Intelligent medical cyber-physical systems in digital healthcare: a post-quantum secure multimodal transformer framework
摘要
The large-scale digitalization of healthcare infrastructures has accelerated the deployment of Medical Cyber-Physical Systems (MCPS), which integrate wearable sensors, diagnostic imaging devices, hospital information systems, and cloud-edge computing platforms. However, modern MCPS environments face critical challenges, including heterogeneous multimodal data fusion, real-time analytics under high-throughput medical streams, interoperability constraints, and increasing vulnerability to quantum-enabled cyber threats. Conventional cryptographic schemes such as RSA and ECC are no longer considered future-resilient in the post-quantum era. To address these limitations, this study proposes a Post-Quantum Secure Multimodal Transformer-based MCPS framework designed for intelligent, scalable, and quantum-resilient healthcare data digitalization. The proposed architecture integrates CRYSTALS-Kyber lattice-based key encapsulation and CRYSTALS-Dilithium digital signature schemes to ensure post-quantum secure communication among edge medical devices and centralized clinical servers. A Multimodal Cross-Attention Transformer (MCAT) is introduced to jointly learn global contextual representations from structured Electronic Health Records (EHR), physiological signal streams, and medical imaging data. Unlike conventional CNN-RNN pipelines, the proposed transformer architecture models long-range dependencies and cross-modal correlations through hierarchical self-attention and adaptive modality weighting mechanisms. Additionally, Bayesian Optimization (BO), Grey Wolf Optimization (GWO), and Whale Optimization Algorithm (WOA) are employed to enhance model convergence stability and predictive generalization under heterogeneous clinical distributions. The framework is experimentally validated using publicly available healthcare datasets, including MIMIC-III (clinical tabular data), PhysioNet ECG datasets, and MedMNIST imaging benchmarks. The proposed system achieves 98.36% classification accuracy, 97.82% precision, 98.11% recall, 97.96% F1-score, and an AUC of 0.991 for disease risk prediction and anomaly detection tasks. Security evaluation demonstrates 36.4% improved resilience against simulated quantum cryptanalytic attacks compared to ECC-based MCPS implementations, while maintaining acceptable encryption latency suitable for real-time clinical environments.