JP2741417B2 - Magnetic card validity determination method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for determining the validity of a magnetic card suitable for use in a prepaid card or the like.

2. Description of the Related Art Generally, information magnetically recorded on a magnetic recording layer provided on a magnetic card used for a prepaid card, etc.
Since a person who has knowledge of magnetic recording can rewrite, forgery or falsification of a card has been used illegally. To resolve these issues,
Conventionally, various methods have been proposed in which two types of magnetic information recording units are provided, different information is given to the two types of magnetic information recording units, and the information is compared with each other to prevent unauthorized use.

For example, Japanese Patent Application Laid-Open No. 62-62478 provides two types of magnetic information recording units, one of which stores key code data and the other magnetic information recording unit uses the key code data. A method of recording encrypted data and processing a magnetic card is disclosed.

However, according to such a conventional method, the magnetic card is
The manufacturing process is complicated due to the layer structure, and the magnetic material forming the magnetic information recording section for recording key code data and encrypted data is the same as the magnetic material used for ordinary magnetic cards. Once decrypted, the encrypted data can be easily rewritten with a commercially available magnetic card reader, and therefore, there has been a problem that the magnetic card can be easily forged or falsified.

An object of the present invention is to provide a magnetic card validity determination method that can solve such a conventional problem.

Means for Solving the Problems According to the present invention, a magnetic layer used as a magnetic information recording track is provided on the surface of a non-magnetic substrate, and has a considerably higher coercive force at room temperature as compared with the coercive force of the magnetic layer. The surface of the non-magnetic substrate having a Curie point considerably lower than the Curie point of the magnetic layer and having a magnetic layer used as a collating track different from the magnetic layer used as the magnetic information recording track In order to determine the validity of the magnetic card in which the collation data created based on the information data magnetically recorded on the magnetic information recording track is thermomagnetically recorded, the magnetic layer used as the collation track provided in the In the method, information data magnetically recorded on the magnetic information recording track is read at room temperature, and collation data is calculated based on the read information data. Read the collation data recorded thermomagnetically on the collation track,
Compare the collation data calculated based on the information data with the collation data read from the collation track.If the collation data matches, the information data read from the magnetic information recording track is used. If the matching data does not match, the information processing is not performed as a counterfeit card.

According to the present invention, in the above-described method for determining the validity of a magnetic card, security can be increased by DC degaussing the collation track before reading the collation data from the collation track. .

Still further, according to the present invention, in the magnetic card validity determination method described above, before performing information processing based on the information data read from the magnetic information recording track, the collation track is thermally demagnetized to perform the collation. When the collation data is read from the data track, and when the collation data is read, the information processing is not performed as a counterfeit card, so that the security can be increased.

Next, the present invention will be described in more detail with reference to the accompanying drawings.

FIG. 1 is a schematic plan view showing a magnetic card as one embodiment of the present invention, and FIG. 2 is an enlarged sectional view taken along line XX 'of FIG. The magnetic card 1 of this embodiment has a magnetic layer 3 formed as stripes on a surface of a non-magnetic substrate 2 for use as magnetic information recording tracks, and a surface portion of the non-magnetic substrate 2 different from the magnetic layer 3. And has a considerably higher coercive force than the coercive force of the magnetic layer 3 at room temperature and has a considerably lower Curie point than the Curie point of the magnetic layer 3 at room temperature. And a magnetic layer 4 to be used.

The non-magnetic substrate 2 may be plastic, paper, or a non-magnetic metal plate. In particular, when using plastic, polyethylene terephthalate (PE) with excellent heat resistance
It is desirable to use a T) or polyimide substrate.

The magnetic layer 3 used as a magnetic information recording track is formed by dispersing barium ferrite powder having a coercive force at room temperature of 2750 Oe and a Curie point of 450 ° C. in an appropriate resin to form an ink, and performing gravure printing, offset printing, nozzle coating or hot coating. It is formed by a method such as a stamp.

The coercive force at room temperature of the magnetic material used for the magnetic layer 4 used as the collating track is so high that it cannot be written by a magnetic head used for writing a normal high coercive force magnetic card, and the magnetic material used as the magnetic information recording track. Desirably, it is at least 2.5 times the layer 3. Generally, it is said that the strength of the recording magnetic field required for saturated writing on a magnetic medium is at least twice as large as the coercive force of the medium. However, the saturation of a sendust head normally used for writing a high coercive force card is considered. Since the magnetic flux density is about 10KG, the coercive force of the medium that can be saturatedly recorded by the sendust head is 5,000 Oe or less.

Therefore, the coercive force at room temperature of the magnetic material used for the magnetic layer 4 of the magnetic card according to the present invention must be greater than 5000 Oe.

Here, the reason why the coercive force at room temperature of the magnetic layer 4 used as a track for comparison is 2.5 times or more the coercive force of the magnetic layer 3 used as a magnetic information recording track will be described.

FIG. 3 is a diagram illustrating DC demagnetization characteristics of magnetic layers having various coercive forces in the case of using a normal magnetic card reader. In FIG. 3, curves B, C and D correspond to curve A
3 shows an example of characteristics of a magnetic layer having a coercive force of 1.8, 2.5 and 3.6 times the coercive force of the magnetic layer represented by. The DC demagnetizing current value on the horizontal axis in FIG. 3 is standardized with the current value at which the magnetic layer represented by the curve A is almost completely demagnetized as 1.

FIG. 4 is a diagram in which the relative output of each curve on the horizontal axis scale 1 in FIG. 3 is read, and the horizontal axis represents the coercive force of each magnetic layer, and rewritten. Note that the coercive force is normalized with the value of the magnetic layer represented by the curve A as 1. As can be seen from FIG. 4, in order for one of the two magnetic layers to be completely unaffected by the current value at which the other is completely demagnetized, the coercive force of the latter is 2.5 times the coercive force of the former. It is necessary to be above.

It will be understood that this is important in implementing the magnetic card validity determination method of the present invention described later.

On the other hand, the Curie point of the magnetic material used for the magnetic layer 4 of the magnetic card according to the present invention is preferably 200 ° C. or less from the heat resistance of the base when plastic is used for the card base 2. If the Curie point of the magnetic layer is 200 ° C or higher, 200
Even if degaussing is performed by applying heat of not less than ° C., a reading error occurs because the nonmagnetic substrate is thermally deformed. It will be understood that this is important in implementing the magnetic card validity determination method of the present invention described later.

In the present embodiment, a gallium-substituted strontium ferrite powder having a coercive force at room temperature of 8000 Oe and a Curie point of 160 ° C. is dispersed in an appropriate resin to form an ink, which is then subjected to gravure printing, screen printing, offset printing, and letterpress printing. Alternatively, it is formed by a nozzle coat or the like.

In order to protect these magnetic layers 3 and 4, a protective layer made of a color ink or the like or a concealing layer (not shown) for making the presence of the magnetic layers invisible is provided on each magnetic layer. good.

Next, with respect to such an embodiment of the magnetic card validity determination method according to the present invention, while writing and reading information to and from the magnetic card, information processing, and overall processing including card update processing, explain.

FIG. 5 is a flowchart showing a procedure of processing of the magnetic card according to the present invention. In FIG. 5, reference numeral 10
The steps in the block indicated by 0 indicate the procedure of the writing process, and the steps in the block indicated by reference numeral 200 are:
The procedure of the validity determination process is shown, and the steps in the block indicated by reference numeral 300 indicate the procedure of the magnetic card update and ejection process.

To describe the writing process, in step 101, information data such as the amount or frequency of this magnetic card when it is issued is recorded on the magnetic layer 3 at room temperature by a normal magnetic head. Next, although not shown in FIG. 5, check codes such as CRC and LRC are obtained by calculation based on the information data recorded on the magnetic layer 3, and this is used as collation data. Then, in the next step 102, the collation data is written to the magnetic layer 4. Since the magnetic layer 4 has a coercive force of 8000 Oe at room temperature and cannot perform saturated writing with a magnetic head normally used in a magnetic card reader, the coercive force of the magnetic layer 4 is 3000 Oe in step 102.
The verification data is thermally written while heating to a temperature below. Thermal writing is performed by a writing device as schematically shown in FIG. As shown in FIG. 6, the writing device can perform saturation recording on a thermal head 5 for heating the magnetic layer 4 of the magnetic card to a temperature near the Curie point and a magnetic material having a coercive force of about 3000 Oe. And a magnetic head 6. The thermal head 5 and the magnetic head 6 may be integrated into the same case, or may be separately mounted close to each other. The sixth
In the figure, arrows indicate the traveling direction of the magnetic card 1. In the writing device having such a configuration, the magnetic card 1 is transported by a transport system (not shown) in the direction of the arrow, and is heated by the thermal head 5 so that the temperature of the magnetic layer 4 reaches the Curie point. The information for specifying the card is recorded by the magnetic head 6.

The operation at this time will be described in more detail. Since the magnetic layer 4 is heated to near the Curie point when passing through the thermal head 5, the coercive force becomes almost zero. Then, the magnetic head 6
Since the temperature slightly decreases during the transfer to the point (2), the coercive force is slightly increased, but sufficient writing can be performed by the magnetic head 6. When the magnetic card 1 is ejected from the writing device and the temperature of the magnetic layer 4 returns to normal temperature, the coercive force becomes
Since it is restored to 8000 Oe again, in this state, data cannot be rewritten with a normal card reader for high coercive force.

In this embodiment, a thermal head is used as a heating unit of the writing device. However, a laser beam or an infrared ray may be irradiated, or the magnetic layer 4 may be heated by a hot roll or hot air.

Next, in order to explain the validity determination processing, the information data recorded on the magnetic layer 3 is read at step 201 in FIG. In step 202, collation data is obtained by calculation based on the information data read from the magnetic layer 3. In step 203, the magnetic layer 4 is
A DC current that completely erases the information data is passed through the magnetic head to perform DC demagnetization. Here, even if the thermomagnetic recording is forged and the data of the magnetic layer 4 is forged using a CrO ₂ tape which is relatively easily available, the collation data is demagnetized in this DC demagnetization step. Therefore, in the comparison data comparison step 205 described later, it is possible to immediately recognize that the magnetic card is a forged magnetic card.

After the DC demagnetization, in step 204, the collation data written on the magnetic layer 4 is read. Then, in Step 205, the collation data calculated in Step 202 and Step 2
Compare with the collation data read in 04. If the collation data do not match, step 209
Then, the magnetic card is regarded as a forged illegal card so that the information processing of the card body is not performed.
If the collation data matches, step 20
Proceeding to 6, the magnetic layer 4 is heated to a temperature higher than the Curie point by a heating means such as a thermal head and laser light (not shown), and thermally demagnetized.

After the thermal demagnetization, the collation data is read from the magnetic layer 4 in step 207. In step 208, it is determined whether or not the collation data has been read in step 207.

If the magnetic layer 4 is formed of a material other than the magnetic material having a low Curie point as in the present embodiment, the collation data remains after the step 206 without being erased. Therefore,
If the collation data has been read, it is determined that the card is a counterfeit card, and the process proceeds to step 209 to prevent the card from performing information processing. If the collation data is not read, it is determined that the card is a valid card, and the process proceeds to step 210, where the information processing inherent in the card is performed based on the information data read in step 201.

Finally, the procedure for updating and ejecting the magnetic card will be described.
In step 301, the information data is updated based on the result of the information processing, and the updated information data is magnetically written to the magnetic layer 3. In step 302, the collation data is also updated, and the updated collation data is thermomagnetically recorded on the magnetic layer 4. In step 303, the magnetic card whose recording data has been updated is ejected from the reading / writing device and returned to the user.

Note that key code data is recorded on the magnetic layer 4, and information data encrypted based on the key code data is recorded on the magnetic layer 3, and a random number stored in the card reader during card processing. The key code may be rewritten based on a random number generated by the generator.

In the embodiment shown in FIG. 1, the magnetic layer 3 used as a magnetic information track and the magnetic layer 4 used as a collation track are formed in separate stripes separated from each other in parallel. The invention is not so limited. For example, as schematically shown in FIG. 7, a magnetic layer 3A used as a magnetic information track and a magnetic layer 4A used as a collation track are formed on the surface of the non-magnetic substrate 2 of the magnetic card 1A. It may be formed on a stripe.
In this case, since the magnetic layer 3A and the magnetic layer 4A are on the same line, for writing and reading of the magnetic layer 3A and for writing and reading of the magnetic layer 4A,
By operating one magnetic head in a timely manner, it can be shared, so that the configuration of the device for writing and reading can be simplified.

As described above, the magnetic material used to record the data for verification of the magnetic card of the present invention has a high coercive force at room temperature and a property of having a low Curie point, and therefore, is generally used. Is difficult to obtain, so you don't have to worry about duplicate cards. Further, since a card device using the magnetic card of the present invention requires thermomagnetic recording means, it is impossible to tamper with collation data with a commercially available magnetic card device.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing a magnetic card as one embodiment of the present invention, FIG. 2 is an enlarged sectional view taken along line XX 'of FIG. 1, and FIG. 3 has various coercive forces. FIG. 4 is a diagram showing an example of the DC demagnetization characteristic of the magnetic layer. FIG. 4 is a diagram in which the relative output of each curve on the horizontal axis scale 1 in FIG. FIG. 6 is a diagram showing an example of a procedure of processing of the magnetic card of the present invention, FIG. 6 is a schematic diagram for explaining an example of a procedure for writing collation data to the magnetic card of FIG. 1, and FIG. FIG. 14 is a schematic plan view showing a magnetic card as another embodiment of the present invention. 1, 1A: magnetic card, 2: non-magnetic substrate, 3, 3A: magnetic layer as magnetic information recording track, 4, 4A: magnetic layer as track for verification, 5: thermal head, 6: ... magnetic head.

Claims (3)

(57) [Claims] 1. A magnetic layer for use as a magnetic information recording track on a surface of a non-magnetic substrate, wherein the magnetic layer has a considerably higher coercive force at room temperature as compared with the coercive force of the magnetic layer and the Curie of the magnetic layer. A magnetic layer having a considerably lower Curie point than the magnetic layer used as a reference track, provided on a surface portion of the non-magnetic substrate different from the magnetic layer used as the magnetic information recording track; A method for determining the validity of a magnetic card in which collation data created based on information data magnetically recorded on the magnetic information recording track is thermomagnetically recorded in the magnetic layer used as (a): Reading information data magnetically recorded on the magnetic information recording track, (b) calculating collation data based on the read information data; Reading the collation data thermomagnetically recorded on the rack; (d) comparing the collation data calculated based on the information data with the collation data read from the collation track; Performing the information processing based on the information data read from the magnetic information recording track when the data match, and not performing the information processing as a counterfeit card when the collation data does not match. A method for determining the validity of a magnetic card. 2. The magnetic card validity judging method according to claim 1, wherein the collation track is DC-demagnetized before the step (c). 3. In the step (e), when the collation data matches, before performing information processing based on the information data read from the magnetic information recording track, the collation track is deleted. Heat demagnetization, read the collation data from the collation track, if the collation data is read, do not perform the information processing as a forged card, the first time the collation data is not read The method according to claim 1 or 2, wherein the information processing is performed.