Information processing system, program, and information processing method

Abstract

To provide an information processing system, a program, and an information processing method capable of improving security.SOLUTION: When a user is registered, encryption means 202 encrypts information about a user's facial image transmitted from a user terminal 5 into a homomorphic cypher, and storage means 204 stores the homomorphic cypher of the information about the user's facial image in a storage unit 22. When the user is authenticated, the encryption means 202 encrypts the information about the user's facial image and usage history information transmitted from an authentication engine 3 into a homomorphic cypher, and authentication means 203 authenticates the user by comparing the homomorphic cypher of the encrypted information about the user's facial image with the homomorphic cypher of the information about the user's facial image already stored in the storage unit 22.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an information processing system, a program, and an information processing method.

Background Art

[0002] Conventionally, as a face authentication system that performs authentication based on face data, there is known a face authentication system that performs personal authentication by comparing input face data with registered face data registered in advance. For example, in the face authentication system described in Patent Document 1, a target person is authenticated using an image of a face portion in a captured image captured by a camera.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a conventional face authentication system, there is a risk of information leakage regarding a user's face image or the like, and even when the user's face image is encrypted, there is a risk of information leakage due to decryption.

[0005] The present invention has been made in consideration of such points, and an object thereof is to provide an information processing system, a program, and an information processing method capable of improving security.

Means for Solving the Problems

[0006] The information processing system of the present invention comprises an encryption means, an authentication means, a storage means, a recommendation means, and a transmission means, During user registration, the encryption means encrypts the user's facial image information transmitted from the user terminal into a homomorphic encryption, and the storage means stores the homomorphic encryption of the user's facial image information in the storage unit. During user authentication, the encryption means encrypts information regarding the user's face image and usage history information transmitted from an authentication engine having an imaging unit that captures the user's face image, respectively, to obtain homomorphic encryption. The authentication means authenticates the user by comparing the homomorphic encryption of the user's face image information transmitted from the authentication engine and encrypted with the homomorphic encryption of the user's face image information already stored in the storage unit. The storage means stores the homomorphic encryption of the authenticated user's usage history information in the storage unit. The recommendation means calculates recommendation information based on the homomorphic encryption of the authenticated user's usage history information and the homomorphic encryption of other usage history information for this user already stored in the storage unit. The transmission means transmits the calculated recommendation information to the authenticated user's terminal.

[0007] In the information processing system of the present invention, When a user registers, user identification information is issued, and the storage means stores a homomorphic encrypted version of the user's facial image information in the storage unit, linked to the user's identification information. The authentication means authenticates the user by comparing the homomorphic encryption of the encrypted user's facial image information with the homomorphic encryption of the user's facial image information already stored in the storage unit, and obtains the user's identification information associated with the homomorphic encryption of the authenticated user's facial image information. The recommendation means calculates recommendation information based on homomorphic encryption of user authentication history information and homomorphic encryption of other user history information corresponding to the user's identification information already stored in the storage unit. The transmission means may be configured to transmit the calculated recommendation information to a user terminal corresponding to the authenticated user's identification information.

[0008] Furthermore, the authentication means may, when comparing the homomorphic encryption of the user's facial image information transmitted and encrypted from the authentication engine with the homomorphic encryption of the user's facial image information already stored in the storage unit, calculate a Euclidean distance for each user identification information, and identify the user identification information whose Euclidean distance is smallest and is less than a predetermined threshold as the user identification information corresponding to the user's facial image information received from the authentication engine.

[0009] Furthermore, during user registration, the encryption means also encrypts the user registration information transmitted from the user terminal to obtain homomorphic encryption, and the storage means stores the homomorphic encrypted user registration information in the storage unit. The recommendation means may also calculate recommendation information by referring to homomorphic encryption of the user's registration information stored in the memory unit.

[0010] The information processing system of the present invention is It comprises encryption means, authentication means, storage means, recommendation means, and transmission means, During user registration, the encryption means encrypts the user's facial image information transmitted from the user terminal into a homomorphic encryption, and the storage means stores the homomorphic encryption of the user's facial image information in the storage unit. When authenticating a user, upon receiving information about the user's face image and usage history information transmitted from an authentication engine having an imaging unit that captures the user's face image, the encryption means encrypts the information about the user's face image transmitted from the authentication engine to obtain homomorphic encryption. The authentication means authenticates the user by comparing the homomorphic encryption of the information about the user's face image transmitted from the authentication engine and encrypted with the homomorphic encryption of the information about the user's face image already stored in the storage unit. The storage unit stores the usage history information for which the user has been authenticated in the storage unit. The recommendation means calculates recommendation information based on the usage history information for which the user has been authenticated and other usage history information for this user already stored in the storage unit. The transmission means transmits the calculated recommendation information to the user terminal of the authenticated user.

[0011] In the information processing system of the present invention, When a user registers, user identification information is issued, and the storage means stores a homomorphic encrypted version of the user's facial image information in the storage unit, linked to the user's identification information. The authentication means authenticates the user by comparing the homomorphic encryption of the encrypted user's facial image information with the homomorphic encryption of the user's facial image information stored in the storage unit, and obtains the user's identification information associated with the homomorphic encryption of the user's facial image information of the authenticated user. The recommendation means calculates recommendation information based on the user's authenticated usage history information and other usage history information corresponding to the user's identification information already stored in the storage unit. The transmission means may be configured to transmit the calculated recommendation information to a user terminal corresponding to the authenticated user's identification information.

[0012] Furthermore, the authentication means may, when comparing the homomorphic encryption of the user's facial image information transmitted and encrypted from the authentication engine with the homomorphic encryption of the user's facial image information already stored in the storage unit, calculate a Euclidean distance for each user identification information, and identify the user identification information whose Euclidean distance is smallest and is less than a predetermined threshold as the user identification information corresponding to the user's facial image information received from the authentication engine.

[0013] Furthermore, during user registration, the encryption means also encrypts the user registration information transmitted from the user terminal to obtain homomorphic encryption, and the storage means stores the homomorphic encrypted user registration information in the storage unit. The recommendation means may also calculate recommendation information by referring to homomorphic encryption of the user's registration information stored in the memory unit.

[0014] The program of the present invention, A program that causes a computer to function as an encryption means, an authentication means, a storage means, a recommendation means, and a transmission means, During user registration, the encryption means encrypts the user's facial image information transmitted from the user terminal into a homomorphic encryption, and the storage means stores the homomorphic encryption of the user's facial image information in the storage unit. During user authentication, the encryption means encrypts information regarding the user's face image and usage history information transmitted from an authentication engine having an imaging unit that captures the user's face image, respectively, to obtain homomorphic encryption. The authentication means authenticates the user by comparing the homomorphic encryption of the user's face image information transmitted from the authentication engine and encrypted with the homomorphic encryption of the user's face image information already stored in the storage unit. The storage means stores the homomorphic encryption of the authenticated user's usage history information in the storage unit. The recommendation means calculates recommendation information based on the homomorphic encryption of the authenticated user's usage history information and the homomorphic encryption of other usage history information for this user already stored in the storage unit. The transmission means transmits the calculated recommendation information to the authenticated user's terminal.

[0015] The program of the present invention, A program that causes a computer to function as an encryption means, an authentication means, a storage means, a recommendation means, and a transmission means, During user registration, the encryption means encrypts the user's facial image information transmitted from the user terminal into a homomorphic encryption, and the storage means stores the homomorphic encryption of the user's facial image information in the storage unit. When receiving information regarding the user's face image and usage history information sent from an authentication engine having an imaging unit that captures an image of the user's face during user authentication, the encryption means encrypts the information regarding the user's face image sent from the authentication engine into a homomorphic encryption, the authentication means authenticates the user by comparing the homomorphic encryption of the information regarding the encrypted user's face image sent from the authentication engine with the homomorphic encryption of the information regarding the user's face image already stored in the storage unit, the storage means stores the usage history information for which user authentication has been performed in the storage unit, the recommendation means calculates recommendation information based on the usage history information for which user authentication has been performed and other usage history information of this user already stored in the storage unit, and the transmission means transmits the calculated recommendation information to the user terminal of the authenticated user.

[0016] The information processing method of the present invention is an information processing method executed by a computer, At the time of user registration, the encryption means encrypts the information regarding the user's face image transmitted from the user terminal into a homomorphic encryption, and the storage means stores the homomorphic encryption of the information regarding the user's face image in the storage unit. At the time of user authentication, the encryption means encrypts the information regarding the user's face image and the usage history information transmitted from an authentication engine having an imaging unit that captures an image of the user's face into homomorphic encryptions respectively, the authentication means authenticates the user by comparing the homomorphic encryption of the information regarding the encrypted user's face image transmitted from the authentication engine with the homomorphic encryption of the information regarding the user's face image already stored in the storage unit, the storage means stores the homomorphic encryption of the usage history information for which user authentication has been performed in the storage unit, the recommendation means calculates recommendation information based on the homomorphic encryption of the usage history information for which user authentication has been performed and the homomorphic encryption of other usage history information of this user already stored in the storage unit, and the transmission means transmits the calculated recommendation information to the user terminal of the authenticated user.

[0017] The information processing method of the present invention is an information processing method executed by a computer, when a user registers, the encryption means encrypts the information on the user's face image transmitted from the user terminal into a homomorphic encryption, and the storage means stores the homomorphic encryption of the information on the user's face image in the storage unit. when authenticating a user, when receiving the information on the user's face image and usage history information transmitted from an authentication engine having an imaging unit for imaging the user's face image, the encryption means encrypts the information on the user's face image transmitted from the authentication engine into a homomorphic encryption, and the authentication means authenticates the user by comparing the homomorphic encryption of the information on the encrypted user's face image transmitted from the authentication engine with the homomorphic encryption of the information on the user's face image already stored in the storage unit. The storage means stores the usage history information for which the user has been authenticated in the storage unit, the recommendation means calculates recommendation information based on the usage history information for which the user has been authenticated and other usage history information of this user already stored in the storage unit, and the transmission means transmits the calculated recommendation information to the user terminal of the authenticated user.

Effect of the Invention

[0018] According to the information processing system, program, and information processing method of the present invention, security can be improved.

Brief Description of the Drawings

[0019] [Figure 1] It is a diagram schematically showing an information processing system according to an embodiment of the present invention. [Figure 2] It is a flowchart showing the operation when a user is registered by the information processing system shown in FIG. 1. [Figure 3] It is a flowchart showing the operation when a user is authenticated by the information processing system shown in FIG. 1. [Figure 4] It is a diagram schematically showing an information processing system according to a modification example. [Modes for carrying out the invention]

[0020] Embodiments of the present invention will be described below with reference to the drawings. Figures 1 to 3 are diagrams showing an information processing system according to this embodiment.

[0021] The information processing system 1 according to this embodiment comprises a facial recognition platform 2 and a plurality of authentication engines 3 (authentication engines A to C). The facial recognition platform 2 and each authentication engine 3 are connected to each other so as to be able to communicate via a network such as an internet connection. Furthermore, the facial recognition platform 2 is connected to a user terminal 5 held by the user so as to be able to communicate via a network such as an internet connection. Each component of this information processing system 1 will be described below.

[0022] Each authentication engine 3 is installed in various service institutions and has an imaging unit 31, such as a camera, that captures a user's facial image. The user's facial image information captured by the imaging unit 31 is transmitted from the authentication engine 3 to the facial recognition platform 2. When the facial recognition platform 2 authenticates the user, various processes are performed on the authenticated user at the service institution where the authentication engine 3 is installed. For example, if the authentication engine 3 is installed at the entrances of office buildings or apartment complexes, when the facial recognition platform 2 authenticates the user, the doors at the entrances of these office buildings or apartment complexes are unlocked. Also, if the authentication engine 3 is installed in taxis, restaurants, hotels, transportation, convenience stores, etc., when the user authenticates the user when making a payment at these service institutions, cashless payment is enabled when the facial recognition platform 2 authenticates the user. In this case, payment information is transmitted from the facial recognition platform 2 to the servers of financial institutions or credit card companies, so the payment amount is automatically debited from the user's bank account or added to the credit card statement. Alternatively, instead of payment being made by the facial recognition platform 2, cashless payment may be made by a service provider equipped with the authentication engine 3. Specifically, when the facial recognition platform 2 authenticates the user, information that the user has been authenticated is sent from the facial recognition platform 2 to the service provider equipped with the authentication engine 3, and as a result, cashless payment is made at the service provider. For example, if the authentication engine 3 is installed inside a taxi and the user's facial image is registered in the facial recognition platform 2, then when the user's facial image is captured by the imaging unit 31 of the authentication engine 3 and the facial recognition platform 2 authenticates the user, payment becomes possible using a credit card or the like registered in the taxi app.

[0023] The facial recognition platform 2 is a computer installed at the system company. Specifically, the facial recognition platform 2 has a control unit 20, a storage unit 22, and a communication interface 24. The storage unit 22 and the communication interface 24 are connected to the control unit 20 by buses. The control unit 20 is a CPU (Central Processing Unit), etc., and functions as a receiving means 201, encryption means 202, authentication means 203, storage means 204, recommendation means 205, and transmission means 206 by executing programs stored in the storage unit 22. The storage unit 22 stores homomorphic encrypted user registration information, homomorphic encrypted user facial image information, and homomorphic encrypted user usage history information, linked to the user's identification information. User registration information includes the user's name, date of birth, username, email address, telephone number of user terminal 5, credit card information, password, etc. Information regarding the user's facial image is the user's facial image data or a hash value extracted from the user's facial image data using a predetermined hash function. The user's usage history information includes the identification information of the authentication engine 3, the location information of the authentication engine 3, the date and time when the user's face image was captured by the imaging unit 31 of the authentication engine 3, and information about the service organization where the authentication engine 3 is installed (e.g., store code, type of service, etc.). The communication interface 24 transmits and receives signals to and from other devices wirelessly or via a wired connection over a network such as an internet line.

[0024] Furthermore, the memory unit 22 stores identification information of the authentication engine 3, information about the service organization where the authentication engine 3 is installed (e.g., store code, business hours, service type, etc.), and location information of the authentication engine 3, all linked together. The memory unit 22 also stores programs executed by the control unit 20. In addition to information about stores where the authentication engine 3 is installed, the memory unit 22 may also store information about stores where the authentication engine 3 is not installed.

[0025] Furthermore, the programs executed by the control unit 20 are not limited to those stored in the storage unit 22. The control unit 20 may also function as a receiving means 201, encryption means 202, authentication means 203, storage means 204, recommendation means 205, and transmission means 206 by executing programs stored on a recording medium attached to the facial recognition platform 2, or programs transmitted to the facial recognition platform 2 from an external device.

[0026] The reception means 201 receives information from various external devices such as each authentication engine 3 and user terminals 5. Specifically, when a user registers, the reception means 201 receives information about the user's face image and user registration information from the user terminal 5. Also, when a user is authenticated, the reception means 201 receives information about the user's face image captured by the imaging unit 31 and user usage history information from the authentication engine 3.

[0027] The encryption means 202 encrypts the user's facial image information and user registration information transmitted from the user terminal 5 during user registration, and converts them into homomorphic encryption. Furthermore, the encryption means 202 encrypts the user's facial image information and usage history information transmitted from each authentication engine 3 during user authentication, and converts them into homomorphic encryption. Here, homomorphic encryption refers to encryption that allows operations on encrypted data without decryption; given two ciphertexts, binary operations such as addition and multiplication can be performed without plaintext or a secret key.

[0028] The authentication means 203 authenticates the user by comparing the homomorphic encryption of the encrypted user's face image with the homomorphic encryption of the user's face image stored in the storage unit 22. As mentioned above, homomorphic encryption is an encryption method that can perform binary operations such as addition and multiplication when given two ciphertexts, even without plaintext or a secret key. Therefore, the authentication means 203 can authenticate the user by comparing the homomorphic encryption of the encrypted user's face image with the homomorphic encryption of the user's face image stored in the storage unit 22 without decrypting the homomorphic encryption of the user's face image.

[0029] The storage means 204 stores homomorphic encrypted versions of the user's face image and user registration information, encrypted by the encryption means 202, in the storage unit 22 when a user is registered. The storage means 204 also stores homomorphic encrypted versions of the user's authentication history information in the storage unit 22.

[0030] The recommendation means 205 calculates recommendation information based on the homomorphic encryption of the user's authenticated usage history information and the homomorphic encryption of this user's usage history information stored in the storage unit 22. The recommendation information includes information useful to the user, such as service campaign information (e.g., discount coupons and free coupon information), service availability date and time information, and special service provision information. As mentioned above, homomorphic encryption is an encryption that can perform binary operations such as addition and multiplication when given two ciphertexts, even without plaintext or a secret key. Therefore, the recommendation means 205 can calculate recommendation information based on the encrypted homomorphic encryption of the user's usage history information and the homomorphic encryption of the user's usage history information stored in the storage unit 22 without decrypting the homomorphic encryption of the user's usage history information. The recommendation means 205 may also calculate recommendation information by referring to the homomorphic encryption of the user's registration information stored in the storage unit 22.

[0031] The transmission means 206 transmits the recommendation information calculated by the recommendation means 205 to the user terminal 5 of the user authenticated by the authentication means 203.

[0032] In this embodiment, when a user registers, the control unit 20 receives the user's face image and registration information from the user terminal 5 and issues the user's identification information. The storage means 204 then stores homomorphic encryption of the user's face image and user registration information in the storage unit 22, linking them to the user's identification information. The authentication means 203 authenticates the user by comparing the homomorphic encryption of the encrypted user's face image with the homomorphic encryption of the user's face image stored in the storage unit 22, and obtains the user's identification information linked to the homomorphic encryption of the authenticated user's face image. The recommendation means 205 calculates recommendation information based on the homomorphic encryption of the authenticated user's usage history information and the homomorphic encryption of the usage history information corresponding to this user's identification information stored in the storage unit 22. The transmission means 206 transmits the calculated recommendation information to the user terminal 5 corresponding to the authenticated user's identification information.

[0033] The user terminal 5 is owned by the user. The user terminal 5 includes, for example, a personal computer, a PC tablet, a smartphone, etc. The user terminal 5 transmits and receives signals to and from other devices (specifically, for example, the facial recognition platform 2) wirelessly or via a wired connection over a network such as the internet. The user terminal 5 can also install a facial recognition application from an online store or the website of the management company of the facial recognition platform 2. Once such a facial recognition application is installed, the user can use the user terminal 5 to register facial image data and input various registration information (for example, name, gender, age, date of birth, username, email address, phone number of the user terminal 5, credit card information, password, etc.). The user terminal 5 also has an imaging unit 51 for capturing the user's face and obtaining a facial image.

[0034] Next, the processing flow of the information processing system 1 of this embodiment will be described. Figure 2 is a flowchart showing the operation when a user is registered by the information processing system 1 shown in Figure 1, and Figure 3 is a flowchart showing the operation when a user is authenticated by the information processing system 1 shown in Figure 1.

[0035] First, we will describe the operation when a user is registered using the information processing system 1 of this embodiment.

[0036] First, a user who wishes to use the information processing system 1 of this embodiment registers a facial image using the user terminal 5. Specifically, the user first installs a facial recognition application on the user terminal 5. When the user launches the facial recognition application on the user terminal 5, a user registration screen is displayed on the touch panel. On this user registration screen, the user enters registration information such as name (Kanji), name (Katakana), gender, age, date of birth, username, phone number of the user terminal 5, email address of the user terminal 5, and password, checks the box to agree to the terms of service, and then presses the registration button. At this point, a facial image capture screen is displayed on the touch panel. When the user captures a facial image using the camera on the user terminal 5 on this capture screen, the various registration information entered on the user registration screen and the user's facial image information are transmitted from the user terminal 5 to the facial recognition platform 2 (step St101). As a result, the receiving means 201 of the facial recognition platform 2 receives the user's registration information and facial image information from the user terminal 5. In addition, the identification information of the user terminal 5 (for example, the serial number of the user terminal 5) is also transmitted from the user terminal 5 to the facial recognition platform 2, which is received by the receiving means 201 of the facial recognition platform 2. When the receiving means 201 receives the user's registration information and facial image information from the user terminal 5, the control unit 20 of the facial recognition platform 2 issues the user's identification information.

[0037] The encryption means 202 encrypts the user's face image information and the user's registration information received by the receiving means 201 to create homomorphic encryption (step St102). Here, the encryption means 202 may encrypt the user's face image itself received by the receiving means 201 to create homomorphic encryption. Alternatively, the control unit 20 may extract a hash value from the user's face image received by the receiving means 201 using a predetermined hash function, and this hash value may be encrypted by the encryption means 202 to create homomorphic encryption. In this embodiment, the user's face image information and the user's registration information received by the receiving means 201 are first converted into 512-dimensional vector data, and the encryption means 202 converts the 512-dimensional vector data of the user's face image information and the user's registration information into homomorphic encryption. Then, the storage means 204 stores the homomorphic encryption of the user's face image information and the user's registration information encrypted by the encryption means 202 in the storage unit 22, linked to the user's identification information (step St103). In this way, user registration is completed.

[0038] Next, the operation when user authentication is performed by the information processing system 1 of this embodiment will be described.

[0039] For example, when a user unlocks a door located at the entrance of an office building or apartment complex at a service provider, or when cashless payment is enabled, the user has their face captured by the imaging unit 31 of an authentication engine 3 (e.g., authentication engine A) installed at the service provider. Information regarding the user's face image captured by the imaging unit 31 of the authentication engine 3 (authentication engine A) and usage history information (specifically, the identification information of authentication engine A, the location information of authentication engine A, the date and time the user's face image was captured by the imaging unit 31 of authentication engine A, information about the service provider where authentication engine A is installed, etc.) is transmitted from the authentication engine 3 to the face recognition platform 2 (step St201). At this time, the user's face image captured by the imaging unit 31 itself may be transmitted from the authentication engine 3 to the face recognition platform 2, or a hash value may be extracted from the user's face image captured by the imaging unit 31 in the authentication engine 3 using a predetermined hash function, and this extracted hash value may be transmitted from the authentication engine 3 to the face recognition platform 2. As a result, the reception means 201 of the facial recognition platform 2 receives information about the user's facial image and usage history information from the authentication engine 3 (authentication engine A).

[0040] The encryption means 202 encrypts the user's facial image information and the user's usage history information received by the receiving means 201 to create homomorphic encryption (step St202). Here, the encryption means 202 may encrypt the user's facial image itself received by the receiving means 201 to create homomorphic encryption. Alternatively, the control unit 20 may extract a hash value from the user's facial image received by the receiving means 201 using a predetermined hash function, and this hash value may be encrypted by the encryption means 202 to create homomorphic encryption. Furthermore, if a hash value related to the user's facial image is transmitted from the authentication engine 3 to the facial authentication platform 2, this hash value may be encrypted by the encryption means 202 to create homomorphic encryption. Also, as described above, the user's facial image information and user registration information received by the receiving means 201 are first converted into 512-dimensional vector data, and the encryption means 202 converts the 512-dimensional vector data of the user's facial image information and user registration information into homomorphic encryption.

[0041] The authentication means 203 then authenticates the user by comparing the homomorphic encryption of the user's face image encrypted by the encryption means 202 with the homomorphic encryption of the user's face image stored in the storage unit 22, and obtains the user's identification information associated with the homomorphic encryption of the authenticated user's face image. Specifically, the authentication means 203 calculates the Euclidean distance between the homomorphic encryption of the user's face image transmitted from the authentication engine 3 and encrypted by the encryption means 202 and the homomorphic encryption of each user's face image stored in the storage unit 22, for each user stored in the storage unit 22. Here, the Euclidean distance is the square root of the sum of the squares of the differences between two points in a 512-dimensional Euclidean space. The homomorphic encryption of the user's face image transmitted from the authentication engine 3 and encrypted by the encryption means 202 is (a1, a2, a3, ..., a 512 ), the homomorphic encryption of each user's face image stored in the memory unit 22 is performed (b1, b2, b3, ..., b 512 When given this condition, the Euclidean distance L is expressed by the following formula.

[0042]

number

[0043] The authentication means 203 then determines that the user identification information corresponding to the homomorphic encryption with the smallest calculated Euclidean distance and smaller than a predetermined threshold is the user identification information captured by the imaging unit 31 of the authentication engine 3. Once user authentication is performed in this manner, the facial recognition platform 2 sends the acquired user identification information back to the service organization where the authentication engine 3 (authentication engine A) is installed. This allows the service organization where the authentication engine 3 (authentication engine A) is installed to perform various processes on the authenticated user. Specifically, it can unlock doors located at entrances to office buildings and apartment complexes, or enable cashless payments. Furthermore, once user authentication is performed, the storage means 204 stores the homomorphic encryption of the user's usage history information (specifically, the identification information of the authentication engine A, the location information of the authentication engine A, the date and time information of when the user's face image was captured by the imaging unit 31 of the authentication engine A, information of the service organization where the authentication engine A is installed, etc.) encrypted by the encryption means 202 in the storage unit 22 (step St203).

[0044] Furthermore, if the Euclidean distance between the homomorphic encryption of the user's face image transmitted from the authentication engine 3 and encrypted by the encryption means 202, and the homomorphic encryption of each user's face image stored in the storage unit 22 is greater than a predetermined threshold for all users stored in the storage unit 22, it is determined that the user's face image data captured by the imaging unit 31 of the authentication engine 3 is not stored in the storage unit 22, and user authentication is not performed. In this case, user identification information is not transmitted from the face authentication platform 2 to the authentication engine 3, and no processing is performed on the user by the authentication engine 3.

[0045] Next, when this user moves to another service facility and unlocks doors located at entrances to office buildings or apartment complexes, or enables cashless payment, the user has their face captured by the imaging unit 31 of the authentication engine 3 (e.g., authentication engine B) installed at this other service facility. Information regarding the user's face image captured by the imaging unit 31 of the authentication engine 3 (or authentication engine B), and usage history information (specifically, the identification information of the authentication engine B, the location information of the authentication engine B, the date and time the user's face image was captured by the imaging unit 31 of the authentication engine B, and information about the service facility where the authentication engine B is installed) is transmitted from the authentication engine 3 to the face recognition platform 2 (step St204). As a result, the receiving means 201 of the face recognition platform 2 receives information regarding the user's face image and usage history information from the authentication engine 3 (or authentication engine B).

[0046] The encryption means 202 encrypts the user's facial image information and the user's usage history information received by the reception means 201, converting them into homomorphic encryption (step St205). The authentication means 203 then authenticates the user by comparing the homomorphic encryption of the user's facial image encrypted by the encryption means 202 with the homomorphic encryption of the user's facial image stored in the storage unit 22, and obtains the user's identification information associated with the homomorphic encryption of the authenticated user's facial image (step St206). Once the user is authenticated, the facial recognition platform 2 sends the obtained user identification information back to the service organization where the authentication engine 3 (authentication engine B) is installed. This allows the service organization where the authentication engine 3 (authentication engine B) is installed to perform various processes on the authenticated user.

[0047] Furthermore, the recommendation means 205 calculates recommendation information based on homomorphic encryption of the user's authentication history information (e.g., identification information of authentication engine B, location information of authentication engine B, information on the date and time when the user's face image was captured by the imaging unit 31 of authentication engine B, information on the service organization where authentication engine B is installed, etc.) and homomorphic encryption of other usage history information corresponding to this user's identification information already stored in the storage unit 22 (e.g., identification information of authentication engine A, location information of authentication engine A, information on the date and time when the user's face image was captured by the imaging unit 31 of authentication engine A, information on the service organization where authentication engine A is installed, etc.) (step St207). As described above, recommendation information includes information useful to the user, such as service campaign information (e.g., discount coupons and free coupon information), service availability date and time information, and special service provision information. Furthermore, the recommendation means 205 may calculate recommendation information by referring not only to the homomorphic encryption of the user's usage history information stored in the storage unit 22, but also to the homomorphic encryption of the user's registration information stored in the storage unit 22. The recommendation information calculated by the recommendation means 205 is transmitted by the transmission means 206 to the user terminal 5 of the user authenticated by the facial recognition platform 2 (step St208). Specifically, the transmission means 206 transmits the calculated recommendation information to the user terminal 5 corresponding to the identification information of the authenticated user. The recommendation information transmitted from the facial recognition platform 2 is then displayed on the touch panel or the like of the user terminal 5. This allows the user to utilize the recommendation information.

[0048] The following is a specific example of how recommendation information can be used. For example, if the memory unit 22 stores information that a user frequently visits a particular type of store (e.g., a beef bowl restaurant) as homomorphic encryption of a user's usage history, then when this user gets into a taxi and, for example, pays the taxi fare cashless upon alighting, the imaging unit 31 of the authentication engine 3 installed in the taxi captures the user's face image, the authentication engine 3 transmits information about the user's face image and usage history information (specifically, the identification information of the authentication engine 3, the location information of the authentication engine 3, the date and time the user's face image was captured by the imaging unit 31 of the authentication engine 3, and information about the taxi in which the authentication engine 3 is installed) from the authentication engine 3 to the face recognition platform 2. The face recognition platform 2 then authenticates the user using the authentication means 203. Furthermore, the recommendation means 205 calculates recommendation information based on homomorphic encryption of the user's authenticated usage history information (i.e., usage history information transmitted from the taxi's authentication engine 3 to the facial recognition platform 2) and other usage history information already stored in the storage unit 22 that corresponds to the user's identification information (i.e., information that this user frequently visits a particular type of store (e.g., a beef bowl restaurant)). Specifically, the recommendation information calculated is information about a particular type of store (i.e., a beef bowl restaurant) that is open at the time the user's facial image was captured by the imaging unit 31 of the authentication engine 3 and is close to the location information of the authentication engine 3. This recommendation information is then transmitted by the transmission means 206 from the facial recognition platform 2 to the user terminal 5 corresponding to the user's identification information authenticated by the authentication means 203. As a result, the user can find information about a particular type of store near where they got off the taxi by viewing the recommendation information displayed on the user terminal 5.

[0049] In this way, when the recommendation means 205 calculates recommendation information, for example, the service provider where the authentication engine 3, which authenticated the user, is installed substantially matches the service provider in the usage history information corresponding to the user's identification information already stored in the storage unit 22, and the date and time when the user's face image was captured by the imaging unit 31 of the authentication engine 3, which authenticated the user, falls within the business hours of the authentication engine 3 and the service provider in the usage history information corresponding to the user's identification information stored in the storage unit 22, and information about a service provider close to the location information of the authentication engine 3, which authenticated the user, is output as recommendation information. However, the method of calculating recommendation information by the recommendation means 205 is not limited to this method, and various other methods may be used as methods for calculating recommendation information. For example, when Recommend 205 calculates recommendation information, it may output recommendation information about a service provider in the same industry that is close to the location information of the authentication engine 3 where the user authentication took place, even if the service provider where the user authentication took place is not the same as the service provider in the usage history information corresponding to the user's identification information already stored in the storage unit 22, and the date and time when the user's face image was captured by the imaging unit 31 of the authentication engine 3 where the user authentication took place falls within the business hours of the service provider in the same industry, and is close to the location information of the authentication engine 3 where the user authentication took place. Thus, various methods can be considered for calculating the recommendation information by the recommendation means 205, based on homomorphic encryption of other usage history information corresponding to the user's identification information already stored in the storage unit 22.

[0050] Furthermore, homomorphic encryption of the user's registration information may be used when calculating the recommendation information. Specifically, the recommendation means 205 calculates the recommendation information by also referring to homomorphic encryption of at least one of the gender and age in the user's registration information stored in the storage unit 22. More specifically, for example, for a user whose registration information indicates that he is a man in his 40s, when the user's face is captured by the imaging unit 31 of the authentication engine 3 installed in the taxi for cashless payment of the taxi fare upon alighting, the recommendation information displayed will be information about a fast-food restaurant that is close to the location of the authentication engine 3 and is open for business. On the other hand, if the user's registration information indicates that he is a woman in his 20s, the recommendation information displayed will not be information about a fast-food restaurant, but rather information about a nail salon or beauty salon that is close to the location of the authentication engine 3 and is open for business.

[0051] Furthermore, as recommendation information, campaign information available at specific stores (for example, discount coupons or free coupons) may be calculated by the recommendation means 205, and the calculated campaign information may be transmitted as recommendation information from the facial recognition platform 2 to the user terminal 5 corresponding to the user's identification information authenticated by the authentication means 203 via the transmission means 206. As a result, the authenticated user will be able to enjoy various services such as discounts on fees.

[0052] According to the information processing system 1, program, and information processing method of this embodiment, which have the above configuration, when a user is registered, the encryption means 202 encrypts the information relating to the user's face image transmitted from the user terminal 5 to create a homomorphic encryption, and the storage means 204 stores the homomorphic encryption of the information relating to the user's face image in the storage unit 22. Furthermore, when a user is authenticated, the encryption means 202 encrypts the information relating to the user's face image and the usage history information transmitted from the authentication engine 3, which has an imaging unit 31 that captures the user's face image, to create homomorphic encryption, and the authentication means 203 authenticates the user by comparing the homomorphic encryption of the information relating to the user's face image transmitted from the authentication engine 3 and encrypted with the homomorphic encryption of the information relating to the user's face image already stored in the storage unit 22, and the storage means 204 stores the homomorphic encryption of the usage history information for which the user has been authenticated in the storage unit 22. Furthermore, the recommendation means 205 calculates recommendation information based on homomorphic encryption of the user's authenticated usage history information and homomorphic encryption of other usage history information of the same user already stored in the storage unit 22, and the transmission means 206 transmits the calculated recommendation information to the authenticated user's terminal 5. This reduces the risk of information leakage of the user's facial image and the user's usage history information, thereby improving security.

[0053] In particular, homomorphic encryption is an encryption method that allows binary operations such as addition and multiplication to be performed when two ciphertexts are given, even without plaintext or a secret key. Therefore, the authentication means 203 can authenticate the user by comparing the encrypted homomorphic encryption of the user's face image with the homomorphic encryption of the user's face image stored in the storage unit 22, without decrypting the homomorphic encryption of the user's face image. Furthermore, the recommendation means 205 can perform calculations on recommendation information based on the encrypted homomorphic encryption of the user's usage history information and the homomorphic encryption of the user's usage history information stored in the storage unit 22, without decrypting the homomorphic encryption of the user's usage history information.

[0054] Furthermore, in the information processing system 1, program, and information processing method of this embodiment, user identification information is issued when a user registers, and the storage means 204 stores homomorphic encrypted information about the user's face image and the user's registration information in the storage unit 22, each linked to the user's identification information. The authentication means 203 authenticates the user by comparing the homomorphic encrypted information about the user's face image with the homomorphic encrypted information about the user's face image already stored in the storage unit 22, and obtains the user's identification information linked to the homomorphic encrypted information about the user's face image of the authenticated user. The recommendation means 205 calculates recommendation information based on the homomorphic encrypted usage history information of the authenticated user and the homomorphic encrypted information about another usage history information corresponding to this user's identification information already stored in the storage unit 22, and the transmission means 206 transmits the calculated recommendation information to the user terminal 5 corresponding to the authenticated user's identification information. In this way, by using the user's identification information, recommendation information can be transmitted to the user terminal 5 of the authenticated user more reliably.

[0055] Furthermore, when the authentication means 203 compares the homomorphic encryption of the user's face image information transmitted and encrypted from the authentication engine 3 with the homomorphic encryption of the user's face image information already stored in the storage unit 22, it calculates a Euclidean distance for each user's identification information and identifies the user's identification information corresponding to the user's face image information received from the authentication engine 3 as the user's identification information with the smallest Euclidean distance that is also smaller than a predetermined threshold.

[0056] Furthermore, in the information processing system 1, program, and information processing method of this embodiment, when a user registers, the encryption means 202 encrypts the user's registration information transmitted from the user terminal 5 into homomorphic encryption, the storage means 204 stores the homomorphic encrypted user registration information in the storage unit 22, and the recommendation means 205 calculates recommendation information by also referring to the homomorphic encrypted user registration information stored in the storage unit 22. This makes it possible to provide users with recommendation information that better suits their needs. In addition, it is possible to reduce the risk of information leakage of user registration information, thereby improving security.

[0057] Furthermore, the information processing system, program, and information processing method according to this embodiment are not limited to the embodiments described above, and various modifications can be made.

[0058] For example, the above description mentions a configuration in which all information regarding the user's facial image, user registration information, and user usage history information are encrypted by the encryption means 202 to become homomorphic encryption. However, this embodiment is not limited to this configuration. One or two of the information regarding the user's facial image, user registration information, and user usage history information may be stored in the storage unit 22 without encryption. For example, when a user registers, if the reception means 201 of the facial recognition platform 2 receives the user's registration information and facial image information from the user terminal 5, the information regarding the user's facial image may be encrypted by the encryption means 202 to become homomorphic encryption, but the user registration information may be stored in the storage unit 22 linked to the user's identification information without being encrypted by the encryption means 202.

[0059] Furthermore, when the receiving means 201 of the facial recognition platform 2 receives user usage history information and facial image information from the user terminal 5 during user authentication, the information regarding the user's facial image may be encrypted by the encryption means 202 to become homomorphic encryption, but the user's usage history information may not be encrypted by the encryption means 202 and may be stored in the storage unit 22 linked to the user's identification information as is. In this case, when the receiving means 201 of the facial recognition platform 2 receives the user's facial image and usage history information transmitted from the authentication engine 3 during user authentication, the encryption means 202 encrypts the information regarding the user's facial image transmitted from the authentication engine 3 to become homomorphic encryption, the authentication means 203 authenticates the user by comparing the homomorphic encryption of the information regarding the user's facial image transmitted from the authentication engine 3 with the homomorphic encryption of the information regarding the user's facial image already stored in the storage unit 22, and the storage means 204 stores the usage history information for which the user has been authenticated in the storage unit 22. Furthermore, the recommendation means 205 calculates recommendation information based on the user's authenticated usage history information and other usage history information of this user already stored in the storage unit 22, and the transmission means 206 transmits the calculated recommendation information to the authenticated user's terminal 5.

[0060] Furthermore, the above description mentions an embodiment in which an encryption means 202 is provided in the facial recognition platform 2 to encrypt information related to the user's facial image and convert it into homomorphic encryption. However, this embodiment is not limited to this embodiment. An information processing system 1a relating to a modified example will be described with reference to Figure 4. For each component of the information processing system 1a shown in Figure 4, components that are substantially the same as those in the information processing system 1 shown in Figure 1 are given the same reference numerals and their descriptions are omitted.

[0061] In the information processing system 1a shown in Figure 4, each authentication engine 3 is connected to an encryption server 4 for communication, and each encryption server 4 is connected to a facial recognition platform 2 for communication. In addition, information regarding the user's facial image and user registration information to be sent from the user terminal 5 to the facial recognition platform 2 during user registration are sent to the encryption server 4.

[0062] The encryption server 4 has an encryption means 41 that encrypts information about the user's face image and user registration information transmitted from the user terminal 5, or information about the user's face image and user usage history information transmitted from the authentication engine 3, into homomorphic encryption. The encryption means 41 generally has the same functionality as the encryption means 202 in the information processing system 1 shown in Figure 1. When a user is registered, the information about the user's face image and user registration information transmitted from the user terminal 5 to the encryption server 4 are encrypted by the encryption means 41, becoming homomorphic encryption, and the homomorphic encryption of the information about the user's face image and the homomorphic encryption of the user registration information are transmitted from the encryption server 4 to the face authentication platform 2. Also, when a user is authenticated, the information about the user's face image and user usage history information transmitted from the authentication engine 3 to the encryption server 4 are encrypted by the encryption means 41, becoming homomorphic encryption, and the homomorphic encryption of the information about the user's face image and the homomorphic encryption of the user usage history information are transmitted from the encryption server 4 to the face authentication platform 2.

[0063] In this information processing system 1a, as in the information processing system 1 shown in Figure 1, when a user is registered, the encryption means 41 encrypts the information regarding the user's face image transmitted from the user terminal 5 into a homomorphic encryption, and the storage means 204 stores the homomorphic encryption of the information regarding the user's face image in the storage unit 22. Furthermore, when a user is authenticated, the encryption means 41 encrypts the information regarding the user's face image and the usage history information transmitted from the authentication engine 3, which has an imaging unit 31 that captures the user's face image, into homomorphic encryption, and the authentication means 203 authenticates the user by comparing the encrypted homomorphic encryption of the information regarding the user's face image with the homomorphic encryption of the information regarding the user's face image already stored in the storage unit 22, and the storage means 204 stores the homomorphic encryption of the usage history information for which the user has been authenticated in the storage unit 22. Furthermore, the recommendation means 205 calculates recommendation information based on homomorphic encryption of the user's authenticated usage history information and homomorphic encryption of other usage history information of the same user already stored in the storage unit 22, and the transmission means 206 transmits the calculated recommendation information to the authenticated user's terminal 5. This reduces the risk of information leakage of the user's facial image and the user's usage history information, thereby improving security.

[0064] Furthermore, as a further modification of the information processing system 1a shown in Figure 4, the control unit 20 of the facial recognition platform 2 may also function as an encryption means, and information regarding the user's facial image captured by the imaging unit 51 of the user terminal 5 and the user's registration information entered into the user terminal 5 may be transmitted to the facial recognition platform 2 without being transmitted to the encryption server 4. In this case, the information regarding the user's facial image transmitted from the user terminal 5 to the facial recognition platform 2 is encrypted by the encryption means in the control unit 20 to become a homomorphic encryption, and this homomorphic encryption of the information regarding the user's facial image is stored in the storage unit 22 by the storage means 204.

[0065] Furthermore, while the above description primarily illustrates the case where the facial recognition platform 2 operates the program, it is not limited to this. Some of the means among the receiving means 201, encryption means 202, authentication means 203, storage means 204, recommendation means 205, and transmission means 206 may be executed by a device other than the facial recognition platform 2. Also, while the above description describes an embodiment in which the storage unit 22 is provided on the facial recognition platform 2, this embodiment is not limited to this embodiment. Instead of the storage unit 22 being provided on the facial recognition platform 2, a separate storage device or cloud data service may store homomorphic encrypted user registration information, homomorphic encrypted information regarding the user's facial image, and homomorphic encrypted user usage history information, linked to the user's identification information.

[0066] Furthermore, in the information processing systems 1 and 1a according to this embodiment, the recommendation means 205 may not be provided, and recommendation information may not be provided to the user. In this case, the facial recognition platform 2 will only perform user authentication. That is, when a user is registered, the encryption means 202 encrypts the information regarding the user's facial image transmitted from the user terminal 5 into homomorphic encryption, and the storage means 204 stores the homomorphic encryption of the information regarding the user's facial image in the storage unit 22. Also, when a user is authenticated, the encryption means 202 encrypts the information regarding the user's facial image and the usage history information transmitted from the authentication engine 3 into homomorphic encryption, and the authentication means 203 authenticates the user by comparing the encrypted homomorphic encryption of the information regarding the user's facial image with the homomorphic encryption of the information regarding the user's facial image already stored in the storage unit 22. [Explanation of Symbols]

[0067] 1.1a Information Processing System 2. Facial Recognition Platform 20 Control Unit 22 Memory section 24 Communication Interfaces 201 Reception Method 202 Encryption method 203 Authentication methods 204 Memory means 205 Recommendation Methods 206 Transmission method 3 Authentication Engine 31 Imaging Unit 4. Encryption Server 41 Encryption methods 5. User terminals 51 Imaging Unit

Claims

1. An information processing system comprising an encryption means, an authentication means, a storage means, a recommendation means, and a transmission means, At the time of user registration, the encryption means encrypts information regarding the user's face image transmitted from the user terminal into a homomorphic encryption, and the storage means stores the homomorphic encryption of the information regarding the user's face image in the storage unit. At the time of user authentication, the encryption means encrypts information regarding the user's face image transmitted from an authentication engine having an imaging unit for imaging the user's face image and the user's usage history information regarding the usage status of the service associated with the authentication engine into homomorphic encryptions respectively. The authentication means authenticates the user by comparing the homomorphic encryption of the information regarding the user's face image encrypted and transmitted from the authentication engine with the homomorphic encryption of the information regarding the user's face image already stored in the storage unit. The storage means stores the homomorphic encryption of the usage history information for which the user authentication has been performed in the storage unit. The recommendation means calculates recommendation information including information useful for the user, which consists of at least any one of service campaign information, service available date and time information, and special service provision information, based on the homomorphic encryption of the usage history information for which the user authentication has been performed and the homomorphic encryption of another usage history information of this user already stored in the storage unit. The transmission means transmits the calculated recommendation information to the user terminal of the authenticated user.

2. User identification information is issued at the time of user registration, and the storage means stores the homomorphic encryption of the information regarding the user's face image in association with the user identification information in the storage unit. The authentication means authenticates the user by comparing the homomorphic encryption of the information regarding the encrypted user's face image with the homomorphic encryption of the information regarding the user's face image already stored in the storage unit, and acquires the user identification information associated with the homomorphic encryption of the information regarding the face image of the authenticated user. The recommendation means calculates recommendation information based on the homomorphic encryption of the usage history information for which the user authentication has been performed and the homomorphic encryption of another usage history information corresponding to the user identification information of this user already stored in the storage unit. The transmission means transmits the calculated recommendation information to the user terminal corresponding to the user identification information of the authenticated user. The information processing system according to Claim 1.

3. When the authentication means compares the somewhat homomorphic encryption of information regarding the user's face image encrypted and transmitted from the authentication engine with the somewhat homomorphic encryption of information regarding the user's face image already stored in the storage unit, it calculates the Euclidean distance for each piece of the user's identification information, and identifies the identification information of the user with the smallest Euclidean distance and smaller than a predetermined threshold value as the identification information of the user corresponding to the information of the user's face image received from the authentication engine. The information processing system according to claim 2.

4. At the time of user registration, the encryption means also encrypts the user registration information transmitted from the user terminal into a somewhat homomorphic encryption, and the storage means stores the somewhat homomorphic encryption of the user registration information in the storage unit. The recommendation means also refers to the somewhat homomorphic encryption of the user registration information stored in the storage unit to calculate the recommendation information. The information processing system according to any one of claims 1 to 3.

5. Comprising an encryption means, an authentication means, a storage means, a recommendation means, and a transmission means. At the time of user registration, the encryption means encrypts the information regarding the user's face image transmitted from the user terminal into a somewhat homomorphic encryption, and the storage means stores the somewhat homomorphic encryption of the information regarding the user's face image in the storage unit. When receiving information regarding a user's face image transmitted from an authentication engine having an imaging unit that captures an image of the user's face at the time of user authentication and the user's usage history information regarding the usage status of the service associated with the authentication engine, the encryption means encrypts the information regarding the user's face image transmitted from the authentication engine to obtain a homomorphic encryption. The authentication means authenticates the user by comparing the homomorphic encryption of the information regarding the user's face image transmitted and encrypted from the authentication engine with the homomorphic encryption of the information regarding the user's face image already stored in the storage unit. The storage means stores the usage history information for which user authentication has been performed in the storage unit. The recommendation means calculates recommendation information including information useful to the user, which consists of at least any one of service campaign information, service available date and time information, and special service provision information, based on the usage history information for which user authentication has been performed and other usage history information of this user already stored in the storage unit. The transmission means transmits the calculated recommendation information to the user terminal of the authenticated user. An information processing system.

6. User identification information is issued at the time of user registration, and the storage means stores the homomorphic encryption of the information regarding the user's face image in association with the user identification information in the storage unit. The authentication means authenticates the user by comparing the homomorphic encryption of the information regarding the encrypted user's face image with the homomorphic encryption of the information regarding the user's face image stored in the storage unit, and obtains the user identification information associated with the homomorphic encryption of the information regarding the face image of the authenticated user. The recommendation means calculates recommendation information based on the usage history information for which user authentication has been performed and other usage history information corresponding to the user identification information of this user already stored in the storage unit. The transmission means transmits the calculated recommendation information to the user terminal corresponding to the user identification information of the authenticated user. The information processing system according to claim 5.

7. The authentication means calculates the Euclidean distance for each piece of user identification information when comparing the homomorphic encryption of information related to the user's face image transmitted from the authentication engine and encrypted with the homomorphic encryption of information related to the user's face image already stored in the storage unit, and identifies the user identification information of the user with the smallest Euclidean distance and smaller than a predetermined threshold as the user identification information corresponding to the information of the user's face image received from the authentication engine. The information processing system according to claim 6.

8. At the time of user registration, the encryption means also encrypts the user registration information transmitted from the user terminal into a homomorphic encryption, and the storage means stores the homomorphic encryption of the user registration information in the storage unit. The recommendation means calculates recommendation information with reference to the homomorphic encryption of the user registration information stored in the storage unit. The information processing system according to any one of claims 5 to 7.

9. A program that causes a computer to function as an encryption means, an authentication means, a storage means, a recommendation means, and a transmission means, At the time of user registration, the encryption means encrypts the information related to the user's face image transmitted from the user terminal into a homomorphic encryption, and the storage means stores the homomorphic encryption of the information related to the user's face image in the storage unit. At the time of user authentication, the encryption means encrypts information on the user's face image transmitted from an authentication engine having an imaging unit for imaging the user's face image and the user's usage history information on the usage status of the service associated with the authentication engine respectively into a homomorphic encryption. The authentication means authenticates the user by comparing the homomorphic encryption of the information on the user's face image transmitted and encrypted from the authentication engine with the homomorphic encryption of the information on the user's face image already stored in the storage unit. The storage means stores the homomorphic encryption of the usage history information for which user authentication has been performed in the storage unit. The recommendation means calculates recommendation information including information useful to the user, which consists of at least any one of service campaign information, service available date and time information, and special service provision information, based on the homomorphic encryption of the usage history information for which user authentication has been performed and the homomorphic encryption of another usage history information of this user already stored in the storage unit. The transmission means transmits the calculated recommendation information to the user terminal of the authenticated user. A program.

10. A program that causes a computer to function as an encryption means, an authentication means, a storage means, a recommendation means, and a transmission means, At the time of user registration, the encryption means encrypts the information on the user's face image transmitted from the user terminal into a homomorphic encryption, and the storage means stores the homomorphic encryption of the information on the user's face image in the storage unit. When receiving information regarding a user's face image transmitted from an authentication engine having an imaging unit that captures an image of the user's face at the time of user authentication and the user's usage history information regarding the usage status of a service associated with the authentication engine, the encryption means encrypts the information regarding the user's face image transmitted from the authentication engine to obtain a homomorphic encryption. The authentication means authenticates the user by comparing the homomorphic encryption of the information regarding the user's face image transmitted and encrypted from the authentication engine with the homomorphic encryption of the information regarding the user's face image already stored in the storage unit. The storage means stores the usage history information for which user authentication has been performed in the storage unit. The recommendation means calculates recommendation information including information useful to the user, which consists of at least any one of service campaign information, service available date and time information, and special service provision information, based on the usage history information for which user authentication has been performed and other usage history information of this user already stored in the storage unit. The transmission means transmits the calculated recommendation information to the user terminal of the authenticated user. A program.

11. An information processing method executed by a computer, comprising: At the time of user registration, the encryption means encrypts the information regarding the user's face image transmitted from the user terminal to obtain a homomorphic encryption, and the storage means stores the homomorphic encryption of the information regarding the user's face image in the storage unit. At the time of user authentication, the encryption means encrypts information regarding the user's face image transmitted from an authentication engine having an imaging unit that captures the user's face image, and the user's usage history information regarding the usage status of the service associated with the authentication engine, respectively, as homomorphic encryption. The authentication means authenticates the user by comparing the homomorphic encryption of the information regarding the user's face image transmitted and encrypted from the authentication engine with the homomorphic encryption of the information regarding the user's face image already stored in the storage unit. The storage means stores the homomorphic encryption of the usage history information for which user authentication has been performed in the storage unit. The recommendation means calculates recommendation information including useful information for the user, which consists of at least one of service campaign information, service available date and time information, and special service provision information, based on the homomorphic encryption of the usage history information for which user authentication has been performed and the homomorphic encryption of another usage history information of this user already stored in the storage unit. The transmission means transmits the calculated recommendation information to the user terminal of the authenticated user. An information processing method.

12. An information processing method executed by a computer, At the time of user registration, the encryption means encrypts the information regarding the user's face image transmitted from the user terminal into homomorphic encryption, and the storage means stores the homomorphic encryption of the information regarding the user's face image in the storage unit. When receiving information regarding the user's face image sent from an authentication engine having an imaging unit that captures the user's face image at the time of user authentication and the user's usage history information regarding the usage status of the service associated with the authentication engine, the encryption means encrypts the information regarding the user's face image sent from the authentication engine to obtain a homomorphic encryption. The authentication means authenticates the user by comparing the homomorphic encryption of the information regarding the user's face image sent and encrypted from the authentication engine with the homomorphic encryption of the information regarding the user's face image already stored in the storage unit. The storage means stores the usage history information for which the user has been authenticated in the storage unit. The recommendation means calculates recommendation information including information useful to the user, which consists of at least any one of service campaign information, service available date and time information, and special service provision information, based on the usage history information for which the user has been authenticated and other usage history information of this user already stored in the storage unit. The transmission means transmits the calculated recommendation information to the user terminal of the authenticated user. An information processing method.

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