To enable a user to easily and safely transfer a part of his or her authority to other users.

This method comprises a step for a client being an authority transferring person to create an authentication ticket describing the range of authority and effectiveness of the authority to be transferred from the authority transferring person to an authority transferred person and to transfer the ticket to the authority transferred person, a step for the client being the authority transferred person to send the authentication ticket transferred from the authority transferring person to an authentication server and to receive authentication whether being an authentication transferred person regularly transferred with authority from the authority transferring person, a step for the authentication server to send a list describing the range of authority and effective date of the authority transferred by the authority transferring person to the client being the authority transferred person, and a step for the client being the authority transferred person to permit a substitutive operation of the authority transferred person in place of the authority transferring person within the limits of range of authority and effective date of the authority described in the list.