JPH0532783B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is an electronic payment system that uses a computer to settle money, receivables, etc., in which a host computer confirms the settlement agreement between two parties. Regarding how to.

[Conventional technology]

2. Description of the Related Art In recent years, so-called electronic payment systems have been put into practical use in which a transaction is concluded between two parties and payments of money, credits, etc. agreed upon by both parties are made using a computer. In this type of electronic payment system, a host computer with an account file in each trader's name is generally connected via a communication line to a terminal placed on each trader's side. When you input payment request data (transaction type, date, time, amount, both accounts, etc.) from the terminal, the host computer simply processes the payment based on the payment request data (for both the corresponding holders on the account file). The bank only executed the process of rewriting the account.

[Problem to be solved by the invention]

In conventional electronic payment systems, payments are executed without confirming mutual agreement between the holders of the payment, resulting in false payment request data being entered maliciously or incorrect data being entered. However, the payment will still be made. As a result, as this type of electronic payment system expands in the future,
There are concerns that major trouble will occur. In addition, by inputting payment request data by both parties to the payment and comparing the two request data on the receiving host computer, it is possible to confirm the fact that both parties have agreed to the payment. Therefore, when the number of payment requests increases, a problem arises in that the burden on the host computer increases significantly.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for confirming a settlement agreement between two parties using only a declaration from one party in an electronic payment system using a computer.

[Means to solve the problem]

In order to achieve the above object, the present invention provides an authentication code (MAC; Message Authentication Code) for each transaction.
tion Code), and keep this key data secret from each other (each trader knows only his or her own key data). At the same time, a key data registration file is provided in the host computer, and key data is registered for each trader. The contents of this key data registration file are also kept secret.

When a transaction is conducted between traders A and B and a settlement is required, one of the traders (referred to as A) uses the agreed payment data and the private key data of the trader to determine in advance. Create an authentication code (MAC) using the algorithm and send it to the other party (B).
). Trader B transmits payment request data including payment data and the authentication code (MAC) communicated by Trader A to the host computer. The host computer generates an authentication comparison code from the received payment data and the private key data of trader A registered in the key data registration file.
A MAC′ is created, and if it matches the input MAC, the payment process is executed.

[Effect]

The authentication code (MAC) that transaction B sends to the host computer together with the payment data is a private key known only to transaction A when transaction agreement is reached between transaction A and B. It was created using the data, and Transaction B
It is impossible to create something similar to MAC.
Therefore, in the host computer, if the MAC' created from the payment data received from trader B and the pre-registered private key data of trader A matches the received MAC, the payment from trader B is accepted. It can be determined that the request data agrees with the transaction partner A, and if they do not match, it can be determined that transaction B has maliciously sent false payment request data or erroneous data has been input. This results in
The host computer can confirm the settlement agreement between the two parties simply by making a declaration from one of the payment parties.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a block diagram of an embodiment of an electronic payment system to which the present invention is applied. 1st
In the figure, 10 is a host computer, 20 -
40 is a terminal used by traders A, B, and C, 50
~70 is the host computer 10 and each terminal 2
This is a communication line connecting 0, 30, and 40. Although only three terminals are shown in this embodiment, it goes without saying that more terminals may actually be connected to the host computer 10.

The host computer 10 is a MAC creation mechanism 11
Similarly, each terminal 20, 30, 40 also has a MAC creation mechanism 21, 31, 41, respectively. The host computer 10 further includes external storage devices 80 and 90. External storage device 80 is used to store account files 81 in the name of each trader. The external storage device 90 is used to store a key data registration file 91 in which private key data determined for each trader is registered in association with the holder of the account file 81. In this embodiment, the key data of traders A, B, and C are a,
Suppose that they are b and c. These key data a, b, and c are kept secret from each other. Further, the key data registration file 91 is made so that it cannot be accessed from the terminals 20, 30, and 40 without permission.

Next, payment processing by this electronic payment system will be explained according to the flowchart shown in FIG. Figure 2 shows a case where when a transaction is established between A and B and payment is required, the MAC is created by trader A, and the payment request data to the host computer 10 is sent by trader B. It is something.

When a transaction is completed between transactors A and B, and settlement is required, transactor A must share the payment data x (settlement type, date, time, amount, both A and B) agreed with transactor B. account number, etc.) and your own private key data a
is input into the terminal 20 to instruct MAC creation (step 101). MAC creation mechanism 21 of terminal device 20
creates an authentication code MAC=f(x,a) from the input payment data x and private key data a using a predetermined algorithm (step 102). This created authentication code MAC=f
Trader A communicates (x, a) to trader B (step 103). Possible contact methods include telephone, facsimile, and computer communication, but the MAC itself does not need to be kept secret, and any method will do.

Transaction B receives the authentication code MAC= from Transaction A.
When f(x, a) is contacted, the payment data x agreed with transactor A and the authentication code f(x, a) communicated from transactor A are entered into the terminal 30 and sent to the host computer 10. (Step 104). The terminal 30 transmits payment request data including the input payment data x and authentication code f(x,a) to the host computer 10 (step 105).

When the host computer 10 receives the payment request data from the transactor B (step 106), it reads the private key data a of the transactor A from the key data registration file 91 of the external storage device 90 (step 107).
From the payment data x received from trader B and the key data a read from the key data registration file 91,
An authentication comparison code MAC'=f(x,a) is created using a predetermined algorithm (step 108). This MAC' is created by the MAC creation mechanism 11 of the host computer 10. Note that the file 91 of private key data a corresponding to transaction party A
Reading is performed by searching the file 91 using the account number of trader A included in the received payment data x as a key. Next, the host computer 10 uses the MAC creation mechanism 11 to create a
MAC' is compared with the MAC received from trader B (step 109), and only if MAC'=MAC, a payment request from trader B is accepted and the payment process is executed (step 110). That is, according to the payment data x received from trader B, the account contents in the names of traders A and B in the account file 81 of the external storage device 80 are rewritten. On the other hand, if MAC′≠MAC, payment processing is rejected (step 111).

Next, the algorithm for MAC creation will be explained. If the secret key data is easily inferred, the reliability of the method of the present invention decreases. For this reason, each MAC creation mechanism 11, 21,
The MAC creation algorithm for 31 and 41 is as follows:
DEA, a well-known cryptographic algorithm
It is suitable to apply the (Data Encryption Algorism) method. DEA has a binary key data length.
The length is 56 digits, making it difficult to guess the key.

Figure 3 shows a specific example of MAC creation using DEA. In Figure 3, 201 is
Encryption processing by DEA, 202 represents exclusive OR processing.

In the invention, the MAC target information, that is, the payment data x, is divided into 64-bit units, and the first 64 bits are encrypted using key data K (56 bits). The result of this processing is also 64 bits.
Next, after calculating the exclusive OR of this processing result and the next 64 bits of the MAC target information, encryption processing is performed using the same key data K. Thereafter, the same process is repeated to obtain the final encrypted data. This encrypted data is also 64 bits, and the latter 32 bits are divided into 4-bit units and expressed in hexadecimal (0-9, A-F), which is referred to as MAC. Therefore, MAC is 8 digits (16
expressed in digits (digital). Note that the encryption process is repeated,
Finally, if the MAC target information is less than 64 bits,
Add zeros and perform encryption processing as 64 bits.

An embodiment of the present invention has been described above, but in FIG.
MAC calculators, pocket computers, etc. are prepared separately, and traders use these devices to perform MAC calculations.
You may also create one. In this case, the terminals 20, 30, and 40 can be used as they are.

〔Effect of the invention〕

As explained above, according to the present invention, in an electronic payment system, it is possible to reliably confirm the fact of a payment agreement between two parties with only a declaration from one party, without placing a significant burden on the host computer. , it is possible to detect fraudulent or erroneous payment request data, greatly improving the efficiency and reliability of the payment system.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of one embodiment of the present invention, and FIG.
The figure is a diagram showing the payment processing procedure in FIG. 1, and FIG. 3 is a diagram showing a specific example of MAC creation. 10...Host computer, 20, 30, 40
...Terminal, 50,60,70...Communication line, 80,
90...External storage device, 11, 21, 31, 41...
MAC creation mechanism, 81...Account file, 91...Key data registration file.

Claims (1)

[Scope of Claims] 1. A host computer equipped with each trader's account file and a plurality of terminals are connected via a communication line, and when a trader requests payment from the terminal, the host computer can check the corresponding information on the account file. In an electronic payment system that rewrites account details, secret key data that only the trader can know is determined for each trader, and the key data for each trader is registered in the host computer. When a settlement agreement is reached, one transactor (A) creates an authentication code using the payment data and his/her own key data, and sends it to the other transactor (B).
Transactor B sends the payment data and the authentication code contacted by Transactionr A to the host computer to request payment, and the host computer transfers the received payment data and the pre-registered transaction. A payment confirmation method for an electronic payment system, characterized in that an authentication comparison code is created using key data of a person A, and when the created authentication comparison code matches a received authentication code, a payment process is executed.