ALI-DPFL: Differentially Private Federated Learning with Adaptive Local Iterations
Xinpeng Ling, Jie Fu, Kuncan Wang, Haitao Liu, Zhili Chen
TL;DR
The work tackles privacy-preserving federated learning when both the privacy budget and the number of communication rounds are constrained. It derives a convergence bound $h( au)$ that depends on the number of local DPSGD iterations $ au$ and uses this to compute an adaptive $ au^*$ each round, forming the ALI-DPFL algorithm. Empirical results on MNIST, Fashion-MNIST, and CIFAR-10 show that ALI-DPFL outperforms fixed-τ FedAvg+DP, PE-DPFL, and Adap DP-FL across IID and non-IID data, especially under stringent resource constraints. Privacy guarantees are established via Rényi DP with composition, ensuring DP under the adaptive scheme. The approach offers practical benefits for resource-limited FL deployments by achieving faster convergence and higher accuracy while maintaining formal privacy protections, with code available at the provided GitHub link.
Abstract
Federated Learning (FL) is a distributed machine learning technique that allows model training among multiple devices or organizations by sharing training parameters instead of raw data. However, adversaries can still infer individual information through inference attacks (e.g. differential attacks) on these training parameters. As a result, Differential Privacy (DP) has been widely used in FL to prevent such attacks. We consider differentially private federated learning in a resource-constrained scenario, where both privacy budget and communication rounds are constrained. By theoretically analyzing the convergence, we can find the optimal number of local DPSGD iterations for clients between any two sequential global updates. Based on this, we design an algorithm of Differentially Private Federated Learning with Adaptive Local Iterations (ALI-DPFL). We experiment our algorithm on the MNIST, FashionMNIST and Cifar10 datasets, and demonstrate significantly better performances than previous work in the resource-constraint scenario. Code is available at https://github.com/cheng-t/ALI-DPFL.
