Physical secure enhancement in optical OFDMA-PON based on two-dimensional scrambling

This paper proposes a novel physical-enhanced chaotic secure strategy for optical OFDMA-PON based on two-dimensional (2-D) scrambling. In order to enhance the physical security, a multi-layer chaotic mapping is proposed to generate the scrambling vectors. It can enhance the chaotic characteristic of Logistic mapping and increase the key space. Furthermore, the 2-D scrambling jointly utilizing frequency subcarriers and time-slots can improve the system resistance to eavesdropper. The feasibility of 15.6 Gb/s 2-D encrypted 64QAM-OFDM downstream signal has been successfully demonstrated in the experiment. The robustness of the proposed method shows its prospect in future OFDM access network.