Quantum-enhanced autonomous DNS over HTTPS security (CITADEL-DoH)

The security of DNS over HTTPS (DoH) faces escalating challenges driven by advances in quantum computing, adversarial artificial intelligence, and increasingly sophisticated attack strategies targeting encrypted communication channels. While existing protection mechanisms remain effective against known threats, they exhibit structural limitations when confronted with adaptive, multi-layered, and post-quantum adversarial models. To address these deficiencies, this study introduces CITADEL-DoH, a unified security architecture integrating quantum-resistant AI through hybrid LWE-CKKS encryption, decentralised trust enforcement via a proof-of-trust (PoT) protocol combined with federated byzantine agreement (FBA), and hardware-assisted integrity verification using FPGA-accelerated verifiable delay functions (VDFs). Novel contributions further include the application of topological data analysis (TDA) for encrypted anomaly detection and liquid time-constant (LTC) networks for adaptive traffic modelling. Experimental evaluation demonstrates 99.3% detection accuracy for domain generation algorithm (DGA) attacks and sub-millisecond query verification latency. Results confirm enhanced scalability, resilience to evasion, and robustness against emerging quantum-era threats.