An exemplary embodiment of secure wireless transmission of power using unidirectional communication signals from a wireless-power-receiving device. The method includes, receiving, from a wireless-power-transmitting device that includes a first communications radio, a first wireless-power-transmission signal at a wireless-power-receiving device that includes a second communications radio. In response to receiving the first wireless-power-transmission signal: broadcasting, via the second communications radio of the wireless-power-receiving device and without establishing a communications channel between the first and second communications radios, a data packet, the data packet including information identifying (i) at least one power requirement of a power source of the wireless-power-receiving device (ii) an amount of power received by the wireless-power-receiving device from the first wireless-power-transmission signal. After broadcasting the data packet, receiving, from the wireless-power-transmitting device, additional wireless-power-transmission signals at the wireless-power-receiving device, wherein the wireless-power-transmitting device transmits each of the additional wireless-power-transmission signals using a predetermined sequence of different transmission characteristics.