Optical Covert Communication Based on Microwave Photonic Filter

Optical communication networks are easy to be eavesdropped by attackers, and traditional encryption algorithms have become more and more difficult to ensure the security of information transmission. Different from the traditional encryption algorithm, optical covert communication processes the signal at the physical layer, and improves the security and reliability of the system by hiding the optical signal in the public channel. Based on a typical microwave photonic filter, an optical covert communication scheme is proposed. On the one hand, the microwave photonic filter makes the scheme imperceptible. On the other hand, the randomness of complementary coding makes the scheme confidential. The feasibility of the scheme is analyzed theoretically, and the experimental results show that the covert channel is successfully transmitted over 50 km single-mode fiber.