KR20060009062A - An apparatus for identifying biometric information and method thereof - Google Patents

Abstract

The present invention provides a method of confirming biometric information, comprising: reading information on a biometric parameter of a user, protecting from a counterfeit biometric parameter, and comparing the received information with a template; The protection step from measuring the mechanical motion (movement) of the biometric parameters, determining the motion parameters unique to the biometric parameters based on the measured results and the determined motion parameters to some extent from a predetermined criterion Rejecting the input biometric parameters by determining that the forgery when the deviation is abnormal.

Biometric, parameter, fingerprint, forgery, biometrics.

Description

An apparatus for identifying biometric information and method thereof

1 is a block diagram illustrating an internal configuration of an apparatus for confirming biometric information according to the present invention.

2 is a flowchart illustrating a process of performing a method of confirming biometric information according to the present invention.

Figure 3 shows a) measurement of the transparency of a finger over time in a real finger with a clear peripheral pulse, b) measurement of the mean squared deviation (MSD) over time, c) measurement of the mathematical center of gravity over time. If you do this is a pulse waveform received at the same time.

Figure 4 shows a) measuring the transparency of a finger over time in a real finger with little peripheral pulse, b) measuring the mean square deviation (MSD) over time, c) measuring the mathematical center of gravity over time. If you do this is a pulse waveform received at the same time.

FIG. 5 illustrates a) when measuring transparency of a finger over time in a counterfeit biometric parameter located on an actual finger; b) measuring mean square deviation (MSD) over time; If you measure according to the pulse wave received at the same time.

FIG. 6A shows the distribution density of the signal received from the fingerprint scanner while the pulse waveform passes through the finger, and FIG. 6B shows the distribution density of the signal received from the fingerprint scanner as usual.

TECHNICAL FIELD The present invention relates to the field of biometrics, and more particularly, to protect against counterfeit biometric parameters in an access control system such as a passport system by determining the motion parameters inherent in the biometric parameters by measuring the mechanical motion of the biometric parameters. The present invention relates to a biometric information verification apparatus and method which can be used as a method.

The global development of biometric systems creates natural prerequisites in the development of counterfeit systems and methods of biometric parameters, as well as in the development of protection methods against counterfeiting in biometric validation. Methods for conditionally distinguishing counterfeit and simulated biometric parameters can be broadly classified into static and dynamic methods. The static method is additionally determined by the instantaneous value of a particular physical value that is specific to the actual biometric parameter and not present in the fake biometric parameter. Examples of such static protection methods include the determination of the electrical resistance of the finger skin for fingerprint sensors and systems, and the identification method according to the shape of the palm.

Another example of static additional protection is a subject's temperature measurement scheme used in both contact biometric systems such as fingerprints and contactless systems such as facial or pupil recognition systems. Additionally, the measured physical value may cause rejection of counterfeit biometric carriers in some cases, but there is a problem that if this physical value is known, the value may also be used in forged biometric parameters.

Taking the forgery method of the electrical resistance of the skin as an example, it is sufficiently possible to produce a fake fingerprint of electrically conductive silicone having an electrical resistance similar to that of the finger skin.

Even in the temperature measuring method, it is sufficient to produce a counterfeit carrier of a material having good thermal conductivity, and it is practically impossible to identify the counterfeit thus produced by the static method.

In addition, the introduction of additional parameter measurements requires the construction of additional hardware such as, for example, an electrode system in a fingerprint sensor for measuring the electrical resistance of the skin or a temperature gauge for measuring the temperature of the living body. Thus, the introduction of additional parametric measurements increases the cost of the biometric verification system, complicates the system, and reduces the reliability of system operation.

Therefore, since the static protection method for the counterfeit biometric carrier is based on the measurement of additional static parameters, there is a problem in that it cannot completely detect the counterfeit carrier and only partially reflect the characteristics of the living body.

Another possible static protection method in the verification procedure through biometric comparison is the precise analysis of the type of input biometric parameters. In practice, counterfeits usually have a lower quality than originals that contain large amounts of detail that cannot be reproduced in the manufacture of counterfeits. For example, in a fingerprint, the details may be in the form of perforated, paleryry edges of the skin, which are essentially different skins from the original and the counterfeit.

However, in the detailed analysis of the form of biometric parameters, it is necessary to first provide a high resolution scanner. For reliable identification of specific points on the fingerprint, the scanner should have a resolution of 500 dpi (1.5 cm ² at that location), and for resolution analysis it is desirable to have a resolution of 1,500 dpi or more. This high resolution essentially complicates the operation of the system in real time mode, which increases the system cost and, finally, makes it possible to fabricate counterfeit biometric carriers in terms of increased resolution and thus cannot guarantee protection.

Known dynamic methods for protection against counterfeits are based on the analysis of changes over time of basic or additional biometric parameters.

The most known biometric parameters that describe a real person are the pulse and pulse waveform generated by contraction of the heart muscle.

The pulse wave recording device and the biometric confirmation system make it possible to find out whether the fingerprint information is forged due to the effect of the volumetric pulse at the fingertip. This method involves reading information on a user's biometric parameters, which involves illuminating blood supply tissue to record a pulse waveform, and using an optoelectronic transducer to light streams caused by dispersion in the blood supply tissue. Converting the signal into an electrical signal, processing the received pulse waveform with the aid of some photosensitive areas located on adjacent blood supply tissue, comparing the received information with a template—and volumetric measurement Protecting against counterfeit biometric parameters with the help of pulse information.

A given method of biometric verification was chosen as the prototype. This method makes it possible to successfully identify the forged carrier of the fingerprint image in the presence of a normal peripheral pulse at the fingertip. However, in some diseases there may be a substantial absence of peripheral pulses, and there is also an intrinsic decrease in peripheral pulses associated with a reduction in capillary size, for example, when cooling the living body or when a person is unstable. Known.

The given feature essentially limits the application of the given method to reveal counterfeit fingerprint data carriers. In addition, a given method of protection is only applicable to systems where light penetrates the object, and the specified system occupies a small portion of the biometric market.

Accordingly, there is a growing demand for a method that can overcome the unreasonableness of the conventional methods for checking whether the forgery of the biometric parameters is counterfeit, and more accurately identify the forgery of the biometric parameters.

The present invention has been made to solve the above problems, an object of the present invention is to improve the reliability of the biometric confirmation system by reducing the error rate when identifying a counterfeit biometric carrier.

According to an aspect of the present invention for achieving the above object, in the biometric information confirmation method, the step of reading information on the biometric parameters of the user, protecting from the counterfeit biometric parameters and template received information And a step of protecting from counterfeit biometric parameters, the method comprising: measuring the mechanical motion (movement) of biometric parameters, determining an athletic parameter unique to the biometric parameters based on the measured results; And a step of rejecting the input biometric parameter by determining that the determined exercise parameter is falsified at a predetermined level or more from the preset reference.

The pulse wave traveling into the blood vessels of a person changes the blood filling, thus changing the transparency of the blood vessels inside the living body. It is also known that according to Newton's third law in a closed system, the law of conservation of impulse must be satisfied, i.e., the internal motion should cause the external motion. Certainly, the human body is a complex system that transcends classical mechanics or dynamics, but many scientists assume that dimensional fission dynamics is one of the basic characteristics of higher organisms. The imposition of a series of treatments of muscle, brain, and electrical movements occurring simultaneously at various levels logically obscures each of the treatments listed above and complicates separate recovery from the chaos of mechanical movement.

Indeed, it is difficult to believe enough that it is possible to reveal the pulse component in microns against the background of the speed of movement of several parts of the body. However, using simple mathematics, we have succeeded in finding the mechanical movement of a finger synchronized with the pulse waveform at the position of the finger in a multicomponent matrix fingerprint sensor.

Human skin is a complex multi-layered structure with mechanical properties that are almost impossible to counterfeit because the skin's surface is composed of discrete keratinocytes, and virtually all counterfeits are made of monolithic materials. Human fingers are inherently many specific elasticities in people engaged in physics or brain research. Thus, the following law is established: In the position on the contact surface, fingers that can be named hard move more along the horizontal axis, fingers that can be named soft move more along the vertical axis, and the amplitude of these motions , Frequency and phase are synchronized with the pulse wave of the human body.

Applicants have established that a given effect is observed even when there is substantially no peripheral pulse at the fingertip, that is, even when the transparency of the fingers does not substantially change due to the narrowing of the capillaries. Replicating the elastic properties of additional skin to all other parameters is a very difficult task, so the observable phenomenon inherently reduces the likelihood that counterfeit biometric carriers, especially fingerprint information, will not be revealed.

Resolving the improvement in reliability of biometric confirmation includes the steps of receiving information on the user's biometric parameters, comparing the received information with the image, and protecting from counterfeit biometric parameters, wherein the forged biometric Protection from the parameters is performed by measuring the movement of a given biometric parameter and by finding the athletic parameter specific to the actual biometric object.

The provided biometric verification method is particularly important when used in the construction of a biometric passport system, which costs several billion dollars and the manufacturing cost of counterfeit biometric parameters cannot exceed $ 100. Thus, if the passport system cannot identify a counterfeit carrier of biometric information, and if the passport system is not equipped with a reliable protection system for the counterfeit biometric carrier, then all costs are spent without cost.

Of course, it is possible to supervise not only the pulse curve but also the possibility of its change using dimensional fission dynamics. In addition, the measurement time (up to 30 seconds) is certainly increased, but the probability of unidentified carriers of counterfeit carriers is reduced, which is essential, especially for the protected object.

Hereinafter, with reference to the accompanying drawings will be described a preferred embodiment of the present invention.

1 is a block diagram illustrating an internal configuration of an apparatus for confirming biometric information according to the present invention. As shown in FIG. 1, the apparatus for confirming biometric information according to the present invention includes a reading unit 10, an exercise measuring unit 20, an exercise parameter calculating unit 30, and a comparing unit 40.

The reading unit 10 is for generating a scanned image obtained by scanning a biometric parameter of a user to be converted into an electrical signal. In the present invention, a fingerprint scanner is used.

The motion measuring unit 20 is for measuring the mechanical motion of the input biometric parameter.

The exercise parameter calculator 30 calculates an exercise parameter unique to the biometric parameter by analyzing the mechanical motion measured by the exercise measurer 20.

The comparator 40 extracts a preset workout parameter of the user from the database 50 and compares the workout parameter with the workout parameter calculated by the workout parameter calculator 30 to determine the authenticity. In addition, when it is determined that the comparison is successful, the comparison unit 40 performs a second comparison step of comparing a template stored in the database 50, that is, an original of the user biometric parameter and the scanned image read by the reading unit 10. If both are matched, a confirmation success signal is transmitted.

2 is a flowchart illustrating a process of performing a biometric verification method according to the present invention. 2 illustrates a case where a fingerprint is used as a biometric parameter. Referring to FIG. 2, an example of a specific operation of a method of using a fingerprint scanner based on the principle of receiving a fingerprint image generated when light passes through a finger is described.

First, information on biometric parameters of a user is read (S10). Place your finger on the fingerprint scanner using the parallel port operating in EEP mode. In the fingerprint scanner, a template, that is, information on an original print and information on a user's plastic card (passport) is read out from a database in advance.

 Then, the step of protecting from the counterfeit biometric parameters is performed (S20). The protection from the counterfeit biometric parameter consists of the following three steps.

The motion measuring unit 20 measures the mechanical motion of the input user fingerprint (S20-1). The motion measuring unit 20 receives pulses of each location from various locations of the fingerprint to generate pulse curves of each location.

Next, the exercise parameter calculator 30 calculates a biometric parameter, that is, an exercise parameter unique to the user fingerprint, based on the result measured by the exercise measurer 20 (S20-2). The exercise parameter calculator 30 calculates an exercise parameter by applying a Fast Fourier Transform technique to the pulse curve generated by the exercise measurer 20.

The comparator 40 compares the calculated exercise parameter with a reference stored in the database 50 and determines that the calculated exercise parameter is forged when a predetermined degree is deviated from the preset reference by more than a predetermined level (S20-3). ). The comparator 40 may determine whether the pulse waveform frequency components coincide with the result of the fast Fourier transform on the pulse curve received from various positions of the fingerprint.

The measurement result is displayed by the biometric confirmation program in the biometric information confirmation device and the external control device. The authenticity judgment and the comparison of the motion parameters are performed by analysis of the spectrum of the received fundamental frequency for 5 seconds. Naturally, the amount of change over 20% of the absence or threshold of pulse motion produces a "NO" signal in the comparison of the motion parameters, and the system returns to a new cycle of reading biometric information.

If the mechanical motion and the volumetric pulse match, the authenticity judgment is considered to be performed positively and the received fingerprint image is compared with the template to determine the verification result (S30).

As a result of the determination, if both match, the comparator 40 transmits a confirmation success signal (S40). Otherwise, if the motion or change in the print exceeds 20%, the biometric parameter is rejected as forged and the system returns to the initial reading phase and gives a warming sound signal. The reading frequency of the fingerprint image for the fingerprint scanner is 50 frames / sec, which is sufficient for the clear display of the pulse, and the device according to the invention is sufficient for the display of the pulse waveform and confirmation of the user in real time mode.

Figure 3 shows a) measurement of the transparency of a finger over time in a real finger with a clear peripheral pulse, b) measurement of the mean squared deviation (MSD) over time, c) measurement of the mathematical center of gravity over time. If you do this is a pulse waveform received at the same time.

FIG. 3 shows that in the majority of people with precise peripheral pulses, it is possible to observe the pulse waveform as the finger moves along the vertical and horizontal axes as well as the change in transparency in the palm of the hand. This conclusion is because it can fix the pulse waveform with the help of a fingerprint scanner that penetrates a known finger, as well as with any other fingerprint scanner (optical, capacitance) with sufficient speed (50 f / s or higher) and resolution. very important.

Figure 4 shows a) measuring the transparency of a finger over time in a real finger with little peripheral pulse, b) measuring the mean square deviation (MSD) over time, c) measuring the mathematical center of gravity over time. If you do this is a pulse waveform received at the same time.

The results show that approximately 5-10% of people have this curve at normal conditions, and this percentage increases in a calm or stressed state. The resulting curve shows that the pulse waveform during mechanical movement of the finger is less sensitive to the peripheral pulse than the change in transparency, thus characterizing the actual finger more reliably.

FIG. 5 illustrates a) when measuring transparency of a finger over time in a counterfeit biometric parameter located on an actual finger; b) measuring mean square deviation (MSD) over time; If you measure according to the pulse wave received at the same time.

FIG. 5 shows the pulse curve for the most complex forged finger in terms of counterfeit detection when a thin lining of transparent silicone with another three-dimensional fingerprint is placed on the actual finger. 5 leads to the absence of a pulsation that such a fake fingerprint carrier is substantially connected to mechanical motion. Perhaps this occurs due to the inherent differences in the elasticity and mechanical inertia properties of the actual finger and counterfeit fingerprint carrier.

Thus, the absence of a mechanical pulse on the finger can prove the appearance of a fake fingerprint carrier and provide a signal for possible forgery of the system, which is particularly important for passport technology where the fingerprint image on the document must be clearly distinguished from the actual finger.

FIG. 6A shows the distribution density of the signal received from the fingerprint scanner while the pulse waveform passes through the finger, and FIG. 6B shows the distribution density of the signal received from the fingerprint scanner as usual.

FIG. 6A shows the change in signal distribution density of the fingerprint in the passage of the pulse waveform when the finger is pressed firmly against the contact surface, and FIG. 6B shows the distribution and width of the MSD compared to the time moment when the blood density of the finger is reduced. Inherently decreases. The MSD is an integrated and relative feature, and so appears, the time dependence of the MSD is insensitive to noise and artifacts and transmits the parameters of the pulse well. Other mathematical features that reflect the width, distribution, or distance between modes (maximum of distribution) can also be used for pulse dependence.

Naturally, the implementation of the biometric verification method shown in the description does not limit the possible application of the present invention and is broader and determined by the degree of development of the technical equipment.

An example of the biometric technique in this embodiment was the fingerprint technique with the most widely used and best features. Of course, the proposed method can also be used to protect biometric parameters related to the movement of the human body, such as facial recognition or pupil recognition.

The invention is also applicable to complexes having other methods of protection against counterfeit biometric parameters that must provide the reliability of biometric systems in accordance with market and customer requirements.

According to the present invention, it is possible to increase the reliability of the biometric information confirming device by reducing the error in discriminating the counterfeit biometric carrier.

Although the present invention has been described in connection with the above-mentioned preferred embodiments, it is possible to make various modifications or variations without departing from the spirit and scope of the invention. Accordingly, the appended claims will cover such modifications and variations as fall within the spirit of the invention.

Claims (6)

In the biometric information confirmation method, Reading information on biometric parameters of a user; Protecting against counterfeit biometric parameters; And Comparing the received information with the template, The protection from the counterfeit biometric parameters is Measuring mechanical movement (movement) of biometric parameters; Determining athletic parameters inherent to biometric parameters based on the measured results; And rejecting the input biometric parameter by determining that the determined exercise parameter is forged when a predetermined degree is deviated from the preset reference by more than a predetermined degree. The method of claim 1, And said biometric parameter is a fingerprint. The method of claim 2, And the mechanical motion of the fingerprint is measured as a function of time of the area of the contact surface of the finger. The method of claim 3, wherein And a contact surface area of the fingerprint is measured using a parameter of a signal distribution density of a biometric carrier including a width of a mean square deviation (MSD). The method of claim 2, And wherein the mechanical motion of the fingerprint is measured as a function of time of an integrated value including the center of gravity of a given biometric parameter. The method of claim 1, And said predetermined degree is 20% of a preset reference.

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