Patent Publication Number: US-2023141541-A1

Title: Authentication control apparatus, authentication system, authentication control method, and storage medium

Description:
TECHNICAL FIELD 
     The present disclosure relates to an authentication control apparatus, an authentication system, an authentication control method, and a storage medium. 
     BACKGROUND ART 
     For example, Patent Literature 1 discloses a system in which face authentication is executed based on an image obtained by capturing, by a camera, a target person to be recognized whose presence in front of the camera has been detected, and when the face authentication has been successfully performed, personal information (name and the like) of the person to be authenticated is displayed. 
     CITATION LIST 
     Patent Literature 
     [Patent Literature 1] Japanese Unexamined Patent Application Publication No. 2006-293913 
     SUMMARY OF INVENTION 
     Technical Problem 
     However, there is a problem in the system disclosed in Patent Literature 1 that, when a third party is present near the target person to be recognized, it is impossible for the target person to be recognized to know that his/her face has been successfully authenticated without his/her personal information being known to the third party. 
     In view of the aforementioned problem, an object of the present disclosure is to provide an authentication control apparatus, an authentication system, an authentication control method, and a storage medium capable of enabling, when a third party is present near a target person to be recognized, the target person to be recognized to know that his/her face has been successfully authenticated without his/her personal information being known to the above third party. 
     Solution to Problem 
     An authentication control apparatus according to a first aspect of the present disclosure includes: image acquisition means for acquiring an image including a person to be authenticated captured by a camera that photographs the person to be authenticated; authentication control means for causing an authentication apparatus that executes face authentication to execute face authentication of the person to be authenticated included in the image acquired by the image acquisition means; and display control means for causing, when the face authentication has been successfully performed, a display apparatus to display privacy protection information of the person to be authenticated whose face has been successfully authenticated for the purpose of letting the person to be authenticated whose face has been successfully authenticated visually recognize that the face authentication has been successful. 
     An authentication system according to a second aspect of the present disclosure includes: a camera that photographs a person to be authenticated; a display apparatus; image acquisition means for acquiring an image that includes a person to be authenticated who has been captured by the camera; authentication control means for causing an authentication apparatus that executes face authentication to execute face authentication of the person to be authenticated included in the image acquired by the image acquisition means; and display control means for causing, when the face authentication has been successfully performed, the display apparatus to display privacy protection information of the person to be authenticated whose face has been successfully authenticated for the purpose of letting the person to be authenticated whose face has been successfully authenticated visually recognize that the face authentication has been successful. 
     An authentication control method according to a third aspect of the present disclosure includes: an image acquisition step of acquiring an image including a person to be authenticated captured by a camera that photographs the person to be authenticated; an authentication control step of causing an authentication apparatus that executes face authentication to execute face authentication of the person to be authenticated included in the image acquired in the image acquisition step; and a display control step of causing, when the face authentication has been successfully performed, a display apparatus to display privacy protection information of the person to be authenticated whose face has been successfully authenticated for the purpose of letting the person to be authenticated whose face has been successfully authenticated visually recognize that the face authentication has been successful. 
     A storage medium according to a fourth aspect of the present disclosure is a computer readable storage medium storing a program for causing an electronic device including at least one processor to execute: an image acquisition step of acquiring an image including a person to be authenticated captured by a camera that photographs the person to be authenticated; an authentication control step of causing an authentication apparatus that executes face authentication to execute face authentication of the person to be authenticated included in the image acquired in the image acquisition step; and a display control step of causing, when the face authentication has been successfully performed, a display apparatus to display privacy protection information of the person to be authenticated whose face has been successfully authenticated for the purpose of letting the person to be authenticated whose face has been successfully authenticated visually recognize that the face authentication has been successful. 
     Advantageous Effects of Invention 
     According to the present invention, it is possible to provide an authentication control apparatus, an authentication system, an authentication control method, and a storage medium capable of enabling, when a third party is present near a target person to be recognized, the target person to be recognized to know that his/her face has been successfully authenticated without his/her personal information being known to the above third party. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is a schematic configuration diagram of an authentication control apparatus  20 ; 
         FIG.  2    is a flowchart showing one example of an operation of the authentication control apparatus  20 ; 
         FIG.  3    is a block diagram showing a configuration of an authentication system  1  according to a second example embodiment; 
         FIG.  4    is a schematic configuration diagram of an authentication apparatus  10 ; 
         FIG.  5    is a flowchart showing one example of an operation of the authentication apparatus  10  (face information registration processing); 
         FIG.  6    is a flowchart showing one example of an operation of the authentication apparatus  10  (face authentication processing); 
         FIG.  7    is a schematic configuration diagram of an authentication control apparatus  20 ; 
         FIG.  8    is a flowchart showing one example of an operation of the authentication control apparatus  20  (privacy protection information registration processing); 
         FIG.  9    is a flowchart showing one example of an operation of the authentication control apparatus  20  (privacy protection information specifying processing); 
         FIG.  10    is an external view of a display terminal  30 ; 
         FIG.  11    is a schematic configuration diagram of the display terminal  30 ; and 
         FIG.  12    is a sequence diagram of an authentication system  1 . 
     
    
    
     EXAMPLE EMBODIMENT 
     First Example Embodiment 
     Referring first to  FIG.  1   , a configuration example of an authentication control apparatus  20  that forms an authentication system according to a first example embodiment will be described. 
       FIG.  1    is a schematic configuration diagram of the authentication control apparatus  20 . 
      As shown in  FIG.  1   , the authentication control apparatus  20  includes: image acquisition means  22   b  for acquiring an image including a person to be authenticated photographed by a camera  31  that photographs the person to be authenticated; authentication control means  22   c  for causing an authentication apparatus  10  that executes face authentication to execute face authentication of the person to be authenticated included in the image acquired by the image acquisition means  22   b ; and display control means  22   a  for causing, when the face authentication has been successfully performed, the display apparatus  30  to display privacy protection information on the person to be authenticated whose face has been successfully authenticated for the purpose of enabling the person to be authenticated whose face has been successfully authenticated to visually recognize that the face authentication has been successful. 
     Next, one example of operations of the authentication control apparatus  20  having the aforementioned configuration will be described. 
       FIG.  2    is a flowchart showing one example of an operation of the authentication control apparatus  20 . 
     First, the image acquisition means  22   b  acquires a captured image including the person to be authenticated photographed by the camera  31  that photographs the person to be authenticated (Step S 1 ). Next, the authentication control means  22   c  causes the authentication apparatus  10  that executes face authentication to execute the face authentication of the person to be authenticated included in the captured image acquired in Step S 1  (Step SS 2 ). Next, when the face authentication has been successfully performed, the display control means  22   a  causes the display apparatus  30  to display privacy protection information on the person to be authenticated whose face has been successfully authenticated for the purpose of enabling the person to be authenticated whose face has been successfully authenticated to visually recognize that the face authentication has been successful (Step S 3 ). 
     As described above, according to the first example embodiment, the privacy protection information on the person to be authenticated whose face has been successfully authenticated is displayed, whereby, even in a case in which a third party is present near the target person to be recognized, it is possible for the target person to be recognized to know that his/her face has been successfully authenticated without his/her personal information being known to the above third party. 
     Second Example Embodiment 
     Hereinafter, an authentication system  1  will be described in detail as a second example embodiment of the present invention. An image acquisition unit is used as the image acquisition means  22   b . This will be referred also to as an image acquisition unit  22   b . Further, an authentication control unit is used as the authentication control means  22   c . This will be referred also to as an authentication control unit  22   c . Further, a display control unit is used as the display control means  22   a . This will be referred also to as a display control unit  22   a . Further, a display terminal is used as the display apparatus  30 . This will be referred also to as a display terminal  30 . 
       FIG.  3    is a block diagram showing a configuration of the authentication system  1  according to the second example embodiment. 
     The authentication system  1  includes an authentication apparatus  10 , an authentication control apparatus  20 , a display terminal  30 , a registration terminal  40 , and a security gate  50  capable of communicating with one another via a network NW (e.g., the Internet). 
     First, a configuration example of the authentication apparatus  10  will be described. 
       FIG.  4    is a schematic configuration diagram of the authentication apparatus  10 . 
     As shown in  FIG.  4   , the authentication apparatus  10  includes a storage unit  11 , a control unit  12 , a memory  13 , and a communication unit  14 . 
      The storage unit  11  is, for example, a non-volatile storage unit such as a hard disk device or a ROM. The storage unit  11  stores a program  11   a  and a face information DB  11   b . 
     The program  11   a  is a program executed by the control unit  12  (a processor). User ID(s) and face feature information on the user (target person to be recognized) are stored (registered) in the face information DB  11   b  in such a way that the user ID(s) and the face feature information are associated with each other. Further, the authentication apparatus  10  compares, in accordance with a face authentication request externally received (received from, for example, the authentication control apparatus  20 ), the face image or face feature information included in the request, with face feature information of each target person to be recognized, and sends the result of the comparison back to the request source. 
     The control unit  12  includes a processor, although it is not shown. The processor is, for example, a Central Processing Unit (CPU). The processor may be one or more than one. The processor executes the program  11   a  loaded from the storage unit  11  into the memory  13  (e.g., RAM), thereby functioning as an image acquisition unit  12   a , a face detection unit  12   b , a feature point extraction unit  12   c , a registration unit  12   d , or an authentication unit  12   e . Some or all of them may be implemented by hardware. 
     The image acquisition unit  12   a  acquires an image including the face of the person to be authenticated. The image acquisition unit  12   a  acquires, for example, the image received by the communication unit  14 . The image received by the communication unit  14  includes an image for registration or an image for authentication (comparison) transmitted from the authentication control apparatus  20 . 
     The face detection unit  12   b  detects a face region from the image acquired by the image acquisition unit  12   a  and outputs the detected face region to the feature point extraction unit  12   c . 
     The feature point extraction unit  12   c  extracts feature points (e.g., feature points of the face such as eyes, nose, or corners of the mouth) from the face region detected by the face detection unit  12   b . 
     When the image acquired by the image acquisition unit  12   a  is an image for registration, the feature point extraction unit  12   c  outputs the face feature information to the registration unit  12   d . The face feature information here is a set of feature points that have been extracted. On the other hand, when the image acquired by the image acquisition unit  12   a  is an image for authentication, the feature point extraction unit  12   c  outputs the face feature information to the authentication unit  12   e . 
     The registration unit  12   d  newly issues a user ID when the face feature information is registered therein. The registration unit  12   d  registers the issued user ID in association with the face feature information extracted from the image for registration in the face information DB  11   b . 
     The authentication unit  12   e  compares the face feature information extracted from the face region detected from the image for authentication with the face feature information in the face information DB  11   b . The authentication unit  12   e  sends information regarding whether face feature information items match each other back to the authentication control apparatus  20 . The information indicating whether or not the face feature information items match each other corresponds to information indicating whether or not authentication has been successful. 
     The communication unit  14  is a communication apparatus that communicates with the authentication control apparatus  20  via the network NW. 
     Next, one example of an operation of the authentication apparatus  10  (face information registration processing) will be described. 
       FIG.  5    is a flowchart showing one example of an operation of the authentication apparatus  10  (face information registration processing). 
      First, the authentication apparatus  10  (the image acquisition unit  12   a ) acquires an image (image for registration) including the face of the person to be authenticated included in a face information registration request (Step S 10 ). For example, the authentication apparatus  10  (the communication unit  14 ) receives the face information registration request from the authentication control apparatus  20  via the network NW. 
     Next, the authentication apparatus  10  (the face detection unit  12   b ) detects the face region from the image for registration acquired in Step S 10  (Step S 11 ). Next, the authentication apparatus  10  (the feature point extraction unit  12   c ) extracts the feature points of the face from the face region detected in Step S 11  (Step S 12 ) and outputs the face feature information to the registration unit  12   d . Lastly, the authentication apparatus  10  (the registration unit  12   d ) issues a user ID and registers the user ID in association with the face feature information in the face information DB  11   b  (Step S 13 ). Note that the authentication apparatus  10  may receive the face feature information from the authentication control apparatus  20  and register the received face feature information in association with the user ID in the face information DB  11   b . Next, the authentication apparatus  10  (the communication unit  14 ) transmits the result of the registration (the user ID issued in Step S 13 ) to the authentication control apparatus  20  that has transmitted the face information registration request. 
     Next, one example of an operation of the authentication apparatus  10  (face authentication processing) will be described. 
       FIG.  6    is a flowchart showing one example of an operation of the authentication apparatus  10  (face authentication processing). 
     First, the authentication apparatus  10  (the image acquisition unit  12   a ) acquires an image (image for authentication) including the face of the person to be authenticated included in the face authentication request (Step S 20 ). For example, the authentication apparatus  10  (the communication unit  14 ) receives the face authentication request from the authentication control apparatus  20  via the network NW. Next, the authentication apparatus  10  (the face detection unit  12   b ) detects the face region from the image for authentication acquired in Step S 20  (Step S 21 ). Next, the feature point extraction unit  12   c  extracts feature points of the face from the face region detected in Step S 21  (Step S 22 ). Alternatively, the authentication apparatus  10  may receive the face feature information from the authentication control apparatus  20 . Next, the authentication apparatus  10  (the authentication unit  12   e ) compares the acquired face feature information with the face information DB  11   b  (Step S 23 ). When the face feature information items match each other (Step S 24 : Yes), the authentication unit  12   e  specifies the user ID of the user whose face feature information items has matched each other (Step S 25 ), and sends information indicating that the face authentication has been successful and the specified user ID back to the authentication control apparatus  20  (Step S 26 ). When there are no face feature information items that match each other (Step S 24 : No), the authentication unit  12   e  sends information indicating that the face authentication has failed back to the authentication control apparatus  20  (Step S 27 ). 
     Next, a configuration example of the authentication control apparatus  20  will be described. 
       FIG.  7    is a schematic configuration diagram of the authentication control apparatus  20 . 
     The authentication control apparatus  20 , which is an information processing apparatus that performs authentication control processing, is, for example, a server apparatus implemented by a computer. 
     As shown in  FIG.  7   , the authentication control apparatus  20  includes a storage unit  21 , a control unit  22 , a memory  23 , and a communication unit  24 . 
     The storage unit  21  is a non-volatile storage unit such as a hard disk device or a ROM. The storage unit  21  stores a program  21   a  and a privacy protection information DB  21   b . 
     The program  21   a  is a program executed by the control unit  22  (processor). The privacy protection information DB  21   b  stores (registers) the user ID(s) and privacy protection information of this user (target person to be recognized) in association with each other. The privacy protection information is information notifying the person to be authenticated whose face has been successfully authenticated that his/her face has been successfully authenticated, the information not including his/her personal information (e.g., the name of the person to be authenticated, the name of the company for which he/she works). The privacy protection information includes information registered by the person to be authenticated (user) in order to notify that his/her face has been successfully authenticated. The privacy protection information is, for example, an image such as an avatar image. The avatar image is specified, for example, (or selected) by the person to be authenticated in the registration terminal  40 . The avatar image is an image including a character, which is an alter ego of the person to be authenticated. The character shown by a symbol G 1  in  FIG.  10    is one example of the avatar image. The character may be any one. For example, the character may be a living creature (e.g., a person, an animal, or a plant) or may be an inanimate object (e.g., a building or a landscape). The living creature or the inanimate object may or may not actually exist. Further, the character may or may not be anthropomorphized. Further, the character may be expressed in two dimensions or in three dimensions. Further, the character may be a video image or may be a still image. Further, the privacy protection information may be “information associated in advance with the person to be authenticated”, “information defined for each person to be authenticated”, or “information specific to the person to be authenticated”. 
     The control unit  22  includes a processor, although it is not shown in the drawings. The processor is, for example, a Central Processing Unit (CPU). The processor may be one or more than one. The processor executes the program  21   a  loaded into the memory  23  (e.g., RAM) from the storage unit  21 , thereby functioning as a display control unit  22   a , an image acquisition unit  22   b , an authentication control unit  22   c , a face authentication result acquisition unit  22   d , a privacy protection information acquisition unit  22   e , a registration unit  22   f , or a specifying unit  22   g . Some or all of them may be implemented by hardware. 
      When, for example, the face authentication has been successfully performed, the display control unit  22   a  causes the display terminal  30  to display the privacy protection information on the person to be authenticated whose face has been successfully authenticated (i.e., privacy protection information specified by the specifying unit  22   g  that will be described later) for the purpose of enabling the person to be authenticated whose face has been successfully authenticated to visually recognize that the face authentication has been successful. Specifically, the display control unit  22   a  transmits a privacy protection information display instruction for displaying the privacy protection information on the person to be authenticated whose face has been successfully authenticated to the display terminal  30  via the communication unit  24 . 
     The image acquisition unit  22   b  acquires an image including the person to be authenticated who is in front of the security gate  50 , the image being captured by the camera  31  (hereinafter this will be referred also to as a captured image). Specifically, the communication unit  24  receives the captured image transmitted from the display terminal  30  and the image acquisition unit  22   b  acquires the captured image received by the communication unit  24 . 
     The authentication control unit  22   c  causes the authentication apparatus  10  that executes the face authentication to execute the face authentication of the person to be authenticated included in the captured image acquired by the image acquisition unit  22   b . Specifically, the authentication control unit  22   c  transmits the captured image acquired by the image acquisition unit  22   b  to the authentication apparatus  10  via the communication unit  24 . In place of the captured image, the face region detected from the captured image (or feature points extracted from the face region) may be transmitted to the authentication apparatus  10 . 
     The face authentication result acquisition unit  22   d  acquires the result of the face authentication executed by the authentication apparatus  10 . Specifically, the communication unit  24  receives the result of the face authentication transmitted from the authentication apparatus  10  and the face authentication result acquisition unit  22   d  acquires the result of the face authentication that the communication unit  24  has received. 
     The privacy protection information acquisition unit  22   e  acquires the privacy protection information. Specifically, the communication unit  24  receives the privacy protection information to be registered transmitted from the registration terminal  40  and the privacy protection information acquisition unit  22   e  acquires the privacy protection information to be registered that has been received by this communication unit  24 . 
     The registration unit  22   f  registers the user ID of the user (person to be authenticated) registered in the authentication apparatus  10  in association with the privacy protection information acquired by the privacy protection information acquisition unit  22   e  in the privacy protection information DB  21   b . 
     The specifying unit  22   g  specifies the privacy protection information associated with the person to be authenticated (user ID) whose face has been successfully authenticated in the storage unit  21  (the privacy protection information DB  21   b ). 
     Next, one example of an operation of the authentication control apparatus  20  (privacy protection information registration processing) will be described. 
       FIG.  8    is a flowchart showing one example of an operation of the authentication control apparatus  20  (privacy protection information registration processing). 
     First, the authentication control apparatus  20  (the privacy protection information acquisition unit  22   e ) acquires an image (image for registration) including the face of the person to be authenticated (privacy protection information registration request person) and the privacy protection information (Step S 30 ). For example, the communication unit  24  receives the privacy protection information registration request transmitted from the registration terminal  40  and the face authentication result acquisition unit  22   d  acquires the privacy protection information registration request that has been received by the communication unit  24 . This privacy protection information registration request includes an image including the face of the person to be authenticated (image for registration) and the privacy protection information to be registered. This privacy protection information to be registered is, for example, the one that has been specified (or selected) by the person to be authenticated in the registration terminal  40 . 
     Next, the authentication control apparatus  20  (the communication unit  24 ) transmits a face information registration request to the authentication apparatus  10  (Step S 31 ). This face information registration request includes an image (image for registration) including the face of the person to be authenticated (the privacy protection information registration request person) acquired in Step S 30 . Next, the authentication control apparatus  20  (the communication unit  24 ) receives the result of the registration (user ID) transmitted from the authentication apparatus  10  (Step S 32 ). 
     Next, the authentication control apparatus  20  (the registration unit  22   f ) registers the privacy protection information acquired in Step S 30  in association with the user ID received in Step S 32  in the storage unit  21  (the privacy protection information DB  21   b ) (Step S 33 ). 
     Next, one example of an operation of the authentication control apparatus  20  (privacy protection information specifying processing) will be described. 
       FIG.  9    is a flowchart showing one example of an operation of the authentication control apparatus  20  (privacy protection information specifying processing). 
     First, the authentication control apparatus  20  (the image acquisition unit  22   b ) acquires a captured image including the person to be authenticated who has been captured by the camera  31  and is in front of the security gate  50  (Step S 40 ). For example, the communication unit  24  receives the captured image transmitted from the display terminal  30  and the image acquisition unit  22   b  acquires the captured image received by the communication unit  24 . Next, the authentication control apparatus  20  (the communication unit  24 ) transmits a face authentication request for requesting face authentication of the person to be authenticated included in the captured image acquired in Step S 40  to the authentication apparatus  10  via the communication unit  24  (Step S 41 ). This face authentication request includes the captured image (image for authentication) acquired in Step S 40 . 
     Next, the authentication control apparatus  20  (the communication unit  24 ) receives the result of the face authentication and the user ID transmitted from the authentication apparatus  10  and the face authentication result acquisition unit  22   d  acquires the result of the face authentication and the user ID that the communication unit  24  has received (Step S 42 ). 
     When the face authentication has been successfully performed (Step S 43 : YES), that is, when the result of the face authentication acquired in Step S 42  indicates that authentication has been successfully performed, the authentication control apparatus  20  (specifying unit  22   g ) specifies the privacy protection information on the person to be authenticated whose face has been successfully authenticated, i.e., the privacy protection information associated with the user ID acquired in Step S 42  in the storage unit  21  (the privacy protection information DB  21   b ) (Step S 44 ). 
     Next, the authentication control apparatus  20  (the display control unit  22   a ) causes the display terminal  30  to display the privacy protection information specified in Step S 44  for the purpose of enabling the person to be authenticated whose face has been successfully authenticated to visually recognize that the face authentication has been successful. Specifically, the display control unit  22   a  transmits a privacy protection information display instruction for causing the privacy protection information specified in Step S 44  to be displayed to the display terminal  30  via the communication unit  24 . This privacy protection information display instruction includes the privacy protection information specified in Step S 44 . 
     On the other hand, when the face authentication has failed (Step S 43 : NO), that is, when the result of the face authentication acquired in Step S 42  indicates that the authentication has failed, the authentication control apparatus  20  (the communication unit  24 ) causes the display terminal  30  to display that the face authentication of the person to be authenticated has failed so that this person to be authenticated can visually recognize that the face authentication has been failed (Step S 46 ). Specifically, the display control unit  22   a  transmits a display instruction for causing the display terminal  30  to display the information indicating that the face authentication has failed to the display terminal  30  via the communication unit  24 . 
     Next, a configuration example of the display terminal  30  will be described. 
       FIG.  10    shows an external view of the display terminal  30  and  FIG.  11    is a schematic configuration diagram. 
     As shown in  FIGS.  10  and  11   , the display terminal  30  is an information processing apparatus including a camera  31 , a display unit  32 , a storage unit  34 , a control unit  35 , a memory  36 , and a communication unit  37 . The display terminal  30  is provided, as shown in, for example,  FIGS.  3  and  10   , in a security gate  50  (or near the security gate  50 ) installed at the entrance of a building or the entrance of a floor inside the building. Further, as shown in  FIG.  3   , the camera  31  is provided, for example, near the security gate  50 . The authentication apparatus  10  and the authentication control apparatus  20  are installed in a remote place from the security gate  50 . 
     The camera  31  captures an image including the person to be authenticated who is in front of the security gate  50 . As shown in  FIG.  1   , the camera  31  captures, for example, a person to be authenticated U who is walking toward the security gate  50  through which this person is going to pass. Alternatively, the camera  31  may photograph the person to be authenticated U who has stopped in front of the security gate  50  through which the person is going to pass, as shown in  FIG.  10   . The camera  31  is provided in, for example, the security gate  50  (or near the security gate  50 ) so that it can photograph the face of the person to be authenticated U, that is, the face of the person to be authenticated U who is facing toward the traveling direction from the front or from substantially the front (so that it can photograph the face of the person to be authenticated U at an angle suitable for face authentication). 
     The display unit  32  is, for example, a display such as a liquid crystal display. For example, a screen G including privacy protection information G 1  (hereinafter this will be referred also to as an avatar image G 1 ) is displayed on the display surface of the display unit  32  (see  FIG.  10   ). The display unit  32  (display surface) is one example of the display area where the privacy protection information according to the present invention is displayed. This screen G includes, besides the privacy protection information G 1 , time information G 2  indicating the time at which the user passes through the security gate  50 , and purpose information G 3  indicating the purpose (e.g., come to work or leave office after working) for passing through the security gate  50 . As shown in  FIG.  10   , the display unit  32  is provided in the security gate  50  (or near the security gate  50 ) in such a way that the person to be authenticated U is able to visually recognize the screen G including his/her privacy protection information G 1 . 
     The storage unit  34  is a non-volatile storage unit such as a hard disk device or a ROM. The storage unit  34  stores a program  34   a . 
     The program  34   a  is a program executed by a control unit  35  (a processor). 
     The control unit  35  includes a processor that is not shown. The processor is, for example, a Central Processing Unit (CPU). The processor may be one or more than one. The processor executes the program  34   a  loaded into the memory  36  (e.g., RAM) from the storage unit  34 , thereby functioning as a display control unit  35   a  or an image acquisition unit  35   b . Some or all of them may be implemented by hardware. 
     When, for example, the communication unit  37  has received the privacy protection information display instruction for displaying the privacy protection information transmitted from the authentication control apparatus  20 , the display control unit  35   a  displays the screen G (see  FIG.  10   ) including the privacy protection information on the display surface of the display unit  32 . The screen G including the privacy protection information may be displayed in advance based on the information stored in the storage unit  34  of the display terminal  30  or may be displayed based on the information received from the authentication control apparatus  20  along with the privacy protection information display instruction. 
     The image acquisition unit  35   b  acquires, from the camera  31 , the captured image including the person to be authenticated who is in front of the security gate  50  and has been captured by the camera  31 . 
     The communication unit  37  is a communication apparatus that communicates with the authentication control apparatus  20  via the network NW. 
     Next, one example of an operation of the authentication system  1  having the aforementioned configuration will be described. 
       FIG.  12    is a sequence diagram of the authentication system  1 . 
     As shown in  FIG.  12   , first, the display terminal  30  (the image acquisition unit  35   b ) acquires a captured image including the person to be authenticated U who is in front of the security gate  50  from the camera  31 , the captured image being captured by the camera  31  (Step S 50 ). 
     Next, the display terminal  30  (the communication unit  37 ) transmits the captured image acquired in Step S 50  to the authentication control apparatus  20  (Step S 51 ). 
     Next, the authentication control apparatus  20  (the communication unit  24 ) receives the captured image transmitted in Step S 51  and the image acquisition unit  22   b  acquires the captured image received by the communication unit  24  (Step S 52 ). 
     Next, the authentication control apparatus  20  (the authentication control unit  22   c ) transmits a face authentication request for requesting face authentication of the person to be authenticated U included in the captured image acquired in Step S 52  to the authentication apparatus  10  via the communication unit  24  (Step S 53 ). This face authentication request includes the captured image acquired in Step S 52 . 
     Next, the authentication apparatus  10  executes, when the communication unit  14  has received the face authentication request transmitted in Step S 53 , face authentication processing (see  FIG.  6   ) (Step S 54 ). 
     Next, the authentication apparatus  10  (the authentication unit  12   e ) transmits the results of the authentication to the authentication control apparatus  20  that has transmitted the face authentication request via the communication unit  14  (Step S 55 ). It is assumed here that information indicating that the authentication has been successfully performed and the user ID of the person to be authenticated U whose face has been successfully authenticated to the authentication control apparatus  20  as the results of the authentication. 
     Next, the authentication control apparatus  20  (the communication unit  24 ) receives the result of the face authentication transmitted in Step S 55  and the user ID, and the face authentication result acquisition unit  22   d  acquires the result of the face authentication and the user ID that the communication unit  24  has received (Step S 56 ). 
     Next, when the face authentication has been successfully performed (when the result of the face authentication acquired in Step S 56  indicates that the authentication has been successfully performed), the authentication control apparatus  20  executes privacy protection information specifying processing (see  FIG.  9   ) in order to specify the privacy protection information on the person to be authenticated U whose face has been successfully authenticated (Step S 57 ). It is assumed here that the avatar image G 1  shown in  FIG.  10    has been specified as the privacy protection information. 
     Next, when the privacy protection information has been successfully specified in Step S 57 , the authentication control apparatus  20  (the display control unit  22   a ) transmits a privacy protection information display instruction for displaying the specified privacy protection information to the display terminal  30  via the communication unit  24  (Step S 58 ). This privacy protection information display instruction includes the privacy protection information specified in the above Step S 57 . 
     Next, when the communication unit  37  has received the privacy protection information display instruction transmitted in Step S 58 , the display terminal  30  (the display control unit  35   a ) displays the screen G including the privacy protection information included in the received privacy protection information display instruction on the display surface of the display unit  32  (Step S 59 ). The display terminal  30  displays the screen G as shown in, for example,  FIG.  10   . 
     When the face authentication has failed (when the result of the face authentication acquired in Step S 56  indicates that the authentication has failed), the processing of Steps S 57 -S 59  is not executed. In this case, information indicating that the authentication has failed is displayed, for example, on the display unit  32 . 
     As described above, according to the second example embodiment, when face authentication has been successfully performed, the privacy protection information on the person to be authenticated whose face has been successfully authenticated is displayed, whereby, even in a case in which a third party is present near the target person to be recognized, it is possible for the target person to be recognized to know that his/her face has been successfully authenticated without his/her personal information being known to the above third party. 
     Next, a modified example will be described. 
     While the example in which the security gate  50  is used has been described in the second example embodiment, this is merely one example. For example, the security gate  50  may be omitted. In this case, the camera  31  captures, for example, an image including the person to be authenticated who is walking. In this case, the authentication apparatus  10  acquires the captured image including the person to be authenticated who is walking, and executes face authentication processing (see  FIG.  6   ) (so-called walkthrough face authentication). 
     When the walkthrough face authentication is executed, the privacy protection information may be displayed on a desired part where the person to be authenticated is going to pass through. The privacy protection information may be displayed, for example, on the display terminal  30  (the display surface of the display unit  32 ) provided in a desired part where the person to be authenticated is going to pass through. In this case, the privacy protection information may be displayed at a timing when the person to be authenticated passes through an area near the display area (e.g., the display surface of the display unit  32 ) in which the privacy protection information is displayed. Note that the privacy protection information may be displayed by projecting the privacy protection information onto the floor surface which is in front of the person to be authenticated. 
     Further, while the example in which the avatar image is used as the privacy protection information has been described in the above second example embodiment, this is merely one example. The privacy protection information may be, for example, a clothing area of the person to be authenticated extracted from the captured image acquired in Step S 20 . 
     Further, the privacy protection information may be the color of the clothing of the person to be authenticated detected from the captured image acquired in Step S 20 . Note that this color may be used as the background color of the avatar image according to the second example embodiment. 
     Further, the privacy protection information may be property information of the person to be authenticated or the color in accordance with the property information. For example, the privacy protection information may be displayed in blue if the amount of money is equal to or larger than a predetermined amount and may be displayed in red if the amount of money is smaller than the predetermined amount. Note that the property information may be specified by providing, for example, a property information storage unit (not shown) that stores the person to be authenticated (user ID) and the property information in association with each other in the authentication control apparatus  20  and referring to this property information storage unit. The property information may be acquired, for example, by a method (see  FIG.  8   ) similar to the method of acquiring the privacy protection information and may be registered in the property information storage unit. The property information is, for example, the one input by the person to be authenticated in the registration terminal  40 . This property information may be, for example, a charged balance in an IC card of the person to be authenticated (user) or a monthly usage amount of this IC card. Further, the property information may be the amount of money in a wallet that the person to be authenticated has or the account balance of a financial institution such as a bank. Further, the color in accordance with the property information may be specified, for example, by providing a color storage unit (not shown) that corresponds to the property information and stores the range of the money amount and the color in association with each other in the authentication control apparatus  20  and referring to this color storage unit. Note that this color may be used as the background color of the avatar image according to the second example embodiment. According to this modified example, when the face authentication has been successfully performed, the property information of the person to be authenticated or the color in accordance with the property information is displayed on the display terminal  30  (the display surface of the display unit  32 ) as the privacy protection information on the person to be authenticated whose face has been successfully authenticated, whereby, even in a case in which a third party is present near the target person to be recognized, it is possible for the target person to be recognized to know that his/her face has been successfully authenticated without his/her personal information being known to this third party. 
     Further, the privacy protection information may be schedule information of the person to be authenticated or the color in accordance with the schedule information. Note that the schedule information can be specified by, for example, providing a schedule information storage unit (not shown) that stores the person to be authenticated (user ID) and the schedule information in association with each other in the authentication control apparatus  20  and referring to this schedule information storage unit. The schedule information can be acquired, for example, by a method (see  FIG.  8   ) similar to the method of acquiring the privacy protection information and can be registered in the above schedule information storage unit. The schedule information is the one that has been input, for example, by the person to be authenticated in the registration terminal  40 . This schedule information may be, for example, a list of the schedule of the person to be authenticated (user) on that day or an upcoming schedule. Further, the color in accordance with the schedule information may be specified by providing, for example, a color storage unit (not shown) that corresponds to the schedule information and stores a schedule item and the color in association with each other in the authentication control apparatus  20  and referring to this color storage unit. Note that this color may be used as the background color of the avatar image according to the second example embodiment. According to this modified example, when face authentication has been successfully performed, the above schedule information of the person to be authenticated or the color in accordance with the schedule information is displayed on the display terminal  30  (the display surface of the display unit  32 ) as the privacy protection information on the person to be authenticated whose face has been successfully authenticated, whereby, even in a case in which a third party is present near the target person to be recognized, it is possible for the target person to be recognized to know that his/her face has been successfully authenticated without his/her personal information being known to the above third party. 
     Further, while the examples of the face authentication have been described in the above second example embodiment, the present invention is not limited to being applied to face authentication and may also be applied to other types of biometrics authentication such as iris authentication or fingerprint authentication. 
     In the first and second example embodiments, the program(s) can be stored and provided to a computer using any type of non-transitory computer readable media. Non-transitory computer readable media include any type of tangible storage media. Examples of non-transitory computer readable media include magnetic storage media (e.g., flexible disks, magnetic tapes, hard disk drives), optical magnetic storage media (e.g., magneto-optical disks), CD-Read Only Memory (ROM), CD-R, CD-R/W, semiconductor memories (e.g., a mask ROM, a Programmable ROM (PROM), an Erasable PROM (EPROM), a flash ROM, or a Random Access Memory (RAM)). Further, the program(s) may be provided to a computer using any type of transitory computer readable media. Examples of transitory computer readable media include electric signals, optical signals, and electromagnetic waves. Transitory computer readable media can provide the program to a computer via a wired communication line (e.g., electric wires, and optical fibers) or a wireless communication line. 
     All the numerical values shown in the above example embodiments are merely examples and it is needless to say that numerical values other than those described above may be used as appropriate. 
     The above example embodiments are merely examples in every aspect. The present invention should not be interpreted in a limited way by the descriptions in the above example embodiments. The present invention may be executed in various other forms without departing from its spirit and main features. 
     The whole or part of the example embodiment disclosed above can be described as, but not limited to, the following supplementary notes. 
     Supplementary Note  1   
     An authentication control apparatus comprising:
     image acquisition means for acquiring an image including a person to be authenticated captured by a camera that photographs the person to be authenticated;   authentication control means for causing an authentication apparatus that executes face authentication to execute face authentication of the person to be authenticated included in the image acquired by the image acquisition means; and   display control means for causing, when the face authentication has been successfully performed, a display apparatus to display privacy protection information of the person to be authenticated whose face has been successfully authenticated for the purpose of letting the person to be authenticated whose face has been successfully authenticated visually recognize that the face authentication has been successful.   

     Supplementary Note 2 
     The authentication control apparatus according to Supplementary Note  1 , further comprising:
     storing means for storing a person to be authenticated and privacy protection information in association with each other; and   specifying means for specifying privacy protection information associated with the person to be authenticated whose face has been successfully authenticated in the storing means,   wherein the display control means causes, when the face authentication has been successfully performed, the display apparatus to display privacy protection information specified by the specifying means for the purpose of enabling the person to be authenticated whose face has been successfully authenticated to visually recognize that the face authentication has been successful.   

     Supplementary Note 3 
     The authentication control apparatus according to Supplementary Note 2, further comprising:
     acquisition means for acquiring privacy protection information to be registered specified by the person to be authenticated; and   registration means for registering the privacy protection information to be registered acquired by the acquisition means in the storing means in association with the person to be authenticated who has specified the privacy protection information to be registered.   

     Supplementary Note 4 
     The authentication control apparatus according to any one of Supplementary Notes  1  to 3, wherein the privacy protection information is information notifying the person to be authenticated whose face has been successfully authenticated of information indicating that his/her face has been successfully authenticated, the information not including his/her personal information. 
     Supplementary Note 5 
     The authentication control apparatus according to any one of Supplementary Notes  1  to 4, further comprising clothing extraction means for extracting a clothing area of the person to be authenticated from the image acquired by the image acquisition means, 
     wherein the authentication control means causes the clothing area that has been extracted by the clothing extraction means to be displayed as the privacy protection information. 
     Supplementary Note 6 
     The authentication control apparatus according to any one of Supplementary Notes  1  to 5, further comprising clothing color detection means for detecting the color of the clothing of the person to be authenticated from the image acquired by the image acquisition means, 
     wherein the authentication control means causes the color of the clothing detected by the clothing color detection means to be displayed as the privacy protection information. 
     Supplementary Note 7 
     The authentication control apparatus according to any one of Supplementary Notes  1  to 5, further comprising:
     property information storing means for storing a person to be authenticated in association with property information; and   property information specifying means for specifying property information associated with the person to be authenticated whose face has been successfully authenticated in the property information storing means,   wherein the authentication control means causes the display apparatus to display the color in accordance with the property information specified by the property information specifying means as the privacy protection information.   

     Supplementary Note 8 
     The authentication control apparatus according to any one of Supplementary Notes  1  to 5, further comprising:
     schedule information storing means for storing a person to be authenticated in association with schedule information; and   schedule information specifying means for specifying schedule information associated with the person to be authenticated whose face has been successfully authenticated in the schedule information storing means,   wherein the authentication control means causes the display apparatus to display the color in association with the schedule information specified by the schedule information specifying means as the privacy protection information.   

     Supplementary Note 9 
     The authentication control apparatus according to any one of Supplementary Notes  1  to 8, wherein the image acquisition means acquires an image including the person to be authenticated who has been captured by the camera and is in front of a security gate. 
     Supplementary Note  10   
     The authentication control apparatus according to any one of Supplementary Notes  1  to 9, wherein the display apparatus is provided in or near the security gate. 
     Supplementary Note  11   
     The authentication control apparatus according to any one of Supplementary Notes  1  to 8, wherein the image acquisition means acquires an image including a person to be authenticated who is walking captured by the camera. 
     Supplementary Note  12   
     The authentication control apparatus according to Supplementary Note  11 , wherein the authentication control means causes the display apparatus to display the privacy protection information at a timing when the person to be authenticated passes through an area near a display area where the privacy protection information is displayed. 
     Supplementary Note  13   
     An authentication system comprising:
     a camera that photographs a person to be authenticated;   a display apparatus;   image acquisition means for acquiring an image that includes a person to be authenticated who has been captured by the camera;   authentication control means for causing an authentication apparatus that executes face authentication to execute face authentication of the person to be authenticated included in the image acquired by the image acquisition means; and   display control means for causing, when the face authentication has been successfully performed, the display apparatus to display privacy protection information of the person to be authenticated whose face has been successfully authenticated for the purpose of letting the person to be authenticated whose face has been successfully authenticated visually recognize that the face authentication has been successful.   

     Supplementary Note  14   
     The authentication system according to Supplementary Note  13 , comprising an information processing apparatus, an authentication control apparatus, and an authentication apparatus capable of communicating with one another via a network, wherein
     the camera and the display apparatus are provided in the information processing apparatus, and   the image acquisition means, the authentication control means, and the display control means are provided in the authentication control apparatus.   

     Supplementary Note 15 
     An authentication control method comprising:
     an image acquisition step of acquiring an image including a person to be authenticated captured by a camera that photographs the person to be authenticated;   an authentication control step of causing an authentication apparatus that executes face authentication to execute face authentication of the person to be authenticated included in the image acquired in the image acquisition step; and   a display control step of causing, when the face authentication has been successfully performed, a display apparatus to display privacy protection information of the person to be authenticated whose face has been successfully authenticated for the purpose of letting the person to be authenticated whose face has been successfully authenticated visually recognize that the face authentication has been successful.   

     Supplementary Note 16 
     A computer readable storage medium storing a program for causing an electronic device including at least one processor to execute:
     an image acquisition step of acquiring an image including a person to be authenticated captured by a camera that photographs the person to be authenticated;   an authentication control step of causing an authentication apparatus that executes face authentication to execute face authentication of the person to be authenticated included in the image acquired in the image acquisition step; and   a display control step of causing, when the face authentication has been successfully performed, a display apparatus to display privacy protection information of the person to be authenticated whose face has been successfully authenticated for the purpose of letting the person to be authenticated whose face has been successfully authenticated visually recognize that the face authentication has been successful.   

     
       
         
           
               
               
             
               
                 Reference Signs List 
               
             
            
               
                 
                   1 
                 
                 Authentication System 
               
               
                 
                   10 
                 
                 Authentication Apparatus 
               
               
                 
                   11 
                 
                 Storage Unit 
               
               
                 
                   11 
                   a 
                 
                 Program 
               
               
                 
                   12 
                 
                 Control Unit 
               
               
                 
                   12 
                   a 
                 
                 Image Acquisition Unit 
               
               
                 
                   12 
                   b 
                 
                 Face Detection Unit 
               
               
                 
                   12 
                   c 
                 
                 Feature Point Extraction Unit 
               
               
                 
                   12 
                   d 
                 
                 Registration Unit 
               
               
                 
                   12 
                   e 
                 
                 Authentication Unit 
               
               
                 
                   13 
                 
                 Memory 
               
               
                 
                   14 
                 
                 Communication Unit 
               
               
                 
                   20 
                 
                 Authentication Control Apparatus 
               
               
                 
                   21 
                 
                 Storage Unit 
               
               
                 
                   21 
                   a 
                 
                 Program 
               
               
                 
                   22 
                 
                 Control Unit 
               
               
                 
                   22 
                   a 
                 
                 Display Control Unit (Display Control Means) 
               
               
                 
                   22 
                   b 
                 
                 Image Acquisition Unit (Image Acquisition Means) 
               
               
                 
                   22 
                   c 
                 
                 Authentication Control Unit (Authentication Control Means) 
               
               
                 
                   22 
                   d 
                 
                 Face Authentication Result Acquisition Unit 
               
               
                 
                   22 
                   e 
                 
                 Privacy Protection Information Acquisition Unit 
               
               
                 
                   22 
                   f 
                 
                 Registration Unit 
               
               
                 
                   22 
                   g 
                 
                 Specifying Unit 
               
               
                 
                   23 
                 
                 Memory 
               
               
                 
                   24 
                 
                 Communication Unit 
               
               
                 
                   30 
                 
                 Display Terminal (Display Apparatus) 
               
               
                 
                   31 
                 
                 Camera 
               
               
                 
                   32 
                 
                 Display Unit 
               
               
                 
                   34 
                 
                 Storage Unit 
               
               
                 
                   34 
                   a 
                 
                 Program 
               
               
                 
                   35 
                 
                 Control Unit 
               
               
                 
                   35 
                   a 
                 
                 Display Control Unit 
               
               
                 
                   35 
                   b 
                 
                 Image Acquisition Unit 
               
               
                 
                   36 
                 
                 Memory 
               
               
                 
                   37 
                 
                 Communication Unit 
               
               
                 
                   40 
                 
                 Registration Terminal 
               
               
                 
                   50 
                 
                 Security Gate 
               
               
                 
                   11 
                   b 
                 
                 Face Information DB 
               
               
                 
                   21 
                   b 
                 
                 Privacy Protection Information DB 
               
               
                 G 
                 Screen 
               
               
                 G 1 
 
                 Privacy Protection Information (Avatar Image) 
               
               
                 G 2 
 
                 Time Information 
               
               
                 G 3 
 
                 Purpose Information 
               
               
                 NW 
                 Network 
               
               
                 U 
                 Person to be Authenticated