A Novel Covert Communication Method using Ambient Backscatter Communications

This paper introduces a novel solution to enable covert communication in wireless systems by using ambient backscatter communication technology. In the considered system, the original message at the transmitter is first divided into two parts: (i) active transmit message and (ii) backscatter message. Then, the active transmit message is transmitted by using the conventional wireless transmission method while the backscatter message is transmitted by backscattering the active transmit signals via an ambient backscatter tag. As the backscatter tag does not generate any active signals, it is intractable for the adversary to detect the backscatter message. Therefore, secret information, e.g., secret key for decryption, can be carried by the backscattered message, making the adversary unable to decode the original message. Simulation results demonstrate that our proposed solution can help to significantly enhance security protection for communication systems.