arXiv AI

StratFL: Countering Covert Model Poisoning Attacks with Strategic Federated Learning

The paper introduces StratFL, a strategy for federated learning that counters covert model poisoning attacks by modeling the interaction between the server and attacker as an imperfect repeated game. It proposes new belief‑update algorithms for both parties and an adversarial search method to detect and mitigate intermittent poisoned updates. Experiments on MNIST and CIFAR‑10 show that StratFL improves accuracy by about 10% over existing defenses while demonstrating convergence of the belief updates across various security scenarios.

arXiv AI
Sep 24

When Clients Are Orchestrated: Strategic Gradient Manipulation to Defeat Federated Learning Servers with Efficient Defense

The paper introduces Fed-ADR, a coordinated attack framework where a malicious orchestrator server directs heterogeneous adversarial clients to adapt their gradient updates in real time, thereby evading existing federated learning defenses and drastically reducing global model accuracy. It also presents a lightweight detection mechanism that estimates true client gradients from historical data to spot coordinated attacks, and an in-situ recovery method that restores model performance without restarting training. Experiments on MNIST, Fashion‑MNIST, and CIFAR‑10 show the attack can drop accuracy from over 90% to below 10%, while the defense can recover accuracy to above 90% within a few rounds at a computational cost at least 20× lower than retraining from scratch.

By Mohamed Shaaban, Ahmed Abdelnaby, Mohamed Elmahallawy
arXiv Machine Learning
Aug 27

Rethinking the Transferable Adversarial Attacks and Robust Defense in Federated Learning

The paper investigates how adversarial examples transfer between client models in federated learning and explores the relationship between these examples and client data distributions. It proposes a defense strategy based on adversarial training that leverages the transferability of model robustness. Experiments on real-life datasets demonstrate that the new attack and defense methods outperform existing state‑of‑the‑art approaches.

By Zuobin Xiong, Deval Mukherjee, Homook Cho, Wei Li
arXiv Machine Learning
Sep 23

FedNIA: Noise-Induced Activation Analysis for Mitigating Data Poisoning in Federated Learning

FedNIA is a defense framework for federated learning that identifies and excludes malicious clients without needing a central test dataset. It works by injecting random noise inputs and analyzing layerwise activation patterns with an autoencoder to detect abnormal behaviors caused by data poisoning. The method can counter various attack types—including sample poisoning, label flipping, and backdoors—even when multiple attackers collaborate, and shows strong performance on non‑iid federated datasets.

By Ehsan Hallaji, Roozbeh Razavi-Far, Mehrdad Saif
arXiv Machine Learning
Oct 22

Remote Rowhammer Attack using Adversarial Observations on Federated Learning Clients

The paper demonstrates a novel remote Rowhammer attack that targets federated learning (FL) servers by manipulating client sensor observations to induce repetitive clustered memory updates. Using a reinforcement learning attacker, the authors show that they can achieve approximately 70% repeated update rate in FL systems with sparse updates, leading to bit‑flips in the server’s DRAM during tasks such as automatic speech recognition and CIFAR‑10 classification. This work highlights a previously underexplored vulnerability where client‑side adversarial behavior can compromise server memory integrity in FL environments.

By Jinsheng Yuan, Yuhang Hao, Weisi Guo, Yun Wu, Chongyan Gu