Abstract: A wireless authentication terminal that connects to a network via a wireless base station, the wireless authentication terminal comprises a communication unit that performs communication compliant with IEEE802.15.4, an authentication processing unit that transmits and receives communication messages and performs authentication processing for connecting to a network, a filter processing unit that changes the communication messages allowed to pass through between the communication unit and the authentication processing unit, an encryption level determination unit that determines a level at which the communication unit encrypts the communication message, and a control unit that controls an operation state of the filter processing unit and the encryption level determination unit based on the phase of the authentication processing in the authentication processing unit.