JP5700524B2 - Personal authentication method and system - Google Patents

Description

  The present invention relates to a personal authentication technique, and more particularly to a cancelable personal authentication technique using biometric information.

  Currently, personal authentication methods that are widely adopted include memory authentication that uses information such as passwords that only the user can know, and ownership authentication that uses an ID card. There is a problem that a person can easily be impersonated by stealing a password or forging an ID card. In response to this problem, it seemed that the impersonation problem was solved by the proposal of biometric authentication using biometric information such as fingerprints and vein patterns. This is because the loss or theft of biological information that is inseparable from the human body cannot theoretically occur, and the biological information cannot be forged or stolen.

  Recently, however, there have been reports of successful impersonation using artificial fingers that have been copied from residual fingerprints, and vulnerability to biometric impersonation attacks has been pointed out. If biometric information is counterfeited or stolen by a malicious third party, the biometric authentication system has operational problems because it uses biometric information. In other words, biometric information such as fingerprints cannot be updated because it is lifelong in the individual, and users who have forged or stolen biometric information can eventually use the system again. It will disappear.

  Furthermore, biometric authentication involves the problem of personal information. Since biometric information such as fingerprints and vein patterns currently used is information that can identify an individual, the system operator is responsible for management under the Personal Information Protection Law. In addition, there are many people who feel a little anxious about entrusting such personal information to others. In particular, fingerprint verification has a great psychological resistance because it is associated with criminal investigations. Due to such psychological factors, it is not difficult to imagine that the biometric authentication system is difficult to accept, particularly in facilities at first glance (for example, commercial facilities, accommodation facilities, amusement facilities, etc.).

  On the other hand, it is also true that biometric authentication has the convenience that it is not necessary to remember a password or carry an ID card. The present invention has been made in view of the above points, and provides a new personal authentication method capable of minimizing problems in system operation and psychological problems of a person to be authenticated while maintaining the convenience of biometric authentication. The purpose is to do.

  As a result of earnestly examining a new personal authentication method that can minimize problems in system operation and psychological problems of the person to be authenticated while maintaining the convenience of biometric authentication, the present inventor has obtained uniqueness as authentication data. The present inventors have conceived a configuration in which secondary information that cannot be reproduced afterwards is generated from the outline of a finger, which is biometric information having a low level, and the position information of a sticker affixed to the fingernail.

  That is, according to the present invention, there is provided a method for performing personal authentication, the step of obtaining a digital image of a finger of a person to be authenticated with a sticker printed sticker attached to a fingernail; Extracting a contour line of a finger; extracting the dab from the digital image; defining a reference point based on the dab; defining a tracking start point based on the dab; Sequentially assigning pixel IDs to the pixels constituting the contour line from the tracking start point, and calculating the separation distance between the pixels constituting the contour line of the finger and the reference point; Generating a table in which the separation distance and the pixel ID are associated as authentication data, and a phase between the authentication data of the person to be authenticated and the authentication data of the registered user. And a step of determining whether the authentication based on the coefficient, the personal authentication method is provided. Moreover, according to this invention, the computer executable program for making a computer perform each step of the said personal authentication method is provided. Further, according to the present invention, an imaging unit for acquiring a digital image of the finger of the person to be authenticated, an authentication data generation unit for generating authentication data from the digital image, and the authentication data of the registered user A personal authentication system comprising: a registration data management unit that manages as registration data; and an authentication unit that determines whether or not authentication is possible based on a correlation coefficient between the authentication data of the person to be authenticated and the registration data. The authentication data generation unit is configured to extract, from the digital image, a finger print printed on a contour of the finger and a sticker affixed to the fingernail, and a reference point based on the dot Functional means for defining, functional means for defining a tracking start point based on the drawing point, and sequentially assigning pixel IDs to each pixel constituting the outline of the finger from the tracking start point Functional means, functional means for calculating a separation distance between each pixel constituting the outline of the finger and the reference point, and a table in which the separation distance and the pixel ID are associated as the authentication data A personal authentication device is provided including functional means for generating.

  As described above, according to the present invention, there is provided a novel personal authentication method and system capable of minimizing problems in system operation and psychological problems of the person to be authenticated while maintaining the convenience of biometric authentication.

The figure for demonstrating the premise of this invention. The functional block diagram of the personal authentication system of this embodiment. The flowchart of the process which the personal authentication system of this embodiment performs. The figure for demonstrating the process which the data generation part for authentication in this embodiment performs. The figure for demonstrating the process which the data generation part for authentication in this embodiment performs. The figure for demonstrating the process which the data generation part for authentication in this embodiment performs. The figure for demonstrating the process which the data generation part for authentication in this embodiment performs. The figure which shows the data for authentication (table) in this embodiment. The figure which shows embodiment of the seal | sticker in this embodiment. The figure which shows the result of the verification experiment about principal acceptance / others rejection. The figure which shows the result of the verification experiment about principal acceptance / others rejection. The figure which shows the simulation result of impersonation tolerance. The figure which shows the simulation result of impersonation tolerance. The figure which shows the relationship between the number of tracking pixels, and personal identification.

  Hereinafter, the present invention will be described with reference to embodiments shown in the drawings, but the present invention is not limited to the embodiments shown in the drawings. In the drawings referred to below, the same reference numerals are used for common elements, and the description thereof is omitted as appropriate.

  First, preconditions in the personal authentication system of the present invention will be described. The user of the personal authentication system of the present invention is required to apply a predetermined seal delivered from the system provider to the fingernail. Fig.1 (a) expands and shows the seal | sticker 12 which is embodiment of the seal | sticker in this invention. The seal 12 is configured as a very small seal with respect to the size of a human fingernail. In addition, although the rectangular seal | sticker 12 was shown in Fig.1 (a), the shape of a seal | sticker is not limited to this, A circle, an ellipse, and any other shape may be sufficient.

  Two dashes are printed on the seal 12. Here, each dab is printed in a different color. In the example shown in FIG. 1 (a), a red dab 14r and a blue dab 14b are printed at a predetermined interval. Each dab is printed in a different color in light of the subsequent image extraction process, and color combinations are not limited to red and blue, and the color distances are appropriately separated. Any combination may be used. Moreover, it is preferable that the distance of the surface base of the seal | sticker 12 on which the dot is printed is largely separated from the dot, and it is preferable to adopt a color having high brightness such as white.

  The user of the personal authentication system of the present invention attaches the seal 12 delivered from the system provider to the fingernail. At this time, how to put the seal is left to the user. As a result, as shown in FIG. 1B, randomness occurs in the relative sticking position of the seal 12 on the user's finger. On the premise of the above-described matters, the description of the personal authentication system of the present invention will be started.

  FIG. 2 shows a functional block diagram of the personal authentication system 100 according to the embodiment of the present invention. As illustrated in FIG. 2, the personal authentication system 100 according to the present embodiment includes an imaging unit 10, an image input IF 20, an authentication data generation unit 30, a registration data management unit 40, an authentication unit 50, and an authentication result. An output unit 60 is included. The imaging unit 10 includes a high-quality digital camera 11 such as a 3CCD camera, and acquires an RGB digital image of the finger of the person to be authenticated (that is, the surface on which the nail is grown). The digital image acquired by the imaging unit 10 is transferred to the authentication data generation unit 30 via the image input IF 20. The authentication data generation unit 30 generates authentication data from the digital image of the person to be authenticated. The generated authentication data is registered in the registration data management unit 40 as registration data for authenticating the person to be authenticated in the registration mode, and is provided to the authentication unit 50 as verification data in the authentication mode. The authentication unit 50 determines whether authentication is possible based on the correlation coefficient between the collation data and each registered data registered in the registered data management unit 40, and notifies the authentication result output unit 60 of the result. The authentication result output unit 60 converts the output of the authentication result into appropriate output data according to the output means and outputs the result.

  The basic configuration of the personal authentication system 100 according to the present embodiment has been schematically described above. Next, the processing executed by the personal authentication system 100 will be specifically described with reference to FIG. In the following description, FIG. 2 will be referred to as appropriate.

  FIG. 3 shows a flowchart of processing executed by the personal authentication system 100. First, the imaging unit 10 acquires a digital image of the finger of the person to be authenticated (that is, the surface on which the nail is grown) (step 101). FIG. 4A shows a digital image acquired by the imaging unit 10. In the digital image, a portion ahead of the first joint of the finger of the person to be authenticated with the seal 12 attached to the nail is shown. The seal 12 is printed with a red drawn dot 14r and a blue drawn dot 14b as shown on the right side of FIG.

  Next, the authentication data generation unit 30 acquires a finger outline from the digital image shown in FIG. 4A (step 102). Specifically, after binarization processing and noise removal processing are performed on the acquired digital image, edge pixels are extracted using a Laplacian filter. Next, by performing thinning processing on the extracted edge pixels, the outline O of the finger is extracted with a thickness of 1 pixel as shown in FIG.

  Next, the authentication data generation unit 30 defines the tracking pixel group O ′ based on the contour line O of the finger (step 103). Specifically, after specifying the maximum value [Xmax] of the X coordinate values of the pixels constituting the outline O of the finger, the value [Xmax−W] obtained by subtracting the predetermined value [W] from the maximum value [Xmax] is obtained. Two pixels having X coordinate values, that is, P1 (Xmax-W, Y1) and P2 (Xmax-W, Y2) are specified. Finally, after deleting all pixels having an X coordinate value smaller than [Xmax-W] from the pixels constituting the contour line O of the finger, a straight line connecting the pixels P1 and P2 is defined. As a result, a tracking pixel group O ′ as shown in FIG. 5A is defined.

  Next, the authentication data generation unit 30 determines the representative coordinate values of the two drawn points 14r and 14b printed on the sticker 12 (step 104). Specifically, first, the pixels constituting the drawn point 14r and the drawn point 14b printed on the seal 12 are acquired from the digital image shown in FIG. Here, since the drawing point 14r and the drawing point 14b are printed in different colors (red and blue), the images of the drawing point 14r and the drawing point 14b can be separately extracted based on the RGB values (or luminance values). it can. In addition, the extraction process of the image of each drawing point can be performed using an appropriate color extraction filter or the like.

Here, the extracted image of the drawn dot 14 is generally composed of a plurality of pixels. Therefore, in this embodiment, the representative coordinate value of the drawing point 14 is determined according to a predetermined rule. An example of the rule for determining the representative coordinate value will be described with reference to FIG. First, the maximum value [Xmax] and the minimum value [Xmin] of the X coordinate values of the pixels constituting the drawing point 14 are acquired to obtain the average value [Xave], and the average value [Xave] is determined as the representative value of the X coordinate value. To do. Rules are provided such as rounding down or rounding up so that the average value of coordinate values can be obtained as an integer. Similarly, the maximum value [Ymax] and the minimum value [Ymin] of the Y coordinate values of the pixels constituting the drawing point 14 are acquired to obtain the average value [Yave], and the average value [Yave] is determined as the representative value of the Y coordinate value. To do. Finally, the representative coordinate value of the plotted point 14 is (Xave,
Yave).

  Next, the authentication data generation unit 30 defines the reference point D according to an appropriate rule based on the representative coordinate value of the drawing point 14 (step 105). Here, various rules for defining the reference point can be assumed and are not particularly limited, but the simplest example is a rule in which either the representative pixel R or the representative pixel B is the reference point D. Can be mentioned. In addition, any pixel (for example, the middle point) on the line segment connecting the representative pixel R and the representative pixel B is set as the reference point D, or any pixel on the straight line passing through the representative pixel R and the representative pixel B (for example, A rule that a reference point D is a pixel separated from the representative pixel by a predetermined pixel distance can be considered. Here, the representative pixel means a pixel corresponding to the representative coordinate value. In the example shown in FIG. 5A, the midpoint of the line segment connecting the representative pixel R of the drawing point 14r and the representative pixel B of the drawing point 14b is defined as the reference point D.

  Next, the authentication data generation unit 30 defines the tracking start point S based on the representative coordinate value of the drawing point 14 (step 106). Specifically, after defining a straight line passing through the reference point D, a pixel existing on the defined straight line among the pixels constituting the tracking pixel group O ′ is defined as the tracking start point S. In the present embodiment, the straight line passing through the reference point D described above can be defined as a straight line that forms a predetermined angle with the straight line passing through the representative pixel R and the representative pixel B.

  FIG. 5A shows, as the simplest example, a straight line passing through the reference point D, the representative pixel R, and the representative pixel B among the pixels constituting the tracking pixel group O ′ (that is, a straight line passing through the reference point D). The pixel existing on the straight line passing through the representative pixel R and the representative pixel B and the 0 ° angle) is defined as the tracking start point S. Since the tracking pixel group O ′ intersects at two points on the straight line passing through the reference point D, one of the pixels is defined as the tracking start point S according to a predetermined rule. In the present embodiment, as shown in FIG. 5B, a pixel existing on the extension line from the representative pixel R to the representative pixel B is defined as the tracking start point S.

  Next, as shown in FIG. 5C, the authentication data generation unit 30 sequentially assigns pixel IDs sequentially from the tracking start point S to all the pixels constituting the tracking pixel group O ′ ( Step 107). In this case, two orders, clockwise and counterclockwise, are assumed as the order in which the pixel IDs are assigned. Therefore, the order in which the pixel IDs are assigned is defined according to a predetermined rule. In the example shown in FIG. 5C, it is defined that IDs are assigned consecutively in the counterclockwise order from the tracking start point S.

  In other embodiments, pixel IDs are not assigned to all the pixels constituting the tracking pixel group O ′, but pixel IDs are assigned only to some of the pixels selected according to a predetermined rule. A serial number can also be given. For example, after defining a line extending through the reference point D and the tracking start point S, the line is rotated and moved in a predetermined direction by a predetermined angle (θ) with the reference point D as the rotation center, and the line and the contour of the finger are moved. It can be configured such that pixel IDs are assigned consecutively only for pixels at the intersection of lines. In this case, the number of pixels to be selected can be reduced by setting the predetermined angle (θ) large. It is also possible to provide a pixel ID with a sequential number for each pixel that separates (α) pixels while tracking one pixel along the contour of the finger. Also in this case, the larger the value (α), the smaller the number of selected pixels.

  Next, as shown in FIG. 7A, the authentication data generation unit 30 calculates the separation distance between each pixel and the reference point D for all the pixels constituting the tracking pixel group O ′ (step 108). ). The separation distance in the present embodiment can be calculated as a pixel distance. FIG. 7B shows a diagram in which the relationship between the pixel ID and the calculated pixel distance is plotted.

  Next, the authentication data generation unit 30 generates a table in which the calculated pixel distance and the pixel ID are associated as authentication data (step 109). FIG. 8 illustrates the generated table (authentication data). Here, the personal identification of the generated authentication data essentially depends on the randomness of the position where the seal 12 is attached. In addition, since the shape of the finger contour line can be expected to vary considerably depending on the individual, it is secondary information determined based on the relative application position of the seal 12 and the shape of the finger contour line. The randomness of the authentication data of this embodiment further increases. This randomness does not guarantee strict uniqueness like a fingerprint or the like, but guarantees necessary and sufficient personal identification in applications where the authentication target is several thousand people. In the present embodiment, the separation distance between each pixel in the linear region connecting the pixel P1 and the pixel P2 shown in FIG. 5A and the reference point D may not be used for generating authentication data.

  When the authentication data is generated in step 109, the process proceeds to step 110, and the mode is determined. In the registration mode, the generated table is registered in the registration data management unit 40 as registered user registration data (step 111). The process is terminated. On the other hand, in the case of the authentication mode, the generated table is provided as reference data to the authentication unit 50 and temporarily stored (step 112). Note that the primary information used to generate the authentication data (finger image and contour coordinate information) is biometric information that is unique and cannot identify an individual. Although this does not cause a problem, in the present embodiment, it is preferable that the primary information is deleted immediately after the authentication data is generated in consideration of the privacy problem.

  However, even if the primary information is deleted, it is not impossible to reproduce the contour of the finger from the information in the table. Therefore, in a further preferred embodiment, the pixel distance is not calculated for all the pixels constituting the tracking pixel group O ′ shown in FIG. 5A, but only a small part separated from each other by a certain distance or more. It is preferable to calculate the pixel distance only for the pixels. By configuring in this way, it is possible to reproduce only a plurality of discrete points from the information in the table to such an extent that the original finger shape cannot be inferred, and the finger shape will not be known to others. Is completely cleared.

  Next, the authentication unit 50 calculates a correlation coefficient between the inquiry data and all registered data registered in the registered data management unit 40 (step 113). As a result, when registration data having a correlation coefficient larger than a predetermined threshold is detected (Yes in step 114), the authentication result output unit 60 is notified that the authentication is successful (step 115), The process ends. On the other hand, when registration data for deriving a correlation coefficient larger than a predetermined threshold is not found (step 114, No), the authentication result output unit 60 is notified that the authentication has failed (step 116). The process ends.

  As described above, the personal authentication method of the present invention is highly convenient because it uses a finger that is a part of the user's body, and the biometric information to be used is in the shape of the contour of the finger, Since there is no personal identification in itself, it does not give psychological resistance to the user. Further, in the present invention, even if biometric information is stolen alone, it is practically impossible to reproduce the authentication data therefrom, and in the unlikely event that the authentication data itself is stolen. However, since the old authentication data can be canceled and new authentication data can be re-registered simply by re-sticking the sticker, the user can continue to use the system thereafter.

  As mentioned above, although this invention was demonstrated with embodiment, this invention is not limited to embodiment mentioned above, For example, about a sticker affixed on a to-be-authenticated person's nail, embodiment as shown in FIG. Is also included. In the embodiment shown in FIG. 9A, three drawn dots 14 (red, blue, and black) having different colors are printed on the seal 12. In this case, in the same manner as described above, the tracking start point S and the reference point D are defined on the basis of the drawing point 14 (red) and the drawing point 14 (blue), while the remaining drawing point 14 (black) is a nail for the imaging system. It can be used to correct the inclination of.

  In another embodiment shown in FIG. 9 (b), only one plot 14 is printed on the seal 12. In this case, the representative pixel of the drawing point 14 is defined as the reference point D, while the tracking start point S is defined according to an appropriate rule. For example, among the pixels constituting the contour of the finger, a pixel having the maximum X coordinate value is defined as the tracking start point S, or a pixel having the same X coordinate value as the reference point D is defined as the tracking start point S. Can be.

  In the above-described embodiment, the configuration has been described in which the colors of the two drawn points are differentiated from each other. However, the present invention is not limited to this, and the size and shape of the two drawn points. You may comprise so that both may be distinguished by making different. Furthermore, in this invention, it can also comprise so that light other than visible light may be irradiated with respect to the drawing point printed with the fluorescent paint, and a drawing point may be extracted based on the light emission luminance. Further, in the present invention, it is also possible to construct a drawing point directly on a fingernail using an ink jet device or the like. In addition, it is included in the scope of the present invention as long as the effects and effects of the present invention are exhibited within the scope of embodiments that can be considered by those skilled in the art.

  Hereinafter, although the authentication system of the present invention will be described more specifically using examples, the present invention is not limited to the examples described later.

  About the authentication system of this invention, verification experiment was conducted in the following procedures.

(Verification of acceptance / rejection of others)
A sticker with two dashes (red and blue) printed at intervals of 2.5 mm was prepared, and subject A was instructed to put the sticker on the favorite position of the thumb nail. Thereafter, the thumb with the sticker was photographed, and registration data was generated based on the acquired digital image. FIG. 10A shows an image from which registration data is based.

  Subsequently, the same thumb of the subject A was photographed four times in such a manner that the thumb was set on the photographing unit every time photographing was performed. Four inquiry data were generated based on the four digital images thus obtained, and a correlation coefficient between each inquiry data and registration data was calculated. FIGS. 10B to 10E show an image that is the basis of each inquiry data together with a correlation coefficient.

  Next, an image (shown in FIG. 11 (a)) that is the basis of the registration data of the subject A is shown as an example for the four subjects B to E, and a sticker is put on the nail of the thumb according to this. Instructed. Thereafter, the thumbs of subjects B to E with the stickers attached were photographed. Each person's inquiry data was produced | generated based on four digital images acquired in that way, and the correlation coefficient between each inquiry data of test subject B-E and registration data of test subject A was calculated. FIGS. 11B to 11E show images that are the basis of the inquiry data of the subjects B to E together with the correlation coefficient.

  Based on the experimental results described above, it is demonstrated that the system of this embodiment can realize the acceptance of others and the rejection of others by setting an appropriate value (for example, k = 0.0.99) for the threshold k of the correlation coefficient. It was done.

(Verification of impersonation resistance)
A simulation was performed in the following procedure using the contour line of the thumb of subject A shown in FIG. First, as shown in FIG. 12A, the reference point D and the tracking start point S are defined at arbitrary positions, authentication data is generated, and this is used as registration data. Next, while keeping the tracking start point S fixed, the position of the reference point D was moved pixel by pixel in the x-axis direction from the initial position, and authentication data at each position was generated each time. Similarly, the position of the reference point D is moved pixel by pixel from the initial position in the y-axis direction, and authentication data at each position is generated each time. FIG. 12B is a diagram showing the relationship between the correlation coefficient between each authentication data generated in the above-described procedure and registered data and the degree of deviation (pixel distance) of the reference point D for each movement axis direction. It is.

  Here, referring to FIG. 12 (b) with the threshold value k for identifying the person and others as “0.995”, referring to FIG. 12B, the reference point is 11 pixels in the x-axis direction (0.55 mm in actual size) from the initial position. If it deviates more than that, it is not authenticated, and if it deviates more than 10 pixels (0.5 mm in actual size) in the y-axis direction, it is understood that it is not authenticated.

  Further, as shown in FIG. 13A, after defining the pixel at the intersection of the line segment extending in the initial direction starting from the reference point D and the contour of the finger as the initial position of the tracking start point S, the fixed reference point A pixel at the intersection of the line segment rotated by 1 ° counterclockwise around D and the outline of the finger is defined as a new tracking start point S. Then, a plurality of authentication data is generated based on the plurality of defined tracking start points S. FIG. 13B is a diagram showing the relationship between the correlation coefficient between each authentication data and registration data generated by the above-described procedure and the deviation (angle θ) from the line segment extending in the initial direction. Here, assuming that the threshold value k for identifying the person and the other person is “0.995” and referring to FIG. 13B, the deviation from the line segment connecting the initial position of the tracking start point S and the reference point D is an angle. If it deviates by 5 °, it turns out that it is not authenticated.

  Here, assuming that the sticking range of the seal is 5.0 × 5.0 mm square, the probability that the reference point D defined by the sticker attached at random substantially matches that of the person from the simulation results described above is (0.55 × 0.5) mm 2 / (5 × 5) mm 2 = 1/90, and the probability that the tracking start point D defined by the randomly attached sticker substantially matches that of the person is 5 ° / 360 ° = 1/72. Therefore, the probability that the person can be impersonated by applying a sticker to the artificial fingernail that completely reproduces the person's finger is 1/90 × 1/72 = 1/6480. Based on the above results, even if the image of the person's finger is stolen alone, it can be said that it is substantially impossible to reproduce the authentication data therefrom.

(Relationship between the number of tracking pixels and personal identification)
Based on the information of subjects A to E acquired in the previous experiment, the effect of reducing the number of tracking pixels used for generating the authentication data was verified. In this verification, the number of tracking pixels was reduced by a method in which a pixel ID is assigned sequentially for each pixel that separates (α) pixels. FIG. 14 is a diagram showing the relationship between the correlation coefficient between registered data and inquiry data and the ratio (%) of the number of pixels used for the calculation with respect to the total number of pixels in the tracking pixel group O ′ for each subject. . As shown in FIG. 14, even when the number of pixels is reduced to 0.56% (in this case, the number of pixels = 8), the correlation coefficient of the inquiry data of the subject A (first to fourth times) Was shown to be significantly greater than the correlation coefficient of the query data for subjects B-E. From this result, it was shown in the present invention that it is not always necessary to use all the pixels of the tracking pixel group O ′ in the generation of the authentication data.

  As described above, according to the present invention, there is provided a novel personal authentication method and system capable of minimizing problems in system operation and psychological problems of the person to be authenticated while maintaining the convenience of biometric authentication. The The present invention will be accepted without resistance even in commercial facilities, lodging facilities, amusement facilities, etc., where the introduction of biometric authentication has been avoided. For example, if the present invention is applied to an accommodation facility such as a hotel, the guest can simply register the sticker handed to the nail at the time of check-in without having to carry an IC card or the like. The entrance and accounting within the facility will be possible, and the convenience for guests will be greatly improved.

DESCRIPTION OF SYMBOLS 10 ... Image pick-up part 11 ... High-quality digital camera 12 ... Sticker 14 ... Drawing point 20 ... Image input IF
DESCRIPTION OF SYMBOLS 30 ... Authentication data generation part 40 ... Registration data management part 50 ... Authentication part 60 ... Authentication result output part 100 ... Personal authentication system

Claims (8)

A method for performing personal authentication,
Obtaining a digital image of the finger of the person to be authenticated with a sticker printed with a sticker printed on the fingernail;
Extracting a contour of the finger from the digital image;
Extracting the dab from the digital image;
Defining a reference point based on the dab;
Defining a tracking start point on the contour of the finger based on the reference point ;
Sequentially assigning pixel IDs sequentially from the tracking start point to each pixel constituting the outline of the finger;
Calculating a separation distance between each pixel constituting the contour line of the finger and the reference point;
Generating a table in which the separation distance and the pixel ID are associated as authentication data;
Determining whether authentication is possible based on a correlation coefficient between the authentication data of the person to be authenticated and the authentication data of the registered user;
Including personal authentication methods. At least two dab points are printed on the seal,
Step is a step of defining a pixel on the straight line passing through the two dabs as a reference point, the personal authentication method of claim 1 defining the reference point. The personal authentication method according to claim 2 , wherein a midpoint of a line segment connecting the two drawn points is defined as the reference point.   The step of defining the tracking start point is a step of defining, as the tracking start point, a pixel existing on a straight line passing through the reference point among the pixels constituting the contour line of the finger. The personal authentication method according to claim 2, wherein the personal authentication method forms a predetermined angle with a straight line passing through the drawing point. The step of defining the tracking start point is a step of defining, as the tracking start point, a pixel existing on a straight line passing through the two drawing points among the pixels constituting the outline of the finger.
The personal authentication method according to claim 4. The two dab points are printed in different colors,
Extracting the dab from the digital image is extracting the two dab separately based on RGB values;
The personal authentication method according to claim 2.   The computer executable program for making a computer perform each step of the personal authentication method as described in any one of Claims 1-6. An imaging unit for acquiring a digital image of the finger of the person to be authenticated;
An authentication data generation unit for generating authentication data from the digital image;
A registered data management unit that manages the authentication data of registered users as registered data;
A personal authentication system including an authentication unit that determines whether authentication is possible based on a correlation coefficient between the authentication data of the person to be authenticated and the registration data,
The authentication data generation unit includes:
Functional means for extracting from the digital image, a contour printed on the finger and a plot printed on a sticker affixed to the fingernail;
Functional means for defining a reference point based on the dab;
Functional means for defining a tracking start point based on the dab;
Functional means for sequentially assigning pixel IDs to the pixels constituting the outline of the finger in order from the tracking start point;
Functional means for calculating a separation distance between each pixel constituting the contour line of the finger and the reference point;
A function unit that generates a table in which the separation distance is associated with the pixel ID as the authentication data;
Personal authentication system .