Mitigating Backdoor Attacks in Federated Learning through Noise-Guided Aggregation

19 Sept 2023 (modified: 11 Feb 2024)Submitted to ICLR 2024EveryoneRevisionsBibTeX
Primary Area: unsupervised, self-supervised, semi-supervised, and supervised representation learning
Code Of Ethics: I acknowledge that I and all co-authors of this work have read and commit to adhering to the ICLR Code of Ethics.
Keywords: Federated Learning, Backdoor Attacks, Generative Learning
Submission Guidelines: I certify that this submission complies with the submission instructions as described on https://iclr.cc/Conferences/2024/AuthorGuide.
TL;DR: We propose a Noise-guided robust aggregation (Nira) method in federated learning to defend against backdoor attacks.
Abstract: Backdoor attack in federated learning (FL) has attracted much attention in the literature due to its destructive power. Advanced backdoor defense methods mainly involve modifying the server's aggregation rule to filter out malicious models through some pre-defined metrics. However, calculating these metrics involves malicious models, leading to biased metrics and defense failure. Therefore, a straightforward approach is to design a metric not tainted by malicious models. For instance, if the server has private data to evaluate model performance, then model performance would be an effective metric for backdoor defense. However, directly introducing data-related information may cause privacy issues, we thus propose $\textit{n}$oise-gu$\textit{i}$ded $\textit{r}$obust $\textit{a}$ggregation, Nira, which trains and evaluates models using pure noise. Specifically, Nira constructs a noise dataset and shares it across the server and clients, enabling clients to train their models over the shared noise and local data. To ensure the generalizability of models trained on noise, Nira encourages clients to align their local data to shared noise in the representation space. Consequently, Nira can filter out models prior to aggregation according to the model performance, e.g., prediction accuracy on noise. We conduct extensive experiments to verify the effectiveness of Nira against backdoor attacks, demonstrating the superiority over previous works by a substantial margin.
Anonymous Url: I certify that there is no URL (e.g., github page) that could be used to find authors' identity.
No Acknowledgement Section: I certify that there is no acknowledgement section in this submission for double blind review.
Submission Number: 1917
Loading