System and method for authentication

An authentication method performed by a server device comprised of a processor that executes a program stored within a memory, the authentication method comprising:

• receiving, from a terminal, an authentication assertion for authentication of a user of the terminal;
• generating a new challenge using time information included in the authentication assertion and a previous challenge used in a previous authentication process with the terminal;
• verifying the authentication assertion using the new challenge;
• and
• transmitting an authentication result for the user of the terminal to the terminal based upon the verifying of the authentication assertion.

A terminal device, comprising:

• a processor;
• a memory;
• and
• a program including a plurality of instructions stored within the memory, the processor to execute the instructions to perform a method comprising:
• storing a first authentication request message received from an authentication server;
• generating a new challenge using a previous challenge used in a previous authentication process when a network connection to the authentication server is not possible;
• generating a second and newer authentication request message by replacing a challenge included in the first authentication request message with the new challenge;
• generating an authentication assertion by performing biometric authentication using the second authentication request message;
• and
• storing the generated authentication assertion.

A server device, comprising:

• a processor;
• a memory;
• and
• a program including a plurality of instructions stored within the memory, wherein the processor executes the instructions to perform a method comprising:
• receiving, from a terminal, an authentication assertion for authentication of a user of the terminal;
• generating a new challenge using time information included in the authentication assertion and a previous challenge used in a previous authentication process with the terminal;
• verifying the authentication assertion using the new challenge;
• and
• transmitting an authentication result for the user of the terminal to the terminal based upon the verifying of the authentication assertion.