# US 12,602,460 B2 · Information processing device and information processing method

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- Number: US 12,602,460 B2
- Document ID: US12602460B2
- Status: Granted
- Kind: B2
- Application number: 18/506,089
- Filed: 2023-11-09
- Published: 2024-07-25
- Granted: 2026-04-14
- Earliest claimed: 2023-01-23
- Assignees: Toshiba Tec Kabushiki Kaisha
- Applicants: Toshiba Tec Kabushiki Kaisha
- Inventors: Naoki Sekine
- Web page: https://patentgrep.com/patent/US12602460B2

## CPC

- G06F 21/316: {by observing the pattern of computer usage, e.g. typical user behaviour}
- G06F 21/31: User authentication
- H04L 63/083: {using passwords (cryptographic mechanisms or cryptographic arrangements for entity authentication using a predetermined code H04L9/3226)}
- G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N)
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)

## Abstract

An information processing device includes a memory that stores a plurality of pieces of user information each for authenticating a user and indicating previous access attempts and unsuccessful login attempts by the user, a communication interface circuit connectable to a terminal, and a processor configured to: in response to a login attempt from the terminal, acquire login information indicating a user from the terminal, search the memory for one of the pieces of user information corresponding to the user, determine a threshold value for determining whether to reject the login attempt at least based on the previous access attempts by the user, compare a number of the unsuccessful login attempts by the user with the determined threshold value, and determine whether to reject the login attempt based on a comparison result of the number of the unsuccessful login attempts and the threshold value.

## Claims

### Claim 1

An information processing device, comprising:
a memory that stores a plurality of pieces of user information each for authenticating a user and indicating previous access attempts and unsuccessful login attempts by the user;
a communication interface circuit connectable to a terminal; and
a processor configured to:
in response to a login attempt from the terminal, acquire login information indicating a user from the terminal,
search the memory for one of the pieces of user information corresponding to the user,
determine a threshold value for determining whether to reject the login attempt at least based on the previous access attempts by the user,
compare a number of the unsuccessful login attempts by the user with the determined threshold value, and
determine whether to reject the login attempt based on a comparison result of the number of the unsuccessful login attempts and the threshold value, wherein
each of the pieces of user information includes a password that was previously entered by a corresponding one of the users during a previous access attempt made by the corresponding one of the users,
the acquired login information includes a first password entered by the user at the login attempt, and
the processor is configured to:
calculate a degree of similarity between the first password and the previously entered password included in said one of the pieces of user information, and
determine the threshold value based on the calculated degree of similarity.

### Claim 2 (depends on 1)

The information processing device according to claim 1, wherein the processor determines to reject the login attempt when the number of the unsuccessful login attempts exceeds the threshold value.

### Claim 3 (depends on 2)

The information processing device according to claim 2, wherein
each of the pieces of user information includes a valid password, and
after the number of the unsuccessful login attempts exceeds the threshold value, the processor determines to reject the login attempt even when the first password matches a valid password included in said one of the pieces of user information.

### Claim 4 (depends on 1)

The information processing device according to claim 1, wherein the processor is configured to determine the threshold value based on a difference between a time of the login attempt and a time of a last one of the previous access attempts by the user.

### Claim 5 (depends on 4)

The information processing device according to claim 4, wherein the processor determines a smaller threshold value for a greater difference between a time of the login attempt and a time of the last one of the previous access attempts.

### Claim 6 (depends on 1)

The information processing device according to claim 1, wherein the processor determines a smaller threshold value for a smaller degree of similarity between the first password and the previously entered password.

### Claim 7 (depends on 1)

The information processing device according to claim 1, wherein the processor is configured to determine, as the degree of similarity, a distance of strings of the first password and the previously entered password.

### Claim 8 (depends on 1)

The information processing device according to claim 1, wherein the processor is configured to determine the threshold value based on a frequency of the previous access attempts within a particular period.

### Claim 9 (depends on 1)

The information processing device according to claim 1, wherein the processor is configured to determine the threshold value based on a number of packets related to the previous access attempts within a particular period.

### Claim 10

An information processing method performed by an information processing device, the method comprising:
storing, in a memory, a plurality of pieces of user information each for authenticating a user of the information processing device and indicating previous access attempts to the information processing device and unsuccessful login attempts by the user;
in response to a login attempt from a terminal, acquiring login information indicating a user from the terminal;
searching the memory for one of the pieces of user information corresponding to the user;
determining a threshold value for determining whether to reject the login attempt at least based on the previous access attempts by the user;
comparing a number of the unsuccessful login attempts by the user with the determined threshold value; and
determining whether to reject the login attempt based on a comparison result of the number of the unsuccessful login attempts and the threshold value, wherein
each of the pieces of user information includes a password that was previously entered by a corresponding one of the users during a previous access attempt made by the corresponding one of the users,
the acquired login information includes a first password entered by the user at the login attempt, and
determining the threshold value includes:
calculating a degree of similarity between the first password and the previously entered password included in said one of the pieces of user information, and
determining the threshold value based on the calculated degree of similarity.

### Claim 11

A non-transitory computer readable medium storing a program causing a computer to execute a method comprising:
storing, in a memory, a plurality of pieces of user information each for authenticating a user of an information processing device and indicating previous access attempts to the information processing device and unsuccessful login attempts by the user;
in response to a login attempt from a terminal, acquiring login information indicating a user from the terminal;
searching the memory for one of the pieces of user information corresponding to the user;
determining a threshold value for determining whether to reject the login attempt at least based on the previous access attempts by the user;
comparing a number of the unsuccessful login attempts by the user with the determined threshold value; and
determining whether to reject the login attempt based on a comparison result of the number of the unsuccessful login attempts and the threshold value, wherein
each of the pieces of user information includes a password that was previously entered by a corresponding one of the users during a previous access attempt made by the corresponding one of the users,
the acquired login information includes a first password entered by the user at the login attempt, and
determining the threshold value includes:
calculating a degree of similarity between the first password and the previously entered password included in said one of the pieces of user information, and
determining the threshold value based on the calculated degree of similarity.