Privacy-Preserving Federated Learning Architectures for Decentralized Multi-Institutional Healthcare Diagnostics
Modern clinical research frequently encounters insurmountable regulatory and ethical barriers when attempting to pool sensitive patient datasets across disparate international hospital networks due to strict medical privacy mandates such as HIPAA and GDPR. This paper proposes a novel decentralized federated learning framework integrated with localized differential privacy mechanisms, enabling multiple clinical institutions to collaboratively train robust diagnostic neural networks without transmitting raw patient records across server boundaries. By embedding cryptographic secure aggregation protocols alongside adaptive noise addition, our architecture neutralizes gradient inversion attacks while preserving model convergence rates. We empirically evaluate the framework across ten distinct clinical datasets comprising multi-center magnetic resonance imaging scans and longitudinal electronic health records. Our experimental benchmarks demonstrate that the decentralized models achieve diagnostic accuracy metrics statistically indistinguishable from centralized training paradigms, suffering a negligible degradation of less than 0.8% in area under the receiver operating characteristic curve (AUC-ROC). Furthermore, we analyze computational overhead, communication bandwidth consumption, and resilience against Byzantine node failures during asynchronous model updates. The findings establish that privacy-preserving federated networks provide an indispensable technological foundation for cross-institutional medical AI collaboration, safeguarding individual confidentiality while maximizing population-level diagnostic generalizability and clinical discovery in the digital era.