JP6737116B2 - Pin pad - Google Patents

Description

The present invention relates to a pin pad, for example, a pin pad provided in an ATM or the like and used when inputting a password.

As a pin pad, which is a terminal for inputting a personal identification number used in ATMs, etc., when the key is pressed, the switch contacts are short-circuited, and the switch-on key input signal is transmitted to the control device via the signal line. There is one in which an input signal is encrypted by a control device and output to the outside (for example, refer to Patent Document 1).

In the operation part of the pin pad described in Patent Document 1, the electronic component of the control device in which the information to be protected is recorded includes a rectangular frame-shaped frame member, a first substrate that closes the opening of the frame member, and a first substrate. It is housed in a box-shaped case formed of two substrates.

A flexible substrate with a wiring pattern for tamper detection is mounted on the wall surface of the frame member.If an unauthorized access to an electronic component occurs, the wiring pattern is cut or short-circuited with other signal lines, Cheating has been detected.
In addition, by covering the surface of the wiring pattern of the flexible substrate with a black resin material (PET, etc.) or attaching a black film, for example, measures are taken so that the wiring pattern cannot be seen from the outside. ..

Japanese Patent No. 5656303

However, in the conventional pin pad, although the above-mentioned measures are taken, there is a concern about security vulnerability.

First, when the flexible substrate on which the wiring pattern for tamper detection is formed is mounted on the surface of the side wall portion of the frame member, the surface of the wiring pattern is made of, for example, a black resin material (PET, etc.). Even if a coating, a black film, or the like is attached, it is relatively easy to melt or scrape the coating to expose the wiring pattern. For example, the surface of the wiring pattern can be exposed by easily and precisely melting only the attack point with heat from a soldering iron, etc., and if the exposed wiring pattern inlet and outlet are shorted with a jumper wire, Even if a hole is made in the wall surface of the frame member to cut the middle portion of the wiring pattern, the cutting of the wiring pattern cannot be electrically detected on the device side. That is, the tamper detection function can be invalidated.

For this reason, it is possible to insert a probe or the like through a hole formed in the side surface of the frame member, make contact with the signal line or electronic component connected to the switch, and read the key input signal when the key is pressed. It becomes possible and the password before encryption can be stolen.

In some cases, the wiring pattern may be formed directly on the side wall surface of the frame member, but like the flexible substrate, the wiring pattern can be exposed relatively easily. It is possible to disable the tamper function by shorting the jumper wire between the and the exit.

Further, when the wiring pattern is formed on the wall surface of the frame member by etching or the like, there is a limit to narrowing the pitch of the wiring pattern, and it is possible to form a small hole in the gap between the wiring patterns.
As described above, in the conventional pin pad, there is a concern about security vulnerability, and there is a concern that the password may be stolen, and there is room for improvement.

SUMMARY OF THE INVENTION In consideration of the above facts, an object of the present invention is to provide a pin pad capable of suppressing the theft of passwords more than ever before.

The pin pad according to claim 1, a keypad wiring board having a switch, a storage unit that stores an encryption program that encrypts an input signal that flows when the switch is pressed, and an encrypted input signal. A control device configured to include an output unit for outputting to the outside and an erasing unit for erasing the encrypted program, having a controller connected to the switch via a signal line, and an opening on one side, wherein the opening is A box-shaped protective case for housing the control device in a sealed state by being closed by the keypad wiring board, and the protective case has a first tamper wire stretched around a flat portion. A frame body having a structure in which a plurality of frame-shaped substrates are laminated and the substrates are adhered to each other by an adhesive, and an opening opposite to the opening on the one side is closed, and a second tamper wire is provided. The erasing unit is configured to include at least one of a disconnection or a short circuit of the first tamper wire and a disconnection or a short circuit of the second tamper wire. Erasure program

In the pin pad according to claim 1, when a key is pressed, a switch is pressed, and a key input signal indicating that the switch has been pressed flows to the control device via a signal line, and is encrypted based on the encryption program in the storage unit. Be converted.

The control device is housed in a box-shaped protective case in a hermetically sealed state, a first tamper is provided on a frame body forming a side portion of the protective case, and a bottom plate forming a bottom portion of the protective case is provided. Since the second tamper wire is provided, a hole or the like is formed in the frame or the bottom plate in an attempt to make contact with the control device housed inside the protective case from the side or bottom of the protective case. When at least one of the disconnection or short circuit of the first tamper wire and the disconnection or short circuit of the second tamper wire occurs due to this, the erasing section detects this and the erasing section erases the encrypted program. By deleting the encryption program, the pin pad cannot be used, and the password theft before encryption can be prevented from being stolen.

Further, since the frame body has a structure in which a plurality of sheet-shaped substrates each having a frame shape in which the first tamper wire is stretched around the plane portion are laminated and the substrates are bonded to each other, they are adjacent to each other. The distance (pitch) between the first tamper line on one substrate and the first tamper line on the other substrate, that is, the pitch between the first tamper lines when the frame body is viewed from the side, is to make the substrate thin. Thus, the pitch of the first tamper lines adjacent to each other formed on the substrate can be made narrower. Further, in the frame body configured by stacking a plurality of sheet-like substrates each having a frame shape in which the first tamper wire is stretched around the plane portion, the first tamper line is embedded in the frame body. Therefore, for example, it is difficult to find the first tamper line from the outside of the frame body as compared with the case where the tamper line is provided on the side surface of the frame body. Therefore, it is extremely difficult to open a hole in the frame body without breaking or short-circuiting the first tamper wire, which is extremely difficult in comparison with the related art, and a high effect of suppressing physical misconduct can be obtained.

Further, since the sheet-shaped substrate forming the frame can be formed of a material that does not melt under the heat of the soldering iron like a general printed circuit board, this allows the substrate to be melted by using the soldering iron. You can no longer expose the tamper wire.

The pin pad according to claim 2, wherein a key pad wiring board having a switch, an encryption processing unit for encrypting an input signal flowing when the switch is pressed and outputting the encrypted signal to the outside, and stopping the encryption. A control device configured to include an encryption process stop unit and connected to the switch via a signal line, and an opening portion on one side, the opening portion being closed by the keypad wiring board And a box-shaped protective case for accommodating the control device in a hermetically sealed state, wherein the protective case is formed by stacking a plurality of substrates in a frame shape in which a first tamper wire is stretched around a flat portion. A frame having a structure in which the substrates are adhered to each other by an adhesive, and a bottom plate that closes the opening on the side opposite to the opening on the one side and has a second tamper wire stretched around. The encryption processing stopping unit stops the encryption when detecting at least one of disconnection or short circuit of the first tamper wire and disconnection or short circuit of the second tamper wire.

In the pin pad according to claim 2, when a key is pressed, a switch is pressed, and a key input signal indicating that the switch has been pressed reaches a control device through a signal line, and the key input signal is transmitted by an encryption processing unit. It is encrypted and the encrypted key input signal is output to the outside.

The control device is housed in a box-shaped protective case in a hermetically sealed state, a first tamper is provided on a frame body forming a side portion of the protective case, and a bottom plate forming a bottom portion of the protective case is provided. Since the second tamper wire is provided, a hole or the like is formed in the frame or the bottom plate in an attempt to make contact with the control device housed inside the protective case from the side or bottom of the protective case. When at least one of the disconnection or short circuit of the first tamper wire and the disconnection or short circuit of the second tamper wire occurs due to this, the encryption processing suspension unit detects this, and the encryption processing suspension unit detects the encryption. Since the encryption of the processing circuit is stopped, the pin pad cannot be used, and the theft of the password before encryption can be suppressed.

Further, since the frame body has a structure in which a plurality of sheet-shaped substrates each having a frame shape in which the first tamper wire is stretched around the plane portion are laminated and the substrates are bonded to each other, they are adjacent to each other. The distance (pitch) between the first tamper line on one substrate and the first tamper line on the other substrate, that is, the pitch between the first tamper lines when the frame body is viewed from the side, is to make the substrate thin. Thus, the pitch of the first tamper lines adjacent to each other formed on the substrate can be made narrower. Further, in the frame body configured by stacking a plurality of sheet-like substrates each having a frame shape in which the first tamper wire is stretched around the plane portion, the first tamper line is embedded in the frame body. Therefore, for example, it is difficult to find the first tamper line from the outside of the frame body as compared with the case where the tamper line is provided on the side surface of the frame body. Therefore, it is extremely difficult to open a hole in the frame body without breaking or short-circuiting the first tamper wire, which is extremely difficult in comparison with the related art, and a high effect of suppressing physical misconduct can be obtained.

Further, since the sheet-shaped substrate forming the frame can be formed of a material that does not melt under the heat of the soldering iron like a general printed circuit board, this allows the substrate to be melted by using the soldering iron. You can no longer expose the tamper wire.

According to a third aspect of the present invention, in the pin pad according to the first or second aspect, the second tamper wire is formed on a surface of the bottom plate on the frame body side, and is formed between the second tamper wire and the frame body. The frame body and the bottom plate are bonded to each other with an adhesive, and the first tamper wire and the second tamper wire are connected in series.

In the pin pad according to claim 3, the second tamper wire is formed on the surface of the bottom plate on the frame body side and is arranged between the frame body and the second tamper wire, and the frame body and the bottom plate are bonded with an adhesive. Since the first tamper wire and the second tamper wire are connected in series, for example, when an attempt is made to open a gap between the bottom plate and the frame body, the frame body and the bottom plate are separated from each other. Since the first tamper wire and the second tamper wire are separated from each other or the second tamper wire formed on the surface of the bottom plate is broken, it is detected that the wire breakage is detected and a physical misconduct is performed. ..

According to a fourth aspect of the present invention, in the pin pad according to any one of the first to third aspects, wiring provided on the keypad wiring board and connected to the control device, and the keypad wiring. A conductive elastic member that is disposed between the plate and the bottom plate, and that elastically presses the second tamper wire and the wiring to electrically connect the second tamper wire and the wiring.

In the pin pad according to claim 4, since the wiring of the keypad wiring board connected to the control device and the second tamper wire of the bottom plate are electrically connected by the conductive elastic member, the second tamper is used. The controller can detect that the wire is broken or shorted.

In addition, the conductive elastic member is arranged between the keypad wiring board and the bottom board and elastically presses the second tamper wire provided on the bottom board and the wiring provided on the keypad wiring board. Therefore, if the bottom plate or the keypad wiring board is removed from the frame, the conductive elastic member and the second tamper wire of the bottom plate are separated from each other, or the conductive elastic member and the keypad wiring board are separated from each other. It can be seen that a physical misconduct was made by detecting that the wire was separated from the wire and the wire was broken.

According to a fifth aspect of the present invention, in the pin pad according to any one of the first to third aspects, the wiring provided on the keypad wiring board and connected to the control device, and the keypad wiring. A flexible cable arranged between the plate and the bottom plate, a first elastic body that presses one end of the flexible cable into contact with the wiring, and the other end of the flexible cable as the second tamper wire. A second elastic body that is pressed into contact with the second elastic body.

In the pin pad according to claim 5, since the wiring of the keypad wiring board connected to the control device and the second tamper wire of the bottom plate are electrically connected by the flexible cable, the second tamper wire is A disconnection or short circuit can be detected by the control device.

Further, the flexible cable is arranged between the keypad wiring board and the bottom plate, one end of which is pressed by the first elastic body to contact the wiring of the keypad wiring board, and the other end of which is pressed by the second elastic body. Since it is contacted with the second tamper wire of the bottom plate, if the bottom plate or the keypad wiring board is peeled off from the frame, the flexible cable and the second tamper wire of the bottom plate are separated from each other. Alternatively, the flexible cable and the wiring of the keypad wiring board are separated from each other, and it is detected that the wire is broken, and it can be understood that a physical misconduct has been performed.

According to a sixth aspect of the present invention, in the pin pad according to the first aspect, a third tamper wire is stretched around the keypad wiring board, and the erasing portion is formed of the first tamper wire. The encryption program is erased when at least one of disconnection or short circuit, disconnection or short circuit of the second tamper line, and disconnection or short circuit of the third tamper line is detected.

In the pin pad according to claim 6, a third tamper wire is stretched around the keypad wiring board, and the erasing portion has a disconnection or short circuit of the first tamper wire, a disconnection or short circuit of the second tamper wire, The encrypted program is erased when at least one of disconnection and short circuit of the third tamper wire is detected.
Therefore, in the pin pad according to the sixth aspect, when the keypad wiring board is physically tampered with, the encryption program is erased and the pinpad becomes unusable, which prevents the password from being stolen before being encrypted. be able to.

According to a seventh aspect of the present invention, in the pin pad according to the second aspect, a third tamper line is stretched around the keypad wiring board, and the encryption processing stop unit is the first pad. The encryption is stopped when at least one of the voltage drop of the tamper line, the voltage drop of the second tamper line, and the voltage drop of the third tamper line is detected.

In the pin pad according to claim 7, a third tamper wire is stretched around the keypad wiring board, and the encryption processing stop unit is configured to disconnect or short-circuit the first tamper wire or disconnect the second tamper wire. Alternatively, the encryption is stopped when at least one of a short circuit and a disconnection or short circuit of the third tamper wire is detected.
For this reason, in the pin pad according to claim 7, when the keypad wiring board is physically fraudulently actuated, the encryption is stopped and the pin pad becomes unusable, thereby suppressing the theft of the password before encryption. You can

Since the pin pad of the present invention has the above-mentioned configuration, it has an excellent effect that the theft of the password can be suppressed more than ever before.

It is an exploded perspective view showing a pin pad concerning a 1st embodiment of the present invention. It is a sectional view showing a part of pin pad concerning a 1st embodiment of the present invention. (A) is a sectional view showing the switch when the key is not pressed, and (B) is a sectional view showing the switch when the key is pressed. It is a top view which shows an inside contact and an outside contact. (A) is a perspective view showing a protective case and a control device, and (B) is an exploded perspective view showing a keypad printed wiring board, a control printed wiring board, a protective case, and a control printed wiring board. It is an exploded perspective view showing a protection case. It is a block diagram which shows the electric system of a pin pad. It is a top view showing the 1st tamper wire and the 2nd tamper wire. It is sectional drawing which shows some pin pads. (A) is a flow chart showing control at a normal time, and (B) is a flow chart showing control at an abnormal time. It is a block diagram which shows the electric system of the pin pad of 2nd Embodiment.

[First Embodiment]
Hereinafter, a first embodiment of a pin pad 10 according to the present invention will be described with reference to the drawings. As shown in FIG. 1, the pin pad 10 of the present embodiment is used, for example, by a user of a financial device such as an ATM to input a password (a personal identification number, for example). The rubber sheet 16, the adhesive layer 20, the disc spring 22, the keypad printed wiring board 24, the control printed wiring board 26, the protective case 28, the main case 30, and the like are included.

(panel)
As shown in FIGS. 1 and 2, the panel 12 is provided on the surface of the pin pad 10 and has a plurality of rectangular holes 32 through which the keys 14 are projected.
The panel 12 is mounted on the upper part of the main case 30 via a rubber sheet 16 so as to cover the opening of the box-shaped main case 30 having an open upper part. A plurality of pins 34 are formed on the lower surface of the panel 12, and the panel 12 is fixed to the main case 30 with an adhesive or the like while the pins 34 are inserted into the holes 36 of the main case 30.

(Key)
The key 14 is pressed when a password (a personal identification number as an example) is input, and its upper portion is exposed above the panel 12 through the rectangular hole 32 of the panel 12.

(Rubber sheet)
The rubber sheet 16 is arranged on the lower side of the key 14, and a protrusion 16A is integrally formed at a portion facing the key 14. The rubber sheet 16 is provided for the purpose of waterproofing and dustproof so that water and dust do not enter the inside of the pin pad through the rectangular hole 32.

(Adhesive layer, keypad printed wiring board, disc spring)
An adhesive layer 20 is arranged below the rubber sheet 16, and a keypad printed wiring board 24 is arranged below the adhesive layer 20. The adhesive layer 20 is adhered to the lower surface of the rubber sheet 16 and the upper surface of the keypad printed wiring board 24.

A hole 20A is formed in the adhesive layer 20 at a position facing the key 14. A disc spring 22 made of a metal plate is arranged between the rubber sheet 16 and the keypad printed wiring board 24 in a portion where the hole 20A is formed. The disc spring 22 is formed in a shallow bowl shape protruding toward the key 14 side, that is, a shallow dome shape.

As shown in FIGS. 3 and 4, the keypad printed wiring board 24 has a circular inner contact 38 at a position facing the disc spring 22, and an inner contact spaced apart radially outward from the inner contact 38. A contact 38 and an annular outer contact 40 arranged coaxially are provided. The disc spring 22, the inner contact 38, and the outer contact 40 constitute a switch 41.

The keypad printed wiring board 24 includes a signal line 39 connected to the inner contact 38 (see the block diagram of FIG. 7) and a signal line 43 connected to the outer contact 40 (see the block diagram of FIG. 7). The signal line 39 and the signal line 43 are electrically connected to a control unit 56 of the control printed wiring board 26 described later via a connector 52 described later.

In the switch 41, normally, as shown in FIG. 3A, the outer peripheral portion of the disc spring 22 contacts the outer contact 40, and the central portion of the disc spring 22 is separated from the inner contact 38. As shown in FIG. 3(B), when the key 14 is pressed and the center portion of the disc spring 22 is deformed (buckled) so as to be convex toward the contact side, the center portion of the disc spring 22 contacts the inner contact 38. The inner contact 38 and the outer contact 40 are electrically connected (that is, switched on).

The keypad printed wiring board 24 can be formed of a general printed circuit board that does not melt by the heat of the soldering iron.

(Protective case)
As shown in FIGS. 1 and 2, a protective case 28 is arranged on the lower surface of the keypad printed wiring board 24. As shown in FIGS. 5 and 6, the protective case 28 has a box shape with an open top, and has a rectangular flat plate-like bottom plate 48 and is fixed on the bottom plate 48 with an adhesive. And a frame portion 50 having a rectangular frame shape with a large thickness.
The bottom plate 48 can be formed of a general printed circuit board that is not melted by the heat of the soldering iron.

As shown in FIG. 6, the frame portion 50 is configured by stacking a plurality of thin-walled frame-shaped substrates 72 in a frame shape, and one thin-walled frame-shaped substrate 72 and the other thin-walled frame-shaped substrate 72 that are adjacent to each other. The substrate 72 is adhered to each other with an adhesive. The thin frame substrate 72 of this embodiment is formed thinner than the keypad printed wiring board 24 and the bottom plate 48.
The thin frame substrate 72 can be formed by a general printed circuit board that is not melted by the heat of the soldering iron.

A tamper wire 62 that meanders in a rectangular wave shape in the circumferential direction is formed on one surface of the thin frame substrate 72 over the entire circumference (in FIG. 6, illustration of the tamper wire 62 is partially omitted). doing.). As shown in FIG. 8, the tamper wire 62 includes a first tamper wire 62A and a second tamper wire 62B arranged in parallel with the first tamper wire 62A. The tamper wire 62A and the second tamper wire 62B are electrically connected in series.

The interval GW between the tamper lines is set to, for example, about 0.1 to 0.2 mm, and the line width LW of the first tamper line 62A and the second tamper line 62B is about 0.2 to 0.3 mm. However, it is preferable to make the interval GW as narrow as possible.

As shown in FIG. 6, the tamper wire 62 of one thin-walled frame-shaped substrate 72 and the tamper wire 62 of the other thin-walled frame-shaped substrate 72 that are stacked and adjacent to each other are connected by a through hole 74, and The tamper wire 62 of the lower thin frame substrate 72 and the tamper wire 62 of the uppermost thin frame substrate 72 are electrically connected in series.

A plurality of semicircular cut-through holes 76 are provided on the inner peripheral portion of the thin frame substrate 72.

A tamper wire 78 having the same structure as the tamper wire 62 of the thin frame substrate 72 is formed over the entire surface of the bottom plate 48 (the tamper wire 78 is partially shown in FIG. 6). Is omitted.). The tamper wire 78 of the bottom plate 48 and the tamper wire 62 of the lowermost thin frame substrate 72 of the frame portion 50 are connected in series via a through hole (not shown). The end of the tamper wire 78 of the bottom plate 48 is connected to the contact terminal 80 exposed on the upper surface of the bottom plate 48.

The frame portion 50 of the present embodiment is adhered to the upper surface of the bottom plate 48 with an adhesive, and the cut-through holes 76 on the lower side of the frame portion 50 are soldered to the fixing pattern 82 formed on the upper surface of the bottom plate 48 ( (Not shown). That is, the frame 50 is firmly fixed to the bottom plate 48 with an adhesive and solder.

A tamper wire 78 is also formed on the upper surface of the bottom plate 48 at a portion to which the frame portion 50 is adhered. The tamper wire 78 formed near the outer periphery of the bottom plate 48 is the bottom plate 48 and the frame portion 50. It is sandwiched between and and is adjacent to the adhesive layer of the adhesive agent that bonds the frame 50 and the bottom plate 48 together.

Further, the upper surface of the protective case 28, that is, the upper surface of the frame portion 50 is adhered to the lower surface of the keypad printed wiring board 24 with an adhesive, whereby the inside of the protective case 28 is hermetically sealed. The tamper wire 62 of the thin-walled frame-shaped substrate 72, which is the uppermost layer of the frame portion 50, is sandwiched between the thin-walled frame-shaped substrate 72 and the keypad printed wiring board 24, and the frame portion 50 and the keypad printed wiring are also provided. Adjacent to the adhesive layer of adhesive that adheres to the plate 24.

(Control printed wiring board)
As shown in FIGS. 2 and 5, a control printed wiring board 26 is arranged inside the protective case 28. The control printed wiring board 26 is mechanically connected to the keypad printed wiring board 24 by a connector 52. Further, a plurality of electronic components 54 are mounted on the control printed wiring board 26, and these electronic components 54 are signal lines of the control printed wiring board 26 and signals of the keypad printed wiring board 24 via the connector 52. Electrically connected to the wire.

As shown in FIG. 7, an MCU (Micro Controller Unit) 54A, which is one of the electronic components 54, includes a control unit 56, a storage unit 58, and the like. The MCU 54A corresponds to a storage unit that stores an encryption program that encrypts an input signal according to the present invention, an output unit that outputs the encrypted input signal to the outside, and an erasing unit that erases the encryption program.

In a normal state (when the key 14 is not pressed), a voltage is applied to the inner contact 38 and the outer contact 40 of the switch 41, and when the key 14 is pressed and the inner contact 38 and the outer contact 40 are short-circuited. That is, when the switch 41 is turned on, a key input signal flows to the control unit 56 of the control printed wiring board 26.

An encryption program for encrypting the key input signal is stored in the storage unit 58, and the control unit 56 encrypts the key input signal based on the encryption program. The encrypted key input signal, that is, the encrypted password is output to the outside of the pin pad 10 through the connector 52, the wiring of the keypad printed wiring board 24, and the external connector 60.

When the control unit 56 detects that any one of the tamper wire 62 of the frame 50, the tamper wire 78 of the bottom plate 48, and the tamper wire 84 of the keypad printed wiring board 24 described later is broken or short-circuited, The encryption program stored in the storage unit 58 is deleted. When the encryption program stored in the storage unit 58 is erased, the control unit 56 cannot encrypt the key input signal, so the pin pad 10 cannot output the encrypted key input signal to the outside. , The pin pad 10 cannot be used. Further, the control unit 56 outputs an alarm signal to the outside through the external connector 60 when detecting that any one of the tamper wire 62, the tamper wire 78, and the tamper wire 84 is broken or short-circuited. be able to.

As shown in FIG. 7, the tamper wire 62 of the frame 50 and the tamper wire 78 of the bottom plate 48 are electrically connected in series, and the tamper wire 62 and the tamper wire 78 are the flexible cable 88 and the key described later. It is connected to the control unit 56 of the control printed wiring board 26 via the pad printed wiring board 24 and the connector 52.

As shown in FIG. 5, a tamper wire 84 having the same structure as the tamper wire 62 of the bottom plate 48 is formed over the entire surface in the middle portion in the thickness direction of the keypad printed wiring board 24. In FIG. 5, only a part of the tamper wire 84 is shown), and this tamper wire 84 is connected to the control section 56 of the control printed wiring board 26 via the connector 52, as shown in FIG. ..

A weak current is constantly applied to the tamper wire 62, the tamper wire 78, and the tamper wire 84, and a current is applied to the tamper wire 62, the tamper wire 78, and the tamper wire 84 in the keypad printed wiring board 24. A battery 66 is installed for this purpose.

Next, a configuration of connection between the tamper wire 62 of the frame portion 50, the tamper wire 78 of the bottom plate 48, and the control portion 56 of the control printed wiring board 26 will be described.
As shown in FIG. 6, contact terminals 80 to which the ends of the tamper wires 78 are connected are formed on the upper surface of the bottom plate 48. Further, contact terminals (not shown) to which the ends of the tamper wires 84 are connected are formed on the lower surface of the keypad printed wiring board 24.

As shown in FIGS. 5, 6 and 9, between the bottom plate 48 and the keypad printed wiring board 24, the contact terminal 80 of the bottom plate 48 and the contact terminal of the keypad printed wiring board 24 are electrically connected to each other. The cable 88 is arranged so that one end of the flexible cable 88 contacts the contact terminal 80 of the bottom plate 48 and the other end of the flexible cable 88 contacts the contact terminal of the keypad printed wiring board 24 as described below. It has become.

Flexible cable pressing members 90 are attached to the upper surface of the bottom plate 48 and the lower surface of the keypad printed wiring board 24, respectively. In the flexible cable pressing member 90, a pressing protrusion 94 formed of an elastic body is attached to a block-shaped resin case 92.

The pressing protrusion 94 of the flexible cable pressing member 90 attached to the upper surface of the bottom plate 48 presses the other end side of the flexible cable 88 against the contact terminal formed on the lower surface of the keypad printed wiring board 24 so as to be in contact therewith. ..

On the other hand, the pressing protrusion 94 of the flexible cable pressing member 90 attached to the lower surface of the keypad printed wiring board 24 presses one end side of the flexible cable 88 against the contact terminal 80 formed on the upper surface of the bottom plate 48 to bring them into contact with each other. ing.

(Action)
Next, the operation of the pin pad 10 of this embodiment will be described with reference to the flowcharts of FIGS.
First, the normal operation of the pin pad 10 will be described with reference to the flow chart of FIG. In the pin pad 10 of the present embodiment, when the key 14 is pressed, the center portion of the disc spring 22 is deformed so as to be convex toward the contact side, the center portion of the disc spring 22 contacts the inner contact 38, and the inner contact 38 and the outer contact 40 are short-circuited (that is, switched on). In step 100, it is determined whether the key 14 has been pressed. If it is determined that the key 14 has been pressed, the process proceeds to step 102.

When the inner contact 38 and the outer contact 40 are short-circuited, a key input signal flows to the control unit 56 of the control printed wiring board 26, and the control unit 56 encrypts the key input signal (step 102).
The encrypted key input signal is output to the outside of the pin pad 10 via the connector 52 and the external connector 60 of the keypad printed wiring board 24 (step 104).

Next, the operation of the pin pad 10 at the time of abnormality will be described.
In the pin pad 10, an attempt is made to externally contact the transmission path of the key input signal flowing to the control printed wiring board 26 when the key 14 is pressed, for the purpose of stealing the password before encryption by a third party. When doing so, the following measures can be considered.
(1) A hole is formed in the side surface of the frame portion 50 of the protective case 28 to allow a probe or the like to enter.
(2) Between the frame portion 50 of the protective case 28 and the bottom plate 48, a gap is formed to allow a probe or the like to enter.
(3) Between the frame portion 50 of the protective case 28 and the keypad printed wiring board 24, a gap is formed to allow a probe or the like to enter.
(4) A hole is formed in the bottom plate 48 to allow a probe or the like to enter.
(5) A hole is formed in the keypad printed wiring board 24 to allow a probe or the like to enter.

The operation at the time of abnormality will be described below with reference to the flowchart of FIG.
First, in the first step 106, no current flows through the tamper wire 62 and the tamper wire 78 of the protective case 28 or the tamper wire 84 of the keypad printed wiring board 24, that is, the protective case 28 and the keypad print. The control unit 56 determines whether or not there is an abnormality in the wiring board 24. If it is determined in step 106 that the tamper line is abnormal, the process proceeds to step 108.

In step 108, the control unit 56 erases the encryption processing encryption program which is the important data stored in the storage unit 58. As a result, the pin pad 10 cannot be used and password theft can be suppressed.

In the next step 110, the controller 56 outputs an alarm signal to the outside. As a result, for example, by receiving an alarm signal with a device or the like connected to the pin pad 10, it is possible to know the unauthorized use of the pin pad 10.

Regarding the fraudulent acts of (1) above, in the pin pad 10 of the present embodiment, when a hole for allowing a probe or the like to enter is formed on the side surface of the frame portion 50 of the protective case 28 with a drill or the like, the pin pad 10 is provided inside the frame portion 50. Since the tamper wire 62 provided is cut off, the control unit 56 can judge the abnormality.
The frame portion 50 has a structure in which sheet-shaped thin frame-shaped substrates 72 each having a tamper wire 62 stretched around a plane portion are laminated, and the tamper wire 62 is embedded inside the frame portion 50 so as not to be seen from the outside. Therefore, it is extremely difficult to expose it to the outside as compared with the tamper wire formed on the outer surface of the frame.

Further, since the frame portion 50 has a structure in which sheet-shaped thin frame-shaped substrates 72 having a tamper wire 62 stretched around the plane portion are laminated, the tamper line 62 of one thin-walled frame-shaped substrate 72 adjacent to each other. And the interval GW (pitch) between the other thin-walled frame-shaped substrate 72 and the tamper line 62, that is, the pitch of the tampered lines 62 when the frame portion 50 is viewed from the side, to reduce the thickness of the thin-walled frame-shaped substrate 72. Thus, the pitch can be made smaller than the pitch of the tamper lines 62 adjacent to each other formed on the substrate (as an example, a pitch of several tens μm, which is smaller than the interval GW dimension between the tamper lines 62).

As described above, the frame portion 50 has a laminated structure of the sheet-shaped thin frame substrate 72 in which the tamper wire 62 is stretched around, so that the pitch of the tamper wire 62 when the frame portion 50 is viewed from the side is It can be made smaller than the case where a tamper wire is formed on the side surface of the portion 50, and it becomes extremely difficult to drill a hole in the frame portion 50 so as not to cut the tamper wire 62 or short-circuit it. Security can be enhanced against attacks from the side of the unit 50.

When the gap between the frame portion 50 and the bottom plate 48 of the protective case 28 is opened against the fraudulent act (2), the adhesive layer between the frame portion 50 and the bottom plate 48 is destroyed and the bottom plate 48 is also destroyed. Since the tamper wire 78 formed on the upper surface of and adjacent to the adhesive layer is broken, the control unit 56 can determine the abnormality.

-Anti-adhesion layer between the frame 50 and the keypad printed wiring board 24 when a gap is opened between the frame 50 of the protective case 28 and the keypad printed wiring board 24 against the misconduct of the above (3). And the tamper wire 62 formed on the uppermost thin-walled frame substrate 72 of the frame 50 and adjacent to the adhesive layer is broken, the control unit 56 can determine the abnormality.

When the hole for allowing the probe or the like to enter the bottom plate 48 is opened by a drill or the like against the illegal act of the above (4), the tamper wire 78 is cut, so that the control unit 56 can determine the abnormality.

When the hole for allowing the probe or the like to enter the keypad printed wiring board 24 is opened with a drill or the like for the fraudulent act (5), the tamper wire 84 is cut, so that the control unit 56 can determine the abnormality.

[Other Embodiments]
Although the embodiments of the present invention have been described above, it is needless to say that the present invention is not limited to the above embodiments and can be implemented in various modes without departing from the scope of the present invention.

In the above embodiment, the encryption program for encrypting the key input signal is stored in the storage unit 58 of the MCU 54A, and the key input signal is encrypted based on the encryption program, that is, the software. However, the key input signal may be encrypted by hardware that does not use an encryption program (software). In this case, as shown in FIG. 11, an encryption processing unit 68 configured by hardware that does not use an encryption program for encrypting a key input signal flowing when the switch 41 is pressed and outputting the encrypted key input signal to the outside. The control printed wiring board 26 may be provided with an encryption processing stop unit 70 that causes an electric current to flow through the tamper wire 62 and stops the encryption processing when it is detected that no current flows through the tamper wire.

10 pin pad 14 key 18 flexible cable sheet 22 disc spring (switch)
24 Keypad printed wiring board (keypad wiring board)
26 Control printed wiring board (control device)
38 Inside contact (switch, contact)
40 Outside contact (switch, contact)
41 switch 46 deforming unit 56 control unit (erasing unit, output unit, storage unit)
58 storage unit 62 tamper line 68 encryption processing unit 70 encryption processing stop unit

Claims (8)

Keypad wiring board with switch,
A storage unit that stores an encryption program that encrypts the input signal that flows when the switch is pressed, an output unit that outputs the encrypted input signal to the outside, and an erase unit that erases the encryption program And a control device connected to the switch via a signal line,
A box-shaped protective case that has an opening on one side, and the opening is closed by the keypad wiring board to house the control device in a sealed state inside,
Equipped with
The protective case includes a frame body having a structure in which a plurality of substrates each having a frame shape in which a first tamper wire is stretched around a flat surface portion is laminated and the substrates are adhered to each other by an adhesive, and the one side of the frame body. And a bottom plate that closes the opening on the side opposite to the opening and has a second tamper wire stretched around it.
The pin pad, wherein the erasing unit erases the encryption program when at least one of a disconnection or a short circuit of the first tamper wire and a disconnection or a short circuit of the second tamper wire is detected. Keypad wiring board with switch,
The switch is configured to include an encryption processing unit that encrypts an input signal flowing when the switch is pressed and outputs the encrypted signal to the outside, and an encryption processing stop unit that stops the encryption, and connects to the switch via a signal line. A connected control device,
A box-shaped protective case, which has an opening on one side, and in which the opening is closed by the keypad wiring board to house the control device in a sealed state,
Equipped with
The protective case includes a frame body having a structure in which a plurality of substrates each having a frame shape in which a first tamper wire is stretched around a flat surface portion is stacked and the substrates are adhered to each other by an adhesive, and the one side of the protective case. And a bottom plate that closes the opening on the side opposite to the opening and has a second tamper wire stretched around it.
The pin pad, wherein the encryption processing stopping unit stops the encryption when detecting at least one of a disconnection or a short circuit of the first tamper wire and a disconnection or a short circuit of the second tamper wire. The first tamper wire is formed on the bottom plate-side surface of the frame body and is arranged between the frame body and the bottom plate, and the frame body, the bottom plate and the first tamper wire are bonded to each other. Or the second tamper wire is formed on the surface of the bottom plate on the frame body side and is arranged between the frame body and the bottom plate, and the frame body, the bottom plate and the The pin pad according to claim 1 or 2, wherein the second tamper wire is adhered with an adhesive, and the first tamper wire and the second tamper wire are connected in series. Wiring provided on the keypad wiring board and connected to the control device,
A conductive elastic member that is arranged between the keypad wiring board and the bottom plate and elastically presses the second tamper wire and the wiring to electrically connect the second tamper wire and the wiring. ,
The pin pad according to any one of claims 1 to 3, further comprising: Wiring provided on the keypad wiring board and connected to the control device,
A flexible cable arranged between the keypad wiring board and the bottom plate,
A first elastic body that presses one end of the flexible cable into contact with the wiring,
A second elastic body for pressing the other end of the flexible cable against the second tamper wire to bring it into contact with the second tamper wire;
The pin pad according to any one of claims 1 to 3, further comprising: A third tamper wire is stretched around the keypad wiring board,
The erasing unit detects the disconnection or short circuit of the first tamper wire, the disconnection or short circuit of the second tamper wire, and the disconnection or short circuit of the third tamper wire, and the encryption program. The pin pad of claim 1, wherein the pin pad is erased. A third tamper wire is stretched around the keypad wiring board,
The encryption processing stopping unit detects the disconnection or short circuit of the first tamper wire, the disconnection or short circuit of the second tamper wire, and the disconnection or short circuit of the third tamper wire. The pin pad according to claim 2, wherein encryption is stopped. The first tamper wire is formed on a surface of the frame body on the side of the keypad wiring board and is arranged between the frame body and the keypad wiring board, and the frame body and the keypad wiring board. The first tamper wire is adhered with an adhesive, or the third tamper wire is formed on the surface of the keypad wiring board on the frame body side so that the frame body and the keypad wiring board are separated from each other. The frame body, the keypad wiring board, and the third tamper wire are bonded to each other with an adhesive, and the first tamper wire and the third tamper wire are arranged in series. The pin pad according to claim 6 or 7, which is connected.

Images