Abstract:
In a personal authentication device, a storing unit of each group stores therein biometric information of the persons belonging to that group. When a subject is to be authenticated, an acquiring unit acquires subject biometric information that is biometric information of the subject. A collating unit decides whether the subject is authentic based on whether there is a match for the subject biometric information in the biometric information in the storing unit. If the subject is determined to be not authentic, the subject biometric information is collated with biometric information in the storing unit of another group.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a technology for authenticating a person within at least one group, among persons grouped into a plurality of groups. 
     2. Description of the Related Art 
     In recent years, a technology for authenticating a person using biometric information, such as a fingerprint or veins in a palm, is being widely examined. The biometric information is unique to each individual and is difficult to falsify. Therefore, the biometric information is suitable for use in personal authentication. It is thought that biometric authentication will continue to be applied in various fields. 
     The biometric authentication using the biometric information is largely divided into two methods: one-to-one authentication and one-to-N authentication. The one-to-one authentication requires an input of identifying information, such as identification (ID) that differs from the biometric information. In the one-to-n authentication, the personal authentication is performed using only the biometric information. In the one-to-one authentication, the biometric information of the subject to be authenticated is identified in advance from registered biometric information using the identifying information. The identified information and the biological information acquired from the subject are collated and whether the subject is the person in question is confirmed. On the other hand, in the one-to-N authentication, all registered biological information and the biological information acquired from the subject are collated, and the subject is identified. 
     The one-to-one authentication and the one-to-N authentication respectively have merits and demerits. Japanese Patent Application Laid-open No. 2004-145608, for example, discloses a conventional technique. All subjects to be authenticated are divided into groups. The one-to-N authentication is performed in a collation device provided for each group and the subject is identified. The identifying information of the identified subject is sent to an authentication server with the biological information acquired from the subject. The authentication server controls the collation devices. The authentication server performs the one-to-one authentication. In addition, when the biological information of the subject is not registered in the collation device of the group, a notification that the biological information of the subject is not registered and the biological information acquired from the subject are transmitted to the authentication server. The authentication server performs the one-to-N authentication. 
     A system that performs biometric authentication and includes a collation device for each group and an authentication server that controls the collation devices, as described above, is, for example, suitable for a work management system that manages attendance of employees in a company having a plurality of stores. In other words, for example, the following use can be considered. An employee is biometrically authenticated when arriving to and leaving work by the collation device installed in each store. Clock-in and clock-out times of each employee are managed by a server that collectively supervises the overall system. 
     In a work management system such as this, a simple authentication is preferred. Therefore, the collation device in each store preferably performs the one-to-N authentication that does not require an input of ID or the like. Generally, in the one-to-N authentication, the biological information acquired from the subject and all registered biological information are collated. Therefore, processing load and processing time tends to increase. However, in the above-described system, the collation device is installed in each store. Therefore, only the biological information of the employee group employed at the respective store need be registered in the collation device of each store. As a result, the increases in processing load and processing time can be controlled. 
     However, in the conventional system, for example, response is insufficient when a subject receives personal authentication by a collation device differing from the collation device by which the subject is ordinarily authenticated, such as when an employee is transferred to another store. In other words, matching biological information is not registered for a subject who does not belong to the group of which the biological information is registered in the collation device, even when the subject receives one-to-N authentication. Therefore, the subject is not authenticated and an error occurs. 
     To prevent the error, the biological information registered in each collation device is required to be constantly updated to the latest information. However, for example, when an employee is frequently transferred or when there is an employee who temporarily works at another store for a short period, the biological information registered in the collation device is updated frequently. As a result, efficiency is poor. 
     In addition, as described in Japanese Patent Application Laid-open No. 2004-145608, when the authentication is not performed by the collation device in each store, the server controlling the collation devices can perform the one-to-N authentication. However, because the biological information of the subjects in all groups is registered in the server supervising the overall system, an enormous amount of time is required for the one-to-N authentication. Furthermore, the server supervising the overall system performs the one-to-N authentication every time an authentication is performed until the biological information of the subject is registered to the collation device in the store to which the subject is transferred. Therefore, the system is unrealistic. 
     Thus, there is a need of a technique for quickly and efficiently performing personal authentication in a system in which all subjects to be authenticated are divided into groups and personal authentication is performed on subjects by group, even when the group to which the subject belongs changes. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to at least partially solve the problems in the conventional technology. 
     According to an aspect of the present invention, a personal authentication device that authenticates a subject from among a plurality of persons belonging to a first group, among persons grouped into a plurality of groups including a second group, includes a storing unit that stores therein biometric information of the persons belonging to the first group; an acquiring unit that acquires biometric information of a subject; a collating unit that collates the biometric information of the subject with at least some of the biometric information present in the storing unit, and determines whether the subject is authentic based on whether there is a match for the biometric information of the subject in the biometric information present in the storing unit; a requesting unit that, when the collating unit determines that the subject is not authentic, sends the biometric information of the subject to an external device that holds biometric information of persons belonging to the second group, and requests the external device to collate the biometric information of the subject with the biometric information of persons belonging to the second group; a receiving unit that receives a result of collation performed by the external device, the result being indicative of whether the subject is authentic; and an updating unit that, when the result received by the receiving unit indicates that the subject is authentic, causes the storing unit to store the biometric information of the subject. 
     According to another aspect of the present invention, a personal authentication device that authenticates a subject from among a plurality of persons belonging to two or more groups, among persons grouped into a plurality of groups, includes a storing unit that stores therein biometric information of the persons belonging to the two or more groups in correspondence with identifying information of respective person; an acquiring unit that, when it can not be determined whether a subject is authentic based on collation of biometric information in any group among the two or more groups, acquires biometric information of the subject; a collating unit that collates the biometric information acquired by the acquiring unit and the biometric information stored in the storing unit, and determines whether the subject is authentic based on whether there is a match for the biometric information of the subject in the biometric information present in the storing unit; and a transmitting unit that, when the collating unit determines that the subject is authentic, transmits the biometric information of the subject and the corresponding identifying information. 
     According to still another aspect of the present invention, a personal authentication device that authenticates a subject from among a plurality of persons belonging to a first group, among persons grouped into a plurality of groups including a second group, the personal authentication device includes: a storing unit corresponding to each of the groups, the storing unit stores therein biometric information of the persons belonging to the corresponding group; an acquiring unit corresponding to each of the groups, the acquiring unit acquires subject biometric information that is biometric information of a subject; a collating unit corresponding to each of the groups, the collating unit collates the subject biometric information with the biometric information in the storing unit, and determines that the subject is an authentic person when there is a match for the subject biometric information in the biometric information in the storing unit; a transmitting unit corresponding to each of the groups, when the collating unit determines that the subject is not authentic, the transmitting unit sends the subject biometric information to a collating unit of other group. The collating unit of the other group collates the subject biometric information received from the collating unit with biometric information in a storing unit of the other group, determines that the subject is an authentic person when there is a match for the subject biometric information in the biometric information in the storing unit of the other group, and sends a result of collation to the collating unit from which the subject biometric information is received; a receiving unit that receives the result of collation from the collating unit of the other group; and an updating unit that, when the result of collation received by the receiving unit indicates that the subject is authentic, causes the corresponding storing unit to store the subject biometric information. 
     The above and other objects, features, advantages and technical and industrial significance of this invention will be better understood by reading the following detailed description of presently preferred embodiments of the invention, when considered in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram of a work management system according to an embodiment of the present invention; 
         FIG. 2  is a detailed block diagram of a store server # 1  shown in  FIG. 1 ; 
         FIG. 3  is a schematic for explaining the contents of a biometric information local DB; 
         FIG. 4  is a detailed block diagram of a work management server shown in  FIG. 1 ; 
         FIG. 5  is a schematic for explaining the contents of a region-based archive DB; 
         FIG. 6  is a flowchart of an operation of the store server # 1  shown in  FIG. 1 ; and 
         FIG. 7  is a sequence diagram of a work management example when an employee is transferred according to the embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Exemplary embodiments of the present invention are below described with reference to the attached drawings. Hereafter, the invention is explained giving a work management system used to manage attendance of employees in a plurality of stores as an example. However, the invention is not limited thereto and can be applied to various personal authentication systems. 
       FIG. 1  is a block diagram of a work management system according to an embodiment of the invention. The work management system includes a plurality of stores # 1  to #M (M is a natural number that is 2 or more), and servers  20 - 1  to  20 -M are respectively installed in the stores # 1  to #M. Biometric sensors  30 - 1  to  30 -M are respectively connected the servers  20 - 1  to  20 -M. The servers  20 - 1  to  20 -M are connected via a network to a work management server  10 . 
     The work management server  10  is installed in a location, such as a head office, that supervises operations of the stores # 1  to #M. The work management server  10  stores and manages attendance information of employees transmitted from each server  20 - 1  to  20 -M. As a result of a one-to-N authentication performed in the servers  20 - 1  to  20 -M, if biometric information of an employee is not registered, the work management server  10  receives the biometric information of the employee from the servers  20 - 1  to  20 -M. Then, the work management server  10  performs the one-to-N authentication using a database in which the biometric information of employees who changed affiliated stores during a predetermined period is registered. The work management server  10  acquires identifying information of employees that cannot be authenticated by the one-to-N authentication. The work management server  10  acquires the identifying information from the servers  20 - 1  to  20 -M as employee ID. Then, the work management server  10  performs a one-to-one authentication using a database in which the biometric information of all employees is registered. Subsequently, the work management server  10  registers the biometric information of the employees authenticated by the one-to-one authentication as the biometric information of employees that changed affiliated stores. The work management server  10  also registers the biometric information of the employee in the servers  20 - 1  to  20 -M that is the transmission source of the biometric information of the employee. 
     The servers  20 - 1  to  20 -M collate the biometric information of the employee acquired by the biometric sensors  30 - 1  to  30 -M and the registered biometric information and performs the one-to-N authentication. When biometric information matching the biometric information of the employee is not registered, the servers  20 - 1  to  20 -M request that the work management server  10  perform further collations. When the work management server  10  performs the personal authentication of the employee, the servers  20 - 1  to  20 -M acquire the biometric information of the employee from the work management server  10  and register the biometric information. The servers  20 - 1  to  20 -M can perform personal authentication during subsequent authentications without requesting that the work management server  10  perform the personal authentication. 
     The biometric sensors  30 - 1  to  30 -M acquire the biometric information of the employee. In other words, the biometric sensors  30 - 1  to  30 -M acquire, for example, a vein pattern of the palm, fingerprints, face image, iris, voice print, or the like of the employee and transmit the acquired information to the servers  20 - 1  to  20 -M. 
     According to the embodiment, the servers  20 - 1  to  20 -M or the work management server  10  collate the biometric information of the employee acquired by the biometric sensors  30 - 1  to  30 -M. The one-to-N authentication performed by the servers  20 - 1  to  20 -M is referred to as a first collation. The one-to-N authentication performed by the work management server  10  is referred to as a second collation. The one-to-one authentication performed by the work management server  10  is referred to as a third collation. The collations will be described in detail hereafter. 
       FIG. 2  is a detailed block diagram of the server  20 - 1 . The servers  20 - 2  to  20 -M have the same or similar configuration. The server  20 - 1  includes a biometric information acquiring unit  201 , a biometric-information storing unit  202 , a first collating unit  203 , a second collation requesting unit  204 , an attendance information generating unit  205 , a transmitting and receiving unit  206 , a collation result judging unit  207 , an update managing unit  208 , a user interface (I/F) unit  209 , and a third collation requesting unit  210 . 
     The biometric information acquiring unit  201  acquires the biological information of the employee from the biometric sensor  30 - 1  and outputs the biometric information to the first collating unit  203 . According to the embodiment, the biometric sensor  30 - 1  recognizes the vein pattern of the palm, and the biometric information acquiring unit  201  acquires the vein pattern of the palm of the employee as the biometric information. 
     The biometric information storing unit  202  in advance stores the biometric information of the employees belonging to the store # 1 . Specifically, the biometric information storing unit  202  stores a biological information local database (biometric information local DB), such as that shown in  FIG. 3 . In the biometric information local DB, employee IDs of the employees belonging to the store # 1 , the biometric information of each employee, and a latest date on which a collation was performed are associated and stored. For example, in  FIG. 3 , an employee ID “A1234” is associated with the vein pattern of the palm of the employee and that the collation was most recently performed on “Jun. 30, 2006” and stored. In addition, the biometric information storing unit  202  receives an instruction from the update managing unit  208 , and registers new biometric information in the biometric information local DB, deletes unnecessary biometric information, and the like. 
     The first collating unit  203  performs the one-to-N authentication (first collation) using the biometric information of the employee acquired by the biometric information acquiring unit  201  and the biometric information local DB stored in the biometric information storing unit  202 . In other words, the first collating unit  203  judges whether the biometric information of the employee is registered in the biometric information local DB. When the biometric information of the employee is registered in the biometric information local DB, the first collating unit  203  notifies the attendance information generating unit  205  of the employee ID corresponding to the biometric information. In addition, the first collating unit  203  notifies the update managing unit  208  that the first collation related to the employee ID has been performed. At the same time, when the biometric information is not registered in the biometric information local DB, the first collating unit  203  outputs the biometric information of the employee to the second collation requesting unit  204 . 
     When the biometric information of the employee is outputted from the first collating unit  203 , the second collation requesting unit  204  generates a second collation request. The second collation request is generated to request that the work management server  10  perform the one-to-N authentication (second collation). The one-to-N authentication judges whether the outputted biometric information matches the biometric information of the employee who changed an affiliated store during the predetermined period. The second collation requesting unit  204  outputs the second collation request to the transmitting and receiving unit  206  with the biometric information of the employee. 
     When a notification of the employee ID is received from the first collating unit  203  or the collation result judging unit  207 , the attendance information generating unit  205  generates the attendance information. The attendance information records a current time as a clock-in time, a clock-out time, and the like of the employee. The attendance information generating unit  205  transmits the attendance information to the transmitting and receiving unit  206 . 
     The transmitting and receiving unit  206  exchanges information with the work management server  10 . Specifically, the transmitting and receiving unit  206  transmits the second collation request and the biometric information of the employee outputted from the second collation requesting unit  204  and the attendance information outputted from the attendance information generating unit  205  to the work management server  10 . In addition, the transmitting and receiving unit  206  receives results of the second collation and the third collation performed by the work management server  10 . When a third collation request is outputted from the third collation requesting unit  210 , the transmitting and receiving unit  206  transmits the third collation request and the biometric information of the employee to the work management server  10 . 
     The collation result judging unit  207  judges whether the employee is authenticated from a second collation result and a third collation result received by the transmitting and receiving unit  206 . When judged that the employee is authenticated, the collation result judging unit  207  notifies the attendance information generating unit  205  and the update managing unit  208  of the employee ID included in the collation result. In addition, the collation result judging unit  207  outputs the biometric information received by the transmitting and receiving unit  206  to the update managing unit  208  with the collation result. When judged that the employee is not authenticated from the second collation result, the collation result judging unit  207  requests that the employee ID be entered in the user I/F unit  209  to perform the third collation. 
     The update managing unit  208  monitors the latest collation dates in the biometric information local DB stored in the biometric information storing unit  202 . The update managing unit  208  deletes data from the biometric information local DB. The data has a latest collation date since which a predetermined period has elapsed. When notification of the performance of the first collation is given from the first collation unit  203 , the update managing unit  208  updates the latest collation date of the subject employee in the biometric information local DB to the current date. Furthermore, the update managing unit  208  newly registers the employee ID and the biometric information outputted from the collation result judging unit  207  to the biometric information local DB. 
     The user I/F unit  209  includes, for example, a display for display and a numeric keypad for input. The user I/F unit  209  prompts the employee to be authenticate to enter the employee ID, according to a request from the collation result judging unit  207 , and outputs the entered employee ID to the third collation requesting unit  210 . 
     When the employee ID is outputted from the user I/F unit  209 , the third collation requesting unit  210  generates the third collation request. The third collation request is generated to request that the work management server  10  perform the one-to-one authentication (third collation). The one-to-one authentication judges whether the biometric information of the employee matches the biometric information registered in correspondence with the employee ID. The second collation requesting unit  204  transmits the third collation request with the biometric information of the employee transmitted during the second collation request, via the transmitting and receiving unit  206 . 
       FIG. 4  is a block diagram of components of the work management server  10  according to the embodiment. The work management server  10  includes a transmitting and receiving unit  101 , an attendance information managing unit  102 , a storing unit  103 , a second collating unit  104 , a third collating unit  105 , and an update managing unit  106 . 
     The transmitting and receiving unit  101  exchanges information with the servers  20 - 1  to  20 -M. Specifically, the transmitting and receiving unit  101  receives the second collation request and the third collation request from the servers  20 - 1  to  20 -M with the biometric information of the employee. Then, the transmitting and receiving unit  101  transmits the collation result from the second collating unit  104  or the third collating unit  105  to the store server that is the transmission source of the second collation request or the third collation request. At this time, when the biometric information is outputted from the second collating unit  104  or the third collating unit  105  with the collation result, the transmitting and receiving unit  101  transmits the biometric information with the collation result. In addition, the transmitting and receiving unit  101  receives the attendance information from the servers  20 - 1  to  20 -M. 
     The attendance information managing unit  102  acquires and manages the attendance information received by the transmitting and receiving unit  101 . Specifically, the attendance information managing unit  102 , for example, associates and stores the employee ID and the clock-in and clock-out times included in the attendance information and calculates work hours of each employee. 
     The storing unit  103  stores in advance the biometric information of all employees belonging to the stores # 1  to #M. The storing unit  103  also stores the employees, among all employees, that changed the affiliated stores during the predetermined period. Specifically, the storing unit  103  stores a region-based archive database (region-based archive DB)  103   a  and a biometric information master database (biometric information master DB)  103   b.    
     For example, as shown in  FIG. 5 , the region-based archive DB  103   a  stores the latest collation date and biological information of the employees that changed the affiliated stores during the predetermined period by the region in which the store is located. In other words, the example in  FIG. 5  shows that, in the region in which the store # 2  and the store # 4  are located, the respective affiliated stores of the employees having the employee ID “A2468” and “A5555” changed to the store # 2  and the store # 4  during the predetermined period (specific date is the latest collation date). The region-based archive DB  103   a  only stores the biometric information of the employees that changed stores during the predetermined period. Therefore, the amount of stored biometric information is relatively small. The one-to-N authentication performed as the second collation does not require much time. In addition, the region-based archive DB  103   a  is divided by regions. Therefore, the amount of biometric information stored for each region is much smaller, thereby reducing the amount of time required for the one-to-N authentication. 
     According to the embodiment, the region-based archive DB  103   a  collects the biometric information of the employees that changed stores by regions. However, if the total number of employees that changed stores is small, the biometric information of the employees that changed stored in all regions can be stored in a same column. In addition, the region-based archive DB  103   a  can group a plurality of stores sharing a common point, rather than by region, and store the biometric information of the employees that changed stores by each group of stores. 
     The biometric information master DB  103   b  associates and stores the employee ID and the biometric information of all employees in the stores # 1  to #M. The biometric information master DB  103   b  is, for example, linked to a human resources department database (not shown) and reflects the increase and decrease in employees. 
     When the transmitting and receiving unit  101  receives the second collation request and the biometric information of the employee, the second collating unit  104  performs the one-to-N authentication (second authentication) using the received biometric information of the employee and the region-based archive DB  103   a  stored in the storing unit  103 . In other words, the second collating unit  104  judges whether the biometric information of the employee is registered in the region-based archive DB  103   a . Then, the second collating unit  104  notifies the transmitting and receiving unit  101  of an identified employee ID or that the authentication was not successful, as the collation result. When the employee ID is identified, the second collating unit  104  outputs the biometric information stored in correspondence with the employee ID to the transmitting and receiving unit  101 . When the employee ID is identified, the second collating unit  104  notifies the update managing unit  106  that the second collation related to the employee ID has been performed. 
     The second collating unit  104  performs the second collation on the region in which the store that is the transmission source of the biometric information of the employee is located. Even when the employee that changed the affiliated store within the same region during the predetermined period cannot be authenticated by the first collation due to repeat changes in the affiliated store, the employee can be quickly authenticated by personal authentication without having to enter the employee ID or the like through the second collation. Therefore, for example, an employee that temporarily works in a plurality of stores within the same region can be quickly and efficiently authenticated by personal authentication, without the biometric information registered in the store server of the respective stores being updated every time the affiliated store is changed or the employee having to enter the employee ID. 
     When the transmitting and receiving unit  101  receives the third collation request, the biometric information of the employee, and the employee ID, the third collating unit  105  reads the biometric information registered in the biometric information master DB  103   b  in correspondence with the received employee ID. Then, the third collating unit  105  performs the one-to-one authentication (third collation) with the biometric information of the employee. In other words, the third collating unit  105  judges whether the biometric information of the employee matches the biometric information registered in the biometric information master DB  103   b . The third collating unit  105  notifies the transmitting and receiving unit  101  of whether the biometric information matches, as the collation result. When the biometric information matches, the third collating unit  105  outputs the collated employee ID and the biometric information to the transmitting and receiving unit  101  and the update managing unit  106 . 
     The update managing unit  106  monitors the latest collation dates in the region-based archive DB  103   a  stored in the storing unit  103 . The update managing unit  106  deletes data from the region-based archive DB  103   a . The data has a latest collation date since which a predetermined period has elapsed. In addition, when notification of the performance of the second collation is given from the second collation unit  104 , the update managing unit  106  updates the latest collation date of the subject employee in the region-based archive DB  103   a  to the current date. Furthermore, the update managing unit  106  newly registers the employee ID and the biometric information outputted from the third collating unit  105  to the region-based archive DB  103   a . At this time, the update managing unit  106  registers the employee ID and the biometric information as the data of the region in which the store server is located. The store server is the transmission source of the employee ID and the biometric information of the employee used in the third collation. 
     Next, an operation of the work management system configured as described above will be explained with reference to a flowchart shown in  FIG. 6 . Hereafter, the work management performed in the store # 1  will be explained.  FIG. 6  is a flowchart of the operations performed by the server  20 - 1 . The other servers  20 - 2  to  20 -M perform the same or similar operations. 
     First, the biometric sensor  30 - 1  installed in the store recognizes biometric information of the employee, such as the vein pattern of the palm. The biometric information acquiring unit  201  in the server  20 - 1  acquires the biometric information of the employee (Step S 101 ). The acquired biometric information of the employee is outputted to the first collating unit  203 . The first collating unit  203  performs the one-to-N authentication (first collation) using the biometric information local DB stored in the biometric information storing unit  202  (Step S 102 ). 
     The first collating unit  203  judges whether the biometric information of the employee is registered in the biometric information local DB (S 103 ). When the biometric information is registered (Yes at Step S 103 ), the first collating unit  203  notifies the attendance information generating unit  205  of the employee ID corresponding to the biometric information. The first collating unit  203  also notifies the update managing unit  208  that the first collation related to the employee ID has been performed. When the attendance information generating unit  205  is notified of the employee ID, the attendance information generating unit  205  generates the attendance information including the employee ID, the current time, distinction of clock-in or clock-out, and the like (Step S 104 ). The transmitting and receiving unit  206  transmits the attendance information to the work management server  10  (Step S 105 ). The attendance information managing unit  102  manages the attendance information after the attendance information is received by the transmitting and receiving unit  101  in the work management server  10 . 
     When the update managing unit  208  receives information relating to the performance of the first collation, the update managing unit  208  updates the latest collation date corresponding to the employee ID in the biometric information local DB to the current date. The update managing unit  208  monitors all latest collation dates in the biometric information local DB as required. The update managing unit  208  deletes data (namely, the employee ID, the biometric information, and the latest collation date) having the latest collation date since which the predetermined period has elapsed. Therefore, data of employees on which the first collation has not been performed by the server  20 - 1  for the predetermined period is deleted from the biometric information local DB. Only the biometric information of the employees belonging to the store # 1  is registered in the biometric information local DB. As a result, the amount of biometric information registered in the biometric information local DB can be kept at a minimum. Processing time required when the one-to-N authentication is performed as the first collation can be reduced. 
     At the same time, when the biometric information of the employee is not registered in the biometric information local DB (No at Step S 103 ), the first collating unit outputs the biometric information of the employee to the second collation requesting unit  204 . The second collation requesting unit  204  generates the second collation request for the biometric information of the employee. The transmitting and receiving unit  206  transmits the generated second collation request to the work management server  10  (Step S 106 ). 
     The transmitting and receiving unit  101  in the work management server  10  receives the transmitting biometric information and the second collation request. The transmitting and receiving unit  101  outputs the biometric information and the second collation request to the second collating unit  104 . The second collating unit  104  performs the one-to-N authentication (second collation) using the data of the region in which the store # 1  is located within the region-based archive DB  103   a  stored in the storing unit  103 . As a result of the authentication, if the biometric information is registered in the region-based archive DB  103   a , the transmitting and receiving unit  101  transmits the employee ID corresponding to the biometric information to the server  20 - 1 , as the collation result. If the biometric information of the employee is not registered in the region-based archive DB  103   a , the transmitting and receiving unit  101  transmits the collation result that the biometric information is not registered in the region-based archive DB  103   a  to the server  20 - 1 . 
     When the biometric information of the employee is registered in the region-based archive DB  103   a , the second collating unit  104  notifies the update managing unit  106  that the second collation related to the identified employee ID has been performed. The update managing unit  106  updates the latest collation date corresponding to the employee ID in the region-based archive DB  103   a  to the current date. The update managing unit  208  monitors all latest collation dates in the region-based archive DB  103   a  as required. The update managing unit  208  deletes data (namely, the store, the employee ID, the biometric information, and the latest collation date) having the latest collation date since which the predetermined period has elapsed. Therefore, data of employees on which the second collation has not been performed by the work management server  10  for the predetermined period is deleted from the biometric information local DB. In other words, the data of the employees that have not changed affiliated stores during the predetermined period is deleted. Only the biometric information of the employees that have changed affiliated stores during the predetermined period is registered in the region-based archive DB  103   a . As a result, the amount of biometric information registered in the region-based archive DB  103   a  can be kept at a minimum. Processing time required when the one-to-N authentication is performed as the second collation can be reduced. 
     The transmitting and receiving unit  206  in the server  20 - 1  receives the collation result transmitted by the transmitting and receiving unit  101 . The transmitting and receiving unit  206  outputs the collation result to the collation result judging unit  207 . Then, the collation result judging unit  207  judges whether the biometric information is registered as the result of the second collation (Step S 107 ). In other words, the collation result judging unit  207  judges whether the collation result includes the identified employee ID or includes that the biometric information is not registered. As a result, if the identified employee ID is included in the collation result (Yes at Step S 107 ), the result of the second collation indicates that the employee is authenticated by personal authentication. The collation result judging unit  207  notifies the attendance information generating unit  205  of the employee ID. The biometric information received with the employee ID is outputted to the update managing unit  208 . The update managing unit  208  newly registers the outputted biometric information in the biometric information local DB stored in the biometric information storing unit  202  (Step S 108 ). As a result, when the employee that has been authenticated by personal authentication by the second collation is subsequently authenticated at the store # 1 , the person authentication is performed by the first collation. The time required for authentication is further reduced. 
     When the attendance information generating unit  205  receives the employee ID, it generates the attendance information (Step S 109 ). The transmitting and receiving unit  206  transmits the attendance information to the work management server  10  (Step S 110 ). The attendance information is managed by the attendance information managing unit  102  after the attendance information is received by the transmitting and receiving unit  101  in the work management server  10 . 
     At the same time, when the identified employee ID is not included and that the biometric information is not registered is included in the collation result (No at Step S 107 ), the second collation result indicates that the employee has not been authenticated by personal authentication. The collation result judging unit  207  judges that the third collation is required to be performed. Therefore, the collation result judging unit  207  displays a message requesting the input of the employee ID on the user I/F unit  209  (Step S 111 ). The employee operates the user I/F unit  209  and enters the employee ID. The employee ID is outputted to the third collation requesting unit  210 . When the employee ID is outputted to the third collation requesting unit  210 , the third collation requesting unit  210  generates the third collation request including the employee ID. The transmitting and receiving unit  206  transmits the employee ID to the work management server  10  with the biometric information of the employee transmitted during the second collation request (Step S 112 ). 
     The transmitting and receiving unit  101  in the work management server  10  receives the transmitted biometric information and the third collation request. The transmitting and receiving unit  101  outputs the transmitted biometric information and the third collation request to the third collating unit  105 . The third collating unit  105  reads the biometric information corresponding with the employee ID included in the third collation request from the biometric information master DB  103   b  stored in the storing unit  103 . The third collating unit  105  performs the one-to-one authentication (third collation) with the biometric information of the employee. As a result, whether the biometric information matching the biometric information of the employee is registered in the biometric information master DB  103   b  is determined. The transmitting and receiving unit  101  transmits the collation result to the server  20 - 1 . At this time, when the collation result indicates that the biometric information is registered, the biometric information is transmitted to the server  20 - 1  with the collation result. 
     When the biometric information matching the biometric information of the employee is registered in the biometric information master DB  103   b , the biometric information and the employee ID is outputted to the update managing unit  106 . The update managing unit  106  newly registers the biometric information and the employee ID in the region-based archive DB  103   a  stored in the storing unit  103 . As a result, the employee that has been authenticated by personal authentication by the third collation will be authenticated by personal authentication by the second collation, even when the employee changes the affiliated store during the predetermined period. Therefore, the employee is authenticated by personal authentication without having to enter the employee ID. 
     The transmitting and receiving unit  206  in the server  20 - 1  receives the collation result from the transmitting and receiving unit  101 . The transmitting and receiving unit  206  outputs the collation result to the collation result judging unit  207 . Then, the collation result judging unit  207  judges whether the biometric information matching the biometric information of the employee is registered in the biometric information master DB  103   b  as a result of the third collation (Step S 113 ). As a result, if the collation result is that the biometric information is registered (Yes at Step S 113 ), the result of the third collation indicates that the employee has been authenticated by personal authentication. The collation result judging unit  207  notifies the attendance information generating unit  205  of the employee ID. The biometric information that is received with the employee ID is outputted to the update managing unit  208 . The update managing unit  208  newly registers the outputted biometric information in the biometric information local DB stored in the biometric information storing unit  202  (step S 114 ). As a result, when the employee that has been authenticated by personal authentication by the third collation is subsequently authenticated at the store # 1 , the person authentication is performed by the first collation. The time required for authentication is further reduced. 
     When notified of the employee ID, the attendance information generating unit  205  generates the attendance information (Step S 115 ). The transmitting and receiving unit  206  transmits the attendance information to the work management server  10  (Step S 116 ). The attendance information managing unit  102  manages the attendance information after the attendance information is received by the transmitting and receiving unit  101  in the work management server  10 . 
     If the biometric information of the employee is not registered in the biometric information master DB  103   b  (No at Step S 113 ), that the biometric information is not registered is contradictory with the biometric information of all employees being registered in the biometric information master DB  103   b . Occurrence of some sort of an error can be considered, such as the biometric information master DB  103   b  not being in a newest state, or recognition of the biometric information by the biometric sensor  30 - 1  being incorrect. Therefore, a procedure is performed, such as notifying an administrator of the occurrence of the error. 
     Next, a specific example of the work management performed when a certain employee is transferred from the store # 1  to the store #M will be explained with reference to a sequence diagram shown in  FIG. 7 . 
     When the employee belongs to the store # 1 , the biometric information of the employee is registered in the biometric information local DB stored in the biometric information storing unit  202  in the server  20 - 1 . Therefore, when the biometric sensor  30 - 1  acquires the biometric information of the employee, the employee is authenticated by the first collation performed by the first collating unit  203  (Step S 201 ). In other words, the first collating unit  203  acquires the employee ID of the employee and outputs the employee ID to the attendance information generating unit  205 . The attendance information generating unit  205  generates the attendance information including the employee ID, the current time, and the like (Step S 202 ). The transmitting and receiving unit  206  transmits the generated attendance information to the work management server  10  (step S 203 ). The attendance information managing unit  102  stores and manages the attendance information received by the transmitting and receiving unit  101  in the work management server  10 . 
     Assume that an employee is transferred to from the store # 1  to the store #M. In other words, when the employee clocks in at the store #M, the biometric sensor  30 -M acquires the biometric information, as when the employee clocks in at the store # 1 . However, the biometric information of the employee is not registered in the biometric information local DB stored in the biometric information storing unit  202  of the server  20 -M. Therefore, when the first collating unit  203  in the server  20 -M performs the first collation (Step S 204 ), the biometric information of the employee is outputted to the second collation requesting unit  204 , as is. The second collation requesting unit  204  generates the second collation request. The transmitting and receiving unit  206  transmits the second collation request to the work management server  10  with the biometric information of the employee (Step S 205 ). 
     The transmitting and receiving unit  101  in the work management server  10  receives the transmitted second collation request and the biometric information of the employee. The second collating unit  104  performs the second collation of the biometric information of the employee (Step S 206 ). In other words, the second collating unit  104  performs the one-to-N authentication of the biometric information of the employee and the region-based archive DB  103   a  stored in the storing unit  103 . The explanation is continued under an assumption that the biometric information of the employee is not registered in the region-based archive DB  103   a . Therefore, the biometric information of the employee is not authenticated even by the second collation performed by the second collating unit  104 . The transmitting and receiving unit  101  transmits the collation result that the biometric information has not been authenticated to the server  20 -M (Step S 207 ). 
     The transmitting and receiving unit  206  in the server  20 -M receives the transmitted collation result. The collation result judging unit  207  judges whether the employee is authenticated. Here, the collation result is that the employee is not authenticated. Therefore, the collation result judging unit  207  controls the user I/F unit  209  and displays the message requesting the input of the employee ID for the third collation. The employee operates the user I/F unit  209  and enters the employee ID (Step S 208 ). The third collation requesting unit  210  generates the third collation request including the employee ID. The transmitting and receiving unit  206  transmits the third collation request to the work management server  10  with the biometric information of the employee transmitted during the second collation request (Step S 209 ). 
     The transmitting and receiving unit  101  of the work management server  10  receives the transmitted third collation request and the biometric information of the employee. The third collating unit  105  performs the third collation of the biometric information of the employee (Step S 210 ). In other words, the third collating unit  105  reads the biometric information corresponding with the employee ID included in the third collation request from the biometric information master DB  103   b  stored in the storing unit  103 . The third collating unit  105  performs the one-to-one authentication with the biometric information of the employee received with the third collation request. If the employee is a regular employee and registration of the biometric information to the biometric information master DB  103   b  is performed appropriately, the biometric information of the employee is authenticated by the third collation performed by the third collating unit  105 . The transmitting and receiving unit  101  transmits the collated employee ID and the registered biometric information to the server  20 -M (Step S 211 ). The third collating unit  105  outputs the employee ID and the biometric information to the update managing unit  106 . The update managing unit  106  associates and stores the employee ID and the biometric information in the region-based archive DB  103   a , as the data of the region in which the store #M is located (Step S 212 ). As a result, the employee is authenticated by the second collation without having to enter the employee ID, even when the employee is transferred again within the region in which the store #M is located 
     The transmitting and receiving unit  206  of the server  20 -M receives the transmitted employee ID and the biometric information. The collation result judging unit  207  judges whether the employee is authenticated. Here, the employee ID is received. Therefore, the collation result judging unit  207  notifies the attendance information generating unit  205  of the employee ID. The collation result judging unit  207  also outputs the employee ID and the biometric information to the update managing unit  208 . The attendance information generating unit  205  generates the attendance information including the employee ID, the current time, and the like (Step S 213 ). The transmitting and receiving unit  206  transmits the attendance information to the work management server  10  (Step S 214 ). The update managing unit  208  associates and registers the employee ID and the biometric information in the biometric information local DB (Step S 215 ). As a result, when the employee subsequently clocks in at the store #M, the employee is authenticated by the first collation performed by the server  20 -M. 
     As described above, according to the embodiment, the biometric information that is not authenticated by the respective store server is authenticated by the work management server supervising the overall system. When the biometric information is to be authenticated, the employee ID and the biometric information is fed back to the store server and registered in the store server. Therefore, an employee who is not authenticated by a first personal authentication at the respective store is quickly authenticated by subsequent personal authentications. In other words, in a system in which all subjects to be authenticated are divided into groups and the personal authentication of a subject is performed by group, the personal authentication is quickly and efficiently performed even when the group to which the subject belongs changes. 
     According to the embodiments, the biometric information local DB and the region-based archive DB  103   a  are updated by a passage of an elapsed time from the latest collation date and the results of the second collation and the third collation. However, the biometric information local DB and the region-based archive DB  103   a  can be updated by periodic reference of a human resources department database (not shown). When such a structure is employed, transfer of employees and the like can be reflected more correctly. 
     According to an aspect of the present invention, personal authentication can be quickly, efficiently, and accurately performed even when the group to which the subject belongs changes. Moreover, there is no need to input identifying information. 
     Although the invention has been described with respect to a specific embodiment for a complete and clear disclosure, the appended claims are not to be thus limited but are to be construed as embodying all modifications and alternative constructions that may occur to one skilled in the art that fairly fall within the basic teaching herein set forth.