On the Robustness of Distributed Machine Learning against Transfer Attacks
Sébastien Andreina, Pascal Zimmer, Ghassan Karame
TL;DR
This work addresses the robustness of distributed machine learning when both learning and inference are distributed across heterogeneous workers. It analyzes transfer-based attacks and proposes a hybrid distributed paradigm with diverse training data, architectures, optimizers, and schedulers to reduce attack transferability, supported by theory and extensive CIFAR10/FashionMNIST experiments. Key findings show substantial improvements in robust accuracy (RA) across CW/SAM/CSE attacks, with RA gains up to around $40\%$ and minimal losses in clean accuracy, particularly as the number of nodes $N$ increases and hyperparameters are independently tuned. The results suggest that increasing node count and hyperparameter diversity can meaningfully enhance robustness in distributed ML, while diversity in architecture/optimizer/scheduler plays a lesser role, highlighting practical directions for robust, privacy-aware distributed deployments.
Abstract
Although distributed machine learning (distributed ML) is gaining considerable attention in the community, prior works have independently looked at instances of distributed ML in either the training or the inference phase. No prior work has examined the combined robustness stemming from distributing both the learning and the inference process. In this work, we explore, for the first time, the robustness of distributed ML models that are fully heterogeneous in training data, architecture, scheduler, optimizer, and other model parameters. Supported by theory and extensive experimental validation using CIFAR10 and FashionMNIST, we show that such properly distributed ML instantiations achieve across-the-board improvements in accuracy-robustness tradeoffs against state-of-the-art transfer-based attacks that could otherwise not be realized by current ensemble or federated learning instantiations. For instance, our experiments on CIFAR10 show that for the Common Weakness attack, one of the most powerful state-of-the-art transfer-based attacks, our method improves robust accuracy by up to 40%, with a minimal impact on clean task accuracy.
