Pareto-Improving Adversarial Attacks with Primal-Dual Regularization
This study addresses the spurious trade-off between transferability and imperceptibility in adversarial attacks under a fixed perturbation budget. We propose ST, a plug-and-play primal-dual wrapper that performs two-step optimization updates grounded in Fenchel duality theory. By incorporating L∞ saturation regularization, ST transcends conventional perceptual priors and reveals the latent advantages of highly transferable attacks while enhancing stealthiness, all without requiring auxiliary models. Experimental results demonstrate that ST effectively expands the Pareto frontier, achieving synergistic optimization of transferability and imperceptibility. Specifically, it maintains or improves attack success rates while yielding 17% and 14% improvements in LPIPS and NIQE metrics, respectively.