Embodiments are directed to a system for transferring power wirelessly from a transmitter to a receiver, the transmitter having a transmitter processor and a transmitter antenna. The system includes the transmitter processor configured to convert electric power signals to an electromagnetic field (EMF); associate each of a plurality of keys with one of a plurality of operating frequencies, and store the plurality of keys associated with the plurality of operating frequencies in a table; select one of the plurality of operating frequencies stored in the table as an active operating frequency, wherein the active operating frequency is assigned as the current operating frequency of the transmitter antenna, and wherein the key associated with the active operating frequency is assigned as an active key; wirelessly transmit to the receiver the EMF at the active operating frequency; and wirelessly transmit to the receiver the table and an identification of the active key.