A second encrypted communication apparatus (300) operates as a PANA authentication client. If any of a plurality of events associated with PANA authentication occurs, a timer management unit (14) activates a timer among a plurality of timers that corresponds to the event that has occurred. When the timer activated by the timer management unit (14) expires, an authentication control unit (13) refers to management information which describes an operation procedure to be taken at timer expiration for each of the plurality of events and executes the operation procedure described in the management information regarding the event that has occurred.