PPBFL: A Privacy Protected Blockchain-based Federated Learning Model

With the rapid development of machine learning and growing concerns about data privacy, federated learning has become an increasingly prominent focus. However, challenges such as attacks on model parameters and the lack of incentive mechanisms hinder the effectiveness of federated learning. Therefore, we propose a Privacy Protected Blockchain-based Federated Learning Model (PPBFL) to enhance the security of federated learning and promote the active participation of nodes in model training. Blockchain ensures that model parameters stored in the InterPlanetary File System (IPFS) remain unaltered. A novel adaptive differential privacy addition algorithm is simultaneously applied to local and global models, preserving the privacy of local models and preventing a decrease in the security of the global model due to the presence of numerous local models in federated learning. Additionally, we introduce a new mix transactions mechanism to better protect the identity privacy of local training clients. Security analysis and experimental results demonstrate that PPBFL outperforms baseline methods in both model performance and security.