JPH02105985A - Data protection system for magnetic card - Google Patents

Abstract

PURPOSE:To prevent original variable data from being obtained unless demodulation is imposed by using a reverse waveform signal by modulating recoding variable data recorded in a 1st magnetic recording area of a magnetic card with a waveform signal. CONSTITUTION:The variable data is modulated with the specific waveform signal to obtain the recording variable data, which is recorded magnetically on a 1st magnetic stripe 5 of a prepaid card 4. When the data is reproduced, the recording variable data which is read out of the 1st magnetic stripe 5 of the prepaid card 4 is demodulated with the reverse waveform signal to obtain the original variable data. Consequently, the recording variable data which is recorded on the 1st magnetic stripe 5 of the prepaid card 4 is disabled to be altered irregularly and the data is protected, so that the safety of the system is obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention uses a magnetic card on which variable data is magnetically recorded.
The present invention relates to a magnetic card recording system capable of repeatedly recording information, and particularly to a data protection method for magnetic cards that protects variable data by preventing the variable data recorded on the magnetic card from being easily tampered with.

[Conventional technology]

This type of magnetic card recording system is known as a system that allows payments to be made using a magnetic card on which variable data such as an advance payment amount is magnetically recorded. In such a magnetic card recording system, a magnetic card is provided with a magnetic recording area for variable data, and variable data such as monetary amounts are recorded in this magnetic recording area by, for example, FME recording.

[Problem to be solved by the invention]

By the way, in conventional magnetic card recording systems, when variable data is magnetically recorded in the magnetic recording area of a magnetic card, the magnetically recorded data is not recorded in a confidential state, so the variable data can be tampered with. be. Therefore, the conventional magnetic card recording system has the drawback that the variable data recorded in the magnetic recording area of the magnetic card can be tampered with and used illegally.

The present invention has been made to solve the above-mentioned drawbacks, and provides a data protection system for magnetic cards that allows variable data recorded in the magnetic recording area of a magnetic card to be easily read and prevented from being written. With the goal.

[Means to solve the problem]

In order to achieve the above object, a magnetic card data protection system according to the present invention uses a magnetic card capable of magnetically recording variable data, and in a magnetic card recording system capable of recording information, the magnetic card has a variable data protection system. A first magnetic recording area for recording data is provided, and a second magnetic recording area is provided for recording control data, and during magnetic recording, variable data is modulated with a predetermined waveform signal prepared in advance. The variable record data obtained by this is written in the first magnetic recording area of the magnetic card, and at the time of reproduction, the variable record data and control data are respectively read from each of the magnetic recording areas of the magnetic card, and the control data and the control data are written in the first magnetic recording area of the magnetic card. It is characterized by demodulating based on a provided reverse waveform signal to obtain regular variable data.

[Effect]

The magnetic card is provided with a first magnetic recording area for magnetically recording variable data and a second magnetic recording area for magnetically recording control data. When this magnetic card is issued, control data for a constant focus interval is recorded in the second magnetic recording area. Further, the variable data is modulated with a predetermined waveform signal to become recordable variable data, and then recorded in the first magnetic recording area of the magnetic card.

When a magnetic card is used to settle the payment, variable recording data and control data are read from each magnetic recording area of the magnetic card.The variable recording data read from the 10th magnetic recording area has a reverse waveform set in advance. Demodulation is performed based on the signal and the control data. This allows variable data to be obtained.

When the variable data is obtained in this way, the payment is made using this variable data, and when the payment is completed, the variable data after the payment is completed is modulated again using a waveform signal provided in advance, After recording variable data, it is magnetically recorded in the first magnetic recording area of the magnetic card.

By operating in this way, payment of the fee using the magnetic card is completed.

According to the magnetic card data protection system of the present invention, the variable recording data recorded in the first magnetic recording area of the magnetic card is modulated with a waveform signal, so unless it is demodulated with a reverse waveform signal, the original Since the variable data cannot be obtained, it becomes extremely difficult to tamper with the variable data. Therefore, according to the present invention, the reliability of the system can be improved.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

1 to 11 are shown for detailed explanation of the present invention.

FIG. 1 is an explanatory diagram showing a magnetic card recording system to which the magnetic card data protection method according to the present invention is applied,
This will be explained using the taxi industry as an example. Also, Figure 2 (1
) is a diagram showing the back side of the prepaid card, which is the magnetic card of this embodiment, and FIG. 2(n) is a diagram showing the front side of the prepaid card, which is the magnetic card of this embodiment.

In FIG. 1, a magnetic card recording system 1 to which a magnetic card data protection system is applied is configured as follows. That is, the magnetic card issuer 2, which is independent from the taxi company, receives cash etc. from the user in advance, and inputs variable data such as the prepaid amount, issue date, issuer, etc. into the magnetic card issuer 3. The magnetic card issuing machine 3 modulates the manually generated variable data as described above with a waveform signal stored in advance in a ROM (not shown), converts it into recordable variable data, and stores it in the first magnetic recording area 5 of the raw magnetic card. By recording, a prepaid card 4, which is a magnetic card, is issued.

As shown in FIG. 2 (1), the prepaid card 4 has a first magnetic stripe 5 on which record variable data such as payment is written, and a second magnetic stripe on which control data is written with a jitter of a reference bit interval. stripe 6
and is provided.

Further, it is assumed that control data is written in the second magnetic stripe 6 of the prepaid card 4 at standard bit intervals in the state of a raw magnetic card.

Further, on the surface of the prepaid card 40, the number of uses 7, an area 7B for displaying the number of uses, the issuer 8, the amount 9, etc. are printed.

A user in possession of a prepaid card 4 issued in this way rides a taxi 12A of Asha 11A, which is equipped with a magnetic card terminal device 10 that allows payment of the fare using the prepaid card 4, and pays the fare using the prepaid card 4. In other words, the usage fee calculated by the taxi meter 13A of the taxi 12A is paid by the magnetic card terminal device 1.
0 is also man-powered. When the prepaid card 4 is inserted into the magnetic card terminal device 10, the magnetic card terminal device 10 detects the first magnetic stripe 5 of the prepaid card 4.
The recording variable data is read from the second magnetic stripe 6, and the control data is read from the second magnetic stripe 6.
The recorded variable data is demodulated based on the reverse waveform signal stored in the control data and the control data to obtain regular variable data. Then, the magnetic card terminal device 10 subtracts the usage fee from the regular variable data, and stores the usage fee, prepaid card issuer, usage date and time, etc. in its internal memory (not shown). Further, the magnetic card terminal device 10 modulates the variable data consisting of the deducted amount data and other data as described above with a waveform signal stored in advance in a ROM (not shown) to record variable data, and converts it into prepaid data. The first magnetic recording area 5 of the card 4 is rewritten, and this prepaid card 4
discharge.

Similarly, the user who owns the prepaid card 4,
Otsusha 11B's taxi 12B is equipped with a magnetic card terminal 'l1io' that allows payments to be made using a prepaid card 4.
The user rides the taxi and pays the fare using the prepaid card 4, that is, the fare calculated by the taxi meter 13B of the taxi 12B is also manually input to the magnetic card terminal device IO. When the prepaid card 4 is inserted into this magnetic card terminal device IO, the magnetic card terminal device 10
The variable recording data is read from the first magnetic stripe 5 of the prepaid card 4, and the control data is read from the second magnetic stripe 6, and the reverse waveform signal stored in advance in a ROM (not shown) and the control data are read out. The recorded variable data is demodulated to obtain regular variable data.

Then, the magnetic card terminal device IO deducts the usage fee from the regular variable data, and stores the usage fee, prepaid card issuer, usage date and time, etc. in its internal memory (
(not shown). Further, the magnetic card terminal device 10 stores variable data consisting of deducted amount data and other data in advance in a ROM (not shown).
The prepaid card 4 is modulated with a waveform signal stored in the prepaid card 4 to become recordable data, and rewritten in the first magnetic recording area 5 of the prepaid card 4, and the prepaid card 4 is ejected.

When both the taxi 12A and the taxi 12B finish their work, they return to the offices of Company A 11A and Company Otsu 11B.

Then, at the business office of the company 11A, IIB, information such as the price stored in the internal memory of the magnetic card terminal device 10 during business hours is stored on a tally card 14 on which unique information of the terminal device, driver, etc. is written. The information such as the price written on the tally card 14 is written in the A company 11A, 1
The information is read together with the unique information by the processing devices 15 installed in each office of 1B.

The processing device 15 tallies information such as the price read from the tally card 14 and unique information.

When the processing device 15 finishes counting 1 and certain conditions are met, each company 11A, IIB requests payment from the magnetic card issuer 2 (D in the figure) and receives the payment (P in the figure).

FIG. 3 is a perspective view showing the magnetic card issuing JLA3.

In FIG. 3, the magnetic card issuing machine 3 includes a processing device t2.
0 and a ticket issuing machine 21. The processing device 20 includes a display 22 and a magnetic disk drive unit W.
123, and 27 connected to the computer 25 via a cable 26. The ticket issuing machine 21 is connected to the combiator 25 via a cable 28, and has a front panel section thereof. A card ejection port 30 is provided in the card slot.

The processing device 20 and ticket issuing machine 21 are placed on a desk.

FIG. 4 shows a magnetic card terminal bag W10 according to an embodiment of the present invention.
FIG. 2 is a front view showing the device installed in a taxi together with a taxi meter 13.

In FIG. 4, the magnetic card terminal device 10 is provided with an amount display 34, an insertion/ejection port 35 into which the prepaid card 4 or tally card 14 is inserted and ejected, and an amount display device 36 on the front thereof. There is. The magnetic card terminal device 10 is connected to a taxi meter 13 via a cable 37.
However, the printer 39 connects to the cable 4 via the cable 38.
1, key human power devices 40 are respectively connected. The taxi meter 13 is provided with a taxi fare display 42 and an arm 43 for indicating whether the taxi is empty or occupied.

FIG. 5 is a configuration diagram showing the ticket issuing machine 21 used in the same embodiment.

In FIG. 5, a storage box 51 containing raw prepaid cards 4 can be attached to and removed from a stepped portion 52 of a main body 50 of the ticket issuing machine 21. As shown in FIG. Further, the storage n 51 is provided with a hole 56 at its bottom 53 from which a portion of the rollers 54 and 55 protrude when the storage n 51 is mounted on the stepped portion 52 of the main body 50. Furthermore, a notch 57 is provided on the side surface of the storage box 51 in contact with the bottom 53, through which only one raw prepaid card 4 can pass.

An intake port 58 for taking in the raw prepaid card 4 is provided on the side surface of the stepped portion 52 of the main body 50.

In the straight line connecting the intake port 58 and the card discharge port 30,
Rollers 61-66 are provided. The roller 6
1 to 66 are provided at intervals such that both ends of the prepaid card 4 can be sandwiched in the traveling direction of the prepaid card 4. Endless belts 67 are wound around the rollers 61, 63, and 65, respectively. Also, the roller 62.64.6
6, an endless belt 68 is passed through each loop.

A printer 70 for printing necessary information on the surface of the raw prepaid card 4 is provided between the rollers 61, 62 and 63, 64. At the bottom of this printer 70 is an auxiliary plate 71 used during printing.
is provided. Between the rollers 63 and 64 and the rollers 65 and 66, there is a writing device 7 for writing the remaining amount, etc. on the first magnetic stripe 5 of the raw prepaid card 4.
A write head 73 for writing reference control data onto the second magnetic stripe 6 of the prepaid card 4 is also provided. The printer 70 is connected to a control circuit 75, and is capable of printing predetermined characters on the surface of the raw prepaid card 4 based on recorded information from the control circuit 45.

The write head 73 is connected to a control circuit 75 via a write circuit 76, and the write head 74 is connected to a control circuit 75 via a signal processing circuit 77. Data can now be written. The rollers 54, 55 are connected to a step motor 78 (4i!, not shown). They are connected through the sides.

Further, the rollers 61 to 66 are connected to a step motor 79 via a mechanism not shown. The step motors 78 and 79 are connected to the control circuit 75 and are driven under the control of the control circuit 75.

The control circuit 75 is configured to take in variable data from the computer 25, convert it into predetermined magnetic recording data, and supply it to the signal processing circuit 77. The control circuit 75 is capable of supplying control data of the reference bit interval to the write circuit 76.

The signal processing circuit 77 modulates variable data using a waveform signal stored in a ROM (not shown) to form recording variable data, and can supply this to the write hand door 4.

Control circuit 75 is adapted to supply control data for a reference bit interval to write head 73.

FIG. 6 is an explanatory diagram showing the signal system of the signal processing circuit 77.

The issued data from the control circuit 75 is temporarily stored in the memory 8 in accordance with the write timing signal Sw under the control of the controller 80.
1 is stored. Also, when the write timing comes, the ROM 82, digital-to-analog converter (DA converter) 83, and voltage frequency oscillator (VFO) 84 operate under the control of the controller 80, and the waveform stored in the ROM 82 is generated. Read it out, create a waveform voltage with the DA converter 83,
This is supplied to the VFO 84.

The VFO 84 generates a clock with a frequency according to the input voltage, and outputs the clock as a read pulse Sm to the memory IJ8.
Supply to 1. As a result, variable recording data is read from the memory 81 and sent to the write head 74 via the amplifier circuit 85.
It is designed to drive.

FIG. 7 shows a magnetic card terminal device lO used in the same embodiment.
FIG.

In FIG. 7, the magnetic card terminal device 10 is constructed as follows. That is, a pair of feed rollers 90 and 91 are provided at a position corresponding to the card insertion/ejection port 35.
is rotatably provided, and a read/write head 92 and a read head 93 are provided adjacent to the rollers 90, 91. The read/write reader 92 reads information written on the first magnetic stripe 5 of the prepaid card 4 and also writes information on the first magnetic stripe 5 of the prepaid card 4 after payment is completed.

Further, the reading head 93 reads control data written on the second magnetic stripe 6 of the prepaid card 4. Next to the read/write head 92,
A reflective photo cuff puller 94 is provided. Next to the photo coupler 94 is a pair of rollers 95.
96 are provided. A punch mechanism 97 is provided on the right side of the rollers 95 and 96 in the drawing.

This punching machine 197 is a mechanism that punches holes at predetermined positions in the area 7B according to the use of the prepaid card 4. A pair of rollers 98 and 99 are provided on the right side of the punch mechanism 97 in the drawing.

A pair of rollers 100, 101 are provided at a constant distance from the rollers 98, 99. A card contact detection sensor 102 which also serves as a stopper is provided on the right side of the rollers 100 and 101 in the drawing. The rollers 90.91, 95.96, 98.99, and 100.101 are connected to the output shaft of a step motor 103 via a mechanism not shown. Further, a reflective photo coupler 104 is provided near the card insertion/ejection port 35 to detect that the prepaid card 4 has been inserted. The read/write head 92 is the recording/reproducing circuit 1
05 to read 7-do 93 is the waveform shaping circuit 106
are connected to the controller 110 via the respective controllers 110 . Photo coupler 94, 104, punch mechanism 97, step motor 103, card contact detection sensor 10
2 are connected to the controller 110, respectively.

FIG. 8 is an explanatory diagram showing a signal system of the recording/reproducing circuit 105 of the magnetic card terminal device 10.

In FIG. 8, the recording variable data read from the read/write head 92 is transferred to the processing device 120 of the controller 110.
under the control of the timing signal S. , it is temporarily stored in the memo 17122 via the waveform shaping circuit 121. To retrieve variable data from the memory 122, the switch 123 is switched to the ROM 124 side, the reverse waveform signal is read out from the ROM 124, the DA converter 125 outputs the waveform (No. 8), and the FO 126 outputs a frequency corresponding to the input voltage. The frequency signal from the VFO 126 is used as a timing signal for reading variable data from the memory 122.

Since the timing is in an inverse relationship to the bit interval of the variable recording data stored in the memory 122,
The variable data is read out from the memory 17122 as the original timing and demodulated. This variable data is taken into the processing device 120 of the controller 110,
The usage fee from the taxi meter 42 is deducted, and the date of use, issuer name, usage fee, and other necessary data are stored in the memory 130 of the controller 110.

The processing device 120 stores the deducted amount and other necessary data in the memory 131 according to the timing signal Swz.
It is designed to be stored in the memory. The variable data thus stored in the memory 131 is modulated and output as follows. First, switch 1
23 to the ROM 132 side, the waveform signal is read from the ROM 132, converted into a waveform signal by the DA converter 125, and inputted to the VFO 126. As a result, VFO126
This allows a frequency signal to be generated depending on the input voltage. This frequency signal from the VFO 126 is used as a timing signal for reading variable recording data from the memory 131. Thereby, the variable recording data modulated by the waveform signal is supplied to the read/write head 92 via the amplifier circuit 133.

The operation of the embodiment configured in this way will be explained.

Here, the overall description of this embodiment is as follows in FIG.
Since this has already been completed, the operation of each device will be mainly explained below.

<Prepaid Card Issuance Operation> The prepaid card 4 is issued by paying cash or the like to the magnetic card issuer 2. That is, when there is a payment such as cash, the magnetic card issuer 2 sends the magnetic card issuer 3 to the magnetic card issuer 3.
Keyboard input bag! 27 to the computer 25 and a card issuance instruction (step 500).
), As a result, the combiator 25 adds the issue date, issuer name, serial number, etc. to the amount data and sends it to the control circuit 75 of the ticket issuing machine 21 via the cable 28 (
Step 501).

As a result, the control circuit 75 rotates the step motor 78 to take out the raw prepaid card 4 from the storage box 51, and also rotates the step motor 78 to rotate the rollers 61 to 66 to transfer the raw prepaid card 4 to the printer 70. The printer is positioned at the bottom and the necessary printing is performed (step 502).

Furthermore, the raw prepaid card 4 is further moved to the left in the drawing, and the write head 73 writes control data to the second magnetic stripe 6 of the prepaid card 4 at standard bit intervals (step 50).
3) Also, the variable data written on the second magnetic stripe 6 of the prepaid card 4 is given from the control circuit 75 to the signal processing circuit 77, where it is modulated with a predetermined waveform signal and made into recordable variable data. This signal processing circuit 77
The recordable data from is written to the first magnetic stripe 5 of the prepaid card 4 via the write head 74 (step 504).

Now, the writing of variable record data to the first t2 magnetic stripe of the prepaid card 4 will be explained with reference to FIGS. 6 and 9.

The controller 80 receives variable data (
9a) in the memo 1J8 according to the timing signal Sw.
1 is stored. In this way, the variable data stored in Memo'J81 is modulated and output as follows. First, a waveform signal is read from the ROM 82 at a predetermined timing, and the 9th waveform signal is read out by the DA converter 83.
A waveform signal as shown in the figure is generated and input to the VFO 85. Thereby, the VFO 85 forms a frequency signal according to the voltage of the input waveform signal shown in FIG. This VFO1
The frequency signal from 26 is used as a timing signal for reading variable record data from memo U131. In other words, the readout timing is variable according to the waveform signal, and the output signal thus read becomes recording variable data in which the bit interval changes according to the waveform signal, as shown in FIG. 9C. As a result, the variable recording data modulated by the waveform signal is supplied to the read/write card 74 via the amplifier circuit 85 and written on the first magnetic stripe 5 of the prepaid card 4.

FIG. 9d shows variable record data written on the first magnetic stripe 5 of the prepaid card 4. FIG.

Regarding the operation of the magnetic card terminal device, especially the reproduction operation> The operation of the magnetic card terminal device 10 will be explained in more detail using FIG. 11.

When the taxi 12 is used and the user reaches the destination, he or she turns his arm 43 and pays the bill. As a result, the taxi usage fee is displayed on the display 42 (step 600).

Here, it is assumed that payment is made using the prepaid card 4 without considering cash payment.

Next, the usage fee is displayed on the display 34 of the magnetic card terminal device 10 (step 601). Next, it is determined whether the prepaid card 4 has been inserted into the card insertion/ejection port 35 of the magnetic card terminal device 10 (step 601). 60
2). Here, when the photocoupler 104 detects that the prepaid card 4 is inserted into the card insertion/ejection port 35, the controller 110
until the step motor 10 contacts the contact sensor 102.
Rotate 2. As a result, recordable variable data is transmitted from the first magnetic stripe 5 of the prepaid card 4 via the read/write head 92, and control data is transmitted from the second magnetic stripe 6 of the prepaid card 4 via the read head 93. are respectively read out (step 60
3).

The control data is shaped by the waveform shaping circuit 106 and input to the controller 110. Further, the variable recording data read out from the first magnetic stripe 5 of the prepaid card 4 by the read/write head 92 becomes a signal as shown in FIG. be done.

Then, in the recording/reproducing circuit 105, the input recording variable data is processed by the waveform shaping circuit 121 to form a signal as shown in FIG. 9F, and then the same signal as FIG.
Obtain as shown in Figure g. This recording variable data is temporarily stored in the memory 122 under the control of the processing device 120 of the controller 110 in accordance with the timing signal Sw+. In addition, in order to retrieve variable data from the memo U122, switch 123 is switched to the ROM124 side, and the ROM12
Read out the reverse waveform signals shown in Figures 4 to 9, and
The A converter 125 converts the signal into a waveform signal, and the VFO 126 forms a frequency signal according to the input voltage.

This frequency signal from the VFO 126 is used as a timing signal for reading variable data from the memory 122. Since the timing is inversely related to the bit interval of the recorded variable data stored in the memory 122, the variable data is read out from the memory 122 and output as a signal identical to the variable data shown in FIG. 9a. 9 is obtained and demodulated as shown in FIG. This variable data is provided to the processing unit 120 of the controller 110. The variable data thus read out is deducted from the desired price. In addition, usage fees, usage dates and times,
The issuer and other data are stored in the memory 130, and the data such as the deducted amount is stored in the processing device 120.
is stored in the memory 131 under the control of.

Then, the processing device 120 of the controller 110 switches the switch 123 to the ROM 132 side to perform rewriting processing (step 605). This rewriting operation is as follows.

First, when a rewriting operation is to be performed, the step motor 103 is rotated in the reverse direction, and if it is the timing to drive the punch mechanism 97, it is driven. Then, the processing device 1
20 stores the deducted amount and other necessary data in the memory 131 in accordance with the timing signal SWZ. The variable data (FIG. 9a) stored in the memo 17131 in this way is modulated and output as follows.

First, switch the switch 123 to the ROM 132 side,
The waveform signal is read from the ROM 132 and the DA converter 12
5, set the waveform signal as shown in Fig. 9, and set the VFO126
Enter. Thereby, the VFO 126 forms a frequency signal according to the input voltage. The frequency signal from this VFO 126 reads variable recording data from the memo U 131.

As a result, variable recording data as shown in FIG. 9C modulated by the waveform signal is supplied to the read/write head 92 via the amplifier circuit 133. Then, the information will be recorded on the first magnetic stripe 5 of the prepaid card 4 as shown in FIG. 9d.

It operates in this way, modulating the variable data/event shown in Figure 9a with the waveform signal shown in Figure 9S to obtain recordable variable data as shown in Figure 9C, and then prepay this recordable variable data. Magnetic recording is performed on the first magnetic stripe 5 of the card 4. Furthermore, when reproducing, the recording variable data read from the first magnetic stripe 5 of the prepaid card 4 (Fig. 9g)
) is demodulated using the reverse waveform signal shown in Figure 9, thereby obtaining the original variable data. Therefore, as long as there is no waveform signal or reverse waveform signal, it is impossible to tamper with the recordable variable data recorded on the first magnetic stripe 5 of the prepaid card 4, thereby ensuring data protection and system safety. It will be possible to achieve this goal.

In the above embodiments, a sine wave is used as the waveform signal and the inverse waveform signal, but the present invention is not limited to this, and triangular waves, square waves, etc. may also be used.

〔Effect of the invention〕

As described above, the present invention modulates variable data with a predetermined waveform signal to obtain recordable variable data, magnetically records this recordable variable data on the first magnetic stripe of a prepaid card, and when reproducing it. , recorded variable data leaked from the first magnetic stripe of a prepaid card,
Since the demodulation is performed using a reverse waveform signal to obtain the original variable data, it is impossible to tamper with the recorded variable data recorded on the first magnetic stripe of the prepaid card, and the data is protected. This has the effect of increasing the safety of the system.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing an embodiment of the present invention, Fig. 2 is an explanatory diagram showing a prepaid card used in the embodiment of the present invention, and Fig. 3 is a perspective view of a magnetic card issuing machine used in the embodiment. 4 is a front view showing the magnetic card terminal device used in the same embodiment, FIG. 5 is a configuration diagram showing details of the magnetic card issuing machine of the same embodiment, and FIG. 6 is a diagram showing the details of the magnetic card issuing machine of the same embodiment. FIG. 7 is an explanatory diagram showing the details of the magnetic card terminal device, FIG. 8 is an explanatory diagram showing the signal system of the magnetic card terminal device, and FIG. 9 is an explanatory diagram showing the signal system of the same embodiment. FIG. 10 is a flowchart showing the operation of the magnetic card issuing machine, and FIG. 11 is a flowchart explaining the operation of the magnetic card terminal device. DESCRIPTION OF SYMBOLS 1... Magnetic card recording system, 2... Magnetic card issuer, 3... Magnetic card issuing machine, 4... Prepaid card (magnetic card), 5... First magnetic stripe, 6... ... Second magnetic stripe, 10... Magnetic card terminal device, 12... Taxi-213... Taxi meter, 14... Tally card, 15... Processing device. Figure 2

Claims (1)

[Claims] In a magnetic card recording system capable of recording information using a magnetic card capable of magnetically recording variable data, the magnetic card is provided with a first magnetic recording area for recording variable data, and control data is recorded. A second magnetic recording area is provided, and during magnetic recording, variable data obtained by modulating the variable data with a predetermined waveform signal provided in advance is written into the first magnetic recording area of the magnetic card and reproduced. Sometimes, recording variable data and control data are read from each of the magnetic recording areas of the magnetic card, and demodulated based on the control data and a previously provided reverse waveform signal to obtain regular variable data. A unique data protection method for magnetic cards.