Granted Patent B2

US 12,591,648 · App. 18/274,667 · Granted Mar 31, 2026

Inventors: Masahiro Nara (Tokyo, JP); Toshihiko Okamura (Tokyo, JP); Toshiyuki Isshiki (Tokyo, JP); Kengo Mori (Tokyo, JP); Hiroto Tamiya (Tokyo, JP)

Assignee: NEC CORPORATION

G06F21/32

Abstract

Claims (64)

1 . A biometric authentication system comprising:

at least one processor; and

memory storing instructions,

wherein the instructions, when executed by the at least one processor, cause the biometric authentication system to:

generate, based on biometric information, initial values of (i) a template used for concealing biometric information and (ii) a verification key used for verification of the concealed biometric information,

store the template in a template storage and store the verification key in a verification key storage,

generate an update value;

update the template stored in the template storage by multiplying a value contained in the template by the update value, and

update the verification key stored in the verification key storage by multiplying a value contained in the verification key by the update value.

2 . The biometric authentication system according to claim 1 , wherein the instructions, when executed by the at least one processor, cause the biometric authentication system to generate a random number and use the random number as the update value.

3 . The biometric authentication system according to claim 1 wherein the instructions, when executed by the at least one processor, cause the biometric authentication system to:

generate concealed authentication information by concealing, using the template, the biometric information which is newly entered, and

determine whether the newly entered biometric information is acceptable by applying the verification key to the concealed authentication information.

4 . A template updating method for a biometric authentication system that comprises a template storage configured to store a template used for concealing biometric information and a verification key storage configured to store a verification key used for verification of the concealed biometric information, the method comprising:

generating, based on the biometric information, initial values of (i) the template and (ii) the verification key,

storing the template in the template storage and storing the verification key in the verification key storage,

generating an update value in the biometric authentication system;

updating the template stored in the template storage by multiplying a value contained in the template by the update value; and

updating the verification key stored in the verification key storage by multiplying a value contained in the verification key by the update value.

5 . The template updating method according to claim 4 , wherein the update value is generated using a random number generated in the biometric authentication system.

6 . The template updating method according to claim 4 , wherein the update value is generated by either a biometric authentication client device comprising the template storage or a biometric authentication server device comprising the verification key storage.

7 . The template updating method according to claim 4 , wherein

concealed authentication information is generated by concealing, using the template, the input biometric information, which is newly entered, and

a determination is made as to whether or not the newly entered biometric information is acceptable by applying the verification key to the concealed authentication information.

8 . A non-transitory computer-readable storage medium storing at least one program to be executed in a biometric authentication system comprising a template storage configured to store a template used for concealing biometric information, a verification key storage configured to store a verification key used for verifying the concealed biometric information, and at least one processor, wherein the at least one program, when executed by the at least one processor, causes the biometric authentication system to:

generate, based on biometric information, initial values of (i) the template and (ii) the verification key,

store the template in the template storage and store the verification key in the verification key storage,

generate an update value in the biometric authentication system,

update the template stored in the template storage by multiplying a value contained in the template by the update value, and

update the verification key stored in the verification key storage by multiplying a value contained in the verification key by the update value.

9 . The non-transitory computer-readable storage medium storing the at least one program according to claim 8 , wherein in the template update process, the update value is generated using the random number generated in the biometric authentication system.

10 . The non-transitory computer-readable storage medium storing the at least one program according to claim 8 , wherein

the template updating process is performed according to a program executed by a first arithmetic unit in a biometric authentication client device comprising the template storage,

the verification key updating process is performed by a program executed by a second arithmetic unit provided in a biometric authentication server device comprising the verification key storage, and

the update value generation process is performed by a program executed by either the first arithmetic unit or the second arithmetic unit.

11 . The non-transitory computer-readable storage medium storing the at least one program according to claim 8 , wherein the at least one program further comprises:

a concealed authentication information generation program for generating concealed authentication information by concealing, using the template, the biometric information which is newly entered; and

a determination program for determining whether the newly entered biometric information is acceptable by applying the verification key to the concealed authentication information.

12 . A biometric authentication client device comprising:

at least one processor; and

memory storing instructions,

wherein the instructions, when executed by the at least one processor, cause the biometric authentication client device to:

acquire input biometric information;

transmit the biometric information to a biometric authentication server device to cause the biometric authentication server device to:

generate, based on biometric information, initial values of (i) a template used for concealing biometric information and (ii) a verification key used for verification of the concealed biometric information;

store the verification key in a verification key storage;

transmit the template to the biometric authentication client device;

store the template in a template storage;

generate an update value;

update the template stored in the template storage by multiplying a value contained in the template by the update value; and

transmit the update value to a biometric authentication server device to cause the biometric authentication server device to update the verification key in the verification key storage by multiplying a value contained in the verification key by the update value.

13 . A biometric authentication server device comprising:

at least one processor; and

memory storing instructions,

wherein the instructions, when executed by the at least one processor, cause the biometric authentication server device to:

generate, based on biometric information, initial values of (i) a template used for concealing biometric information and (ii) a verification key used for verification of the concealed biometric information;

store the verification key in a verification key storage;

transmit the template to the biometric authentication client device to cause the biometric authentication client device to:

store the template in a template storage;

generate an update value;

update the template stored in the template storage by multiplying a value contained in the template by the update value; and

transmit the update value to the biometric authentication server device;

update the verification key stored in the verification key storage by multiplying a value contained in the verification key by the update value; and

transmit the update value to the biometric authentication client device storing the template.

Assignments (1)

Continuity (1)

References Cited (18)