Information processing device and information processing method

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.

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.