Authentication system, authentication device, authentication method, and program

1. An authentication system, comprising a memory comprising instructions and at least one processor configured to execute the instructions to:

register, for each user, first authentication information and second authentication information in a storage;

perform first authentication based on a similarity between the first authentication information that has been input and the registered first authentication information;

perform second authentication based on a match between the second authentication information that has been input and the registered second authentication information; and

restrict a plurality of users having similar first authentication information to each other from registering the same second authentication information as each other,

acquire the first authentication information on a user who has performed a predetermined registration application,

set the second authentication information on the user who has performed the predetermined registration application such that the set second authentication information is prevented from being the same as the second authentication information on another user having similar first authentication information to the user who has performed the predetermined registration application, and

register the second authentication information as the second authentication information on the user who has performed the predetermined registration application;

further acquire a part of the second authentication information specified by the user who has performed the predetermined registration application, and

set a remaining part of the second authentication information on the user who has performed the predetermined registration application such that the set second authentication information is prevented from being the same as the second authentication information on the another user;

identify, from among other users having the same part as the part of the user who has performed the predetermined registration application, another user having dissimilar first authentication information; and

set the remaining part of the identified another user as the remaining part of the user who has performed the predetermined registration application.

2. The authentication system according to claim 1 , wherein the at least one processor is configured to:

identify, for each remaining part of the other users having the same part as the part of the user who has performed the predetermined registration application, other users having the most similar first authentication information to the first authentication information on the user who has performed the predetermined registration application; and

set, as the remaining part of the user who has performed the predetermined registration application, the remaining part of another user from among the identified other users who has the most dissimilar first authentication information to the first authentication information on the user who has performed the predetermined registration application.

3. The authentication system according to claim 1 , wherein, when there are no other users having dissimilar first authentication information among the other users having the same part as the part of the user who has performed the predetermined registration application, the at least one processor sets a remaining part that is yet to be used, as the remaining part of the user who has performed the predetermined registration application.

4. The authentication system according to claim 1 , wherein the at least one processor is configured to randomly set the second authentication information on the user who has performed the predetermined registration application such that the set second authentication information is prevented from being the same as the second authentication information on another user having similar first authentication information to the first authentication information on the user who has performed the predetermined registration application.

5. The authentication system according to claim 1 , wherein the at least one processor is configured to:

extract the first authentication information on a user matching the second authentication information that has been input, from among pieces of first authentication information registered in the storage; and

perform the first authentication based on the first authentication information that has been input and the extracted first authentication information.

6. The authentication system according to claim 1 ,

wherein the first authentication information includes biometric authentication information,

wherein the first authentication includes biometric authentication,

wherein the second authentication information includes a passcode having a predetermined number of digits,

wherein the second authentication includes passcode authentication, and

wherein the at least one processor is configured to restrict a plurality of users having similar biometric authentication information to each other from registering the same passcode as each other.

7. The authentication system according to claim 1 ,

wherein the at least one processor is configured to:

further register payment information in association with the first authentication information and the second authentication information, and

execute, when the first authentication and the second authentication are successful, payment processing based on the payment information on a user for which the first authentication and the second authentication are successful.

8. The authentication system of claim 1 , further comprising:

an authentication device, comprising at least one processor configured to:

receive an input operation;

transmit, based on the input operation, information required for each of the first authentication and the second authentication; and

execute predetermined processing when the first authentication and the second authentication are successful.

9. An authentication method, comprising:

registering, for each user, first authentication information and second authentication information in a storage;

performing first authentication based on a similarity between the first authentication information that has been input and the registered first authentication information;

performing second authentication based on a match between the second authentication information that has been input and the registered second authentication information; and

restricting a plurality of users having similar first authentication information to each other from registering the same second authentication information as each other,

acquiring the first authentication information on a user who has performed a predetermined registration application,

setting the second authentication information on the user who has performed the predetermined registration application such that the set second authentication information is prevented from being the same as the second authentication information on another user having similar first authentication information to the user who has performed the predetermined registration application, and

registering the second authentication information as the second authentication information on the user who has performed the predetermined registration application;

further acquiring a part of the second authentication information specified by the user who has performed the predetermined registration application, and

setting a remaining part of the second authentication information on the user who has performed the predetermined registration application such that the set second authentication information is prevented from being the same as the second authentication information on the another user;

identifying, from among other users having the same part as the part of the user who has performed the predetermined registration application, another user having dissimilar first authentication information; and

setting the remaining part of the identified another user as the remaining part of the user who has performed the predetermined registration application.

10. A non-transitory computer-readable information storage medium having stored thereon a program for causing a computer to:

register, for each user, first authentication information and second authentication information in a storage;

perform first authentication based on a similarity between the first authentication information that has been input and the registered first authentication information;

perform second authentication based on a match between the second authentication information that has been input and the registered second authentication information; and

restrict a plurality of users having similar first authentication information to each other from registering the same second authentication information as each other;

acquire the first authentication information on a user who has performed a predetermined registration application,

set the second authentication information on the user who has performed the predetermined registration application such that the set second authentication information is prevented from being the same as the second authentication information on another user having similar first authentication information to the user who has performed the predetermined registration application, and

register the second authentication information as the second authentication information on the user who has performed the predetermined registration application;

further acquire a part of the second authentication information specified by the user who has performed the predetermined registration application, and

set a remaining part of the second authentication information on the user who has performed the predetermined registration application such that the set second authentication information is prevented from being the same as the second authentication information on the another user;

identify, from among other users having the same part as the part of the user who has performed the predetermined registration application, another user having dissimilar first authentication information; and

set the remaining part of the identified another user as the remaining part of the user who has performed the predetermined registration application.