Security-Enhanced OFDM-PON Using Hybrid Chaotic System

A dual-field encryption scheme of an orthogonal frequency division multiplexing passive optical network (OFDM-PON) is proposed based on analog–digital hybrid chaotic system. In our scheme, the downstream data are encrypted in optical field, and the upstream data are encrypted in electrical field. The hybrid chaotic system circumvents the security vulnerabilities of both analog and digital chaos, e.g., the periodicity of digital chaos is masked by the analog one, and the time delay signature of the analog system is concealed by injecting digital chaos. Meanwhile, the key space dimension of the system is enlarged. Simulation results show both the feasibility and security of the proposed OFDM-PON system.