Random Gradient Masking as a Defensive Measure to Deep Leakage in Federated Learning
Joon Kim, Sejin Park
TL;DR
Deep Leakage from Gradients (DLG) challenges privacy in Federated Learning by enabling reconstruction of private data from gradients. The paper introduces Random Gradient Masking and compares it with Noising, Clipping, and Pruning across MNIST, CIFAR-10, and lfw, using SSIM-based leakage assessments and convergence tests. Key findings show Masking and Clipping defend against DLG with minimal impact on training accuracy, while Noising and Pruning can degrade performance; a BatchNorm-specific masking workaround expands applicability. The work provides a practical privacy-utility toolkit for FL, demonstrating scalable defenses that preserve model utility while reducing leakage risk.
Abstract
Federated Learning(FL), in theory, preserves privacy of individual clients' data while producing quality machine learning models. However, attacks such as Deep Leakage from Gradients(DLG) severely question the practicality of FL. In this paper, we empirically evaluate the efficacy of four defensive methods against DLG: Masking, Clipping, Pruning, and Noising. Masking, while only previously studied as a way to compress information during parameter transfer, shows surprisingly robust defensive utility when compared to the other three established methods. Our experimentation is two-fold. We first evaluate the minimum hyperparameter threshold for each method across MNIST, CIFAR-10, and lfw datasets. Then, we train FL clients with each method and their minimum threshold values to investigate the trade-off between DLG defense and training performance. Results reveal that Masking and Clipping show near to none degradation in performance while obfuscating enough information to effectively defend against DLG.
