Patent Publication Number: US-2016224779-A1

Title: Portable key device and device control method

Description:
TECHNICAL FIELD 
     The present invention relates to a technique of device control by a portable key device using biometric authentication technology. 
     BACKGROUND ART 
     Functions of portable devices, such as cellular phones, smartphones, and tablet PCs, have been increasing and opportunities of using the portable devices for settlement or business of a company have also been increasing. With this increase, security technology for preventing impersonation has become more important. 
     A portable device is locked with a secret code or a pattern, for example. However, when the portable terminal is stolen or lost, for example, and a third party acquires the portable terminal, the secret code or the pattern may be analyzed, so that the portable device is illicitly used. 
     In order to prevent impersonation and surely authenticate a person, it is effective to perform identification confirmation by biometric authentication using a biometric feature that is different between individuals, instead of using the secret code or the pattern lock. 
     A portable device incorporating therein a small device of fingerprint authentication, which is one type of biometric authentication, has been developed these days. This device uses identification confirmation by biometric authentication to prevent illicit use by impersonation by a third party (see Patent Literature 1, for example.) 
     CITATION LIST 
     Patent Literature 
     Patent Literature 1: Japanese Patent Application Publication No. 2009-286343 
     SUMMARY OF INVENTION 
     Technical Solution 
     However, biometric authentication may fail because of a manner of biometric input or a change in biometric information, as defined as a false rejection rate, for example, although a user oneself performs the biometric authentication. Further, in order to prevent impersonation, biometric input is requested every time the portable device is unlocked. Therefore, ease of use is not good, as compared with the secret code or the pattern lock. 
     Furthermore, because fingerprint recognition uses a fingertip only, the size of the device can be reduced and the device can be incorporated into the portable device. Meanwhile, a finger vein authentication device using a vein pattern inside a finger, a palm vein authentication device using a palm and an iris authentication device using an iris of an eye, for example, use internal information of a living body. Therefore, as compared with the fingerprint authentication, those devices have advantages that the internal information of the living body can be hardly copied, authentication is less affected by the condition of the living body, such as rough hands, and authentication accuracy is higher than the fingerprint authentication because the information amount is large. However, it is difficult to reduce the sizes of those devices, and is therefore difficult to incorporate those devices into the portable device. 
     In order to solve these problems, the present invention provides a technique of device control by a portable key device that incorporates a wireless communication function therein and uses biometric authentication technology allowing an advantage of identification confirmation by biometric authentication to be used and reducing the number of authentications. 
     Solution to Problem 
     An example of a solution by the present invention is set forth below. 
     Two portable key devices with a wireless communication function, communicating with each other (for example, wireless key devices, portable devices having an application installed therein, such as cellular phones or smartphones, or biometric authentication devices with a wireless communication function) are prepared. A biometric authentication operation is performed in a state where wireless communication is established. When biometric authentication is successful, an authentication success context is saved in either of the portable key devices, to make that device transit to a state of emitting an unlock signal. Upon receiving the unlock signal, a control object device does not request further biometric authentication, but is unlocked and becomes operable. When reception of that signal is stopped, the control object device is locked. 
     In the state where the wireless communication between the two portable key devices is established, the portable device is in the state of emitting the unlock signal. When the wireless communication is interrupted, the biometric authentication success context is discarded, the portable device transits to a state where emission of the unlock signal is stopped. In order to emit the unlock signal again, the portable device requests the biometric authentication. 
     Advantageous Effects of Invention 
     According to the present invention, a biometric authentication success context is saved and the number of biometric authentications required of a user is reduced, and use by another person is limited by discarding the authentication success context when a key device is left behind, for example, thereby improving both ease of use and safety. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  illustrates a device control system using wireless communication according to an embodiment of the present invention. 
         FIG. 2  illustrates a device control system using a server-using biometric authentication device according to an embodiment of the present invention. 
         FIG. 3  illustrates a device control system using a wearable biometric authentication device according to an embodiment of the present invention. 
         FIG. 4  illustrates a device control system using a wearable device according to an embodiment of the present invention. 
         FIG. 5  illustrates the wearable biometric authentication device according to the embodiment of the present invention. 
         FIG. 6  illustrates an example of the wearable device according to the embodiment of the present invention. 
         FIG. 7  illustrates a circuit example of the wearable device according to the embodiment of the present invention. 
         FIG. 8  is a flowchart of a biometric authentication operation according to an embodiment of the present invention. 
         FIG. 9  is a flowchart of an operation of a portable device according to an embodiment of the present invention. 
         FIG. 10  is a flowchart of an operation of a control object device according to an embodiment of the present invention. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Embodiments of the present invention are described below. 
     First Embodiment 
       FIG. 1  is an overall conceptual diagram of the present embodiment. The present embodiment uses a biometric authentication device  100 , a portable device  101 , and control object devices  102  to  104 . 
     The biometric authentication device  100  includes a communication unit and a biometric information input unit. Registered biometric data used for data matching and connection information of a portable device  101  that is a connection destination are preregistered in the biometric authentication device  100 . Registration of the registered biometric data and the connection information is performed by the biometric authentication device alone or by the biometric authentication device connected to an upper device, such as a PC (Personal Computer). Although the description will be made referring to a finger vein as a living body used for authentication, other biometric authentication using a fingerprint, a palm print, a palm vein, an iris, or a face, for example, can be used. 
     The information on connection with the portable device  101  corresponds to paring information between devices in a wireless standard, such as Bluetooth (registered trademark), for example, and is connection information enabling only between a specific biometric authentication device and a specific portable device to establish secure wireless one-to-one connection therebetween. Further, the biometric authentication device  100  incorporates a battery or the like therein and can be used in a mobile environment. 
     The portable device  101  includes a communication unit, an input/output unit (for example, a display with a touch panel), and a computing unit (processor). 
     The control object devices  102  to  104  are devices controlled by this biometric authentication device. Examples of a control object are login control of a PC  102 , locking, opening, and closing of a door of a room access management device  103 , a settlement process of a settlement terminal  104 . 
       FIG. 8  is a flowchart of an operation of the biometric authentication device  100 . 
     After a user turns the power of the biometric authentication device  100  from off to on (S 701  to S 702 ), the biometric authentication device  100  starts connection with the portable device  101  via wireless communication (S 703 ). When the wireless communication has not been established in a certain period of time, the biometric authentication device transits to a power-OFF state (S 701 ). When the wireless communication has been established, the biometric authentication device  100  prompts the user to input biometric information and performs biometric authentication (S 704 ). When the biometric authentication is successful, the biometric authentication device  100  saves an authentication success context therein, and the portable device  101  having received information on success of the authentication transits to an unlocked state (S 705  and S 706 ). When the authentication fails, the biometric authentication device  100  transits to the power-OFF state (S 701 ). After the context is saved and the portable device  101  transits to the unlocked state, the biometric authentication device  100  and the portable device  101  continue to monitor a state of the wireless communication (S 708 ). During a period in which the wireless communication between the biometric authentication device  100  and the portable device  101  is established, the portable device  101  continues to be in the unlocked state (S 709 ). The user always carries the biometric authentication device and the portable device therewith to keep them in a communicable range of the wireless communication, thereby capable of using the portable device without an unlocking operation, such as input of a password. 
     When the biometric authentication device  100  or the portable device  101  is dropped or left behind, the distance between the biometric authentication device  100 , the portable device  101  increases to the communicable range or more, and the wireless communication is interrupted, the portable device  101  transits to a locked state (S 710 ), and the biometric authentication device  101  discards the authentication success context (S 711 ) and transits to the power-OFF state. 
       FIG. 9  is a flowchart related to an operation of the portable device  101 . 
     When the portable device  101  is turned on (S 801 ) and is brought close to the biometric authentication device  100  in which that portable device  101  is preregistered by connection information, the portable device  101  and the biometric authentication device  100  automatically establish connection via wireless communication, and the biometric authentication device  100  transits to a state of waiting for input from a living body (S 802  and S 803 ). It is assumed that the wireless connection is achieved by secure one-to-one connection between the specific biometric authentication device  100  and the specific portable device  101  by exchange of encryption keys, for example. 
     When a user inputs a living body into the biometric authentication device  100  in this state, the biometric authentication device  100  measures biometric information of the living body input thereto to create authentication biometric data, and performs biometric authentication by matching the authentication biometric data and registered biometric data that is preregistered. When it has been determined as a result of the matching that the authentication biometric data and the registered biometric data are the same, the authentication is successful. Thus, an authentication success context is created and saved in the device, and success of the authentication is transmitted to the portable device wirelessly. When the authentication fails, the biometric authentication device transits to a power-OFF state in order to reduce the amount of battery consumption. 
     The portable device waits for reception of the success of authentication, while monitoring the wireless communication (S 804  and S 805 ). In this state, when the wireless communication is interrupted, the portable device returns to a state where it monitors the wireless communication, and the biometric authentication device  100  stops the biometric authentication (S 806  and S 802 ). In a case where the biometric authentication is successful, the portable device  101  that has received the success of authentication starts emitting an unlock signal for switching a control object device from a locked state to an unlocked state (S 807 ). 
     Thereafter, the portable device  101  continues to be in a state of emitting the unlock signal and the biometric authentication device  101  continues to save the authentication success context, during a period in which the wireless communication between the biometric authentication device  100  and the portable device  101  is maintained. 
     The biometric authentication device  100  and the portable device  101  monitor the state of the wireless communication (S 809 ). When the wireless communication between the biometric authentication device  100  and the portable device  101  is interrupted at least once, the biometric authentication device  100  discards the authentication success context and transits to the power-OFF state, and the portable device  101  transits to a state where the emission of a lock signal is stopped. 
       FIG. 10  is a flowchart related to an operation of the control object devices  102  to  104 . 
     First, the power of the control object device is switched from off to on (S 901  and S 902 ). In this state, the control object device is locked, that is, cannot receive an operation. The control object device then waits for an unlock signal from the portable device  101 . 
     Upon receiving the unlock signal, the control object device starts authentication of the portable device. When the unlock signal has been determined to be the one for the control object device, the authentication is successful, so that the control object device saves its authentication context therein (S 904  to S 906 ). In this authentication, the control object device can further communicate with the portable device  101  to request information. Although the control object device can further request a context of biometric authentication information to the portable device  101 , a user is not requested to newly input biometric information. When the authentication has failed, the control object device continues to be in the locked state (S 902 ). 
     When saving the authentication context, the control object device is unlocked and is placed in an operable state (S 907 ), and the user can use the control object device. 
     In an unlocked state, the control object device continues to monitor the unlock signal from the portable device  101  and continues to be in the unlocked state where the control object device is operable during a period in which the control object device receives the unlock signal (S 909 ). When receiving of the unlock signal has stopped, the control object device is placed in the locked state where it cannot be operated, discards the authentication context, and returns to the state of waiting for the unlock signal (S 910 ,  5911 , and S 902 ). 
     The operations of the biometric authentication device  100 , the portable device  101 , and the control object devices  102  to  104  provide the following advantageous effects. 
     In order to unlock the control object device  102  to  104  to make it operable, biometric information is requested in addition to the biometric authentication device  100  and the portable device  101 . With this configuration, a person other than the user oneself cannot unlock the control object device and therefore the safety can be enhanced. 
     The control object device unlocks itself based on the presence or absence of the unlock signal, but does not request newly reading of biometric information from the user&#39;s body when unlocking itself. The user carries the biometric authentication device  100  and the portable device  101  therewith while putting them in pockets of a cloth or the like, thereby establishing wireless communication and saving the biometric authentication success context. Because the wireless communication is left established, the portable device continues to emit the unlock signal. Therefore, the user can unlock the control object device by approaching to the control object device. It is unnecessary to read biometric information every time the unlocking is performed. 
     Meanwhile, in a case where the biometric authentication device  100  or the portable device  101  is away from the other device by being stolen or left behind, for example, the distance between the portable device  101  and the biometric authentication device  100  exceeds the communication range. Therefore, the wireless communication is interrupted, the biometric authentication device  100  discards the authentication success context and transits to the power-OFF state, and the portable device  101  stops emission of the unlock signal. In order to recover from this state, it is necessary to turn on the biometric authentication device  100  to communicate with the portable device, and perform biometric authentication. That is, only the user can place the device into the state of emitting the unlock signal again. Even if a third party acquires either one of the biometric authentication device and the portable device or third parties acquire them separately, the third party/parties cannot use it/them because of having no biometric information. 
     It is desirable that the user retains the biometric authentication device  100  and the portable device  101  carried by the user in separate pockets of a cloth/clothes, separate pieces of baggage, or the like not to drop or leave behind both together. In the present embodiment, an authentication application is installed into a smartphone, so that the smartphone is used as the portable device  101 . Therefore, the portable device  101  can be used as the smartphone that also has functions other than a portable key. Other than the smartphone, a notebook PC or a tablet PC can be used, so long as it can be carried by the user. 
     Further, the portable device  101  is continuously used by the user for a purpose other than the authentication. Therefore, the portable device  101  is put in place from which the portable device  101  can be easily taken out, for example, a chest pocket or a bag. The biometric authentication device  100  is desirably put in a place integrated with the user oneself, from which the biometric authentication device  100  is hardly dropped, such as a trouser&#39;s pocket, because it is unnecessary for the user to use the biometric authentication device  100  after the authentication is successful and it is enough that the biometric authentication device  100  keeps the wireless communication with the portable device  101  established. In s case of a combination of a biometric authentication terminal used only for a portable key and the portable device  101  that can be also used for another purpose, it is considered that the user carries the portable device  101  and the biometric authentication device  100  while putting them in different places, for example, in the place from which the portable device  101  can be easily taken out and in the place which does not hinder an action of the user or from which the biometric authentication device  100  is hardly dropped. Therefore, possibilities of losing both together can be reduced. 
     For improving the security, a radio wave output of wireless communication of the biometric authentication device  100  or the portable device  101  can be set in such a manner that connection can be established only in short distance, for example, about one meter to about three meters. 
     The control object device to be unlocked can be used in combination with the PC  102  with a wireless function installed therein, a door access management device  103 , a settlement terminal  104 , or the like. 
     In a case of the PC  102 , the portable device  101  in the state of emitting the unlock signal approaches to the PC  102  that is in a logout state, the PC  102  and the portable device  101  are connected to each other by wireless communication, and the PC  102  is placed into a logon state at a time of completion of mutual authentication. By this procedure, the user can log-on the PC  102  in the same manner as that in identification confirmation performed in every log-on operation by performing biometric authentication once, without performing biometric authentication in every log-on operation. 
     In a case of the door access management  103 , the portable device  101  in the state of emitting the unlocked signal approaches to the door access management device. When the door access management device and the portable device  101  are connected by wireless communication and mutual authentication is completed, a door is unlocked. By this procedure, without performing biometric authentication in every entrance or exit, it is possible to allow entrance to a room and exit from the room by performing biometric authentication once, in the same manner as that in the case of performing identification confirmation in every entrance to the room, as in the case of the PC. 
     In a case of the settlement terminal  104 , the portable device in the state of emitting the unlock signal is brought close to the settlement terminal  104  when settlement is performed, thereby the portable device  101  and the settlement terminal  104  are connected via wireless communication, mutual authentication is completed, and settlement is performed. In this procedure, a simple operation for the settlement terminal  104  can be requested in order to confirm the settlement. In this manner, the user can perform settlement in the same manner as that in the case where identification confirmation is performed in every settlement, without performing biometric authentication in every settlement, but by performing biometric authentication once. 
     The user can set a valid time of the authentication success context in the biometric authentication device  100 . When a time from success in the biometric authentication and creation of the context is counted and the time set by the user passes, the biometric authentication device  100  discards the authentication success context saved therein, and transits to the power-OFF state. Alternatively, the biometric authentication device  100  includes a clock therein. When the time set by the user has come, the biometric authentication device  100  discards the authentication success context in the authentication device and transits to the power-OFF state. 
     When the user sets the time of discarding the context at night, it is possible to discard the authentication success context at a specified time to make the portable device  101  transit to the locked state, even if the user performs authentication in the morning, uses the portable device  101  until night, and thereafter leaves the biometric authentication device  100  and the portable device together after work. 
     Further, when the record of the wireless communication between the biometric authentication device  100  and the portable device  101  is used, a place where the biometric authentication device or the portable device is lost can be estimated in a case where the biometric authentication device or the portable device is lost. A time at which the wireless connection between the biometric authentication device and the portable device is interrupted is recorded on the biometric authentication device or the portable device or is recorded on a server on a network by the portable device  101 . When the biometric authentication device  100  or the portable device  101  is lost by being left behind, for example, the time of interruption of the wireless connection is checked, and the place where the other device is lost can be estimated from an action by the user at that time (for example, position information by GPS, room access record, or the like). 
     As described above, two devices, i.e., the biometric authentication device  100  and the portable device  101 , and wireless communication are used, thereby enabling identification confirmation to be performed in the same manner as that in a case of performing the biometric authentication every time the control object device is used, without performing the biometric authentication in every identification confirmation but by performing biometric authentication once. Also, the result of the identification confirmation can be used for PC log-on, access management, and settlement. 
     The function of inputting the biometric information, registered biometric data, and the function of biometric authentication can be provided in a device separate from two portable key devices in a communicable manner, so long as the two portable key devices (the biometric authentication device  100  and the portable device  101 ) that can perform wireless communication mutually are provided and at least one of them has a function of saving therein the biometric authentication success context, although described in embodiments set forth below. 
     Second Embodiment 
     A second embodiment is described. The second embodiment is mostly the same as the first embodiment and therefore the detailed description is omitted. A difference between the second embodiment and the first embodiment is as follows. According to the first embodiment, registered biometric data is registered in the biometric authentication device  100  and, when the biometric authentication device  100  is lost, the registered biometric data in the biometric authentication device  10  is also lost. 
     Therefore, the registered biometric data is stored in a place different from the biometric authentication device  100  and the portable device  101 , such as a server  105 , as illustrated in  FIG. 2 . When wireless communication between the biometric authentication device  100  and the portable device  101  is established, the portable device  101  communicates with the server  105  to download the registered biometric data from the server  105 . Upon completing the download of the registered biometric data, the portable device  101  transmits the downloaded registered biometric data to the biometric authentication device  100 . The biometric authentication device  100  uses the registered biometric data thus received to perform matching with input biometric information, thereby performing biometric authentication. 
     When the authentication is successful, the biometric authentication device  100  creates a context of biometric authentication success, saves the created context within the biometric authentication device  100 , and thereafter discards the received registered biometric data. After this, the same processing is performed as that in the first embodiment. 
     When the authentication fails, the biometric authentication device  100  discards the registered biometric data received, and transits to the power-OFF state. 
     By the above-described method, it is possible to protect the registered biometric data even if the biometric authentication device  100  is lost. 
     Third Embodiment 
     A third embodiment is described. A biometric authentication device may be configured to be a wearable biometric authentication device  106  that is in a form worn by a user, such as a watch or a bracelet. Although it is detected that a key device is away from the user, based on interruption of wireless communication according to the first and second embodiments, a wearable device that is to be worn on the user&#39;s body is used according to the present embodiment, so that it is detected that the wearable device is away from the user&#39;s body. 
       FIG. 3  is a conceptual diagram of the wearable biometric authentication device  106 . In this case, it is assumed that the wearable biometric authentication device  106  includes a living body detection function  107 , such as a pulsimeter, as illustrated in  FIG. 5 , and can detect removal of the wearable biometric authentication device  106  from a human body. Alternatively, the wearable biometric authentication device  106  may have a shape illustrated in  FIG. 6  and a circuit structure illustrated in  FIG. 7 , so that it is necessary to open an opening/closing mechanism  109  in order to remove the wearable biometric authentication device  106  and the opening/closing function  109  detects removal from a living body. That is, the wearable biometric authentication device  106  may have a structure that involves a change in shape when being removed from the living body, so that the removal from the living body is detected by detecting the change in shape. 
     The wearable biometric authentication device  106  performs biometric authentication only while being worn by a user, as in the first and second embodiments, and creates an authentication success context and saves the context therein when the authentication is successful. 
     Because the wearable biometric authentication device  106  is completely integrated with the user according to the present embodiment, the wearable biometric authentication device  106  is not lost even if wireless connection between the wearable biometric authentication device  106  and the portable device  101  is interrupted. Thus, it is unnecessary to discard the authentication success context in the biometric authentication device  100 . 
     The authentication success context in the wearable biometric authentication device  106  is discarded only when the user removes the wearable biometric authentication device  106  or when the discard is instructed by a switch or the like provided in the wearable biometric authentication device  106 . 
     In a case where the user maintains a state in which the user wears the wearable biometric authentication device  106  on the user&#39;s body, the wearable biometric authentication device still stores the authentication success context, when the wireless communication between the wearable biometric authentication device and the portable device is interrupted and thereafter the biometric authentication device and the portable device approach to each other so that the wireless communication is established again. Thus, it is possible to unlock the portable device again without performing the biometric authentication. 
     Further, according to the present embodiment, the wearable biometric authentication device  106  can save the biometric authentication success context and emit the unlock signal, without using the portable device  101 . Also in this case, when the wearable biometric authentication device  106  is removed from the body of the user, the removal is detected, so that the biometric authentication success context is discarded and emission of the unlock signal is stopped. In this manner, effects are achieved. 
     Fourth Embodiment 
     An embodiment illustrated in  FIG. 4  is an embodiment in a case where the authentication success context created by the biometric authentication device is further transferred to and used by another device. In addition to the biometric authentication device  100  and the portable device  101 , another wearable device  111  with a wireless communication function, such as a watch or a bracelet, is used. It is assumed that the wearable device  111  has a function of detecting that it is worn by a user by a living body detection function, shape change detection, or the like, as in the third embodiment. 
     When an authentication is successful, the biometric authentication device  100  creates the authentication success context and transmits it to the wearable device  11 . The wearable device  111  receives and saves the context and sends back success in receiving the context to the biometric authentication device  100 . At a time at which the biometric authentication device  100  receives this, the biometric authentication device  100  discards the authentication success context. 
     The wearable device  111  monitors, using the living body detection function, that the user wears the wearable device  111 . At a time at which the wearable device  111  is removed from the user, the wearable device  111  discards the authentication success context. 
     When the wearable device  111  saving the authentication success context therein approaches to a portable device  101 , which has a wireless function and is locked, for example, a cellular phone or a smartphone, the wearable device  111  establishes wireless connection with the portable device and device authentication is mutually performed. When the device authentication is successful, the portable device  101  transits to a state of emitting an unlock signal. Thereafter, the portable device  101  maintains the state of emitting the unlock signal during a period in which the wireless connection with the wearable device is established. 
     When the portable device  101  is in the state of emitting the unlock signal, it is possible to use the portable device  101  as a PC  102 , a door access management  103 , and a settlement terminal  104 , as in the first embodiment. 
     In a case where the portable device  101  is lost by being stolen or left behind, for example, when the distance between the wearable device  111  and the portable device  101  increases to the communicable range of wireless communication or more and the wireless communication is therefore interrupted, the portable device  101  transits to the state of stopping emission of the unlock signal, so that a third party cannot use the portable device  101 . 
     Because the wearable device  111  has a function of detecting that it is worn by the user, as in the third embodiment, it is guaranteed that the wearable device is integrated with the user while it is detected that the wearable device is worn by the user even after wireless connection with the portable device  101  is interrupted. Therefore, it is unnecessary to discard the authentication success context saved inside the wearable device, and the portable device transits to the state of emitting the unlock signal when the wireless connection with the portable device is established again. 
     The authentication success context may be discarded when the wireless connection between the portable device  101  and the wearable device  111  is interrupted. Alternatively, the context may be discarded when the wireless connection is interrupted and the wearable device is removed. 
     According to the present embodiment, the wearable device worn by the user does not include a biometric authentication device. Therefore, a biometric authentication device that is large in case size but is high in authentication accuracy, such as a vein authentication device or an iris authentication device, can be used. Further, it is enough that the wearable device incorporates the wireless communication function therein. Therefore, it is possible to reduce the size of the wearable device and save the power thereof. 
     LIST OF REFERENCE SIGNS 
     
         
           100  Biometric authentication device 
           101  Portable device 
           102  PC 
           103  Door access management 
           104  Settlement terminal 
           105  Server 
           106  Wearable biometric authentication 
           107  Living body detection function 
           108  Wrist band 
           109  Closing/opening detection mechanism 
           110  Battery 
           111  Wearable device