Intrusion detection-embedded chaotic encryption via hybrid modulation for data center interconnects.

We propose a chaotic encryption scheme embedded with intrusion detection to safeguard against unauthorized optical access in data center interconnects (DCIs). A hybrid modulation scheme is designed, combining two different modulation methods to achieve dynamic spectral efficiency by adjusting a segmentation parameter. Furthermore, a chaotic hybrid symbol permutation method is introduced to disrupt the distribution characteristics of the constellation sets. An intrusion detection mechanism based on two-stage constellation same-set ratio testing is proposed, using confidence intervals to distinguish between legitimate and unauthorized signals. Finally, the encrypted 56 Gbaud signal is verified over an 80 km link. The results demonstrate that the proposed scheme can effectively detect unauthorized optical access and provide adjustable spectral efficiency, thereby enhancing the resistance of DCIs to optical intrusion.