Authentication system for authenticating communication terminal

An authentication device for repeatedly performing an authentication process on a communication terminal each time a predetermined period of effective authentication elapses, comprising:

• a flag manager for managing whether the communication terminal whose authentication has been successful is in an operational state or an aborted state;
• a timer manager for counting said predetermined period for the communication terminal, and stops counting said predetermined period while said communication terminal is in the aborted state as determined by said flag manager;
• and
• an authentication processor for performing the authentication process in response to a request from said communication terminal or the elapse of said predetermined period in said timer manager, and keeping the authentication effective for the communication terminal whose authentication has been successful until said predetermined period expires as determined by said timer manager.

A method of authentication in a system for repeatedly performing an authentication process on a communication terminal each time a predetermined period of effective authentication elapses, comprising the steps of:

• starting counting said predetermined period for the communication terminal whose authentication has been successful;
• stopping counting said predetermined period and keeps the authentication effective for the communication terminal while said communication terminal is in an aborted state;
• and
• performing said authentication process again on said communication terminal when said predetermined period elapses.

A program for operating a computer as an authentication device for repeatedly performing an authentication process on a communication terminal each time a predetermined period of effective authentication elapses, said program controlling said computer to perform a process comprising the steps of:

• starting counting said predetermined period for the communication terminal whose authentication has been successful;
• stopping counting said predetermined period and keeps the authentication effective for the communication terminal while said communication terminal is in an aborted state;
• and
• performing said authentication process again on said communication terminal when said predetermined period elapses.

A communication terminal for being repeatedly authenticated each time a predetermined period of effective authentication elapses, comprising:

• an aborted state manager for managing whether the communication terminal is to be in an operational state or an aborted state;
• an information processor for processing information when the communication terminal is held in the operational state by said aborted state manager, and indicating a transition to said aborted state to an authentication device when the communication terminal changes from said operational state to said aborted state;
• and
• a communication function unit for sending and receiving packets while the communication terminal is held in the aborted state by said aborted state manager, and instructing said aborted state manager to bring the communication terminal into the operational state when the communication function unit receives a packet indicative of a transition to the operational state.