arXiv Machine Learning

SWB-DM: A Calibrated Sliced-Wasserstein-Barycenter Aggregator with Delayed-Momentum Caching for Byzantine-Robust Federated Learning under Partial Participation

The paper introduces SWB-DM, a Byzantine‑robust federated learning aggregator that treats each slice of a client update as a one‑dimensional distribution, computes a trimmed Wasserstein barycenter across clients, and uses a medoid‑based gauge‑fixing step to recover coordinate identity. It further incorporates delayed‑momentum caching to decouple robustness from the specific clients sampled each round. Extensive experiments on CIFAR‑10, CIFAR‑100, FEMNIST, and a 500‑client scalability run reveal distinct failure modes of existing defenses and demonstrate that SWB‑DM achieves significant gains, especially when compared under equal round budgets.

arXiv Machine Learning
Oct 15

A Byzantine-Robust Federated Learning with Nesterov Momentum

The paper introduces Byrd-NAFL, a Byzantine‑robust federated learning algorithm that incorporates Nesterov momentum at the server while keeping workers stateless. It applies any soft γ‑Byzantine resilient aggregation rule and provides finite‑time convergence guarantees for smooth non‑convex losses across all momentum factors β∈[0,1). Experiments on MNIST, CIFAR‑10, and Sentiment140 demonstrate faster convergence and higher accuracy than existing benchmarks under various attacks.

By Lihan Xu, Xiaoyi Fan, Gang Wang, Runhao Zeng, Xiping Hu, Yanjie Dong
arXiv AI
1d ago

FedReason: Large Language Models as Weight-Space Meta-Aggregators for Heterogeneous Federated Learning

FedReason introduces a large language model (LLM) that dynamically selects aggregation rules for federated learning by inspecting client model weights in a sandboxed environment. The LLM evaluates candidate rules on a small proxy dataset and submits a Python program that the server executes until the next call, defaulting to FedAvg if the output is invalid. Experiments on CIFAR-10 and CIFAR-100 with ResNet-18 under various heterogeneity and Byzantine scenarios show FedReason outperforming FedAvg by an average of 1.26 percentage points and matching the best server‑side rule on CIFAR‑100, while incurring modest API costs.

By Ali Mohammadi Ruzbahani, Abbas Yazdinejad, Hadis Karimipour
arXiv Machine Learning
Sep 7

Resilience Beyond Stationary Client Unavailability: Unlocking Efficient and Unbiased Federated Learning

The paper introduces FedSWE, a federated learning algorithm designed to handle non‑stationary and heterogeneous client availability without requiring prior real‑time knowledge of which devices are online. FedSWE compensates for missed computations, stabilizes global updates, and mixes local updates through implicit gossiping, all while adding only modest memory and computational overhead. The authors prove that FedSWE converges to a stationary point for non‑convex objectives and achieves linear speedup in certain scenarios, and they validate these claims with experiments on real‑world datasets featuring diverse client unavailability patterns.

By Ming Xiang, Stratis Ioannidis, Edmund Yeh, Carlee Joe-Wong, Lili Su
arXiv Machine Learning
Sep 23

Communication-Efficient Byzantine-Robust Federated Conformal Prediction via Partial Sharing

PRISM‑FCP is a federated conformal prediction framework that achieves Byzantine robustness while reducing communication costs. It does so by partially sharing model updates—transmitting only a subset of parameters per round—to dampen the influence of poisoned clients during training, and by filtering out suspected Byzantine clients during calibration using histogram‑based techniques. Experiments on synthetic data and UCI datasets show that PRISM‑FCP maintains near‑nominal coverage and offers favorable trade‑offs between communication overhead and predictive performance.

By Ehsan Lari, Reza Arablouei, Stefan Werner