JP2018049415A - Authentication device, authentication method, program, and system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce consumption of power.SOLUTION: A portable authentication device includes: a biological information acquisition unit (301) for acquiring biological information on a subject; a communication unit for wirelessly communicating with a terminal device which the subject can carry around; and a control unit. The control unit is configured to carry out authentication processing based on the obtained biological information and change accuracy of the authentication processing on the basis of the strength of a signal received from the terminal device.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an authentication device, an authentication method, a program, and a system, and more particularly, to an authentication device, an authentication method, a program, and a system that perform authentication using biological information of a subject.

  As security consciousness increases, attention is paid to authentication using biometric information or authentication using a combination of biometric information and ID or password, instead of conventional authentication using only ID (identification) and password.

  In authentication using biometric information acquired by a sensor, generally, normal biometric information is registered on the device side (PC (Personal Computer) or server), and the biometric information acquired on the device side and the normal biometric information are registered. Matching calculation using biological information is performed. The reason for this is that the device side has a high-performance device (CPU (Central Processing Unit) and memory), and can perform complex computation (high-precision computation) for biometric authentication processing at high speed. Because.

  Thereby, the sensor side can be completed with an inexpensive and simple hardware configuration, and the downsizing and low cost of the sensor can be realized.

  In recent years, there is a demand for biometric authentication to improve security even when using a large-scale on-premises system or cloud service. However, registering personal data related to biometric authentication in the cloud server has a risk of leaking privacy information of many users who register the personal data.

  In order to avoid such a risk, FIDO (Fast IDentity Online) in which an online authentication protocol called UAF (Universal Authentication Framework) is implemented has been proposed. According to FIDO, a method is proposed in which a biometric sensor has biometric information and performs a matching operation in the sensor.

  A wearable fingerprint authentication platform has been proposed by DDS Corporation. In this proposed method, the device performs authentication based on the user's fingerprint, and stores the ID for obtaining permission to use the device when the user is successfully authenticated.

  Japanese Patent Laid-Open No. 2002-123778 (Patent Document 1) discloses a method in which a mobile phone acquires biometric information and collates the acquired biometric information with biometric information stored in advance in the mobile phone. To do. Moreover, the portable personal digital identification device disclosed in Japanese translations of PCT publication No. 2004-518229 (Patent Document 2) collates the biological information measured by the device with the biological information stored in advance in the device. , Carry out authentication.

JP 2002-123778 A JP-T-2004-518229

  In Patent Document 1, when a device such as a PC equipped with an authentication sensor performs biometric authentication of a user in order to obtain permission to use the device, the user uses the device from a bag every time the device is used. It is necessary to take out, and it is inferior to usability.

  Since the authentication device of Patent Document 2 is a type that an individual can wear, the above usability problem can be solved. Since the authentication device of Patent Document 2 is a relatively small type, the performance of a mountable arithmetic processing unit (CPU) may be limited. In this case, when high-accuracy authentication processing is frequently executed, power consumption by the arithmetic processing unit increases. When a low-performance arithmetic processing unit is installed in order to suppress power consumption, the time required for the authentication process becomes long.

  The present disclosure has been made in view of such problems, and an object thereof is to provide an authentication device, an authentication method, a program, and a system capable of suppressing power consumption.

  A portable authentication device according to an aspect of the present disclosure includes a biological information acquisition unit that acquires biological information of a subject, a communication unit that wirelessly communicates with a terminal device that can be carried by the subject, and a control unit. The control unit is configured to execute an authentication process based on the acquired biometric information, and to vary the accuracy of the authentication process based on the strength of the signal received from the terminal device.

  Preferably, the control unit of the authentication device executes an authentication process having the first accuracy when the strength of the received signal from the terminal device is equal to or higher than the threshold, and the first accuracy when the strength is lower than the threshold. It is comprised so that the authentication process which has higher 2nd precision may be performed.

  Preferably, the control unit is further configured to vary the accuracy of the authentication processing based on an elapsed time since the second accuracy authentication processing was recently executed and the strength of the received signal.

  Preferably, the control unit is further configured to vary the accuracy of the authentication processing based on the position of the authentication device and the strength of the received signal.

  Preferably, the communication unit further wirelessly communicates with a target device that can be an operation target of the subject, and the control unit authenticates the subject to the communication unit when the subject is authenticated by the authentication process. Authentication information is transmitted to the target device.

  Preferably, the control unit is further configured to vary the accuracy of the authentication process based on the type of the target device and the strength of the received signal.

  Preferably, the control unit is further configured to vary the accuracy of the authentication process based on the type of function of the target device and the strength of the received signal.

  Preferably, the communication method between the authentication device and the terminal device is different from the communication method between the authentication device and the target device.

  An authentication method according to another aspect of the present disclosure includes a step of acquiring biological information of a subject, a step of wirelessly communicating with a terminal device portable by the subject, and an authentication accuracy based on a strength of a signal received from the terminal device. And performing an authentication process using biometric information according to the determined accuracy.

  In still another aspect of the present disclosure, a program for causing a computer to execute an authentication method is provided. This authentication method includes a step of acquiring biological information of a subject, a step of communicating with a terminal device that the subject can carry, a step of determining the accuracy of authentication from the strength of a signal received from the terminal device, and the determined accuracy And performing an authentication process using biometric information.

  In yet another aspect of this disclosure, a system is provided. The system includes a portable authentication device and a terminal device that can be carried by a subject. The authentication device includes a biological information acquisition unit that acquires biological information of the subject, a communication unit that wirelessly communicates with the terminal device, and a control unit. The control unit is configured to execute an authentication process based on the acquired biometric information, and to vary the accuracy of the authentication process based on the strength of the signal received from the terminal device.

  According to this disclosure, power consumption for the authentication process can be suppressed.

It is a figure which shows the structure of the authentication system 1 concerning Embodiment 1. FIG. 2 is a diagram illustrating a specific example of a hardware configuration of a biometric sensor 300. FIG. It is a figure which shows the specific example of the hardware constitutions of the portable terminal. 3 is a diagram illustrating a specific example of a hardware configuration of the device 100. FIG. 3 is a diagram illustrating an example of a functional configuration of a biometric sensor 300. FIG. 3 is a flowchart of authentication processing according to the first exemplary embodiment; 3 is a flowchart of authentication processing according to the first exemplary embodiment; 3 is a flowchart of authentication processing according to the first exemplary embodiment; It is a figure which shows typically the authentication process in the system of FIG. 1, or the flow of data. 10 is a flowchart of processing according to the second exemplary embodiment. It is a flowchart of the process of step S3a of FIG. It is a figure which shows an example of the content of table TB0 concerning Embodiment 2. FIG. It is a figure which shows typically the embodiment of the authentication process concerning Embodiment 2. FIG. It is a figure which shows typically the embodiment of the authentication process concerning Embodiment 2. FIG. It is a figure which shows typically the embodiment of the authentication process concerning Embodiment 2. FIG. It is a figure which shows an example of the content of the tables TB1 and TB2 concerning Embodiment 3.

  Embodiments will be described below with reference to the drawings. In the following description, the same parts and components are denoted by the same reference numerals. Their names and functions are also the same.

[Overview]
The outline according to each embodiment is as follows.

  The portable authentication device includes a biological information acquisition unit that acquires biological information of a subject, a communication unit that wirelessly communicates with an external device including a terminal device that can be carried by the subject, and a processor as a control unit. The processor executes an authentication process for confirming the validity of the subject based on the acquired biological information. That is, whether or not the subject is the person can be confirmed by the authentication process. The authentication device varies the accuracy of authentication processing (hereinafter also referred to as authentication accuracy) based on whether or not communication (connection) is established with the terminal device. The authentication device determines whether communication is established based on the strength (unit: dB) of the signal received from the terminal device.

  Regarding the power consumption and authentication accuracy, generally, the amount of power consumed by the processor is large when executing authentication processing with high authentication accuracy, and is small when executing authentication processing with low authentication accuracy. In other words, the authentication device can maintain the authentication accuracy of the validity of the subject when executing the authentication processing with high authentication accuracy, and suppresses the power consumption when executing the authentication processing with low authentication accuracy. Can do. The authentication apparatus according to each embodiment varies the authentication accuracy based on the strength of the received signal from the terminal device.

  In each embodiment, a fingerprint image is shown as biometric information, but biometric information is not limited to a fingerprint image. For example, it may be a vein pattern image, an iris pattern image, or the like.

  In each embodiment, the “fingerprint image information” may include a fingerprint image and / or a feature amount of the fingerprint image.

[Embodiment 1]
<System configuration>
FIG. 1 is a diagram illustrating a configuration of an authentication system 1 according to the first embodiment. Referring to FIG. 1, an authentication system 1 is a biometric sensor 300 (corresponding to an authentication device) that acquires biometric information of a subject and a mobile terminal 200 (corresponding to a terminal device that can be carried by the subject) that communicates with the biometric sensor 300. ).

  In the authentication system 1, the portable terminal 200 and the biometric sensor 300 can be carried by the same user (subject). The biometric sensor 300 uses the biometric information to perform an authentication process, and uses or operates the device 100 or the function of the device 100 based on the result of the authentication process (login operation or function use of the device 100) Can be allowed. The device 100 corresponds to a device (target device) that is permitted to operate (or use) based on the result of the authentication process. In the first embodiment, the device 100 is an image processing device (for example, a copier, a printer, or an MFP (Multi-Function Peripherals) that is a combination of these), but the type of the device 100 is an image processing device. It is not limited. For example, a system that manages permission / prohibition of entry may be used.

  The biometric sensor 300 is a wearable terminal such as a pendant, a wristwatch, or a bag accessory. The biometric sensor 300 communicates with the mobile terminal 200 by short-range wireless communication. This short-range wireless communication follows, for example, a BLE (Bluetooth Low Energy) method that enables communication with extremely low power, but the communication method is not limited to BLE. In addition, the portable terminal 200 or the biometric sensor 300 communicates with the device 100 wirelessly. This wireless communication includes short-range wireless communication such as NFC (Near Field Radio Communication).

<Configuration of Biometric Sensor 300>
FIG. 2 is a diagram illustrating a specific example of the hardware configuration of the biometric sensor 300. Referring to FIG. 2, a biometric sensor 300 includes a CPU (Central Processing Unit) 30 corresponding to a control unit that controls the whole, and a ROM (Read Only Memory) 31 for storing programs and data executed by the CPU 30. And a RAM (Random Access Memory) 32, a sensor 33, a button 34 operated to accept a user instruction to the biometric sensor 300, and a communication controller 35 that controls wireless communication.

  The communication controller 35 includes a modem circuit, an amplifier circuit, and the like, and performs wireless communication via an antenna (not shown). The communication controller 35 performs wireless communication with external devices including the mobile terminal 200 and the device 100.

  The sensor 33 has a plurality of electrodes. The sensor 33 measures the capacitance that changes according to the distance between the surface of the finger placed on the sensor surface and the electrode, and acquires a fingerprint image from the measured capacitance. Note that the method for acquiring a fingerprint image is not limited to a method based on a change in capacitance, and may be a method for acquiring a fingerprint image with an imaging element such as a CCD (Charge Coupled Device), for example.

<Configuration of mobile terminal 200>
FIG. 3 is a diagram illustrating a specific example of the hardware configuration of the mobile terminal 200. Referring to FIG. 3, a portable terminal 200 includes a CPU 20 corresponding to a control unit that controls the whole, a ROM 21 and a RAM 22 for storing programs and data executed by the CPU 20, a display 23, and a user receiving information on the portable terminal 200. Are provided with an operation panel 25, a communication controller 27, and a memory interface 28.

  The display 23 and the operation panel 25 may be provided as an integrated touch panel. The communication controller 27 includes a modem circuit, an amplification circuit, and the like for wireless communication between the biometric sensor 300 and the device 100.

  A memory card 29 as an example of a storage medium is detachably attached to the memory interface 28. Memory interface 28 includes a circuit that is controlled by CPU 20 to write data to memory card 29 or a circuit that reads data from memory card 29.

<Configuration of Device 100>
FIG. 4 is a diagram illustrating a specific example of the hardware configuration of the device 100. FIG. 4 shows a configuration of an MFP as the device 100, for example. Referring to FIG. 4, device 100 includes a CPU (Central Processing Unit) 150 for controlling the whole, a storage unit 160 for storing programs and data, and an image storage unit 153 for mainly storing image data. , An information input / output unit 170, a communication unit 157 for communicating with an external device including the mobile terminal 200 or the biometric sensor 300, a user authentication unit 175, and various processing units.

  The storage unit 160 stores programs executed by the CPU 150 and various data. Data stored in the storage unit 160 includes a registration ID 161. The registration ID 161 indicates information to be referred to for permitting the user to operate (or use) the device 100. For example, the registration ID 161 includes information referred to by the CPU 150 to determine whether to permit a login request to the device 100 or use of the function of the device 100. The input / output unit 170 includes a display unit 171 including a display and an operation unit 172 operated by a user to input information to the device 100. Here, the display unit 171 and the operation unit 172 may be provided as an integrally configured touch panel.

  The user authentication unit 175 performs authentication processing for the user when the user operates the device 100 (or uses the function of the device 100). The registration ID 161 is used for this authentication process. Communication unit 157 includes a transmission unit 158 for transmitting data to an external device and a reception unit 159 for receiving data from the external device.

  The various processing units described above optically read an image processing unit 151, an image forming unit 152, an image output unit 154, a facsimile control unit 155 for controlling a facsimile function, and a document placed on a document table (not shown). An image reading unit 173 for obtaining image data. These various processing units read and write image data in the image storage unit 153. Since the functions of the respective units included in the various processing units are well known, detailed description thereof will not be repeated here.

<Functional Configuration of Biometric Sensor 300>
FIG. 5 is a diagram illustrating an example of a functional configuration of the biometric sensor 300. These functions are realized by a program executed by the CPU 30 or a combination of the program and a circuit. Here, a description will be given as a function of the CPU 30 for simplifying the description. Here, collation information 310, authentication information 311 and flag 312 are stored in the storage unit (ROM 31 or RAM 32). Referring to FIG. 5, the CPU 30 obtains a fingerprint image (biometric information) of the user from the output of the sensor 33, and an authentication unit 302 that executes an authentication process based on the acquired fingerprint image information. A communication control unit 306 for controlling communication via the communication controller 35, and a flag processing unit 305 for processing the flag 312.

  The authentication unit 302 includes a first collation unit 303 and a second collation unit 304 that collate (match) the information on the fingerprint image acquired by the sensor 33 with the collation information 310 stored in advance in the ROM 31. The first verification unit 303 executes an authentication process having the first accuracy. The second verification unit 304 executes an authentication process having a second accuracy that is an authentication accuracy higher than the first accuracy. Therefore, the authentication process including the verification process by the first verification unit 303 is also referred to as “low-precision authentication process”, and the authentication process including the verification process by the second verification unit 304 is also referred to as “high-precision authentication process”.

  The verification information 310 includes information on a fingerprint image of a legitimate user of the biometric sensor 300. The authentication unit 302 calculates the similarity between the acquired fingerprint image and the fingerprint image of the verification information 310 from the result of the verification process of the first verification unit 303 or the second verification unit 304. When determining that the calculated similarity is equal to or greater than the threshold value, the authentication unit 302 reads the authentication information 311 from the ROM 31 and transmits the read authentication information 311 to the device 100 via the communication control unit 306. On the other hand, if it is determined that the similarity is less than the threshold value, the authentication unit 302 passes (omits) reading processing of the authentication information 311 from the ROM 31. Therefore, in this case, the authentication information 311 is not transmitted to the device 100.

  The communication control unit 306 performs pairing with the mobile terminal 200 via the communication controller 35 to establish a connection (communication). Thereafter, the communication control unit 306 maintains the established connection. The communication control unit 306 detects the intensity (unit: dB) of a signal received from the mobile terminal 200 during communication, and compares the detected signal intensity with a threshold value. A flag update request based on the comparison result is output to the flag processing unit 305.

  The flag processing unit 305 sets the flag 312 stored in the RAM 32 to ON or OFF in accordance with a flag update request from the communication control unit 306.

<Verification processing>
As a background of the present embodiment, a main fingerprint image matching process will be described. Main fingerprint image verification processing for authenticating users includes, for example, a pattern matching method for comparing (matching) fingerprint images, a feature point extraction method (maneuver method) with higher accuracy of the verification processing than the pattern matching method, and There is a frequency analysis method with higher accuracy of matching processing than the feature point extraction method.

  The feature point extraction method is a method of extracting feature amounts from a fingerprint image and collating the extracted feature amounts. In the feature point extraction method, a process of extracting a feature (feature amount) from the acquired fingerprint image is required as a pre-process of the matching process. The feature point extraction method collates a feature amount extracted from the acquired fingerprint image with a feature amount (corresponding to the collation information 310) registered in advance in the storage unit. The collation result indicates the similarity between both feature amounts. In the frequency analysis method, a cross section obtained by slicing a fingerprint indicated by an image is regarded as a signal waveform, a result of frequency analysis of the signal waveform is extracted as a feature, and the extracted features are collated. The frequency analysis method is applied to hybrid authentication in combination with the minutiae method. Note that the verification method is not limited to these.

  In the first embodiment, the biometric sensor 300 performs a verification process according to the feature point extraction method as the authentication process. In the fingerprint image, the end point or branch point of the fingerprint is a feature point. Also, feature point attributes and the relative positional relationship between feature points are referred to as feature quantities. In addition, the verification information 310 has a feature amount corresponding to each of a plurality of feature points of the fingerprint image. The first matching unit 303 executes the matching process using, for example, 50 feature points among the plurality of feature points of the fingerprint image. The second matching unit 304 executes the matching process using, for example, 100 feature points among the plurality of feature points of the fingerprint image. Note that the number of feature points used for the matching process of the first matching unit 303 is not limited to 50, and the number of feature points used for the matching process of the second matching unit 304 is not limited to 100. The number of feature points used for the matching process of the second matching unit 304 may be larger than the number of feature points used for the matching process of the first matching unit 303. In this way, by varying the number of feature points (that is, feature quantities) used in the matching process, the accuracy of the authentication process using the matching process of the first matching unit 303 is increased, and the matching process of the second matching unit 304 is performed. The accuracy of the used authentication process can be different.

<Processing flowchart>
6, 7 and 8 are flowcharts of the authentication process according to the first embodiment. Of these flowcharts, the processing flow in the biometric sensor 300 is stored in the ROM 31 as a program. The CPU 30 reads the program from the ROM 31 and executes it. Of these flowcharts, the processing flow in the portable terminal 200 is stored in the ROM 21 as a program. The CPU 20 reads the program from the ROM 21 and executes it.

  FIG. 9 is a diagram schematically showing an authentication process or a data flow in the system of FIG. The outline of the process will be described with reference to FIG. First, the biometric sensor 300 acquires biometric information from the user while establishing a connection with the mobile terminal 200 (step S60 described later), and uses the acquired biometric information to authenticate with accuracy according to the value of the flag 312. Processing is executed (steps S9, S19 and S21 described later). When the authenticity of the user is confirmed by the authentication process, the biometric sensor 300 executes a login process (step S25 described later) for the device 100.

The authentication process according to the first embodiment will be specifically described with reference to FIGS.
(Setting process of flag 312)
In the first embodiment, the value of the flag 312 indicates whether or not the biometric sensor 300 is located near the mobile terminal 200. The setting process of the value of the flag 312 will be described with reference to FIG. Here, the mobile terminal 200 is in a state in which the power is turned on and communication with the biometric sensor 300 is possible. Referring to FIG. 7, CPU 30 of biometric authentication sensor 300 performs pairing with portable terminal 200 in the login mode to establish a communication connection. During the communication establishing the connection with the portable terminal 200 in this way, the CPU 30 repeatedly executes the process of FIG.

  First, during communication (steps S71 and S79), the communication control unit 306 of the biometric sensor 300 acquires the strength of a signal received from the mobile terminal 200 (step S72), and whether or not the reception strength is equal to or greater than a threshold value. Is determined (step S73). When the communication control unit 306 determines that the reception intensity is greater than or equal to the threshold (YES in step S73), the communication control unit 306 outputs an update request for turning on the flag 312 to the flag processing unit 305, and the flag processing unit 305 In response to the update request, the flag 312 is set to “ON” (step S77). Thereafter, the process ends.

  On the other hand, when the communication control unit 306 determines that the reception strength is less than the threshold (NO in step S73), the communication control unit 306 outputs an update request for turning off the flag 312 to the flag processing unit 305, and the flag processing unit In step S75, the flag 312 is set to “OFF” in accordance with the update request. Thereafter, the process ends.

  As described above, during the communication in which the connection is established, the value of the flag 312 set based on the strength of the received signal from the mobile terminal 200 indicates whether or not the biometric sensor 300 is located near the mobile terminal 200. It is. That is, when the flag 312 indicates “off”, that is, when the strength of the received signal is less than the threshold, it is indicated that the biometric sensor 300 is located away from the mobile terminal 200. When the flag 312 indicates “on”, that is, when the strength of the received signal is equal to or greater than the threshold, it is indicated that the biometric sensor 300 is located near the mobile terminal 200.

(Authentication process)
Next, an authentication process performed by the biometric sensor 300 will be described with reference to FIG. While this authentication process is being executed, the process of FIG. 7 is also executed. The CPU 30 of the biometric sensor 300 starts processing when receiving a login mode start instruction based on a user operation received via the button 34. During the login mode, the biometric sensor 300 can accept a user login request for the device 100 from the user.

  When the process is started, the CPU 30 first sets the variable C to 0, and initializes the flag 312 to “off” (step S3). The value of the variable C is referred to in order to determine whether the login request described later in the login mode is the first input (that is, C = 0) or the second time or more (that is, C = 1). Is done.

  The CPU 30 determines whether a login request has been received based on a user operation received via the button 34 (step S5). CPU 30 repeats the process of step S5 while it is not determined that the login request has been accepted (NO in step S5). If CPU30 determines with having received the login request (it is YES at step S5), it will determine whether the variable C is 0 (step S7). If it is determined that the variable C is 0 (YES in step S7), the authentication unit 302 uses the second verification unit 304 to execute a high-accuracy authentication process (step S9). The CPU 30 determines authentication success (OK) or authentication failure (NG) based on whether or not the similarity indicated by the result of the high-accuracy authentication processing is equal to or greater than a threshold value (step S11). When it is determined that the authentication has failed ("NG" in step S11), the CPU 30 ends the process.

  When it is determined that the authentication is successful (“OK” in step S11), the communication control unit 306 performs pairing with the portable terminal 200 and establishes a connection with the portable terminal 200 (step S13). . When the communication control unit 306 establishes communication with the mobile terminal 200, the communication control unit 306 outputs an update request for turning on the flag 312 to the flag processing unit 305. The flag processing unit 305 sets the flag 312 to “ON” in accordance with the update request (step S15). Here, when the connection is established, the setting process of the flag 312 shown in FIG. 6 is started.

  CPU30 performs a login process (step S25). In the login process, the communication control unit 306 reads the authentication information 311 from the ROM 31 and transmits it to the device 100. The CPU 150 of the device 100 performs an authentication process for verifying the authentication information 311 received from the biometric authentication sensor 300 via the communication unit 157 and the registration ID 161 of the storage unit 160, and based on the result of the verification, a login request from the user Allow.

  The CPU 30 sets 1 to the variable C after the login process (step S27). Thereafter, the CPU 30 determines whether or not a user operation for instructing the end of the login mode is accepted via the button 34 (step S29). When the CPU 30 accepts the login mode end instruction operation (YES in step S29), the CPU 30 ends the series of processes. However, when the login mode end instruction operation is not accepted (NO in step S29), the process of step S5 is performed. Return to.

  If the CPU 30 determines in step S7 that the variable C is not 0 (that is, C = 1) (NO in step S7), the CPU 30 determines whether or not the flag 312 indicates ON (step S17). . When the flag 312 indicates ON (YES in step S17), the authentication unit 302 executes the above-described low-accuracy authentication process using the first verification unit 303 (step S19). On the other hand, when the flag 312 indicates OFF (NO in step S17), the authentication unit 302 executes the above-described high-accuracy authentication process using the second verification unit 304 (step S21).

  The CPU 30 determines authentication success (OK) or authentication failure (NG) based on whether or not the above-described similarity indicated by the result of the low-accuracy authentication process (step S19) or the high-accuracy authentication process (step S21) is greater than or equal to the threshold value. (Step S11). When it is determined that the authentication has failed ("NG" in step S23), the CPU 30 ends the process.

  When it is determined that the authentication is successful (OK) ("OK" in step S23), the above-described login process is executed (step S25).

  According to the process of FIG. 6, when the CPU 30 accepts the first login request in the login mode (YES in step S5), the CPU 30 performs a high-accuracy authentication process (step S9). If the result of the high-accuracy authentication process is “OK (authentication successful)” (“OK” in step S11), the biometric sensor 300 establishes a connection with the mobile terminal 200 owned by the user (step S13), and sets a flag 312. Set to ON (step S15). Thereafter, the CPU 30 transmits information (authentication information 311) necessary for using the device 100 to the device 100, and executes a login process (step S25).

  In the login mode, when a login request is received next (YES in step S5, NO in step S7), while the biometric sensor 300 is located near the portable terminal 200 (a connection has been established and the flag 312 is on). (In step S17, YES), the biometric sensor 300 reads the biometric information and performs low-accuracy authentication processing (step S19). If the authentication is successful (“OK” in step S23), the CPU 30 logs in. Processing (step S25) is executed.

  On the other hand, when the biometric sensor 300 is not located close to the portable terminal 200 (the state where the flag 312 is OFF even if the connection is established) (NO in step S17), the biometric sensor 300 reads the biometric information and is high. An accuracy authentication process is performed (step S21). If the authentication is successful (“OK” in step S23), the CPU 30 executes a login process (step S25). As described above, the accuracy of the authentication processing to be executed can be automatically switched based on the value of the flag 312 (off / on), that is, whether or not the biometric sensor 300 is away from the mobile terminal 200. Therefore, even when the accuracy of the authentication process is switched, it is not necessary to change the user operation content, and the operability is excellent.

(Login process in device 100)
In step S25 described above, the device 100 receives the authentication information 311 from the biometric sensor 300 via the receiving unit 159. The user authentication unit 175 collates the received authentication information 311 with the registration ID 161 of the storage unit 160, and when the collation results match, the CPU 150 activates each unit. Thus, when the device 100 determines that the user is a valid user (registered in the device 100), the device 100 enables the user to use (operate) the device 100.

  On the other hand, when the collation result by the user authentication unit 175 does not match, the CPU 150 does not activate each unit. Therefore, when the device 100 determines that the user is not a valid user of the device 100, the device 100 prohibits the user from using (operating) the device 100 without permitting the user.

(Authentication process)
FIG. 8 is a flowchart of the authentication process according to the first embodiment. With reference to FIG. 8, the biometric information acquisition unit 301 acquires a fingerprint image as biometric information (step S60). The authentication unit 302 executes processing for removing noise from the fingerprint image (step S61). The authentication unit 302 identifies a plurality of feature points from the fingerprint image from which noise has been removed, and extracts feature amounts for each feature point (step S62).

  The authentication unit 302 determines the number N of feature points to be used for the matching process based on the authentication accuracy (step S63). For example, when high-precision authentication processing is performed (steps S9 and S21), the number N of feature points is 100, and in the case of low-precision authentication processing (step S19), the number N of feature points is 50. It is.

  The authentication unit 302 sets 1 to a variable A for counting the number of feature points, and sets a score S described later to 0 (step S64).

  The authentication unit 302 determines whether or not the condition (A> N) is satisfied (step S65). At this time, since A = 1, it is determined that the condition (A> N) is not satisfied (NO in step S65).

  The authentication unit 302 collates the feature amount of the first feature point with the feature amount corresponding to the feature point of the collation information 310, and performs a predetermined calculation based on the result of the collation to calculate the feature amount between the feature amounts. A score S indicating the similarity is calculated (step S66).

  The authentication unit 302 calculates the sum of the scores S calculated for each feature point, and determines whether or not the condition (total of S> threshold) is satisfied (step S67). When it is determined that the condition (total of S> threshold) is not satisfied (NO in step S67), authentication unit 302 increments the value of variable A by 1 (step S68), and then returns to the process of step S65. .

  When it is determined that the condition (A> N) is satisfied in the process of step S65 (YES in step S65), the authentication unit 302 uses the acquired biometric information (fingerprint image) for collating the user (legitimate user). It is determined that it does not match the information 310 (step S69), an authentication failure ('NG') is output, and the process ends.

  When the authentication unit 302 determines in step S67 that the condition (total of S> threshold) is satisfied (YES in step S67), the acquired biometric information (fingerprint image) is information for verifying the user (authorized user). If it is determined that it matches 310 (step S 70), authentication success (“OK”) is output, and the process ends.

  According to the process of FIG. 8, the fingerprint image acquired by the biometric authentication sensor 300 and the matching information 310 are collated, and the feature amounts of the feature points are collated, and the score S (similarity) is based on the collation result. ) Is calculated. Based on whether or not the integrated value of the score S of each feature point exceeds a threshold value, the legitimacy of the user of the acquired fingerprint image is determined. In the embodiment, in the high-accuracy authentication process, the number of feature points to be verified (N = 100) is larger than the number of feature points (N = 50) in the low-accuracy authentication process. Is possible.

(Personal rejection rate and acceptance rate of others)
The accuracy of the authentication process described above will be described using the principal rejection rate and the stranger acceptance rate. In the case of high-accuracy authentication processing, the processing time is generally relatively long, but the rejection rate is 1/100 to 1/1000, while the acceptance rate for others is 1 / 100,000 to 1/1000. Ten thousand. That is, the authentication success rate is higher than the probability of erroneous authentication. In contrast, in the case of low-accuracy authentication processing, the processing time is generally relatively short, but the rejection rate is 1/10 to 1/100, and the acceptance rate for others is 1/100 to 1/100. 1000. That is, the probability of erroneous authentication is higher than the authentication success rate.

  In the first embodiment, the case where the flag 312 in the biometric authentication sensor 300 is set to “off” is exemplified when the reception strength is reduced, that is, when the mobile terminal 200 and the biometric authentication sensor 300 are separated. It is not limited to the case. For example, when a certain time has elapsed since the execution of the high-accuracy authentication process, or when the user of the biometric authentication sensor 300 leaves the room where the device 100 is placed, or the authentication unit 302 receives the biometric information acquisition unit 301. When the biometric information (fingerprint image) acquired by is compared with the biometric information (fingerprint image) acquired last time and based on the comparison result, it is determined that they are different biometric information (fingerprint image), the flag 312 is It may be set to 'OFF'. Alternatively, the flag 312 may be set to “OFF” in accordance with a combination of two or more of these.

[Embodiment 2]
The second embodiment shows a modification of the first embodiment. In Embodiment 1, the authentication accuracy is changed based on the value of the flag 312, but the changing method is not limited to this. For example, in the second embodiment, the accuracy is variably determined based on the value of the flag 312 and the type of the device 100 that requires the user to log in. Therefore, even when the flag 312 is “on”, the high-accuracy authentication process is always performed depending on the type of the device 100.

  FIG. 10 is a flowchart of processing according to the second embodiment. In FIG. 10, the processing of step S3, step S19 and step S21 in FIG. 6 is changed to the processing of step S3a, step S19a and step S21a, respectively, but the other processing is the same as those of FIG. . Therefore, in the process of FIG. 10, the process of step S3a, step S19a, and step S21a is mainly demonstrated, and the detail about another process is not repeated.

  Referring to FIG. 9, in step S3a, authentication unit 302 acquires the type of device 100 (step S3a). Details of this will be described later. In step S19a, the authentication unit 302 determines authentication accuracy based on the value of the flag 312 ('off') and the acquired type, and executes authentication processing according to the determined accuracy (step S19a). Similarly, in step S21a, the authentication unit 302 determines the authentication accuracy based on the value ('on') of the flag 312 and the acquired type, and executes authentication processing according to the determined accuracy (step S21a). ). A method for determining the authentication accuracy will be described later.

(Acquisition processing of type of device 100)
FIG. 11 is a flowchart of the process of step S3a of FIG. A processing flow in the biometric sensor 300 in the flowchart is stored in the ROM 31 as a program. The CPU 30 reads the program from the ROM 31 and executes it. Of these flowcharts, the processing flow in the device 100 is stored in the storage unit 160 as a program. The CPU 150 reads out the program from the storage unit 160 and executes it.

  Referring to FIG. 11, in order to acquire the type of device 100, authentication unit 302 transmits a model request to device 100 (step S35), and CPU 150 of device 100 receives the request from biometric sensor 300. Is determined (step S39). When the request is not received (NO in step S39), the process of step S39 is repeated.

  When the request is received (YES in step S39), the CPU 150 reads out the type of the device 100 stored in the predetermined storage area and transmits it to the biometric sensor 300 as the request source (step S41).

  The authentication unit 302 of the biometric sensor 300 receives the type from the device 100 (step S36), and stores the received type in the RAM 32 or the like (step S37). Thereafter, the process proceeds to step S5 described above.

(Determination of authentication accuracy and authentication processing)
A method for determining the authentication accuracy in step S19a and step S21a in FIG. 10 will be described. In order to determine the authentication accuracy, the CPU 30 searches the table TB0 stored in the ROM 31. FIG. 12 is a diagram illustrating an example of the contents of the table TB0 according to the second embodiment. In the table TB0, a set of the value of the flag 312 (“ON” or “OFF”) and the type of the device 100 (type ID (1), ID (2)... ID (i). Correspondingly, authentication accuracy (High or Low) is stored. 'High' indicates high accuracy authentication processing, and 'Low' indicates low accuracy authentication processing. The authentication unit 302 searches the table TB0 based on the combination of the value of the flag 312 determined in step S17 and the type of the device 100 acquired in step S3a, and the authentication corresponding to the set based on the search result. Read the accuracy from table TB0. Thereby, the accuracy of the authentication process to be executed is determined. In step S19a and step S21a, the authentication unit 302 executes an authentication process according to the determined accuracy.

  In the second embodiment, the table TB0 is provided with the biometric authentication sensor 300, but may be provided on the device 100 side. In this case, the device 100 stores the table TB0 in the storage unit 160. In this case, the biometric sensor 300 transmits the value of the flag 312 to the device 100. The device 100 reads the corresponding authentication accuracy from the table TB0 of the storage unit 160 based on the combination of the value of the flag 312 received from the biometric authentication sensor 300 and its type. Then, the device 100 transmits the read authentication accuracy to the biometric authentication sensor 300 that is a request source.

(Another example of accuracy determination method)
FIGS. 13, 14 and 15 are diagrams schematically illustrating an embodiment of the authentication processing according to the second embodiment. In the first embodiment, the low-accuracy authentication process is executed when the flag 312 is “on”. However, in the second embodiment, the type of the device 100 or the type of function of the device 100 when the flag 312 is “on”. The high-precision authentication process is executed by

  For example, when the flag 312 is in the “on” state, it is determined as low accuracy when the type of the device 100 indicates the entrance gate of the site, and when the type indicates the entrance gate of the security area, it is determined as high accuracy. (See FIG. 13).

  The accuracy of the authentication process is not limited to the type of the device 100, and may be determined based on the type of function that the device 100 has. For example, when the flag 312 is in the “on” state, when the user uses the security printing function of the device 100, the accuracy is determined to be high, and the normal printing function is determined to be low accuracy.

  Further, the accuracy of the authentication process is not limited to the type of device 100 or the type of function, and may be determined based on the operation mode of the device 100 and the user attribute. For example, when the flag 312 is in the “on” state and the device 100 is a server or MFP and the device 100 is in the administrator login mode, it is determined that the accuracy is low in the case where the user attribute indicates normal. In the case of showing an administrator, the accuracy may be determined (see FIG. 14).

  Further, the accuracy of the authentication processing may be varied according to the position of the biometric sensor 300 even when the flag 312 is in the “on” state. For example, when the biometric authentication sensor 300 detects that its own position is within a predetermined area, high-accuracy authentication may always be performed while it is within the security area, for example.

(Another example of accuracy determination method)
In the first embodiment, the high-accuracy authentication process is executed when the flag 312 is “off”. However, in the second embodiment, depending on the type of the device 100 or the type of function of the device 100 when the flag 312 is “off”. Perform low-precision authentication processing. For example, even if the flag 312 is turned “off” after executing the high accuracy authentication process and the flag 312 is turned “on”, the low accuracy authentication process is executed instead of the high accuracy authentication process under a certain condition.

  Referring to FIG. 15, a case where a user carrying biometric authentication sensor 300 uses device 100 (MFP or PC) placed in the room after entering the room, or a case where the function of device 100 (MFP) is used. explain.

  In FIG. 15, the authentication unit 302 executes high-accuracy authentication processing based on the model of the device 100 (gate) when entering the room (step T1). At this time, information indicating the legitimacy of the user is held in the gate until the user leaves the room. At this time, the flag 312 is set to “ON” (step T2). Thereafter, the communication between the biometric sensor 300 and the portable terminal 200 is cut off, and the flag 312 is set to “OFF” (step T3).

  Based on the fact that the type of the device 100 is MFP when the flag 312 is “off”, the low-accuracy authentication processing is executed, and the login processing (step S25) is executed between the biometric authentication sensor 300 and the device 100. (Steps T4 and T5).

[Embodiment 3]
The third embodiment shows a modification of the first and second embodiments. In the first and second embodiments, the authentication accuracy is high or low, but may be three or more. In the third embodiment, the tables TB1 and TB2 are searched to determine the authentication accuracy.

  FIG. 16 is a diagram illustrating an example of the contents of the tables TB1 and TB2 according to the third embodiment. The tables TB1 and TB2 are stored in the ROM 31 and searched by the authentication unit 302. The authentication unit 302 searches the table TB1 when the flag 312 is “ON”, and searches the table TB2 when the flag 312 is “OFF”. Each of the tables TB1 and TB2 has the same configuration. The table TB1 will be described as a representative. The table TB1 includes authentication accuracy (three or more authentication accuracy (1), ID (1), ID (2)... ID (i)... ID (n)) corresponding to each type of device 100. Accuracy (2), accuracy (3), accuracy (4), accuracy (2)... Accuracy (i)... Accuracy (n)) are registered. Here, there is a relationship of accuracy (1)> accuracy (2)>... Accuracy (5)> accuracy (i)>. Therefore, the authentication unit 302 can selectively determine one of the three or more authentication accuracies by searching the table TB1 or TB2 based on the type of the device 100 according to the value of the flag 312. it can.

  Specifically, when the flag 312 is set to “ON” after performing the high-accuracy authentication process, the authentication is performed according to the type of the device 100 by searching the table TB1 in the subsequent authentication process. The accuracy can be changed. Specifically, for example, when the type of the device 100 indicates an entrance gate, the accuracy of the authentication process is determined to be accuracy (1), and when the type of the device 100 indicates an entrance gate, the accuracy of the authentication process is accurate ( 2).

  In addition, the accuracy of the authentication process may be changed based on an elapsed time from when the high-accuracy authentication process or the login process was executed last time. For example, when the flag 312 is “ON” and the elapsed time from the execution of the previous high-accuracy authentication process is within a predetermined time, the accuracy is determined to be lower. Further, when the flag 312 is “ON” and the elapsed time from the immediately preceding login process to the device 100 (step S25) is within a predetermined time, it is determined with lower accuracy.

  Specifically, for example, depending on the type (MFP) of the device 100 within a predetermined time (for example, 3 minutes) after executing the high-accuracy authentication process according to the accuracy determined by the type of the device 100 (entrance gate). When determining the accuracy of the authentication process, it may be determined as a lower accuracy (4). Further, when the user logs in again to the device 100 within a predetermined time (for example, 1 minute) after logging out of the device 100, the accuracy of the authentication process is reduced to a lower accuracy (5). It may be determined.

[Embodiment 4]
The fourth embodiment shows a modification of each of the above embodiments. In each embodiment, the authentication accuracy is classified by the number of feature points to be collated, but the authentication accuracy classification method is not limited to the number of feature points.

  For example, the type of biometric information matching process may be different. Specifically, a frequency analysis method may be used in the high accuracy authentication process, and a feature point extraction method may be used in the low accuracy authentication process. Alternatively, hybrid authentication combining a frequency analysis method and a minutiar method may be used for the high-accuracy authentication processing, and a feature point extraction method may be used for the low-accuracy authentication processing.

  For example, although the number of feature points to be collated is the same, the threshold for determination (see step S67) may be set high in the high-accuracy authentication process and low in the low-accuracy authentication process.

[Embodiment 5]
In the fifth embodiment, a program for causing the biometric authentication sensor 300, the portable terminal 200, and the device 100 to execute the above-described authentication processing of each embodiment is provided. Such a program is a computer-readable record such as a biometric sensor 300, a portable disk 200 or a flexible disk attached to the computer of the device 100, a CD-ROM (Compact Disk-Read Only Memory), a ROM, a RAM, and a memory card. It can also be recorded on a medium and provided as a program product. Alternatively, the program can be provided by being recorded on a recording medium such as a hard disk built in the computer. A program can also be provided by downloading via a network. The program is executed by one or more processors such as the CPU 30 (CPU 20, CPU 150) or a combination of a processor and a circuit such as an ASIC (Application Specific Integrated Circuit).

  Note that the program may be a program module that is provided as part of an OS (Operating System) of a computer and that performs necessary processing by calling necessary modules in a predetermined arrangement at a predetermined timing. In that case, the program itself does not include the module, and the process is executed in cooperation with the OS. A program that does not include such a module can also be included in the program of the fourth embodiment.

  The program according to the fifth embodiment may be provided by being incorporated in a part of another program. Even in this case, the program itself does not include the module included in the other program, and the process is executed in cooperation with the other program. A program incorporated in such another program can also be included in the program according to the fourth embodiment.

  The provided program product is installed in a program storage unit such as a hard disk and executed. The program product includes the program itself and a recording medium on which the program is recorded.

[Effect of the embodiment]
According to the embodiment, one of the high accuracy authentication process and the low accuracy authentication process is executed based on at least the value of the flag 312. Therefore, it is possible to avoid a case where only the high-precision authentication process is executed (or the high-precision authentication process is frequently executed), and the power consumption by the arithmetic processing unit (authentication unit 302) is increased. Can deal with. Further, it is possible to avoid the case where only the low-accuracy authentication processing is executed (or the low-accuracy authentication processing is frequently executed), and it is possible to cope with the problem that high authentication accuracy cannot be obtained.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  DESCRIPTION OF SYMBOLS 1 Authentication system, 21,31 ROM, 22,32 RAM, 33 sensor, 100 apparatus, 175 user authentication part, 200 portable terminal, 300 biometric authentication sensor, 301 biometric information acquisition part, 302 authentication part, 303 1st collation part, 304 Second verification unit, 305 flag processing unit, 306 communication control unit, 310 verification information, 311 authentication information, 312 flag, TB0, TB1, TB2 table.

Claims (11)

A portable authentication device,
A biological information acquisition unit that acquires biological information of the subject;
A communication unit that wirelessly communicates with a terminal device that the subject can carry;
A control unit,
The controller is
An authentication apparatus configured to execute an authentication process based on the acquired biometric information and to vary the accuracy of the authentication process based on the strength of a signal received from the terminal apparatus. The controller is
When the strength of the received signal from the terminal device is greater than or equal to a threshold, authentication processing having a first accuracy is executed, and when the strength is less than the threshold, authentication having a second accuracy higher than the first accuracy The authentication device according to claim 1, wherein the authentication device is configured to perform a process. The control unit further includes:
The authentication device according to claim 1, wherein the authentication device is configured to vary the accuracy of the authentication processing based on an elapsed time since the authentication processing of the second accuracy was recently executed and an intensity of the received signal. . The control unit further includes:
The authentication device according to claim 1, wherein the authentication device is configured to vary the accuracy of the authentication processing based on a position of the authentication device and a strength of the received signal. The communication unit further wirelessly communicates with a target device that can be an operation target of the subject,
The controller is
The authentication unit configured to cause the communication unit to transmit authentication information for authenticating the subject when the subject is authenticated by the authentication process. The authentication device according to any one of claims. The control unit further includes:
The authentication device according to claim 5, wherein the authentication device is configured to vary the accuracy of the authentication process based on a type of the target device and an intensity of the received signal. The control unit further includes:
The authentication device according to claim 6, wherein the authentication device is configured to vary the accuracy of the authentication processing based on a type of function of the target device and an intensity of the received signal.   The authentication device according to claim 5, wherein a communication method between the authentication device and the terminal device is different from a communication method between the authentication device and the target device. Obtaining biological information of the subject;
The subject wirelessly communicating with a portable terminal device;
Determining the accuracy of authentication from the strength of the signal received from the terminal device;
Performing an authentication process using the biometric information according to the determined accuracy. A program for causing a computer to execute an authentication method,
The authentication method is:
Obtaining biological information of the subject;
A subject communicating with a portable terminal device;
Determining the accuracy of authentication from the strength of the signal received from the terminal device;
Executing authentication processing using the biometric information according to the determined accuracy. A portable authentication device;
A test subject portable terminal device,
The authentication device
A biological information acquisition unit that acquires biological information of the subject;
A communication unit that wirelessly communicates with the terminal device;
A control unit,
The controller is
A system configured to execute an authentication process based on the acquired biometric information and to vary the accuracy of the authentication process based on the strength of a signal received from the terminal device.

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