Biometric authentication device and method, computer-readable recording medium recorded with biometric authentication computer program, and computer system

• US 8,816,818 B2
• Filed: 12/04/2009
• Issued: 08/26/2014
• Est. Priority Date: 12/16/2008
• Status: Expired due to Fees

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Yamada, Shigefumi, Niinuma, Koichiro
• Primary Examiner(s): Syed, Nabil
• Assistant Examiner(s): WILSON, BRIAN P
• Application Number:
  US12/631,263
• Publication Number:
  US 20100148922A1
• Time in Patent Office: 1,726 Days
• Field of Search: None
• US Class Current: 340/5.82
• 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 memory; and

a processor coupled to the memory and configured to;

acquire input biometric information of a user, and generate input biometric data representing the input biometric information;

store registered biometric data representing registered biometric information of at least one registered user who is registered in advance;

execute either a first verification process or a second verification process, wherein the first verification process calculates a first degree of similarity representing a degree of similarity between the input biometric information and the registered biometric information, and the second verification process calculates 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;

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

store the first degree of similarity calculated by the first verification process with a correlation with the registered biometric data representing the registered biometric information verified against the input biometric information; and

change, by referring to the first degree of similarity correlated with the registered biometric data, 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.

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 processor 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 processor 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 processor 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 processor, 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 processor assesses that the authentication success rate shows the over-time reduction.

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

every time the processor assesses whether or not to authenticate the user using the first degree of similarity calculated by the first verification process, quality information regarding the input biometric data is obtained and stored 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 processor changes the first verification process to the second verification process for execution 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 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 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, 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, 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 processor stores 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 processor 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, the second verification process to the first verification process for execution.

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

verification of the user'"'"'s input biometric information against the registered biometric information represented as the registered biometric data of the at least one registered user with either the first or the second verification process further comprises assessing, when a maximum value found among the first or the second degree of similarity calculated for each of the registered users of the registered biometric information is equal to or smaller than the predetermined verification assessment threshold value and is larger than a user determination threshold value being smaller than the predetermined verification assessment threshold value, the user as the registered user corresponding to the maximum value, and

the processor stores the first or the 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.

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 comprises:

a memory; and

a processor coupled to the memory and configured to;

receive the input biometric data from the terminal;

store therein registered biometric data representing registered biometric information of at least one registered user who is registered in advance;

execute either a first verification process or a second verification process, wherein the first verification process calculates a first degree of similarity representing a degree of similarity between the input biometric information and the registered biometric information, and the second verification process calculates 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;

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

store the first degree of similarity calculated by the first verification process with a correlation with the registered biometric data representing the registered biometric information verified against the input biometric information;

change, by referring to the first degree of similarity correlated with the registered biometric data, 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; and

permit the user to use the computer system when the processor authenticates the user.

12. A computer, comprising:

a memory; and

a processor coupled to the memory and configured to;

acquire input biometric information of a user, and generate input biometric data representing the input biometric information;

store registered biometric data representing registered biometric information of at least one registered user who is registered in advance;

execute either a first verification process or a second verification process, wherein the first verification process calculates a first degree of similarity representing a degree of similarity between the input biometric information and the registered biometric information, and the second verification process calculates 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;

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

store the first degree of similarity calculated by the first verification process with a correlation with the registered biometric data representing the registered biometric information verified against the input biometric information;

change, by referring to the first degree of similarity correlated with the registered biometric data, 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; and

permit the user to use the computer when the processor authenticates the user.

13. A non-transitory computer readable recording medium recording a computer program allowing a device having a storage 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 advance, the program causing the computer to execute:

executing either a first verification process or a second verification process, wherein the first verification process comprises calculating a first degree of similarity representing a degree of similarity between the input biometric information and the registered biometric information, and the second verification process comprises 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;

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

storing the first degree of similarity calculated by the first verification process with a correlation with the registered biometric data representing the registered biometric information verified against the input biometric information; and

changing, by referring to the first degree of similarity correlated with the registered biometric data, 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.

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 processor having a memory against registered biometric information of a registered user represented in registered biometric data by executing either a first or a second verification process, the method comprising:

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 the 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.