A method for mutual authentication that includes establishing a first inductive coupling between a wireless-power receiver and a wireless-power transmitter to transfer power from the wireless-power transmitter to the wireless-power receiver by a power signal and using the power signal to transmit a first response to a physically unclonable function to the wireless-power transmitter. The method further including generating a second response to the physically unclonable function and communicating information derived from the second response to initiate a mutual authentication process between the wireless-power receiver and the wireless-power transmitter during a subsequent inductive coupling.