JPH04315280A - Personal authentication device - Google Patents

Abstract

PURPOSE:To surely prevent an IC card from being illegally used by another person at the personal authentication device to certify whether a user to use the IC card is the previously registered owner of the IC card or not. CONSTITUTION:An AND circuit 22 is provided at a write control line 21 of a memory 10 for dictionary to store (register) the feature information of fingers for personal authentication inside the IC card and after the feature information of the fingers is once written, the gate of the AND circuit 22 is closed by fusing a fuse 27 connected to one input of this AND circuit 22 so as to prevent the feature information of fingers from being written in the memory 10 for dictionary again.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention authenticates whether or not a user who uses a portable storage medium such as an IC card used as a credit card is the pre-registered owner of the portable storage medium. Regarding a personal authentication device.

0002

2. Description of the Related Art In recent years, with the rapid increase in the use of credit cards, cash cards, etc., the increase in fraudulent use of these cards has become a problem. Examples of fraudulent card use include cases where a card lost by its owner is used by a person who found it, or cases where a forged card is used. In order to prevent such unauthorized use of a card, it is necessary to check whether the card is genuine or whether the user of the card is the owner.

[0003] Conventionally, a personal identification number has generally been used as a means of authenticating that the card is not a forgery or that the user of the card is a legitimate user.

0004

[Problem to be Solved by the Invention] However, since this PIN number generally uses four or more digits, it is easy for the card owner to forget it, and it is difficult for the authorized user to authenticate the card. There was a problem that there were cases where it could not be used. Conversely, if the card owner specifies an easy-to-remember number, such as a birthday or phone number, as the PIN number, the PIN number may be easily guessed by others, and unauthorized use by others may be prevented. It may not be possible to prevent it. Furthermore, in order to deal with the problem of forgetting the PIN number, it was necessary to make it possible to change the PIN written on the card, making it possible for the card issuer to commit fraud.

[0005] As a method to solve such problems,
There is a method of using physical characteristic information of the card user instead of the PIN number. That is, an IC card is used as a card, some physical characteristic information of the card holder is registered in advance in the memory of the IC card, and each time the card is used, the physical characteristic information of the card user is inputted. ,
If the card user is authenticated as a legitimate user by comparing the registered physical characteristic information, the card holder will not have to remember the PIN number.
Also, if you use physical characteristic information that does not change,
Since there is no need to change the physical characteristic information registered on the card, the number of times the card can be registered can be limited, and unauthorized use by the card issuer can be prevented.

However, if the physical characteristic information for personal authentication registered in the card can be changed after registration, if the personal authentication means is located outside the card, the card issuer can use it fraudulently, and the personal authentication If the means are inside the card, there is a possibility that it could be used fraudulently by a third person.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a personal authentication device that can reliably prevent unauthorized use of a portable storage medium by another person.

[0008]

[Means for Solving the Problems] The personal authentication device of the present invention includes a registration means for registering physical characteristic information of an individual acquired in advance in a portable storage medium, and an operation for registering the physical characteristic information by the registration means. a limiting means for limiting the number of times to a predetermined number; an input means for inputting personal physical characteristic information for comparison; and a limit means for inputting physical characteristic information of an individual for comparison; and determining means for determining whether or not a predetermined relationship is established between the two pieces of physical characteristic information by comparing the two pieces of physical characteristic information.

[0009]

[Operation] By limiting the registration of physical characteristic information to a portable storage medium to a predetermined number of times (for example, once), the physical characteristics of the owner of the portable storage medium can be registered only a limited number of times. Registration becomes impossible, and therefore, unauthorized use of the portable storage medium by others can be reliably prevented.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 schematically shows the appearance of an IC card with a personal authentication function according to this embodiment. In the figure, 1 is a card body, and on its surface there are a pressure sensor 2 for inputting finger characteristic information, and external connection contacts 3 for electrical connection with an external device (terminal device). It is provided.

FIG. 3 shows a state in which a finger 4 is placed on the pressure sensor 2 in order to perform personal authentication using the IC card with a personal authentication function according to this embodiment. Authentication as to whether or not the use of the card is valid is performed with the finger 4 placed on the pressure sensor 2 as shown in FIG. When it is determined that the use of the card is legitimate, the card becomes usable. On the other hand, if it is determined that the card is invalid, the card does not change its state and becomes usable.

At this time, the I with the personal authentication function of this embodiment
With a C card, it cannot be determined from the outside that the card cannot be used. However, in the case of a bank cash card, for example, when the card is inserted into the card reader of the bank teller terminal,
If the bank teller terminal issues normal operation commands, the user can determine that the card is ready for use, and if it displays a message indicating that the card has not been authenticated, the user can determine that the card is ready for use. It can be determined that this is not the case. Furthermore, it goes without saying that the card may be provided with a device for displaying whether or not the card is in a usable state.

FIG. 1 schematically shows an electric circuit of an IC card with a personal authentication function according to this embodiment. In the figure, 5 is an A/D converter that converts the output signal of the pressure sensor 2 into a digital signal. 6 is image memory, A/D
The card user's finger characteristic information obtained from the output of the converter 5 is temporarily stored. 7 is a dictionary buffer memory,
Temporarily stores the cardholder's finger characteristic information. 8 is a control unit that performs various processes for personal authentication. A microprocessor 9 controls the entire IC card. Reference numeral 10 denotes a dictionary memory in which characteristic information of the cardholder's fingers is stored (registered). Reference numeral 11 denotes a registration restriction circuit that limits the registration of finger characteristic information in the dictionary memory 10 to a predetermined number of times, for example, once in this embodiment.

The control section 8 processes the output signal of the A/D converter 5 and stores information representing the characteristics of the card user's finger in the image memory 6, and also stores this characteristic information and the dictionary memory. 10 via the microprocessor 9 and the control unit 8 and compared with the feature information transferred to the dictionary buffer memory 7, it is determined whether the feature information of the two fingers match. If the finger characteristic information matches, it is determined that the card is valid for use, and a signal is output to the microprocessor 9 to permit use of the card.

FIG. 4 shows the registration restriction circuit 11 in detail. The registration restriction circuit 11 once registers the dictionary memory 1.
This circuit is designed to prevent finger characteristic information from being written twice once finger characteristic information is written (registered) in 0, and is configured as follows, for example. A write control line 21 connected to the dictionary memory 10 is connected to the output of an AND circuit 22. A write line 23 from the microprocessor 9 is connected to one input of the AND circuit 22.
The other input of is grounded via a resistor 24 and connected to a power source 26 via a switch 25. Further, the other input of the AND circuit 22 is grounded through a fuse 27 and a switch 28 in series, and a connection point between the fuse 27 and the switch 28 is connected to a predetermined potential through a resistor 29. . In addition, the switches 25 and 28
is controlled on and off by the microprocessor 9.

Next, a method for acquiring finger characteristic information using the pressure sensor 2 will be explained in detail.

FIG. 5 schematically shows the appearance of the pressure sensor 2. The pressure sensor 2 is configured by arranging minute sensors 2a in a matrix.

FIG. 6 shows A- of the pressure sensor 2 shown in FIG.
It is a sectional view taken along arrow A. In the figure, 11 is a glass substrate;
12 is an electrode formed on the glass substrate 11; 13 is a silicon substrate also formed on the glass substrate 11;
4 is a diaphragm formed between the glass substrate 11 and the silicon substrate 13. Note that as a method for forming the diaphragm 14, for example, an anisotropic etching technique can be used. Further, the silicon substrate 13 has a low resistance layer 13a as an electrode on the glass substrate 11 side. A uniform potential is applied to each microsensor 2a to this low resistance layer 13a by a power source (not shown). The electrodes 12 are individually taken out to the outside for each microsensor 2a.

FIG. 7 shows an enlarged view of a finger placed on the pressure sensor 2 constructed as described above. In the figure, when a finger 4 is placed on the pressure sensor 2, the unevenness of the surface of the finger 4 caused by the joints of the finger 4 causes the pressure sensor to
Variations occur in the pressure applied to each microsensor 2a. Here, in the micro sensor 2a to which a pressure greater than a certain value is applied, the low resistance layer 13a and the electrode 12 come into contact and the two become at the same potential. In the sensor 2a, the low resistance layer 13a and the electrode 12 are not in contact with each other, and no voltage is applied to the electrode 12. Therefore, by individually detecting the potential of the electrode 12 for each microsensor 2a, image information corresponding to the unevenness of the finger skin can be obtained.

Next, the processing operation for authenticating whether or not the use of the card is valid in the IC card with the personal authentication function of this embodiment will be explained. Processing operations in this authentication are broadly divided into registration processing and verification processing.

[0022] First, a registration process for registering the cardholder's finger characteristic information will be described. FIG. 8 is a flowchart showing the processing operation of the control section 8 at this time. First, image information corresponding to the unevenness of the finger skin is captured as described above (step S1). Next, a sum signal is extracted by adding the density of each pixel of the image information in the direction of the width of the finger (step S2).

FIG. 9 is a conceptual diagram for explaining this addition signal, and schematically represents the finger image information 19 and the addition signal 20. The addition signal 20 is a one-dimensional signal obtained by adding the density of each pixel (each output value of the pressure sensor 2) of the finger image information 19 in the direction of the width of the finger, that is, the y direction shown in the figure. This addition signal 20 has a steep valley at the position of the horizontal wrinkle corresponding to the joint of the finger, and the individuality (parameter representing the characteristic of the finger) is included in this valley part. Finally, this addition signal 20 is temporarily stored in the dictionary buffer memory 7 (step S3).

Next, the addition signal temporarily stored in the dictionary buffer memory 7 is transferred to the dictionary memory 11 via the microprocessor 9 and the registration restriction circuit 11. At the time of registration, the switches 25 and 28 of the registration restriction circuit 11 are both set to the off state, so that one input of the AND circuit 22 becomes a logical "1" level, and the gate is opened. Therefore, the addition signal transferred from the microprocessor 9 via the write line 23 is sent to the dictionary memory 10 via the AND circuit 22 and the write control line 21, and is written into the dictionary memory 10.

After writing the addition signal into the dictionary memory 10 in this manner, the microprocessor 9 switches the switches 25 and 2.
8 is turned on, current flows from the power supply 26 to the fuse 27, and the fuse 27 is blown. As a result, one input of the AND circuit 22 becomes a logical "0".
” level, the gate is closed, and the dictionary memory 10
It will no longer be possible to write to.

Next, a description will be given of a verification process when the card user's finger characteristic information is input and is compared with the card owner's finger characteristic information registered as described above. FIG. 10 is a flowchart showing the processing operation of the control unit 8 at this time. First, in the same manner as in the registration process described above, image information of a finger is input (step S11), and an addition signal is calculated (step S12). Subsequently, the card owner's addition signal (characteristic information) registered in advance in the dictionary memory 10 is read out (step S13), and it is temporarily stored in the dictionary buffer memory 7. Next, the addition signal calculated in step S12 and the dictionary buffer memory 7
Positioning is performed with the temporarily stored addition signal (step S14), and then both addition signals are compared (step S15).

[0027] Here, the alignment processing and verification processing will be explained in detail. The alignment process refers to the position of the finger when the registration was performed as described above and step S1.
The deviation from the finger position when inputting the finger image information in step 1 (
In other words, this is a process for correcting a deviation between two added signals. Furthermore, the matching process is a process of quantifying the degree of coincidence between the two added signals after alignment.

Now, let the number of elements of both addition signals be N, the i-th element of the addition signal read from the dictionary memory 10 is Ad(i), and the i-th element of the addition signal calculated in step S12. Let be A(i). Here, if the fingers corresponding to the two addition signals are the same finger and the difference between the two addition signals is a length of m pixels, then the element Ad of the addition signal read from the dictionary memory 10 (i)
is the element A(i+
m), so Ad(i) and A(i+m)
The difference between them is "0". Therefore, at this time, the value S which is the sum of the squares of the errors for each element of the two added signals
(m), that is, when m≧0

[0029]

[Math 1]

[0030] When m<0

[0031]

[Math 2]

When calculating S(m), in principle,
0”. That is, S(m) is a parameter representing the degree of coincidence between the two added signals, and the smaller the value of S(m), the higher the degree of coincidence. In this example, m is varied within a certain range, and alignment is achieved at the position corresponding to the value of m when the value of S(m) is the smallest (the value of m at this time is assumed to be M). Assuming that S(M)
The value of is the result of matching.

[0033] When the alignment process and the collation process are completed in this way, image information is input in step S11 with the cardholder's finger registered in the dictionary memory 10 based on the collation result S(M) at this time. It is determined whether or not the finger of the card user is the same as that of the card user (step S16).
). In this embodiment, a threshold value TH for determining whether the fingers are the same is determined in advance, and the matching result S(M
) is greater than a threshold value TH to determine whether they are the same or not. That is, S(M)≦TH
If S(M)>TH, it is determined that they are the same, and if S(M)>TH, it is determined that they are not the same.

If it is determined that they are the same, the microprocessor 9 makes the IC card usable (step S17). On the other hand, if it is determined that they are not identical,
The microprocessor 9 does not change the state of the IC card. Therefore, if it is determined that they are not the same, this IC card cannot be used.

As described above, according to the above embodiment, a gate is provided in the write control line of the dictionary memory for storing (registering) finger characteristic information for personal authentication inside the IC card, and the finger characteristic information is stored in the IC card. Once written, by closing this gate, it is possible to prevent the finger characteristic information from being written into the dictionary memory again. Therefore, unauthorized use of the IC card by others can be reliably prevented.

In the above embodiment, the number of registrations of finger characteristic information is limited to one time, but it does not necessarily have to be one time, and may be, for example, two times.

Further, in the above embodiment, the case where finger characteristic information is used as the physical characteristic information is explained, but the invention is not limited to this; for example, finger fingerprint information may be used as the finger characteristic information. Other physical feature information may also be used, such as the retinal pattern of the eye.

Furthermore, in the above embodiment, the case where the personal authentication means is provided inside the card has been described, but the present invention can be similarly applied to the case where the personal authentication means is provided outside the card.

Further, in the above embodiments, an IC card is used as a portable storage medium, but the present invention is not limited to this. For example, a simple memory card may be used, and the shape is not limited to a card shape. , may be of other shapes.

[0040]

As described in detail above, according to the present invention, it is possible to provide a personal authentication device that can reliably prevent unauthorized use of a portable storage medium by another person.

[Brief explanation of the drawing]

[Fig. 1] IC with personal authentication function according to an embodiment of the present invention
FIG. 2 is a block diagram schematically showing the electric circuit of the card.

FIG. 2 is a perspective view schematically showing the appearance of the IC card with a personal authentication function shown in FIG. 1;

FIG. 3 is a schematic side sectional view showing a state in which a finger is placed on the pressure sensor of the IC card with a personal authentication function shown in FIG. 1;

FIG. 4 is a detailed configuration diagram of a registration restriction circuit.

FIG. 5 is a plan view schematically showing the appearance of the pressure sensor.

FIG. 6 is a sectional view taken along line A-A in FIG. 5;

FIG. 7 is an enlarged schematic side sectional view showing a state in which a finger is placed on the pressure sensor.

FIG. 8 is a flowchart illustrating a registration process when registering characteristic information of a cardholder's finger.

FIG. 9 is a conceptual diagram for explaining an addition signal calculated by a control unit.

FIG. 10 is a flowchart illustrating a matching process when comparing the card user's finger characteristic information with the card owner's finger characteristic information.

[Explanation of symbols]

1... Card body, 2... Pressure sensor, 3... Contact for external connection, 4... Finger, 5... A/D converter, 6...
Image memory, 7...Dictionary buffer memory, 8...Control unit, 9...Microprocessor, 10...Dictionary memory, 11...Registration restriction circuit.

Claims (1)

[Claims] Claim 1: Registration means for registering physical characteristic information of an individual acquired in advance in a portable storage medium; Limiting means for restricting the registration operation of the physical characteristic information by the registration means to a predetermined number of times. , an input means for inputting personal physical characteristic information for comparison, and by comparing the physical characteristic information inputted by this input means with the physical characteristic information registered in the portable storage medium. 1. A personal authentication device comprising: a determination means for determining whether a predetermined relationship is established between both pieces of physical characteristic information.