Brownian Motion Encryption for Physical-Layer Security Improvement in CO-OFDM-PON

This letter proposes a hybrid symbol substitution and interleaving technique based on Brownian motion for security improvement in the coherent optical orthogonal frequency division multiplexed (CO-OFDM) passive optical network systems. The parameters of Brownian motion are generated by using the chaotic maps. Brownian motion-based hybrid symbol substitution and symbol interleaving are used to encrypt the OFDM signals. In our demonstration, 36.67-Gb/s encrypted OFDM signals are experimentally transmitted over a 100-km single mode fiber. Experimental results verify that the proposed technique is promising for physical-layer security-enhanced CO-OFDM-based access network systems.