Chaotic digital filter-based physical layer security with data-assisted tri-level encryption for heterogeneous access networks

Due to the increasing demand for robust network cybersecurity, future communication technologies must consider security as a mandatory design feature. However, existing physical layer security techniques can be excessively complex and too expensive to support resource-constrained devices in heterogeneous access networks with high connection densities. To address this challenge, a physical layer security technique employing chaotic digital filters (CDFs) with private security keys is proposed and experimentally validated, for the first time, in a 12 Gbit/s intensity modulation and direct detection optical system with a 25 km standard single-mode fiber. Noise-like private security key-based CDFs have security key-dependent changes in amplitude and phase frequency response, with permutation entropies of $\gt 0.99$, thus achieving data-assisted tri-level encryption by directly distorting the data signals, inducing interferences between data signals, and also intensifying the interferences via illegal detections. As CDFs are digitally integrable and offer features of “security-by-design,” “openness-by-design,” and “dynamic security at the traffic level,” the proposed technique facilitates an open and interoperable security solution with the utmost security for heterogeneous access networks.