Privacy Preserving using Decentralized Federated Learning with Partial Dense-layer Weight Sharing
摘要
Federated Learning (FL) enables participants to collaboratively train a model without sharing raw data. Traditional FL models depend on a central server and full model sharing, leading to a significant issue in healthcare related to privacy concerns and communication overhead. However, to address such issues, we introduce Decentralized Federated Learning with Partial Head Sharing DFL-PHS, a framework that eliminates the central server, allowing peer-to-peer model updates sharing. Instead of sharing entire model parameters, participants only share a subset of weights from the final dense layers, minimizing information breach while maintaining the model’s performance. We apply our proposed framework to COVID-19 chest X-ray binary classification, where we conduct a comparative study across four scenarios: local training, centralized FL (CFL), single-site training (SST) and DFL-PHS. Evaluations are conducted on three dataset sizes (small, medium, large) and four partial sharing ratios (25%, 50%, 75%, 100%). We also assess privacy through a Membership-Inference Attack (MIA), with only 25% head sharing, the attack operates at or below chance (ROC-AUC 0.37 with advantage -0.30 on the small scale and ROC–AUC