arXiv Machine Learning

Catastrophic Overfitting is Weight Drift the Training Loss Cannot See

arXiv AI
Jun 2

SORA: Free Second-Order Attacks in Fast Adversarial Training

arXiv:2606. 00738v1 Announce Type: cross Abstract: Adversarial Training (AT) is a leading defense against adversarial examples but often suffers from Catastrophic Overfitting (CO) in efficient single-step variants, where robustness to multi-step attacks collapses despite high single-step performance.

By Mazdak Teymourian, Ramtin Moslemi, Farzan Rahmani, Mohammad Hossein Rohban
arXiv AI
Oct 26

Catastrophic Overfitting, Entropy Gap and Participation Ratio: A Noiseless $l^p$ Norm Solution for Fast Adversarial Training

arXiv:2505. 02360v3 Announce Type: replace-cross Abstract: Adversarial training is a cornerstone of robust deep learning, but fast methods like the Fast Gradient Sign Method (FGSM) often suffer from Catastrophic Overfitting (CO), where models become robust to single-step attacks but fail against multi-step variants.

By Fares B. Mehouachi, Saif Eddin Jabari
arXiv Machine Learning
Sep 24

Median Temporal Ensembling: Training-Free Robust Aggregation for Action-Chunked Visuomotor Policies

The paper introduces Median Temporal Ensembling, a training‑free aggregation method for action‑chunked visuomotor policies that replaces the standard exponential weighted mean with a coordinate‑wise median. This approach remains robust against adversarial corruption, maintaining a high recovery rate even as attack strength increases, and performs at least as well as the mean across numerous configurations while improving in many cases. It also handles non‑adversarial failures such as blank camera frames and shows limited impact on clean data, though it cannot counteract uniform shifts applied to all predictions.

By Yuhang Jiang
arXiv AI
3d ago

SecPO: Principled Adversarial Training for Prompt Injection Security

SecPO introduces a principled adversarial training framework to defend large language models against prompt injection attacks. By approximating an ideal injection‑invariant reference model and employing a new SecPO loss, the authors improve security while preserving utility. Combined with an efficient adversarial training pipeline that synthesizes strong injected inputs, the resulting SecPO + AT model significantly reduces attack success rates compared to existing defenses and maintains performance across multiple benchmarks.

By Sizhe Chen, Yibo Peng, Jaewon Chang, Chawin Sitawarin, David Wagner
arXiv Machine Learning
Oct 22

ExGrad: Beyond Suppression - Explicit Clean-Gradient Subtraction in Adversarial Training

ExGrad introduces explicit clean‑gradient subtraction in adversarial training by constructing clean‑input, adversarial‑input, and adversarial‑weight‑perturbed gradients and solving a globally solvable three‑variable problem to select coefficients. Across CIFAR‑10, CIFAR‑100, and ImageNet‑100, ExGrad consistently outperforms AWP and PGD‑AT, with the strongest gains at larger affine radii. The method demonstrates that negative clean coefficients, when properly tuned, improve robust accuracy without sacrificing clean performance.

By Zhiyuan Ye, Xiangyu Zhou, Ji Qi, Hao Zhang, Yi Zhou