JPS60167045A - Data protection system - Google Patents

Abstract

PURPOSE:To easily identify that illegal transaction is carried out by utilizing the property that coded data can not be rewritten even by rewriting data on a journal by recording a key of coding on an IC card. CONSTITUTION:A CPU2 reads coded transaction end data which is received from the host CPU of a banking organ out of a floppy disk 11 and decodes the data to record the original data and coded data of the transaction end data on a bankbook 12 together and also record the key of coding on the IC card 13. Then, original data on a journal which is recorded on the bankbook 12 and coded data corresponding to it are inputted on a keyboard later, and then the CPU2 decodes said coded data by the same decoding method as that in the transaction by using the coding key inputted from the IC13, and collates the result with the original data inputted from the keyboard 4. If they are coincident with each other, a report for illegal rewriting is displayed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a data protection system for journals in financial transaction terminals installed by financial institutions in businesses and homes, for example.

[Technical Background of the Invention] Traditionally, Kim A11's terminal devices were installed in Kim A11's stores, but with the liberalization of internet lines, terminal devices were installed in businesses and homes to provide online access. It has become possible to conduct transactions. In a system using such a terminal fi@, the journal that records transaction data is
Although it is recorded on both the financial institution's host computer and the terminal device, the journal on the terminal device side does not remain in the hands of the financial institution, unlike in the past. Therefore, financial institutions are required to take measures against falsification of journals on terminal devices intentionally or negligently by corporate or home users.

``Problems with the background technology'' Paper or floppy disks are commonly used as recording media for journals in terminal devices installed in companies and homes, but since these are rewritable recording media, they are not authorized If it is rewritten by a procedure other than the one described above, it is necessary to make it possible to later determine that it has been rewritten. Note that rewritable recording media include FROM (Programmable Read Only Memory) and laser recording memory, but since they cannot be reused, it would be costly to record all of the journal data. The amount of recorded data needs to be as small as possible.

[Purpose of the Invention] This invention was made in view of the above circumstances, and its purpose is to prevent data recorded on a rewritable recording medium such as paper or a 70-bit disc from being processed by unauthorized procedures. The object of the present invention is to provide a data protection method that can later determine if the data has been rewritten.

[Summary of the Invention] This invention records original journal data and encrypted data on a rewritable recording medium, and records an encryption key on a non-rewritable recording medium. Taking advantage of the fact that the encrypted data cannot be rewritten even if the original data in the journal is rewritten, the two types of data can later be compared using an encryption key recorded on a non-rewritable recording medium. This makes it possible to determine whether the data has been rewritten outside of the normal procedure.

[Embodiment of the Invention] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

In Figures 1 and 2, 1 is a terminal device installed by a financial institution in a company or home, and is used to process transactions specified by operations of users at companies or homes. It is configured. That is, 2 is a CPU (central processing unit) that controls the whole, and 3 is an IC card input/output device that inputs and outputs data to and from an IC card 13 in which a PROM is placed on the card as an example of a non-rewritable recording medium. , 4 is a keyboard for inputting passwords, transaction data, etc., 5 is a CRT display device, 6 is a floppy disk device for writing and reading data on the floppy disk, and 7 is a printer for printing transaction results, etc. . Further, reference numeral 8 is a turntable that converts electrical signals and acoustic signals with the handset 10 of a telephone 1119 for online connection to the host 1 of the financial institution and a computer (not shown). The transaction data journal is stored in the floppy disk device 6 mentioned above.
70 disc 11 or printer
1 on paper 12 or both.

Next, the operation in such a configuration will be explained.

First, the transaction procedure according to the regular procedure will be explained with reference to the flowchart shown in FIG. For example, a company or home user may record a transfer destination account number as transaction request data for a transaction, such as a transfer between the user's savings accounts, using the operational guidance displayed on the CRT display device 5 of the terminal device 1. Insert the IC card 13 into the IC card input/output device 3. Then, the CPU
2 is supplied with the transfer destination account number from the IC card input/output device 3. Also, if you key in the transfer source's PIN number, transfer destination account number, and transfer amount from the keyboard 4,
The CPU 2 temporarily stores this data on the floppy disk 11 along with the transfer destination account number input from the IC card 13.
(Step 1).

Next, the CPU 2 displays guidance for online connection to the financial institution's host computer, and following the guidance, the user dials the phone number of the financial institution's host computer using the telephone 9, and the call is established. After confirming this, place the receiver 10 on the Cub U8 (Step 2). Next, the CPU 2 reads the transaction request data from the floppy disk 11, encrypts the data, and sends it to the host computer (step 3).

Next, the financial institution's host computer decrypts the received transaction request data, checks transaction conditions such as the balance of the transfer source account, and updates the ledger if the conditions are met (step 4). Next, the financial institution's host computer creates data indicating that the transaction has been completed, encrypts the data, and sends it to the terminal @1, so the CPU
2 receives the encrypted transaction completion data and temporarily records this data on the diskette 11 (step 5). Next, the CPU 2 reads the encrypted transaction completion data received from the financial institution's host computer from the floppy disk 11, decrypts it, and decodes the resulting transaction completion data created by the host computer. The encrypted data is also recorded on the paper 12, and the encryption key used for decryption is recorded on the IC card 13 (step 6). Next, the user confirms that communication with the host computer has ended and removes the receiver 10 from the cover 8 (step 7). In this way, transaction completion data when a business or home user conducts a transaction using the terminal @1 is recorded on the form 12 as both the original data and the encrypted data, and is also recorded on the IC card.
An encryption key used to decrypt encrypted data into original data is recorded on the card 13.

Next, an example of a method for determining whether or not the user has intentionally or negligently rewritten the original data, such as the amount, on the form 12 after a transaction will be described with reference to the flowchart shown in FIG. First, journal the terminal device.
The check program is specified to operate (step 11). Next, the original data of the journal recorded on the paper 12 and the corresponding encrypted data are input from the keyboard 4f)s, and the encryption key corresponding to the original data is input from the IC card 13 (step 12). next,
The CPU 2 uses the encryption key input from the IC card 13 to decrypt the encrypted data input from the keyboard 4 using the same decryption method as at the time of transaction, and converts the result into the original data input from the keyboard 4. (Step 13). The comparison result is then displayed on the CRT display device 5 (step 14). In this way, it is possible to determine whether the original data of the journal has been rewritten outside of the normal procedure.

In the above embodiment, an IC card is used as the non-rewritable recording medium, but a laser recording memory can be used in the same manner. Furthermore, the same method can be applied to a floppy disk as the journal recording medium. Furthermore, when recording transaction request data in addition to transaction completion data as data to be recorded in the journal, it is possible to rewrite both the encrypted data and the original transaction request data when sent from the terminal device to the host computer. The same method can be implemented by recording the corresponding encryption key on a recording medium that cannot be changed. Furthermore, although the data is encrypted and decrypted in the terminal device, the present invention is not limited to this, and the data may be encrypted and decrypted in the IC card.

[Effect of the invention] As described in detail above, according to the present invention, paper or 70
It is possible to provide a data protection method that can later determine if data recorded on a removable recording medium such as a disk is replaced outside of regular procedures.

[Brief explanation of the drawing]

The drawings are for explaining one embodiment of the invention.
FIG. 1 is a perspective view of the terminal device, FIG. 2 is a block diagram schematically showing the configuration of the terminal device, and FIGS. 3 and 4 are flowcharts showing the processing procedure. DESCRIPTION OF SYMBOLS 1... Terminal device, 2... CPU, 3... IC card input/output device, 4... Keyboard, 5... CRT display device, 6... Floppy disk device, 7
...Printer, 8...Coupler, 9...Telephone, 1
o...Telephone receiver, 11...Floppy disk (recording medium), 12...Paper, 13...IC card (recording medium). Applicant's agent Patent attorney Ni β Suzue Figure 3jI4

Claims (1)

[Claims] In a terminal device to which a rewritable recording medium and a non-rewritable recording medium are connected, journal data and its encrypted data are both recorded on the rewritable recording medium, and the A data protection system characterized in that by recording a key on the non-rewritable recording medium, it is possible to determine if the journal data has been tampered with later.