Phase Masking and Time-Frequency Chaotic Encryption for DFMA-PON

We propose a novel physical layer security-enhanced digital filter multiple access-based passive optical network (DFMA-PON), for the first time to our best knowledge, by using phase masking and hybrid time-frequency domain chaotic scrambling. In the proposed secure DFMA-PON, all digital orthogonal filters have different random phase and the random phase is controlled by a hyperchaotic Chen system. The hyperchaotic Chen system is also adopted for the generation of scrambling matrices. In our demonstration, an encrypted signal has been experimentally transmitted over a 25-km standard single mode fiber in an intensity modulation/direct-detection DFMA-PON system. The experimental results verify that various attacks can be effectively prevented and indicate the proposed scheme as a promising solution for physical layer secure DFMA-PON systems.