Secure Strategy for OFDM-PON Using Digital Chaos Algorithm With Fixed-Point Implementation

We propose a scheme for security improvement in the orthogonal frequency division multiplexing (OFDM) passive optical network based on a fixed-point digital chaos algorithm with a low computational precision. The dynamical degradation problem is improved by introducing the transmitted data as a perturbation source. In our demonstration, aperiodic key streams are generated from a fixed-point chaos with its trajectory disturbed by the upstream data, and then used to encrypt the downstream data. A 7.64-Gbps encrypted OFDM signal is successfully transmitted over a 25-km standard single mode fiber. The experimental results indicate that the proposed scheme suggests an effective and promising solution to meet the demands for low implementation complexity and high security level.