Chaotic 4D Modulation With Intrusion Detection for Secure Data Centers

Digital chaotic physical layer encryption plays a crucial role in safeguarding data transmission security within data center interconnections (DCIs). However, existing encryption schemes remain vulnerable to active attacks, such as illegal optical access. To address these challenges, we propose a chaotic four-dimensional (4D) modulation scheme integrated with intrusion detection, which aims at enhancing the security of DCIs. The proposed scheme utilizes chaotic permutation and substitution encryption during the 4D modulation process, along with cross-polarization permutation to protect performance gains. Additionally, we propose a cost-effective and easily implementable intrusion detection method based on constellation same set ratio (CSSR). By dynamically adjusting the confidence region through CSSR analysis, the scheme enhances its robustness against noise interference. The proposed scheme is validated through 392 Gbit/s encrypted data transmission over an 80 km standard single-mode fiber, simulating attack scenarios including optical eavesdropping and illegal optical access. These results demonstrate that the proposed scheme achieves an information entropy of 3.999956, with a key space extending to 10³⁶⁰. The intrusion detection mechanism provides dynamic noise tolerance without requiring additional equipment, enabling the identification of illegal signals across various optical signal-to-noise ratios. This scheme provides a novel approach for resisting illegal optical access at the physical layer, with potential application in secure DCIs.