whether a purchase price included in the data decrypted by the received data and the received sales price match, and the execution unit includes the received first encrypted code. And the received second encryption code is determined to have the predetermined correspondence, and the settlement process is executed only when the purchase price and the sale price match. Electronic payment system. 3. The electronic payment system according to claim 1, wherein the sales data further includes a product related to the sales transaction and a sales transaction date, and a product included in the sales data decrypted by the decryption unit. Means for recording purchase data including a sales transaction date and a purchase price in the database in association with the received user ID, and relating to the user ID of the user in response to a request from the user who has accessed from the user terminal Means for reading out the purchase data added and recorded from the database and transmitting the purchase data to the user terminal. 4. An electronic payment method for performing a payment for a sales transaction performed on a network using an electronic payment system including a server computer connected to the network, wherein the database provided in the electronic payment system is provided. For each user, a user ID, an encryption / decryption key, and an account ID of an account for payment are recorded, and at a user terminal of a user who is a purchaser involved in the sales transaction, the purchase price related to the sales transaction is recorded. The trade data including the user is encrypted with an encryption key corresponding to the decryption key of the user to generate a first encryption code, and the generated first encryption code is used together with the user ID of the user for the payment. A second encryption code transmitted to the server and having a predetermined correspondence with the first encryption code.
Transmitting the second encryption code transmitted from the user terminal to the electronic payment system, and transmitting the second encryption code to the electronic payment system at the seller's computer. In the payment system, a user ID that receives a first encryption code transmitted from the user terminal together with the first encryption code
Using the encryption / decryption key recorded in the database in association with the first encryption code transmitted from the user terminal and the second encryption code transmitted from the computer of the seller.
It is determined whether or not the encrypted code has the predetermined correspondence. If the first encrypted code and the second encrypted code have the predetermined correspondence, the decryption means A process for debiting an amount corresponding to the purchase price included in the data decrypted from the account specified by the account ID recorded in the database in association with the user ID. Payment Method. 5. An electronic payment system used in the electronic payment method according to claim 4.