JP6790839B2 - Secure element, UIM card, authentication method, and authentication program - Google Patents

Description

The present invention relates to the technical field of Secure Element such as an IC chip.

In recent years, biosensors for acquiring biometric information such as fingerprints, irises, and veins are increasingly incorporated in smartphones and the like. By mounting the biometric sensor on a smartphone or the like, biometric authentication using biometric information can be realized in place of or in addition to the conventional password authentication.

On the other hand, in most biometrics, biometric information is managed by a server, and authentication (collation of biometric information) is often performed by the server. In this case, it is not necessary to store biological information in a smartphone or the like, and there is an advantage that it can be centrally managed by a secure server. However, every time the number of services using biometric authentication increases, it becomes necessary to manage the biometric information on the server on the service provider side, so there is a demerit that personal biometric information is managed everywhere. In addition, servers that centrally manage biometric information are more likely to be targeted by targeted attacks, increasing the risk and management burden on the service provider side that handles biometric information.

By the way, a UIM (User Identity Module) card as a secure element is inserted in a smartphone or the like, or an embedded secure element is built in, and the secure element manages confidential information such as a telephone number. .. The secure element is resistant to failure analysis attacks and power analysis attacks, and is suitable for securely storing important data such as encryption keys or performing authentication processing using keys.

Therefore, the UIM (Secure Element) is effective for being used as a storage for storing biometric information. For example, Patent Document 1 discloses that UIM manages biometric information and performs authentication processing.

Japanese Unexamined Patent Publication No. 2010-14174

However, since the CPU performance of the UIM (secure element) is inferior to that of the smartphone, it is difficult to perform processing such as feature extraction required for biometric authentication. In order to solve such a problem, it is conceivable to reduce the quality of biometric information and perform authentication, but there is a problem that the authentication accuracy is lowered.

Therefore, the present invention can manage biometric information by itself so as not to manage biometric information on a server, perform biometric authentication without lowering the authentication accuracy, and secure the result of biometric authentication to an external device. The purpose is to provide a secure element or the like that can be transmitted to.

In order to solve the above problem, the invention according to claim 1 is a secure element having a processing unit and a storage unit and transmitting the result of user authentication to an external device, and the storage unit performs the authentication. The authentication program stores the authentication program to be performed, and the authentication program acquires the feature amount data extracted from the biometric information of the user and the user ID of the user for each user. Means, a generation means for generating a private key and a public key by a public key cryptosystem for each user, a user ID and feature amount data acquired by the acquisition means for each user, and the generation means generate Authentication means for storing the private key in association with the storage unit, the first transmission means for transmitting the public key generated for each user to the external device, and the external device for each user. A user who receives a user ID corresponding to the target user and feature quantity data extracted from the biometric information of the user to be authenticated, and stores the user corresponding to the user to be authenticated in the storage unit. Corresponds to the authentication means for authenticating the user by collating the feature amount data registered in association with the user ID same as the ID and the received feature amount data, and the user who is the authentication target. A means for creating signature data using a private key registered in association with a user ID that is the same as the user ID, and the external source of the user ID corresponding to the user to be authenticated. The device is made to function as a second transmission means for transmitting the authentication result and the signature data.

The invention according to claim 2 is the secure element according to claim 1, wherein the acquisition means further acquires a service ID for identifying a service provided by the external device, and the registration means is a registration means. The service ID is further registered in association with the user ID, the feature amount data, and the private key, and the first transmission means transmits the public key to a program operating on the external device, and the service ID is transmitted. The authentication means further receives the service ID of the program from the program operating on the external device, and is registered in the storage unit in association with the same user ID and service ID as the received user ID and service ID. The feature amount data is collated with the received feature amount data to authenticate the user, and the creation means is associated with the same user ID and service ID as the received user ID and service ID. Signature data is created using the private key registered in the storage unit, and the second transmission means is used for the program that is the source of the user ID corresponding to the user to be authenticated. It is characterized in that the result of the authentication and the signature data are transmitted.

The invention according to claim 3 is the secure element according to claim 1 or 2, wherein the generation means uses elliptic curve cryptography as the public key cryptosystem.

The invention according to claim 4 is the secure element according to any one of claims 1 to 3, wherein the authentication program has the processing unit as a secure application program executed in an external secure area. It further functions as an opening means for establishing a secure channel for communication between authentication programs, and the acquisition means uses the feature amount data extracted from the biometric information of the user by the secure application program. The authentication means receives the feature amount data extracted from the biometric information of the user to be authenticated by the secure application program from the secure application program via the secure channel. It is characterized by doing.

The invention according to claim 5 is a UIM card equipped with the secure element according to any one of claims 1 to 4.

The invention according to claim 6 comprises a processing unit and a storage unit, and the processing unit performs the authentication stored in the storage unit in a secure element that transmits a user authentication result to an external device. It is an authentication method performed based on an authentication program, and is an authentication method for each user, an acquisition process for acquiring feature amount data extracted from the biometric information of the user, a user ID of the user, and the user. Each time, a generation step of generating a private key and a public key by a public key cryptosystem, a user ID and feature amount data acquired by the acquisition process, and a private key generated by the generation means are generated for each user. A registration step of associating and storing in the storage unit, a first transmission step of transmitting the public key generated for each user to the external device, and an authentication target from the external device. A user ID corresponding to a certain user and a user ID corresponding to the user to be authenticated are stored in the storage unit after receiving the feature amount data extracted from the biometric information of the user to be authenticated. An authentication process that authenticates the user by collating the feature amount data registered in association with the same user ID with the received feature amount data, and the use corresponding to the user to be authenticated. The creation process of creating signature data using a private key registered in association with the same user ID as the user ID, and the external source of the user ID corresponding to the user to be authenticated. It is characterized by including the signature data and a second transmission step of transmitting the signature data to the device.

The invention according to claim 7 is an authentication program for performing the authentication stored in the storage unit in a secure element having a processing unit and a storage unit and transmitting the result of user authentication to an external device. Then, the processing unit is used for each user to acquire the feature amount data extracted from the biometric information of the user, the acquisition means for acquiring the user ID of the user, and the public key cryptography for each user. A generation means for generating a private key and a public key by a method, for each user, the user ID and feature amount data acquired by the acquisition means are associated with the private key generated by the generation means and stored in the storage unit. The registration means to be stored, the first transmission means for transmitting the public key generated for each user to the external device, and the user ID corresponding to the user to be authenticated from the external device. And, the feature amount data extracted from the biometric information of the user to be authenticated is received, and the storage unit is associated with the same user ID as the user ID corresponding to the user to be authenticated. An authentication means that authenticates the user by collating the registered feature amount data with the received feature amount data, and corresponds to the same user ID as the user ID corresponding to the user to be authenticated. The signature data and the signature data for the external device which is the source of the user ID corresponding to the user who is the authentication target, the creation means for creating the signature data using the private key registered attached. It is characterized in that it functions as a second transmission means for transmitting.

According to the present invention, the feature amount data extracted from the biometric information of the user is stored in the storage unit before the authentication, and the public key of the public key cryptosystem is transmitted to the external device. By collating the feature amount data extracted from the biometric information of the user to be authenticated externally with the registered feature amount data and performing authentication, the server that manages the biometric information is not accessed and the authentication is performed. , Bioauthentication can be performed without lowering the authentication accuracy. In addition, the authentication result can be safely transmitted to the external device by transmitting the signature data created by the previously transmitted public key and the paired private key together with the authentication result.

It is a block diagram which shows the outline structure example of the mobile terminal 1 which concerns on this embodiment. It is a block diagram which shows the outline structure example of the IC chip C mounted on the UIM card 2 which concerns on this embodiment. It is a block diagram which shows the configuration example which concerns on the fingerprint authentication in the mobile terminal 1 which concerns on this embodiment. It is a figure which shows the outline structure example of the feature amount table T provided on the flash memory 23 which concerns on this embodiment. It is a sequence diagram which shows an example of the secure channel opening process which concerns on this Embodiment. It is a conceptual diagram which shows an example of the flow at the time of fingerprint registration which concerns on this embodiment. It is a flowchart which shows an example of the process in the Trust Zone at the time of fingerprint registration which concerns on this embodiment. It is a conceptual diagram which shows an example of the flow at the time of fingerprint authentication which concerns on this embodiment. It is a flowchart which shows an example of the process in the Trust Zone at the time of fingerprint authentication which concerns on this embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The embodiment described below is an embodiment when the present invention is applied to an IC chip (secure element) mounted on a UIM card inserted in a mobile terminal such as a smartphone.

[1. Configuration of mobile terminal 1]
FIG. 1 is a block diagram showing a schematic configuration example of the mobile terminal 1 according to the present embodiment. As shown in FIG. 1, the mobile terminal 1 includes a control unit 11, a storage unit 12, a wireless communication unit 13, a display unit 14, an input unit 15, a CLF interface 16a, an IC card interface 16b, a fingerprint sensor 18, a CLF 19 and the like. These components are connected to each other via the bus 17. Further, a UIM card 2 is inserted in the mobile terminal 1 and is connected to the IC card interface 16b and the CLF 19. The mobile terminal 1 is, for example, a mobile phone, a smartphone, a tablet terminal, or the like.

The control unit 11 is composed of a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. The storage unit 12 is composed of a non-volatile memory such as a flash memory. A general-purpose OS (Operating System) and middleware are stored in the ROM or the storage unit 12. Further, the storage unit 12 is an application that provides services such as an API (Application Program Interface) and a service application (net banking, online trading, shopping cart, etc.) installed in the mobile terminal 1, and provides a service for normal termination of fingerprint authentication. Application software (software composed of application program language) including (premise of provision) is stored. The API is an interface for using the functions of the operating system from the application software. The application software is, for example, a program that can be downloaded from a predetermined server.

Further, the control unit 11 forms a so-called Trust Zone. The Trust Zone is a secure area that is a memory space that is physically separate from the memory space in which the general-purpose OS operates. A dedicated OS called Secure OS runs in the Trust Zone to manage secure information. While the normal general-purpose OS operation can be seen from the Trust Zone side, the Trust Zone cannot be recognized from the general-purpose OS side. With this mechanism, it is possible to prevent attacks from the outside. In the present embodiment, the first fingerprint application for performing fingerprint authentication, which will be described later, operates in the Trust Zone. The Trust Zone was developed by ARM, but a similar mechanism has been formulated and standardized as "TEE (Trusted Execution Environment)" on the Global Platform, and other TEEs are used instead of the Trust Zone. Can also be adopted.

The wireless communication unit 13 has an antenna and controls wireless communication performed with a base station in the mobile communication network. The display unit 14 has, for example, a touch panel type display panel, and controls the display on the display panel and receives operation instructions from the user U. The input unit 15 has an operation button for inputting an operation instruction from the user U, and outputs a signal corresponding to the operation button to the control unit 11. The CLF interface serves as an interface between the control unit 11 and the CLF 19, and the IC card interface 16b serves as an interface between the control unit 11 and the UIM card 2.

The UIM card 2 is one of the UICCs (Universal Integrated Circuits), and is equipped with, for example, a contact type IC chip whose functions have been expanded based on a conventional SIM (Subscriber Identity Module).

The fingerprint sensor 18 detects a fingerprint image showing the fingerprint of a finger placed on the fingerprint sensor 18.

The CLF 19 is a non-contact IC chip that performs non-contact communication specified by the NFC standard, and is an antenna for transmitting and receiving various signals to and from a reader (not shown) in the field of non-contact communication. It is connected to the. Then, when the user U holds the mobile terminal 1 over the reading device, the command transmitted from the reading device is transmitted to the UIM card 2 via the interface (not shown), and is transmitted from the UIM card 2. The response to the command is returned to the reader. The CLF 19 can be operated by the OS of the mobile terminal 1.

[2. Configuration of IC chip C]
FIG. 2 is a block diagram showing a schematic configuration example of an IC chip C mounted on the UIM card 2 according to the present embodiment. As shown in FIG. 2, the IC chip C (an example of a “secure element”) includes a CPU 21 (an example of a “processing unit”), a RAM 22, a flash memory 23, an I / O circuit 24, and the like, and these components are They are connected to each other via the bus 25.

The IC chip C is a so-called secure element, which is designed to withstand malicious analysis attacks from the outside and forms a secure environment.

The RAM 22 stores, for example, data temporarily required for the OS, middleware, and various applications to function.

The flash memory 23 (an example of a “storage unit”) is, for example, a NOR type flash memory that stores an OS, middleware, an application (TEL application), and the like. Further, in the present embodiment, the second fingerprint application for performing fingerprint authentication is installed in the flash memory 23, and is executed by the CPU 21.

The I / O circuit 24 has eight connection terminals C1 to C8 defined by ISO7816 and the like. Here, the C1 terminal is a power supply terminal (VCC), and the C5 terminal is a ground terminal (GND). The C2 terminal is a reset terminal (RST), and the C3 terminal is a clock terminal (CLK). Further, the C7 terminal is used for communication between the CPU 21 and the control unit 11. Further, the C6 terminal is used for communication between the CPU 21 and the CLF 19. SWP (Single Wire Protocol) is applied to the communication protocol between the CPU 21 and the CLF 19.

Next, the configuration related to fingerprint authentication in the mobile terminal 2 will be described. FIG. 3 is a block diagram showing a configuration example related to biometric authentication in the mobile terminal 1 according to the present embodiment. First, in providing the service, the service application 31 is used between the first fingerprint application 33 operating in the Trust Zone 32 and the second fingerprint application 29 operating in the IC chip C (secure element) when performing fingerprint authentication. Build a logical secure channel (the flow of building a secure channel will be described later). The fingerprint sensor 18 detects the fingerprint of the user of the mobile terminal 1 and outputs a fingerprint image. The first fingerprint application 33 and the second fingerprint application 29 execute a process related to fingerprint authentication based on the fingerprint image.

Next, the feature amount table T provided in the area allocated to the second fingerprint application 29 in the flash memory 23 will be described with reference to FIG. The feature amount table T is created when the second fingerprint application 29 is installed on the IC chip C (secure element), and stores the authentication information related to the fingerprint authentication process for a predetermined number (“3” in this embodiment). To do. The authentication information is information registered for each service application 31 and each user, and is managed by an index.

The authentication information is composed of AID, a user ID for identifying a user, feature amount data (data obtained by digitizing feature points of a fingerprint image), and information indicating a private key. The AID is information for identifying a service application that requires fingerprint authentication. By holding the AID, fingerprint authentication can be performed for a plurality of service applications, and it is not necessary to install an authentication application for each service application. The private key is one of the key pairs (private key and public key) created by the second fingerprint application 29 for each combination of AID and user ID by the public key cryptosystem. The public key, which is another key of the key pair, is transmitted to and held by the service application 31. The feature amount data is information obtained by executing the feature point extraction process on the fingerprint image for each combination of the AID and the user ID.

When the CPU 21 receives a command from the CLF 19, the CPU 21 executes a command process according to the command and responds to the command to the CLF 19. When the CPU 21 receives a command from the control unit 11, the CPU 21 executes command processing according to the command and responds to the command to the control unit 11.

[3. Secure channel opening process]
Here, the secure channel opening process will be described with reference to FIG. The process of establishing a secure channel (secure communication path) is performed according to the secure channel protocol (hereinafter referred to as "SCP").

First, the first fingerprint application 33 transmits a SELECT command in order to form a communication path with the second fingerprint application 29 (step S1). The SELECT command sets the AID (here, the AID indicating the second fingerprint application 29), which is an ID that identifies the application that is the destination of the communication path, and the logical channel number that identifies the communication path (logical channel) with the application. Including. On the other hand, the second fingerprint application 29 executes a process for forming a communication path in response to a command and responds (step S2). As a result, a communication path (logical channel) identified by the logical channel number is formed, and thereafter, the first fingerprint application 33 includes the logical channel number in the command, so that the communication path identified by the logical channel number is formed. It is possible to communicate with the second fingerprint application 29 via. Next, the first fingerprint application 33 performs secure processing (mutual authentication processing for protecting commands by SCP) to make the communication path (logical channel) formed so far into a secure communication path in order to increase the confidentiality of the communication path. ) Is executed.

Mutual authentication is based on the premise that each other knows the key (Key ID01, Key ID02, Key ID03) that is the basis of the cryptographic operation according to the algorithm determined by the protocol, and the first fingerprint application 33. The second fingerprint application 29 is an act of authenticating each other. Specifically, the first fingerprint application 33 transmits the INITIALIZE UPDATE command and the EXTERNAL AUTHENTICATE command, which are commands for mutual authentication, and the second fingerprint application 29 executes processing according to each command.

First, the first fingerprint application 33 generates a random number called Host challenge, and issues a Host challenge and an INITIALIZE UPDATE command including key version information (sometimes called "key version number") which is a value indicating a key version. It is transmitted to the fingerprint application 29 (step S3). The second fingerprint application 29 and the first fingerprint application 33 have a plurality of key versions (sometimes referred to as "key versions") of key combinations consisting of three keys used for mutual authentication. The key version number included in the INITIALIZE UPDATE command indicates the key version used for secure processing among the multiple key versions held by each other (that is, the key version used by the first fingerprint application 33 for secure processing is specified. To do).

On the other hand, the second fingerprint application 29 generates a random number called Card challenge, and is based on the Card challenge and the key version key (Key ID01, Key ID02, Key ID03) specified by the key version number. In addition, three session keys corresponding to each Key ID are generated. For example, a session key of Key ID 01 is generated based on Key ID 01. The usage of each session key is used according to each protocol (for example, a session key for MAC generation, a session key for data encryption, and a session key for key encryption are generated). Further, the second fingerprint application 29 calculates a ciphertext called Card cryptogram using the session key using the generated Card challenge and the received Host challenge as materials, and transmits the Card challenge and Card cryptogram to the first fingerprint application 33. (Step S4).

Next, the first fingerprint application 33 generates a session key based on the key version key (the key held by the first fingerprint application 33) specified by the Card challenge and the key version number as in the case of the second fingerprint application 29 side. Then, using the Card challenge and Host challenge as materials, a Card cryptogram is generated using the session key. The first fingerprint application 33 is a legitimate partner whose key value is known by the second fingerprint application 29 by comparing the card cryptogram generated by itself with the card cryptogram received from the second fingerprint application 29 side and confirming whether they match. Make sure there is. Upon confirming this, the first fingerprint application 33 calculates a ciphertext called Host cryptogram using the session key using the Card challenge and Host challenge as materials, and issues an EXTERNAL AUTHENTICATE command including the Host cryptogram to the second fingerprint application 29. Transmit (step S5).

On the other hand, the second fingerprint application 29 uses the Card challenge and Host challenge as materials as in the case of the first fingerprint application 33 side, generates a Host cryptogram using the session key, and generates the Host cryptogram and the first fingerprint application by itself. By comparing the Host cryptograms received from the 33 side and confirming that they match, it is confirmed that the first fingerprint application 33 is a legitimate partner who knows the key value. Upon confirming this, the second fingerprint application 29 notifies the first fingerprint application 33 that mutual authentication has been completed (step S6).

After the mutual authentication is completed, the command is protected by generating and verifying a check code called MAC (Message Authentication Code) using the session keys generated by each other (steps S7 to S10).

[4. Fingerprint authentication processing]
Next, the fingerprint authentication process by the service application 31, the first fingerprint application 33, and the second fingerprint application 29 will be described. In addition, in order to perform the fingerprint authentication process between the service application 31, the first fingerprint application 33 and the second fingerprint application 29, a registration process for registering the information necessary for performing the fingerprint authentication process between the two is performed. Must be done in advance. Therefore, the registration process will be described first, and then the authentication process will be described.

The registration process will be described with reference to FIGS. 6 and 7. FIG. 6 is a diagram showing a rough flow at the time of fingerprint registration, and FIG. 7 is a flowchart showing an operation example of processing at the time of registration by the second fingerprint application at the time of fingerprint registration.

As shown in FIG. 6, first, when the fingerprint sensor 18 detects the fingerprint image of the user, it is passed to the first fingerprint application 33 of the Trust Zone 32. The fingerprint image referred to here is detected by placing the finger on the fingerprint sensor 18 in advance according to a message such as "Please place your finger on the fingerprint sensor 18 because the fingerprint is registered" to the user. In parallel with this, the service application 31 passes the AID that identifies the service application 31 and the user ID that identifies the user who puts a finger on the fingerprint sensor 18 to the first fingerprint application 33.

Next, the first fingerprint application 33 (control unit 11 that executes) performs preprocessing such as filter processing for performing feature point extraction processing on the fingerprint image received from the fingerprint sensor 18, and then features. The point extraction process is performed to obtain feature amount data based on the fingerprint image.

Next, the first fingerprint application 33 (control unit 11 that executes) passes the AID and user ID received from the service application 31 and the feature amount data to the second fingerprint application 29 of the IC chip C (secure element). ..

Next, the second fingerprint application 29 (CPU 21 that executes the second fingerprint application 29) creates a key pair (private key / public key) by the public key cryptosystem.

Next, the second fingerprint application 29 (the CPU 21 that executes the second fingerprint application 29) associates the AID, the user ID, and the feature amount data received from the first fingerprint application 33 with the secret key, and registers them in the feature amount table T.

Next, the second fingerprint application 29 (CPU 21 for executing) passes the public key to the service application 31 together with a response indicating that the fingerprint registration has been completed normally, or gives a response indicating that the fingerprint registration has ended abnormally. Pass it to the service application 31. The above is the general flow when registering a fingerprint.

Next, an operation example of the registration processing by the second fingerprint application 29 will be described with reference to FIG. 7. The registration processing by the second fingerprint application 29 is executed when the AID, the user ID, and the feature amount data are received from the first fingerprint application 33.

As shown in FIG. 7, first, the second fingerprint application 29 (CPU 21 that executes the second fingerprint application 29) creates a key pair (private key / public key) by the public key cryptosystem (step S111). As a method for creating a key pair by the public key cryptosystem, a conventionally known method can be adopted, but it is preferable to use elliptic curve cryptography in which the time required for the creation process is shorter than that of RSA cryptography.

Next, in the second fingerprint application 29 (CPU 21 that executes), the same combination of AID and user ID as the combination of AID and user ID received from the first fingerprint application 33 is registered in the feature amount table T. Whether or not it is determined (step S112). At this time, if it is determined that the second fingerprint application 29 (CPU 21 for executing) is registered (step S112: YES), the feature amount data received from the first fingerprint application 33 and the processing in step S111 are performed. By overwriting and registering with the created private key (step S113), the process proceeds to step S117. That is, the newly acquired feature data and the newly created private key are registered in the feature amount table T. The reason for overwriting and registering the same combination of AID and user ID is to cope with changes in biological information with the passage of time. The weak points of biometric authentication are aging, changes in body shape, and in the case of fingerprints, if they become thinner or scratched due to wear, the authentication accuracy will decrease even for the same person (there will be a discrepancy with the registered information). I will end up). Therefore, when the authentication accuracy is lowered or when a certain period of time has passed since the previous registration, it is preferable to register the biometric information again. Therefore, it is necessary to allow the same person to re-register the feature amount.

On the other hand, when it is determined that the second fingerprint application 29 (CPU 21 for executing) is not registered (step S112: NO), then it is determined whether or not the number of registered cases in the feature amount table T is the maximum. (Step S114). At this time, when the second fingerprint application 29 (CPU 21 for executing) determines that the number of registered cases in the feature amount table T is the maximum (step S114: YES), the registration of the feature amount data is abnormally completed. A response (NG) indicating that is output to the service application 31 (step S116), and the registration processing by the second fingerprint application 29 is completed.

On the other hand, when the second fingerprint application 29 (CPU 21 for executing) determines that the number of registered cases in the feature amount table T is not the maximum (step S114: NO), the second fingerprint application 29 (CPU 21 for executing the feature amount table T) is placed in the free area of the feature amount table T. 1 The AID, user ID, and feature amount data received from the fingerprint application 33 are associated with the secret key created in the process of step S111 and registered in the feature amount table T (step S115), and the process proceeds to step S117. ..

When the second fingerprint application 29 (CPU 21 for executing) finishes the process of step S113 or the process of step S115, then a response (OK) indicating that the registration of the feature amount data is normally completed and the process of step S111 The public key created in is output to the service application 31 (step S117), and the registration processing by the second fingerprint application 29 is completed.

The service application 31 holds the public key received from the second fingerprint application 29 in association with the user ID previously passed to the second fingerprint application 29.

The authentication process will be described with reference to FIGS. 8 and 9. FIG. 8 is a diagram showing a rough flow at the time of fingerprint authentication, and FIG. 9 is a flowchart showing an operation example of the authentication processing by the second fingerprint application at the time of fingerprint authentication.

As shown in FIG. 8, first, when the fingerprint sensor 18 detects the fingerprint image of the user, it is passed to the first fingerprint application 33 of the Trust Zone 32. The fingerprint image referred to here is detected based on the fact that the finger is placed in advance according to a message such as "Please put your finger on the fingerprint sensor 18 because fingerprint authentication is performed". In parallel with this, the service application 31 passes the AID that identifies the service application 31 and the user ID that identifies the user who puts a finger on the fingerprint sensor 18 to the first fingerprint application 33.

Next, the first fingerprint application 33 (control unit 11 that executes) performs preprocessing such as filter processing for performing feature point extraction processing on the fingerprint image received from the fingerprint sensor 18, and then features. The point extraction process is performed to obtain feature amount data based on the fingerprint image.

Next, the first fingerprint application 33 (control unit 11 that executes) passes the AID and user ID received from the service application 31 and the feature amount data to the second fingerprint application 29 of the IC chip C (secure element). ..

Next, the second fingerprint application 29 (the CPU 21 that executes the second fingerprint application 29) is associated with the feature amount data associated with the same combination of the AID and the user ID received from the first fingerprint application 33 from the feature amount table T. And get the private key. Next, the second fingerprint application 29 (CPU 21 that executes the second fingerprint application 29) collates the acquired feature amount data with the feature amount data received from the first fingerprint application 33 to calculate a score, and the score is preset. Determine if the threshold is exceeded. At this time, if the score exceeds the threshold value, it is determined that the authentication is OK, and if the score does not exceed the threshold value, it is determined that the authentication is NG. Then, when the authentication is OK, the signature data is created by the private key acquired from the feature amount table T.

Next, the second fingerprint application 29 (CPU 21 that executes) passes the signature data to the service application 31 together with the response indicating the authentication OK, or passes the response indicating the authentication NG to the service application 31. The above is the general flow of fingerprint authentication.

Next, an operation example of the authentication processing by the second fingerprint application 29 will be described with reference to FIG. In the authentication processing by the second fingerprint application 29, the feature amount data based on the AID, the user ID corresponding to the user to be authenticated, and the fingerprint image of the user to be authenticated is received from the first fingerprint application 33. It is executed as an opportunity.

As shown in FIG. 9, first, the second fingerprint application 29 (the CPU 21 that executes the second fingerprint application 29) is characterized by the same combination of AID and user ID as the combination of AID and user ID received from the first fingerprint application 33. It is determined whether or not it is registered in the table T (step S131). At this time, if it is determined that the second fingerprint application 29 (CPU 21 for executing) is not registered (step S131: NO), a response (NG) indicating that the fingerprint authentication has ended abnormally is sent to the service application 31. Output (step S132), and end the authentication processing by the second fingerprint application 29.

On the other hand, when it is determined that the second fingerprint application 29 (CPU 21 for executing) is registered (step S131: YES), it is associated with the combination of the AID and the user ID received from the first fingerprint application 33. Acquire the feature amount data and the private key registered in the feature amount table T (step S133).

Next, the second fingerprint application 29 (CPU 21 that executes) collates the feature amount data received from the first fingerprint application 33 with the feature amount data acquired in the process of step S133 to calculate a score (step S134). ). As a method for calculating the score, a conventionally known method can be adopted.

Next, the second fingerprint application 29 (CPU 21 for executing) can arbitrarily set the score calculated in the process of step S134 according to a preset threshold value (how strict the fingerprint authentication is performed). ) Is exceeded (step S135). At this time, when the second fingerprint application 29 (CPU 21 for executing) determines that the score does not exceed the preset threshold value (step S135: NO), a response indicating that the fingerprint authentication has ended abnormally. (NG) is output to the service application 31 (step S132), and the authentication processing by the second fingerprint application 29 is completed.

On the other hand, when the second fingerprint application 29 (CPU 21 for executing) determines that the score exceeds a preset threshold value (step S135: YES), it signs with the private key acquired in the process of step S133. Data is created (step S136). The second fingerprint application 29 (CPU 21 that executes the second fingerprint application 29) creates signature data by, for example, encrypting a random number generated by itself with a private key. Next, the second fingerprint application 29 (CPU 21 for executing) outputs a response (OK) indicating that the fingerprint authentication has been completed normally and the signature data created in the process of step S136 to the service application 31 (step S137). , The registration processing by the second fingerprint application 29 is completed.

The service application 31 associates the signature data received from the second fingerprint application 29 with the user ID previously passed to the second fingerprint application 29 when the response (OK) is received. It decrypts with the held public key, and if it can be decrypted normally, it judges the user as a legitimate user and starts providing the service.

As described above, the IC chip C (secure element) of the present embodiment includes a CPU 21 (an example of a "processing unit") and a flash memory 23 (an example of a "storage unit"), and carries the result of user authentication. It is transmitted to the service application 31 of the terminal 1 (an example of an "external device"), and the flash memory 23 stores the second fingerprint application 29 (an example of an "authentication program") and the CPU 21 ("acquisition means", ". An example of "generation means", "registration means", "first transmission means", "authentication means", "creation means", and "second transmission means") is for each user based on the second fingerprint application 29. In addition, the feature amount data extracted from the fingerprint image of the user (an example of "biological information") and the user ID of the user are acquired, and the private key and public disclosure are performed for each user by public key cryptography. A key is generated, and the acquired user ID and feature amount data are associated with each user and stored in the flash memory 23, and the public key generated for the user is stored for each user. Is transmitted to the mobile terminal 1, and the user ID corresponding to the user to be authenticated and the feature amount data extracted from the fingerprint image of the user to be authenticated are received from the mobile terminal 1 and flashed. The feature amount data registered in the memory 23 in association with the same user ID as the user ID corresponding to the user to be authenticated is collated with the received feature amount data to authenticate the user. , Create signature data using the private key registered in association with the same user ID as the user ID corresponding to the user to be authenticated, and use it corresponding to the user to be authenticated. The authentication result and signature data are transmitted to the mobile terminal 1 that is the source of the person ID.

Therefore, according to the IC chip C (secure element) of the present embodiment, the feature amount data extracted from the user's fingerprint image externally (the first fingerprint application 33 of the Trust Zone 32) is stored in the flash memory 23 before authentication. At the same time, the public key of the public key encryption method is transmitted to the mobile terminal 1, and the feature amount extracted from the fingerprint image of the user who is also the authentication target in the external (first fingerprint application 33 of Trust Zone 32) at the time of authentication. By collating the data with the registered feature amount data and performing authentication, biometric authentication can be performed without accessing the server that manages the fingerprint image and without lowering the authentication accuracy. Further, the authentication result can be safely transmitted to the mobile terminal 1 by transmitting the signature data created by the previously transmitted public key and the paired private key together with the authentication result.

Further, the CPU 21 of the present embodiment further acquires an AID for identifying the service application 31 (an example of "an example of a service ID for identifying a service provided by an external device"), and further acquires a user ID, feature amount data, and feature amount data. AID is further registered in association with the private key, and at the time of authentication, AID is further received from the service application 31 in addition to the user ID and feature amount data, and the same user ID and AID as the received user ID and AID are received. The feature amount data registered in the flash memory 23 is collated with the received feature amount data to authenticate the user, and the same user ID and AID as the received user ID and AID are used. Signing data is created using the private key registered in the flash memory 23 in association with the result of authentication for the service application 31 which is the source of the user ID corresponding to the user to be authenticated. Send the signature data. By further associating and registering the AID in the feature amount table T in this way, fingerprint authentication can be performed for a plurality of service applications 31, and it is not necessary to install an authentication application for each service application 31. ..

Further, the CPU 21 of the present embodiment uses elliptic curve cryptography as the public key cryptosystem. As a result, the key pair can be generated at a higher speed than when the RSA encryption is used.

Furthermore, communication is performed between the second fingerprint application 29 of the present embodiment and the first fingerprint application 33 (an example of the "secure application program") executed in the Trust Zone 32 (an example of the "external secure area"). A secure channel for this is established, and the CPU 21 acquires the feature amount data extracted from the user's fingerprint image by the first fingerprint application 33 from the first fingerprint application 33 via the secure channel, and the first fingerprint application 33 The feature amount data extracted from the fingerprint image of the user to be authenticated is received from the first fingerprint application 33 via the secure channel. As a result, the second fingerprint application 29 can safely acquire the feature amount data from the first fingerprint application 33, and the security level at the time of authentication can be improved.

[5. Modification example]
Next, a modified example of the above embodiment will be described. The modifications described below can be combined as appropriate.

[5.1. Modification 1]
In the above embodiment, the UIM card including the IC chip C (secure element) is inserted in the mobile terminal 1, but the IC chip C (secure element) is embedded in the substrate of the mobile terminal 1. It may be (so-called embedded Secure Element).

[5.2. Modification 2]
In the above embodiment, the AID and the user ID are passed from the service application 31 to the second fingerprint application via the first fingerprint application 33 (see FIGS. 6 and 8), but via the first fingerprint application 33. Instead, the service application 31 may directly deliver it to the second fingerprint application.

[5.3. Modification 3]
In the above embodiment, only fingerprint authentication has been described, but the present invention can also be applied to other biometric authentication such as iris authentication and vein authentication.

1 Mobile terminal 11 Control unit 12 Storage unit 13 Wireless communication unit 14 Display unit 15 Input unit 16a CLF interface 16b IC card interface 17 Bus 18 Fingerprint sensor 19 CLF
2 UIM card C IC chip (secure element)
21 CPU
22 RAM
23 Flash memory 24 I / O circuit 25 Bus

Claims (7)

It is a secure element that has a processing unit and a storage unit and sends the result of user authentication to an external device.
The storage unit stores an authentication program for performing the authentication, and stores the authentication program.
The authentication program uses the processing unit.
An acquisition means for acquiring the feature amount data extracted from the biometric information of the user and the user ID of the user for each user.
A generation means for generating a private key and a public key by a public key cryptosystem for each user.
A registration means for each user, in which the user ID and feature amount data acquired by the acquisition means are associated with the secret key generated by the generation means and stored in the storage unit.
A first transmission means for transmitting a public key generated for the user to the external device for each user.
The user ID corresponding to the user to be authenticated and the feature amount data extracted from the biometric information of the user to be authenticated are received from the external device, and the use of the authentication target is stored in the storage unit. An authentication means that authenticates the user by collating the received feature amount data with the feature amount data registered in association with the same user ID as the user ID corresponding to the user.
A creation means for creating signature data using a private key registered in association with a user ID that is the same as the user ID corresponding to the user to be authenticated.
A second transmission means for transmitting the authentication result and the signature data to the external device that is the source of the user ID corresponding to the user to be authenticated.
A secure element characterized by functioning as. The secure element according to claim 1.
The acquisition means further acquires a service ID for identifying a service provided by the external device.
The registration means further registers the service ID in association with the user ID, the feature amount data, and the private key.
The first transmission means transmits the public key to a program running on the external device,
The authentication means further receives the service ID of the program from the program operating on the external device, and registers it in the storage unit in association with the same user ID and service ID as the received user ID and service ID. Authenticate the user by collating the received feature amount data with the feature amount data that has been received.
The creation means creates signature data using the private key registered in the storage unit in association with the same user ID and service ID as the received user ID and service ID.
The second transmission means is a secure element that transmits the result of the authentication and the signature data to the program that is the source of the user ID corresponding to the user to be authenticated. The secure element according to claim 1 or 2.
The generation means is a secure element characterized by using elliptic curve cryptography as the public key cryptosystem. The secure element according to any one of claims 1 to 3.
A secure channel has been established for communication between the authentication program and the secure application program executed in the external secure area.
The acquisition means acquires the feature amount data extracted from the biometric information of the user by the secure application program from the secure application program via the secure channel.
The authentication means is a secure element characterized in that the secure application program receives feature amount data extracted from the biometric information of the user to be authenticated from the secure application program via the secure channel. A UIM card equipped with the secure element according to any one of claims 1 to 4. In a secure element provided with a processing unit and a storage unit and transmitting the result of user authentication to an external device, the processing unit performs the authentication method based on the authentication program stored in the storage unit for performing the authentication. There,
For each user, the feature amount data extracted from the biometric information of the user, the acquisition process of acquiring the user ID of the user, and the acquisition process.
A generation process for generating a private key and a public key by a public key cryptosystem for each user,
For each user, a registration step of associating the user ID and feature amount data acquired by the acquisition step with the secret key generated by the generation means and storing them in the storage unit.
A first transmission step of transmitting the public key generated for the user to the external device for each user,
The user ID corresponding to the user to be authenticated and the feature amount data extracted from the biometric information of the user to be authenticated are received from the external device, and the use of the authentication target is stored in the storage unit. An authentication process that authenticates the user by collating the feature amount data registered in association with the same user ID as the user ID corresponding to the user and the received feature amount data.
The creation process of creating signature data using the private key registered in association with the same user ID as the user ID corresponding to the user to be authenticated.
A second transmission step of transmitting the signature data and the signature data to the external device that is the source of the user ID corresponding to the user to be authenticated.
An authentication method characterized by including. An authentication program for performing the authentication stored in the storage unit in a secure element having a processing unit and a storage unit and transmitting the result of user authentication to an external device.
The processing unit
An acquisition means for acquiring the feature amount data extracted from the biometric information of the user and the user ID of the user for each user.
A generation means for generating a private key and a public key by a public key cryptosystem for each user.
A registration means for each user, in which the user ID and feature amount data acquired by the acquisition means are associated with the secret key generated by the generation means and stored in the storage unit.
A first transmission means for transmitting a public key generated for the user to the external device for each user.
The user ID corresponding to the user to be authenticated and the feature amount data extracted from the biometric information of the user to be authenticated are received from the external device, and the use of the authentication target is stored in the storage unit. An authentication means that authenticates the user by collating the received feature amount data with the feature amount data registered in association with the same user ID as the user ID corresponding to the user.
A creation means for creating signature data using a private key registered in association with a user ID that is the same as the user ID corresponding to the user to be authenticated.
A second transmission means for transmitting the signature data and the signature data to the external device that is the source of the user ID corresponding to the user to be authenticated.
An authentication program characterized by functioning as.