Theory and performance analyses in secure CO-OFDM transmission system based on two-dimensional permutation

Security in optical orthogonal frequency division multiplexing (OFDM) network has traditionally been considered to be addressed in higher layers of the network, while the physical layer is vulnerable to various attacks. As the dramatic increase of network capacity and secret sensitivity, the issue of physical layer security becomes more and more important. This paper proposes a novel physical-enhanced chaotic secure strategy for optical OFDM system based on two-dimensional (2-D) permutation. A controlled Logistic map is adopted for the chaotic mapping. The 2-D secure algorithm jointly utilizes frequency subcarriers and time-slots permutation to guarantee the secure of physical layer security of optical OFDM transmission system. This method performs dynamic permutations over frequency and time dimensions, resulting in a robust protection on transmitted information. Experiment is performed to confirm the good effectiveness of the proposed method.