The present invention provides a technology of effectively avoiding tracing on a terminal performed with an identification number being a target and DoS attack without making any significant changes to a communication system.In the wireless communication system of the present invention, under a control of a control communication processing portion 113 of an access point, a hash function arithmetic operation processing portion 112 generates a third identification number to be updated using a current identification number, hash key and random number for any wireless communication terminal, a control communication processing portion 113 sends an update instruction signal containing the random number to the wireless communication terminal and updates the current identification number stored in the identification number storage portion 121 to a second identification number. When the wireless communication terminal receives an update instruction signal, the current identification number is updated to the second identification number and the hash function arithmetic operation processing portion generates a third identification number using the current identification number, hash key and random number stored in the self number storage portion.