BIOMETRIC AUTHENTICATION DEVICE AND METHOD, COMPUTER-READABLE RECORDING MEDIUM RECORDED WITH BIOMETRIC AUTHENTICATION COMPUTER PROGRAM, AND COMPUTER SYSTEM

• US 20100148922A1
• Filed: 12/04/2009
• Published: 06/17/2010
• Est. Priority Date: 12/16/2008
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: YAMADA, Shigefumi, Niinuma, Koichiro
• Granted Patent: US 8,816,818 B2
• Time in Patent Office: Days
• US Class Current: 340/5.820
• CPC Class Codes: G06F 21/32 using biometric data, e.g. fingerprints, iris scans or voiceprints
• CPC Class Codes: G06V 30/2504 Coarse or fine approaches, e.g. resolution of ambiguities or multiscale approaches
• CPC Class Codes: G06V 40/1365 Matching; Classification

Abstract

A computer system checks whether or not an authentication success rate for a registered user shows an over-time reduction based on the history of the results of the previous biometric authentication processes in which the high-speed verification process is executed, when the authentication success rate is determined as showing an over-time reduction for the registered user, the computer system instead executes a precise verification process for verifying input biometric information against registered biometric information to make verification with a higher precision than with the high-speed verification process.

Claims

1. A biometric authentication device, comprising:

a biometric information acquisition section that acquires input biometric information of a user, and generates input biometric data representing the input biometric information;

a storage section that stores therein registered biometric data representing registered biometric information about at least one registered user who is registered in advance;

a first verification process section that executes a first verification process of calculating a first degree of similarity representing a degree of similarity between the input biometric information and the registered biometric information;

a second verification process section that executes a second verification process of calculating a second degree of similarity representing the degree of similarity between the input biometric information and the registered biometric information by verifying the input biometric information against the registered biometric information with higher precision than with the first verification process;

an authentication assessment section that authenticates, when the first or second degree of similarity takes a value larger than a predetermined verification assessment threshold value, the user as a registered user corresponding to the registered biometric information;

a verification history update section that stores the first degree of similarity calculated by the first verification process into the storage section with a correlation with the registered biometric data representing the registered biometric information verified against the input biometric information; and

a verification process change section that changes, by referring to the first degree of similarity correlated with the registered biometric data stored in the storage section, when an authentication success rate indicating a rate of authenticating the registered user as the user is determined as showing an over-time reduction, the first verification process to the second verification process for execution to the registered biometric information.

2. The biometric authentication device according to claim 1, wherein

when an average value of the first degree of similarity calculated by the first verification process in a predetermined period of time or an average value of the first degree of similarity calculated by the first verification process for a predetermined number of times is smaller than a predetermined threshold value, the verification process change section assesses that the authentication success rate shows the over-time reduction.

3. The biometric authentication device according to claim 1, wherein

when a value distribution of the first degree of similarity calculated by the first verification process in a predetermined period of time or a value distribution of the first degree of similarity calculated by the first verification process for a predetermined number of times takes a value larger than a predetermined threshold value, the verification process change section assesses that the authentication success rate shows the over-time reduction.

4. The biometric authentication device according to claim 1, wherein

when a reduction amount indicating a reduction of the first degree of similarity calculated by the first verification process at a second timing later than a first timing with respect to the first degree of similarity calculated by the first verification process at the first timing is larger than a predetermined threshold value, the verification process change section assesses that the authentication success rate shows the over-time reduction.

5. The biometric authentication device according to claim 1, wherein

when a ratio of frequency of authenticating, by the authentication assessment section, the user as the registered user corresponding to the registered biometric information based on the first degree of similarity to frequency of assessing whether or not the user is the registered user corresponding to the registered biometric information based on the first degree of similarity is smaller than a predetermined threshold value, the verification process change section assesses that the authentication success rate shows the over-time reduction.

6. The biometric authentication device according to claim 1, wherein

every time the authentication assessment section assesses whether or not to authenticate the user using the first degree of similarity calculated by the first verification process, finds quality information about the input biometric data, and stores the quality information in the storage section with a correlation with the registered biometric data representing the registered biometric information verified against the input biometric information, and

when the authentication success rate shows the over-time reduction, the verification process change section changes the first verification process to the second verification process for execution to the registered biometric information only when the quality information indicates that the input biometric data is lower in quality than the registered biometric data at the time of registration.

7. The biometric authentication device according to claim 1, wherein

an amount of information included in the input biometric information or in the registered biometric information to be used in the second verification process is larger than an amount of information included in the input biometric information or in the registered biometric information to be used in the first verification process.

8. The biometric authentication device according to claim 1, wherein

the input biometric data is an input image being a result of capturing the input biometric information, the registered biometric data is a registered image being a result of capturing the registered biometric information, the first verification process is executed to calculate, for use as the first degree of similarity, a degree of coincidence between a plurality of characteristic points extracted from the input image and a plurality of characteristic points extracted from the registered image, and the second verification process is executed to calculate, for use as the second degree of similarity, a degree of coincidence between a characteristic amount representing the plurality of characteristic points extracted from the input image and a relationship thereamong, and a characteristic amount representing the plurality of characteristic points extracted from the registered image and a relationship thereamong.

9. The biometric authentication device according to claim 1, wherein

the verification history update section stores, in the storage section, the second degree of similarity calculated by the second verification process with a correlation with the registered biometric data representing the registered biometric information verified against the input biometric information, and

the verification process change section changes, when assessing that the authentication success rate shows an over-time increase by referring to the second degree of similarity correlated with the registered biometric data stored in the storage section, the second verification process to the first verification process for execution to the registered biometric information.

10. The biometric authentication device according to claim 9, wherein

by verifying the user'"'"'s input biometric information against the registered biometric information represented in a plurality of the registered biometric data stored in the storage section with either the first or second verification process, further implements a user determination section of assessing, when a maximum value found among the first or second degree of similarity calculated for each of the plurality of the registered biometric information is equal to or smaller than the verification assessment threshold value and is larger than a user determination threshold value being smaller than the verification assessment threshold value, the user as a registered user corresponding to the maximum value, and

the verification history update section stores, in the storage section, the first or second degree of similarity corresponding to the maximum value with a correlation with the registered biometric data of the registered user assessed as being the user by the user determination section.

11. A computer system having a terminal and a server connected to the terminal via a communication network, wherein

the terminal acquires input biometric information of a user, generates input biometric data representing the input biometric information, and transmits the input biometric data to the server when the user uses the computer system,

the server includes:

a communication section that receives the input biometric data from the terminal;

a storage section that stores therein registered biometric data representing registered biometric information about at least one registered user who is registered in advance;

a first verification process section that executes a first verification process of calculating a first degree of similarity representing a degree of similarity between the input biometric information and the registered biometric information;

a second verification process section that executes a second verification process of calculating a second degree of similarity representing the degree of similarity between the input biometric information and the registered biometric information by verifying the input biometric information against the registered biometric information with higher precision than with the first verification process;

an authentication assessment section that authenticates, when the first or second degree of similarity takes a value larger than a predetermined verification assessment threshold value, the user as a registered user corresponding to the registered biometric information;

a verification history update section that stores the first degree of similarity calculated by the first verification process into the storage section with a correlation with the registered biometric data representing the registered biometric information verified against the input biometric information;

a verification process change section that changes, by referring to the first degree of similarity correlated with the registered biometric data stored in the storage section, when an authentication success rate indicating a rate of authenticating the registered user as the user is determined as showing an over-time reduction, the first verification process to the second verification process for execution to the registered biometric information; and

a section that permits the user to use the computer system when the authentication assessment section authenticates the user.

12. A computer, comprising:

a biometric information acquisition section that acquires input biometric information of a user, and generates input biometric data representing the input biometric information;

a storage section that stores therein registered biometric data representing registered biometric information about at least one registered user who is registered in advance;

a first verification process section that executes a first verification process of calculating a first degree of similarity representing a degree of similarity between the input biometric information and the registered biometric information;

a second verification process section that executes a second verification process of calculating a second degree of similarity representing the degree of similarity between the input biometric information and the registered biometric information by verifying the input biometric information against the registered biometric information with higher precision than with the first verification process;

an authentication assessment section that authenticates, when the first or second degree of similarity takes a value larger than a predetermined verification assessment threshold value, the user as a registered user corresponding to the registered biometric information;

a verification history update section that stores the first degree of similarity calculated by the first verification process into the storage section with a correlation with the registered biometric data representing the registered biometric information verified against the input biometric information;

a verification process change section that changes, by referring to the first degree of similarity correlated with the registered biometric data stored in the storage section, when an authentication success rate indicating a rate of authenticating the registered user as the user is determined as showing an over-time reduction, the first verification process to the second verification process for execution to the registered biometric information; and

a section that permits the user to use the computer system when the authentication assessment section authenticates the user.

13. A computer readable recording medium recording a computer program allowing a device having a storage section to implement biometric authentication on input biometric information of a user of the device and registered biometric information of a registered user represented in registered biometric data stored in the storage section in advance, the program that cause the computer to execute:

a first verification process section that executes a first verification process of calculating a first degree of similarity representing a degree of similarity between the input biometric information and the registered biometric information;

a second verification process section that executes a second verification process of calculating a second degree of similarity representing the degree of similarity between the input biometric information and the registered biometric information by verifying the input biometric information against the registered biometric information with higher precision than with the first verification process;

an authentication assessment section that authenticates, when the first or second degree of similarity takes a value larger than a predetermined verification assessment threshold value, the user as a registered user corresponding to the registered biometric information;

a verification history update section that stores the first degree of similarity calculated by the first verification process into the storage section with a correlation with the registered biometric data representing the registered biometric information verified against the input biometric information; and

a verification process change section that changes, by referring to the first degree of similarity correlated with the registered biometric data stored in the storage section, when an authentication success rate indicating a rate of authenticating the registered user as the user is determined as showing an over-time reduction, the first verification process to the second verification process for execution to the registered biometric information.

14. A biometric authentication method that authenticates a user by verifying input biometric information of the user represented in input biometric data generated by a biometric information acquisition section against registered biometric information of a registered user represented in registered biometric data stored in a storage section by executing either a first or second verification process, the method comprising the operations of:

assessing whether or not an authentication success rate being a rate of authentication when the registered user corresponding to the registered biometric information is the user shows an over-time reduction by referring to a first degree of similarity indicating a result of a biometric authentication process previously executed by the first verification process,

verifying, when the authentication success rate does not show the over-time reduction, the input biometric information against the registered biometric information by the first verification process, and calculating the first degree of similarity representing a degree of similarity between the input biometric information and the registered biometric information,

verifying, when the authentication success rate shows the over-time reduction, the input biometric information against the registered biometric information by the second verification process with a higher precision than with the first verification process, and calculating a second degree of similarity representing a degree of similarity between the input biometric information and the registered biometric information, and

authenticating, when the first or second degree of similarity shows a value larger than a predetermined verification assessment threshold value, the user as the registered user corresponding to the registered biometric information.