Quantum-enhanced privacy aggregation for healthcare monitoring in wireless body area networks

Abstract The rapid proliferation of wireless body area networks (WBANs) has intensified the need for architectures that simultaneously guarantee quantum-resistant security, patient privacy, and clinical-grade diagnostic fidelity. This paper introduces quantum-enhanced privacy aggregation (QEPA), a framework that establishes a new state-of-the-art in secure IoMT by fulfilling the “Triple Constraint” of Privacy, Robustness, and Diagnostic Fidelity, albeit with a critical dependency on line-of-sight quantum channels. QEPA’s defense-in-depth architecture integrates four synergistic innovations: (i) BB84 Quantum Key Distribution providing information-theoretic security ( $$\Pr [\text {eavesdrop}] \le 2^{-8168}$$ ), though constrained to static or low-mobility scenarios due to free-space optical requirements; (ii) lightweight homomorphic encryption (LightHE) over $$\mathbb {Z}_{2^{40}}[x]/(x^{4096}+1)$$ enabling exact integer arithmetic with $$\mathcal {O}(d \log d)$$ complexity; (iii) Hierarchical Federated Learning with Krum-based Byzantine resilience against $$f/N = 1/3$$ compromised nodes; and (iv) SHAP-based explainable AI achieving 97.8% attribution fidelity against cardiologist-validated ground truth. Evaluated on a large-scale WBAN with $$N=1500$$ sensors across 200 virtual patients, QEPA demonstrates near-optimal utility, achieving 96.8% diagnostic accuracy (only 0.3% below FedAvg) with NRMSE = $$9.7 \times 10^{-3}$$ , while providing unprecedented efficiency: 8.05 $$\times$$ lower latency (31.8 ms) and 5.96 $$\times$$ lower energy (3.32 mJ) versus Paillier, alongside 17.1 $$\times$$ communication compression (7.68 kbit). Critically, QEPA reduces membership inference risk to 1.5% (vs. 28.3% in FedAvg) while maintaining $$\epsilon \le 0.01$$ differential privacy and resisting quantum attacks with $$>2^{400}$$ -operation hardness. While the current implementation’s reliance on line-of-sight QKD limits deployment in high-mobility clinical environments, these results establish QEPA as quantum-safe framework suitable for FDA-cleared life-critical medical telemetry in controlled settings, with clear pathways toward non-line-of-sight quantum networking.