JP7403430B2 - Authentication device, authentication method and authentication program - Google Patents

Description

The present invention relates to an authentication system that prevents unauthorized access due to phishing.

Conventionally, two-step authentication has been used as a user authentication mechanism to prevent unauthorized access by third parties. With two-step authentication, when a user logs into their account, in addition to entering their ID and password, they also use their registered phone number or email address to approve notifications sent to another device ( For example, by inputting a security code, the login is completed (see, for example, Patent Document 1).

Japanese Patent Application Publication No. 2007-058469

However, the login screen displayed in conventional authentication systems can be easily imitated, and there is a possibility that phishing sites can be created to deceive users. This phishing site outputs a legitimate notification by relaying the user's input to the official authentication system, and by having the user approve this notification, it is able to steal the key information returned by the authentication system, which is the cause of the spoofing damage. It was one of the

An object of the present invention is to provide an authentication device, an authentication method, and an authentication program that can construct an authentication system that is difficult to phish.

The authentication device according to the present invention includes a first key sharing unit that shares destination information including a first key that is randomly generated in association with a user ID with an authenticated first terminal; In response to access based on the destination information input to the terminal, a randomly generated second key is linked to the user ID that is linked to the first key included in the destination information. a second key transmitter that transmits to the second terminal; a key receiver that receives the second key input to the first terminal and the shared destination information from the first terminal; , upon confirming that the user IDs associated with each of the first key and the second key included in the destination information received by the key receiving unit are the same, a message is sent to the second terminal. and an authentication information transmitter that transmits authentication information for the user ID to complete login.

The first key sharing unit may notify the first terminal indicating the destination information in response to a login request from the second terminal.

The authentication information transmitter may confirm that the session key used when receiving the login request and the session key used when access based on the destination information is received are the same.

The first key sharing unit may notify the first terminal indicating the destination information in response to a request from the first terminal.

The first key sharing unit may mutually generate the first key in synchronization with the first terminal based on a key shared with the first terminal in advance.

The destination information may be a URL, and may be input by the user into an address bar of a browser running on the second terminal.

The authentication method according to the present invention includes a first key sharing step of sharing destination information including a first key randomly generated in association with a user ID with an authenticated first terminal; In response to access based on the destination information input to the terminal, a randomly generated second key is linked to the user ID that is linked to the first key included in the destination information. a second key transmitting step of transmitting the second key to the second terminal; a key receiving step of receiving the second key input to the first terminal and the shared destination information from the first terminal; , upon confirming that the user IDs associated with each of the first key and the second key included in the destination information received in the key receiving step are the same, the information is sent to the second terminal. Then, the computer executes an authentication information sending step of sending the authentication information of the user ID to complete the login.

The authentication program according to the present invention is for causing a computer to function as the authentication device.

According to the present invention, an authentication system that is difficult to phish is constructed.

It is a figure which shows the transition example of the screen shown to each terminal by the authentication method in embodiment. It is a diagram showing a functional configuration of an authentication device in an embodiment. FIG. 3 is a sequence diagram illustrating the flow of processing according to the authentication method in the embodiment.

An example of an embodiment of the present invention will be described below.
The authentication system of this embodiment displays destination information (one-time domain) including a one-time random key on an authenticated terminal, allows the user to access this destination from a new terminal, and then performs authentication. This makes authentication difficult for phishing by preventing phishing sites from obtaining one-time passwords.

FIG. 1 is a diagram showing an example of transition of screens presented to each terminal in the authentication method according to the present embodiment.
First, when a user accesses a login destination site (authentication device) using a browser from a user terminal X such as a personal computer or a mobile terminal, a login preparation screen is displayed on the terminal X.

After inputting the user ID on the login preparation screen, when the login button is pressed (1), a login explanation screen is displayed on the user terminal X. Separately, a notification is sent from the authentication device to the user terminal Y, such as an authenticated mobile terminal, and a login permission screen is displayed based on this notification.

The one-time domain is displayed on the login permission screen, and the user accesses the one-time domain from user terminal X by reading this character string and inputting it into the address bar of the active browser (2).

In response to this access, the authentication device displays a re-authentication screen containing a one-time password on user terminal X, which is the access source, and the user enters this one-time password into user terminal Y and presses the approval button. do.
Thereby, the authentication device authenticates the user at user terminal X and completes the login.

FIG. 2 is a diagram showing the functional configuration of the authentication device 1 in this embodiment.
The authentication device 1 is an information processing device (computer) such as a server device or a personal computer, and includes a control unit 10, a storage unit 20, various data input/output devices, communication devices, and the like.

The control unit 10 is a part that controls the entire authentication device 1, and realizes each function in this embodiment by appropriately reading and executing various programs stored in the storage unit 20. The control unit 10 may be a CPU.

The storage unit 20 is a storage area for various programs and various data for causing the hardware group to function as the authentication device 1, and may be a ROM, RAM, flash memory, hard disk drive (HDD), or the like. Specifically, the storage unit 20 stores a program (authentication program) for causing the control unit 10 to execute each function of the present embodiment, as well as information linking a user's ID and a generated key.

The control unit 10 includes a first key sharing unit 11 , a second key transmitting unit 12 , a key receiving unit 13 , and an authentication information transmitting unit 14 .

The first key sharing unit 11 shares destination information including a first key (character string) that is randomly generated in association with a user ID, with the authenticated user terminal Y (first terminal). .
Here, the destination information may be, for example, a URL (one-time domain), and is generated by linking a predetermined domain name to a first key. This destination information is displayed on user terminal Y and is input by the user into the address bar of the browser operating on user terminal X (second terminal).
For example, the following methods can be adopted as the destination information sharing means.

(A) The first key sharing unit 11 sends a notification to the user terminal Y indicating destination information in response to a login request from the user terminal X.
In this case, upon receiving an ID input on the login preparation screen displayed on the user terminal X, the first key sharing unit 11 generates a first key linked to this ID. At this time, the first key sharing unit 11 may further accept input of a password associated with the ID and verify the validity of the password.
Note that data is sent to user terminal It's okay to be hurt.

(B) The first key sharing unit 11 notifies user terminal Y indicating destination information in response to a request from user terminal Y.
In this case, the user receives the notification from the authentication device 1 that has been accessed by following the notification to the user terminal Y or the instructions on the login explanation screen of the user terminal X, or by voluntarily operating the user terminal Y.

(C) The first key sharing unit 11 mutually generates first keys in synchronization with the user terminal Y based on keys for each user ID shared with the user terminal Y in advance.
In this case, the user terminal Y generates a one-time password using, for example, an algorithm defined in RFC6238 or the like, adds a preset domain name, and uses the password as destination information. The first key sharing unit 11 generates the first key in synchronization with the user terminal Y based on the generation timing of the first key in the user terminal Y or the timing of access from the user terminal X based on the destination information. May be shared.

Note that notifications indicating destination information include notifications that include destination information, notifications that include screen data for displaying a login permission screen that includes destination information, and notifications that include screen data for displaying a login permission screen that includes destination information. It may be a notification that includes a URL.
Alternatively, only a notification is sent to the user terminal Y, and the user terminal Y receives the destination information from the authentication device 1 using the identifier of the own terminal, the data of the login permission screen including the destination information, or the login permission screen including the destination information. You may also obtain a URL for displaying.

The second key transmitter 12 randomly generates a key in response to access based on the destination information input to the user terminal X, in association with the user ID associated with the first key included in this destination information. The second key (one-time password) is sent to user terminal X.

The key receiving unit 13 receives from the user terminal Y the second key input to the user terminal Y and the shared destination information.

When the authentication information transmitting unit 14 confirms that the user IDs associated with the first key and the second key included in the destination information received by the key receiving unit 13 are the same, the authentication information transmitting unit 14 transmits the information to the user terminal The authentication information for this user ID is then sent to complete the login.
At this time, the authentication information transmitter 14 confirms that the session key used when receiving the login request on the login preparation screen is the same as the session key used when access based on the destination information is received. You may confirm that the login operation has been performed from the login preparation screen. If the session keys are different, a warning may be displayed indicating that a phishing site has been displayed.

FIG. 3 is a sequence diagram illustrating the flow of processing according to the authentication method in this embodiment.
This example is a flow of using a user terminal Y held by a user and already registered in the authentication device 1 to enable a service to be used at a newly used user terminal X.
It is assumed that the authentication device 1 holds a link between the user ID that identifies the user and the identifier of the terminal Y held by the user, and the authentication device 1 sends a notification to the terminal Y using the identifier of the terminal Y. It shall be possible to send.
Note that the authentication device 1 may hold a password associated with a user ID or a value (for example, a hash value) that can verify the correctness of the password.

In step S1, the user terminal X accesses the authentication device 1 in response to a user's operation.

In step S2, the authentication device 1 transmits to the user terminal X screen data for displaying a login preparation screen.

In step S3, the user terminal X receives a user ID input from the user, and transmits it to the authentication device 1 in response to pressing the login button.

In step S4, after verifying the validity of the password for the user ID, the authentication device 1 (first key sharing unit 11) randomly generates a first key K and associates it with the user ID. Further, the authentication device 1 adds predetermined domain information to the first key K and uses it as destination information (one-time domain).

In step S5, the authentication device 1 (first key sharing unit 11) transmits a notification indicating the one-time domain to the user terminal Y, transitions the login preparation screen of the user terminal prompt the user to enter the one-time domain in the address bar.

In step S6, the user terminal Y displays a login permission screen based on the notification and presents the one-time domain to the user.

In step S7, the user reads the one-time domain displayed on the user terminal Y and inputs it into the address bar of the browser on the user terminal X, so that the user terminal X accesses the authentication device 1.

In step S8, the authentication device 1 (second key transmitting unit 12) randomly generates a second key L for accessing the one-time domain, and generates a first key K included in the one-time domain. Link it with the user ID that was linked to. Then, the authentication device 1 transmits to the user terminal X screen data for displaying a re-authentication screen in which the second key L is written as a one-time password.
User terminal X displays a re-authentication screen and presents a one-time password to the user.

In step S9, the user inputs the read one-time password into the login permission screen of user terminal Y and presses the approval button. The user terminal Y transmits the one-time domain along with the input one-time password to the authentication device 1.

In step S10, the authentication device 1 (key receiving unit 13) receives a one-time password and a one-time domain from the user terminal Y. The authentication device 1 (authentication information transmitting unit 14) then links the received one-time password, that is, the user ID linked to the second key L, to the first key K included in the one-time domain. Make sure that the user ID specified is the same as the user ID. If the user IDs are the same, the authentication device 1 transmits the authentication information of the user ID to the user terminal X that displayed the re-authentication screen regarding this user ID, and completes the login.
This allows the user to use the service at the user terminal X using the received authentication information.

According to the present embodiment, the authentication device 1 shares destination information including a first key that is randomly generated in association with a user ID with an authenticated user terminal Y, and In response to access based on the input destination information, a randomly generated second key is sent to the user terminal X in association with the user ID associated with the first key included in this destination information. .
When the authentication device 1 receives the second key input to the user terminal Y and the shared destination information from the user terminal Y, the authentication device 1 inputs the second key and the second key included in the destination information, respectively. It is confirmed that the user IDs linked with are the same, and the authentication information of the user ID is sent to the user terminal X to complete the login.

In conventional authentication systems, the attacker uses the ID and password obtained from a phishing site that mimics the login preparation screen to send a notification to the user terminal using the legitimate site, allowing the user to log in from the legitimate site. There was an issue where the one-time password learned from the notification was sent again to the phishing site.
In contrast, the authentication system of this embodiment displays the destination information (one-time domain) on the user terminal Y that receives the notification, so that even if the user is currently accessing a phishing site, a new legitimate site can be accessed. phishing can be prevented. Therefore, by using the authentication device 1 of this embodiment, an authentication system that is difficult to phish is constructed.

Furthermore, the authentication device 1 requires the user to enter the one-time domain and one-time password twice.
If a one-time password is not used, it is necessary to have sufficient data length to protect the one-time domain from brute force attacks, but this increases the operational burden on the user. In this embodiment, by dividing the one-time domain into two parts, the one-time domain can be set to a length that is easy for a person to input visually.
Furthermore, manually entering a one-time domain carries the risk of errors, especially if you enter the domain name incorrectly, which could lead to a connection to a phishing site. At this time, by requesting the second key input, the authentication device 1 can prevent unauthorized acquisition of authentication information only from the leaked key.

The authentication device 1 can provide various variations as an authentication procedure, especially a procedure for sharing the first key with the user terminal Y.
For example, the authentication device 1 may notify user terminal Y indicating destination information in response to a login request from user terminal X, or may notify user terminal Y of destination information in response to a request from user terminal Y. A notification indicating the
Alternatively, the authentication device 1 may generate the first key in synchronization with the user terminal Y based on a key shared with the user terminal Y in advance. This reduces the communication load between the authentication device 1 and the terminal.

The authentication device 1 verifies that the session key used when the login request is received and the session key used when accessed based on the destination information are the same, thereby determining whether, for example, the login preparation screen is a legitimate site. You can confirm that

In this embodiment, by using a URL as the destination information, the user can be reliably guided to the authorized site by inputting the URL into the address bar of the browser running on the user terminal X.

Although the embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above. Further, the effects described in the embodiments described above are merely a list of the most preferable effects resulting from the present invention, and the effects according to the present invention are not limited to those described in the embodiments.

In this embodiment, the case where the destination information is a URL has been mainly described, but the destination information is not limited to this, and any information that can be accessed by the authentication device 1 may be used, for example, such as a telephone number or an e-mail address.
Further, the user ID input on the login preparation screen is identification information for sending a notification to the user terminal Y, and may be a telephone number, an e-mail address, etc. that identifies the user terminal Y.

The authentication method by the authentication device 1 is realized by software. When realized by software, a program constituting this software is installed in an information processing device (computer). Furthermore, these programs may be recorded on removable media such as CD-ROMs and distributed to users, or may be distributed by being downloaded to users' computers via a network. Furthermore, these programs may be provided to the user's computer as a web service via a network without being downloaded.

1 Authentication device 10 Control unit 11 First key sharing unit 12 Second key transmitting unit 13 Key receiving unit 14 Authentication information transmitting unit 20 Storage unit

Claims (8)

a first key sharing unit that shares destination information including a first key that is randomly generated in association with a user ID with the authenticated first terminal;
In response to access based on the destination information input to the second terminal, a second randomly generated second key is linked to the user ID that is linked to the first key included in the destination information. a second key transmitter that transmits the key to the second terminal;
a key receiving unit that receives the second key input to the first terminal and the shared destination information from the first terminal;
When it is confirmed that the user IDs associated with each of the first key and the second key included in the destination information received by the key receiving unit are the same, a message is sent to the second terminal. , an authentication information transmitter that transmits authentication information of the user ID to complete login. The authentication device according to claim 1, wherein the first key sharing unit notifies the first terminal indicating the destination information in response to a login request from the second terminal. 3. The authentication device according to claim 2, wherein the authentication information transmitting unit confirms that a session key when the login request is received is the same as a session key when the access based on the destination information is received. The authentication device according to claim 1, wherein the first key sharing unit notifies the first terminal indicating the destination information in response to a request from the first terminal. The authentication device according to claim 1, wherein the first key sharing unit mutually generates the first key in synchronization with the first terminal based on a key shared with the first terminal in advance. 6. The authentication device according to claim 1, wherein the destination information is a URL, and is input by the user into an address bar of a browser running on the second terminal. a first key sharing step of sharing destination information including a first key randomly generated in association with a user ID with the authenticated first terminal;
In response to access based on the destination information input to the second terminal, a second randomly generated second key is linked to the user ID that is linked to the first key included in the destination information. a second key sending step of sending the key to the second terminal;
a key receiving step of receiving the second key input into the first terminal and the shared destination information from the first terminal;
When it is confirmed that the user IDs associated with each of the first key and the second key included in the destination information received in the key receiving step are the same, the second key is sent to the second terminal. , an authentication information sending step of transmitting authentication information for the user ID to complete login. An authentication program for causing a computer to function as an authentication device according to any one of claims 1 to 6.

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