JP4374000B2 - Card holder with anti-skimming function for RFID - Google Patents

Description

  The present invention relates to a card holder having a skimming prevention function for RFID (Radio Frequency Identification) including a non-contact IC card, and more particularly, makes a contained RFID easily usable as necessary. The present invention also relates to a card holder that can prevent skimming when not in use and facilitate reading of stored information when in use.

  As one of the means used by companies for advertising their company names and their products, advertising cards with printed advertisements are created. These advertising cards are generally placed in restaurants so that they can be taken home freely, and are distributed free of charge at places where many people gather, such as around the station and event venues.

However, since the distributed advertising card is often discarded immediately, it is difficult to increase the advertising effect. In view of this, an advertising card has been devised in which a function and privilege other than the advertisement are added to make it practical and have been devised to maintain the advertising effect for a long period of time.
For example, the advertising card described in Patent Document 1 maintains the advertising effect by holding the advertising card for a period until the mouth of the refreshing agent by providing the oral refreshing agent on the card on which the advertisement is described so as to be peelable. It is possible.

By the way, in the case of the advertising card of patent document 1, the perforation is provided so that the advertisement information posting part of the advertising card can be left even after using the refreshing agent. However, this perforation, on the contrary, may leave the advertising card part, leaving only the cooling agent. In addition, although a refreshing agent such as gum is a food that can be stored, the flavor can be lost after a long period of time, so the period of distribution is limited.
Therefore, it is desirable to provide a storable and practical card for the holder so that it can be held for a long time.

Therefore, the inventor noticed that the advertising card and the bank card stored in a wallet or the like have approximately the same size, and considered using the advertising card to prevent skimming of the bank card or the like. It was. In particular, since prevention of skimming of non-contact IC cards, which has been rapidly spreading in recent years, is a social urgent matter, it has been conceived that an advertising card is provided with a non-contact IC card skimming prevention function.
Utility Model Registration No. 3058830 Utility Model Registration No. 3066214 Utility Model Registration No. 3106094

  In order to prevent skimming of a non-contact IC card, a non-contact IC card sending envelope described in Patent Document 2, a portable container described in Patent Document 3, and the like have been devised. However, in the former case, skimming cannot be prevented after the non-contact IC card is delivered to the customer. In the latter case, there is a problem that the cost is increased because the material is made of a special material, and the currently used bag must be replaced.

  In addition, using a technique for preventing skimming by shielding electromagnetic waves and magnetism as in Patent Documents 2 and 3, depending on the frequency of electromagnetic waves generated by a skimmer (a device that illegally reads information recorded on a card) is sufficient. There was a problem that the effect could not be obtained.

  In view of the problems as described above, the present invention provides a housing by attaching a card having an anti-skimming function for RFID, which includes a thin metal plate and a decorative plate laminated on the front and back of the thin metal plate. A card holder for preventing unauthorized reading of a non-contact IC card, wherein a sliding part movable in the opening direction, a bottom part and a sliding part are provided inside a container having an opening formed by combining a lid part and a bottom part. A card having an RFID skimming prevention function is attached to the lid, which has an urging means for locking the both ends and moving the slide, and a stopper for stopping the slide at a predetermined position in the container. The same thin metal plate as that used for the card with the RFID skimming prevention function is attached to the bottom, and the slide portion is moved to the open state. The reader can read the non-contact IC card inserted in the slide portion. When the slide portion is in the closed state, the card having the RFID skimming prevention function and the metal thin plate prevent the non-contact IC card from being read. .

  In this card holder, a card having an RFID skimming prevention function includes a metal thin plate made of gold, silver, copper, or aluminum, and a decorative plate made of PET (polyethylene terephthalate) or PVC (polyvinyl chloride). Is provided.

  Further, in this card holder, a ferrite plate is attached to the slide portion, and when the slide portion is moved, the ferrite plate facilitates reading of the non-contact IC card by the reader.

  According to the card holder of the present invention, it is possible to prevent the information recorded on the non-contact IC card accommodated when being carried from being read, and to temporarily read this information by a simple operation when used. Further, since a card having a skimming prevention function on which an advertisement or the like is printed is fitted in a replaceable manner, a card with a different design can be mounted according to the user's preference, and the decorativeness can be enhanced. Furthermore, when a non-contact IC card is used, the recorded information can be easily read by the reader.

Embodiments of the present invention will be described with reference to the drawings.
First, an operation when a reader or a skimmer reads information recorded on a non-contact IC card will be briefly described.
FIG. 2 shows an antenna coil 5 of a non-contact IC card reader, a magnetic field 8 generated by the coil 5, and an antenna coil 4 of the non-contact IC card and a demagnetizing field (A) 6 generated by the coil. .
In the case of a non-contact IC card which is currently widely used, communication is not started from the card side in order to prevent interference. The reader periodically issues a request command signal, and the card responds to the request command signal.

  When a current flows through the coil 5 on the reader side, a magnetic field 8 is generated, and a part thereof passes through the non-contact IC card side coil 4. At this time, the card-side coil 4 converts the magnetic flux into a current, which is used as a power source for the IC. Further, a magnetic field (demagnetizing field (A)) 6 opposite to the magnetic field 8 from the reader 5 is generated, and thereby a response to the request command signal of the reader 5 is performed.

  FIG. 1 is a schematic cross-sectional view of a card 1 having a non-contact IC card skimming prevention function. As shown in the figure, the card 1 includes a thin metal plate 2 and decorative plates 3a and 3b. One of gold, silver, copper, and aluminum is used for the metal thin plate 2, and the decorative plates 3 a and 3 b are obtained by laminating the metal thin plate 2 using PET (polyethylene terephthalate) or PVC (polyvinyl chloride). It is. The metal thin plate 2 will be described later.

  As shown in FIG. 3, when the card 1 is arranged close to the non-contact IC card 4, an eddy current 9 is generated in the thin metal plate 2 of the card 1 when receiving the magnetic field 8 generated by the reader 5. The eddy current 9 generates a demagnetizing field (B) 7 that cancels the magnetic field 8 of the reader 5, and the non-contact IC card 4 is not activated. Therefore, information recorded on the non-contact IC card 4 is not read.

  Thus, skimming of the non-contact IC card 4 can be prevented by using the eddy current. However, the eddy current generated in the thin metal plate 2 varies depending on the thickness, relative magnetic permeability, and electrical conductivity of the metal, and the information recorded on the non-contact IC card can be read by not starting the IC chip. It has not been known in the past how much eddy current is appropriate to prevent.

To activate a proximity IC card with a cryptographic coprocessor, a magnetic field strength of 4 A / m is required. In ISO 14443 and ISO 18092, the maximum magnetic field strength is set to 12 A / m. If the magnetic field strength exceeds this value, the non-contact IC card is damaged. That is, it is necessary to use a thin metal plate having an attenuation factor that can suppress the magnetic field intensity to one third or less for a card having a skimming prevention function.
In view of this point, the following Experiments 1 to 3 were performed in order to clarify a metal suitable for a card having a skimming prevention function.

<Experiment 1>
First, an experiment as shown in FIG. 4 is performed using ferrite, which is a metal that generates a small amount of eddy current, and the receiving antenna 4 and the transmitting antenna 5 are placed apart from each other. The attenuation rate between the case where the ferrite test piece 100 is arranged between (inside) and the case where the ferrite test piece 100 is similarly arranged on the back surface (outside) of the receiving antenna 4 was examined. Table 1 shows measured values at the receiving antenna 4.

  The thickness of the ferrite test piece 100 used in Experiment 1 is 0.5 mm, the thickness (d) of the substrates (the receiving antenna 4 and the transmitting antenna 5) is 1.6 mm, and the distance between the substrates, that is, the receiving antenna 4 and the transmitting antenna 5 is The installation interval (L) was 25 mm, the measured value (dBm) when the test piece 100 was not disposed was -19.3961, and the frequency was 13.56 MHz. Note that the value of this frequency is the same as the operating frequency of the non-contact IC card in conformity with the ISO 14443 standard.

  In Table 1, “inner side” of “shield material position” indicates the distance a from the receiving antenna 4 to the test piece 100 shown in FIG. 4, and “outer side” indicates the distance b from the receiving antenna 4 to the test piece 100. ing. Moreover, the measured value (dBm) of an attenuation factor and the value converted into the decibel value (dB) are shown side by side.

According to Table 1, ferrite exhibits a magnetic field shielding effect when placed inside, that is, between the receiving antenna 4 and the transmitting antenna 5, but amplifies the magnetic field when placed on the outside, that is, the back surface of the receiving antenna 4. I understand that.
As described above, Experiment 1 revealed that skimming cannot be prevented with a metal having a small eddy current, such as ferrite, and this may be promoted. Therefore, such a metal cannot be used for the card 1.

<Experiment 2>
Next, in order to investigate the magnetic field attenuation rate due to the thickness of the metal, changes in the magnetic field attenuation rate were measured by the KEC method using aluminum plates having different thicknesses from the deposited one to 2 mm. FIG. 5 shows the measurement results, where the vertical axis represents the attenuation rate and the horizontal axis represents the frequency.

  According to FIG. 5, it can be seen that the attenuation rate of aluminum at the frequency of 13.56 MHz described above is generally higher as it is thicker. Therefore, if a thick aluminum plate is used as the metal thin plate 2 used for the card 1, it is considered that a high skimming prevention effect can be provided.

  However, since the card 1 needs to be carried together with the non-contact IC card, it is desirable that the card 1 has a thickness that does not cause inconvenience when stored in a wallet or the like. Therefore, considering that the decorative plates 3a and 3b are laminated, the thickness of the thin metal plate is set to 100 μm at the maximum. In addition, since the measurement by the KEC method is performed in an anechoic chamber, the result of Experiment 2 may be different from the actual usage situation. Therefore, the following experiment 3 was performed.

<Experiment 3>
From Experiment 2, it is conceivable to use aluminum for the metal thin plate 2 in the card 1. Therefore, an experiment similar to Experiment 1 was performed using an aluminum plate. That is, as shown in FIG. 4, the aluminum test piece 100 is disposed between the receiving antenna 4 and the transmitting antenna 5 that are spaced apart (inner side), and the rear surface (outer side) of the receiving antenna 4 is aluminum. The attenuation rate was measured when the test piece 100 was placed. The results are shown in Table 2.

  The thickness of the aluminum test piece 100 used in Experiment 2 is 35 μm, the substrate thickness (d) is 1.6 mm, and the installation interval (L) between the substrates, that is, the reception antenna 4 and the transmission antenna 5 is 25 mm. When not arranged, the measured value (dBm) was -19.3961 and the frequency was 13.56 MHz.

  According to Table 2, aluminum exhibits a magnetic field shielding effect both inside, that is, when interposed between the receiving antenna 4 and the transmitting antenna 5, and when placed outside, that is, on the back surface of the receiving antenna 4. I understand that. In particular, when the inner position is −1.6 mm and the outer position is 0 mm, the former converted value is −12.96 dB and the latter converted value is −10.69 dB. Even if it is assumed that there is a measurement error of about 1 dB, the respective values are -11.96 dB and -9.69 dB, so that the aluminum test piece 100 can be used either inside or outside the receiving antenna 4. It was revealed that a high attenuation rate can be obtained when the is installed in the vicinity.

  FIG. 6 is a graph of the values shown in Table 1 and Table 2. In the figure, the vertical axis represents the converted value (dB) of the attenuation rate. Further, the horizontal axis indicates the distance a to the test piece 100 in which a positive value is arranged on the inner side, and the distance to the test piece 100 in which a negative value is arranged on the outer side, where 0 is the position of the receiving antenna 4. represents b. It can be seen that aluminum exhibits a high attenuation factor when placed in the vicinity of the receiving antenna.

From the above experiments 1 to 3, it was found that aluminum is suitable as the metal used for the thin metal plate 2 when trying to obtain the effect of preventing skimming by the action of eddy current.
Next, the availability of metals other than aluminum will be examined. Table 3 shows the conductivity, relative permeability, and skin depth at 10 MHz of various metals such as gold, silver, copper, and aluminum.

As described above, the eddy current varies depending on the metal thickness, relative magnetic permeability, and electrical conductivity. Therefore, from the values shown in Table 3, when gold, silver, or copper is used for the metal thin plate 2, it is considered that an effect superior to aluminum can be obtained.
Regardless of which metal is used, the card 1 is provided with decorative plates 3a and 3b on the front and back of the thin metal plate 2. The decorative plates 3a and 3b include advertisements such as company names and product names, and commemorative photos. It is possible to print a desired character or picture. Further, the produced card 1 can be distributed in the same way as a conventional advertising card. For example, if distributed at a financial institution or the like, it is possible to further improve skimming.

Next, an embodiment of the card holder provided by the present invention will be described.
7 and 8 are a perspective view and an exploded perspective view of the card holder 10 according to the present invention. As shown in FIG. 8, the card holder 10 is formed by combining a lid portion 11, a slide portion 12, and a bottom portion 13. The lid portion 11 has six claw portions 110 on the side portion. Further, a groove 112 is provided on the upper surface of the lid portion 11 along the inner edge so that the card 1 having the above-described skimming prevention function can be fitted therein.

  The bottom portion 13 includes six concave portions 130 corresponding to the claw portions 110 of the lid portion 11, and the claw portion 110 and the concave portion 130 are fitted when the case 10 is assembled. Further, the same metal plate 133 as the metal thin plate 2 used in the card 1 having the above-described skimming prevention function is bonded to the bottom portion 13, and the first spring 131, the second spring 132, and the second spring 132 are attached. And a button 14 that cooperates. In this embodiment, the metal plate 133 is an aluminum plate. The first spring 131 is locked at one end to the column (A) 15 of the bottom portion 13 and at the other end to the column (B) 16 provided on the slide portion 12, and when the holder 10 is in the closed state. It is in a stretched state.

  The slide portion 12 is formed slightly smaller than the lid portion 11 and the bottom portion 13 and has a holding claw 120 and a stopper 121. The holding claw 120 is for holding the non-contact IC card 4 so that the card 4 is not displaced or detached when the non-contact IC card 4 is placed on the slide portion 12. A ferrite plate 123 is bonded to the slide portion 12.

  The card holder 10 is carried in a closed state as shown in FIG. At this time, the card 1 made using the aluminum thin plate 2 is fitted on the upper surface of the holder, and the aluminum plate 133 bonded to the bottom 13 is provided on the bottom surface. Since the non-contact IC card 4 is interposed between these aluminum plates, it does not start even if it receives a magnetic field from the reader 5 or the gap.

  On the other hand, the card holder 10 is used in an open state as shown in FIG. When the user presses the button 14 in the closed state, the first stopper 121 of the slide portion 12 that is fastened to the button 14 is released, and the first spring 131 that is in the extended state contracts in the closed state. As a result, the slidable portion 12 urged out of the housing body including the lid portion 11 and the bottom portion 13 can be used for the non-contact IC card 4. At this time, since the second stopper 122 of the slide portion 12 is accommodated in the stopper receiving portion 134 of the bottom portion 13, the slide portion 12 is not detached from the card holder 10 and separated. The button 14 is urged by the second spring 132 and returns to the original position.

Here, as described above, the ferrite plate 123 is bonded to the slide portion 12. This point will be described in detail.
As is clear from Experiment 1, ferrite has an effect of promoting reading of the non-contact IC card 4 when receiving a magnetic field from the reader 5. Therefore, by adhering the ferrite plate 123 to the slide portion 12, when the card 4 is used, the information recorded in the non-contact IC card 4 accommodated in the card holder 10 can be surely read by the reader 5. I have to.
In order to clarify the effect of such ferrite, an experiment as shown in FIG. 4 was performed again using ferrite plates having different thicknesses and relative magnetic permeability.

<Experiment 4>
First, in order to clarify the relationship between the effect of promoting the reading of information of the non-contact IC card 4 and the thickness, a ferrite test piece 100 having a different thickness is brought into close contact with the back surface (outside) of the receiving antenna 4 to thereby read the reader. The amplification factor when receiving a magnetic field from 5 was measured. As a result, the values shown in Table 4 were obtained. This value is graphed as shown in FIG.

表４および図７より、フェライトの試験片１００が厚いほど増幅率が高いことがわかる。すなわち、フェライト板の厚さと増幅率とは比例関係にあるといえる。

From Table 4 and FIG. 7, it can be seen that the thicker the ferrite test piece 100, the higher the amplification factor. That is, it can be said that the thickness of the ferrite plate is proportional to the amplification factor.

<Experiment 5>
Next, in order to clarify the relationship between the effect of promoting the reading of information of the non-contact IC card 4 and the relative permeability, the ferrite test piece 100 having a different relative permeability is closely attached to the back surface (outside) of the receiving antenna 4. Then, the amplification factor when receiving the magnetic field from the reader 5 was measured. As a result, the values shown in Table 5 were obtained.

  From the previous experiment 4, it became clear that the thickness of the ferrite plate and the amplification factor have a proportional relationship. In Experiment 5, since ferrite plates having different thicknesses are used, conversion gains with respect to a thickness of 0.1 mm are obtained for the test pieces D, E, F, and B, and this is indicated as the gain at the same thickness. Yes.

  Here, paying attention to the relative magnetic permeability and the converted amplification factor, it can be seen that the value indicated as the converted amplification factor is generally larger as the relative permeability is higher. That is, it can be said that the relative permeability and the amplification factor of ferrite are in a proportional relationship. When the proportionality constant is obtained by dividing the conversion gain by the relative permeability, it is 0.26260 (average value).

  As already described, the maximum magnetic field strength in ISO14443 is 12 A / m. Since the maximum magnetic field intensity generated by the high-power IC card reader is 10 A / m, the amplification factor for amplifying this to 12 A / m is 1.584 dB. On the other hand, the maximum magnetic field strength generated by a generally used IC card reader is 7.5 A / m, and the amplification factor for amplifying this to 12 A / m is 4.082 dB. In calculating the proportionality constant described above, considering that there was a variation of about ± 10% depending on the test piece, the minimum amplification factor was 1.425 dB (1.584 dB × 90%), and the maximum amplification factor was 4.490 dB. (4.02 dB × 110%).

From the above, when the relative permeability is μr and the thickness is t, the range of the amplification factor of the ferrite plate suitable for use in the present invention can be expressed as the following formula (1).
1.584 dB ≦ 0.2660 × μr × t ≦ 4.082 dB (1)
In considering the above-described proportionality constant calculation, considering that there is a variation of about ± 10% depending on the test piece, the minimum proportionality constant is 0.2394 (0.2660 × 90%), and the maximum proportionality constant is 0.2926. (0.266 × 110%).

Considering this point, the following formula (2) is obtained.
5.413 ≦ μr × t ≦ 17.050 (2)
However, in order not to damage the IC card, when the proportional constant is set to 0.2926, which is the maximum, Equation (3) is obtained.
5.413 ≦ μr × t ≦ 13.950 (3)
That is, if a ferrite plate whose product of relative permeability and thickness (mm) is a value within the range of Equation (3) is used while considering the type of reader, the non-contact IC card can be damaged. And efficient communication.

  As already shown in Table 2, when the ferrite plate is disposed outside the receiving antenna 4, the magnetic field is amplified. Therefore, when using the non-contact IC card 4 accommodated in the card holder 10, it is desirable to open the holder 10 and hold it over the reader 5 so that the surface on the lid 11 side faces the transmitting antenna. Then, since the magnetic field is amplified by the ferrite plate 123 located on the back surface of the card 4, the information recorded on the IC card 4 can be read smoothly. At this time, the communicable distance between the IC card 4 and the reader 5 is increased, which is more convenient for the user. Table 6 shows the communicable distance between the case where the non-contact IC card is used alone and the case where the ferrite is adhered (IRL05AB, IVM06, IRLF04AB (0.1) listed as names in Table 6) All are products of TDK Corporation).

カードホルダ１０は、使用が済んだらスライド部１２を手などで収容体に押込むことにより、再び閉状態となる。

When the card holder 10 is used, the slide part 12 is again closed by pushing the slide part 12 into the container by hand.

  As described above, according to the card 1 having the RFID skimming prevention function, the information stored in the non-contact IC card can be obtained by carrying it together with the RFID including the non-contact IC card. It is possible to prevent a situation in which the data is illegally read without knowing.

  Furthermore, according to the card holder of the present invention, when the slide part 12 is accommodated in the closed state when being carried, the card attached to the upper surface of the lid part 11 and the aluminum plate 133 bonded to the bottom part 13 are skimmed. Demonstrate the prevention function. In use, the slide portion 12 slides to the open state, and the non-contact IC card 4 is not completely sandwiched between the card 1 and the aluminum plate 133, and a large deviation occurs. Therefore, the IC card 4 is activated by the magnetic field from the reader, and the stored information can be read. Since it is possible to temporarily read a non-contact IC card as needed by simply pressing a button, it is convenient to respond quickly when, for example, passing a ticket gate of public transportation. After use, the slide part 12 is pushed back to the closed state, thereby preventing skimming again.

Furthermore, for example, if an advertisement is applied to the back surface of the slide portion 12, it is possible to exert an advertising effect by touching the eyes of the user or the like only when the card holder 10 is used.
The card 1 attached to the holder 10 can be exchanged, and the user can mount a card with a different surface printing according to his / her preference to make a highly decorative card holder.

  In the present invention, a card holder that accommodates only one non-contact IC card 4 has been described. However, the present invention is not limited to this, and a structure that can accommodate a plurality of cards can also be adopted. Alternatively, not only the non-contact IC card but also other cards, business cards, etc. can be accommodated together.

FIG. 3 is a schematic cross-sectional view of an RFID skimming prevention card. Schematic explaining the operation of a general non-contact IC card and a non-contact IC card reader. Schematic explaining the example of skimming prevention using the skimming prevention card for RFID. Schematic which shows the measurement experiment of an attenuation factor. The figure which shows the attenuation factor by the thickness of aluminum. The figure which shows the distance dependence of the received voltage of a ferrite and aluminum. The perspective view of the card holder of this invention. The disassembled perspective view of the card holder of this invention. The figure which shows the relationship between the thickness of a ferrite, and an amplification factor.

Explanation of symbols

1 card 2 metal thin plate 3a decorative plate 3b decorative plate 4 non-contact IC card (card side coil, receiving antenna)
5 Non-contact IC card reader (reader side coil, transmitting antenna)
6 Demagnetizing field (A)
7 Demagnetizing field (B)
8 Magnetic field 9 Eddy current 10 Card holder 100 Test piece 11 Lid portion 110 Claw portion 12 Slide portion 120 Holding claw 121 First stopper 122 Second stopper 123 Ferrite 13 Bottom portion 130 Recess portion 131 First spring 132 Second spring 133 Aluminum plate 134 Stopper Receiver 14 Button 15 Pillar (A)
16 Pillar (B)

Claims (3)

A card holder for preventing unauthorized reading of a stored non-contact IC card by attaching a card having an anti-skimming function for RFID consisting of a thin metal plate and a decorative plate laminated on the front and back of the thin metal plate. ,
Inside the container having an opening formed by combining a lid part and a bottom part, a slide part movable in the opening direction, and both ends fixed to the bottom part and the slide part are attached to move the slide part. Biasing means, and a stopper for stopping the slide portion from moving at a predetermined position in the container,
A card having the RFID skimming prevention function is attached to the lid part, and the same metal thin plate as that used for the card having the RFID skimming prevention function is attached to the bottom part, and the slide part is moved. The non-contact IC card inserted into the slide portion can be read by a reader when the slide portion is in the open state, and when the slide portion is accommodated in the closed state, the card having the RFID skimming prevention function and the thin metal plate Prevents the reading of the non-contact IC card. The card holder according to claim 1,
The card having the RFID skimming prevention function is
A metal thin plate made of gold, silver, copper, or aluminum;
A decorative board made of PET (polyethylene terephthalate) or PVC (polyvinyl chloride);
A card holder comprising: In the card holder according to claim 1 or 2,
A card holder, wherein a ferrite plate is attached to the slide portion, and the ferrite plate facilitates reading of the non-contact IC card by a reader when the slide portion is moved and opened.

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