Investigating Physical-Layer and Cross-Layer Security Technologies in Modern Networks

As attacks get more sophisticated, traditional network security hole fixes don’t always work. We need advanced, all-around security solutions to protect contact and data transmission in complex settings. This study proposes a comprehensive solution. This study includes physical-layer encryption (PLE), quantum key distribution (QKD), cross-layer intrusion detection systems (IDS), machine-learning-based hazard detection, and cross-layer protocol design. PLE reduces noise and encryption by ensuring secure communication, whereas QKD increases security via coupling and key changes. To secure networks, cross-layer IDS detects borders and unusual activity. Using machine learning, systems get smarter by categorizing threats and anticipating their occurrence. To ensure interaction safety, the cross-layer protocol employs quantum entanglement, updated keys, and translations. An ablation analysis shows how important each technique is, and detailed comparison studies with tables and figures show that this combined strategy does better than traditional methods in terms of throughput, latency, encryption strength, false positive rate, accuracy of detection, energy efficiency, protocol effectiveness, security score, and the number of false positives. This novel, low-cost technology protects networks and lets systems adapt to new threats, improving speed and reliability.