Enhancing Adversarial Transferability via Information Bottleneck Constraints
Biqing Qi, Junqi Gao, Jianxing Liu, Ligang Wu, Bowen Zhou
TL;DR
The paper addresses the limited transferability of adversarial attacks in black-box settings by introducing IBTA, an information-bottleneck based framework that emphasizes invariance to non-essential input features. It derives a simple mutual information lower bound MILB to approximate $I(\mathcal{E}; X \mid Y_{adv})$ and utilizes MINE to quantify MI, enabling scalable optimization. Empirical results on ImageNet show consistent transferability improvements across non-targeted and targeted attacks when IBTA is integrated with existing methods, including in ensemble and adversarially trained scenarios. The work provides a principled approach to concentrating perturbations on invariant, class-relevant features, with practical implications for evaluating defenses and strengthening robustness research, and it releases code for reproducibility.
Abstract
From the perspective of information bottleneck (IB) theory, we propose a novel framework for performing black-box transferable adversarial attacks named IBTA, which leverages advancements in invariant features. Intuitively, diminishing the reliance of adversarial perturbations on the original data, under equivalent attack performance constraints, encourages a greater reliance on invariant features that contributes most to classification, thereby enhancing the transferability of adversarial attacks. Building on this motivation, we redefine the optimization of transferable attacks using a novel theoretical framework that centers around IB. Specifically, to overcome the challenge of unoptimizable mutual information, we propose a simple and efficient mutual information lower bound (MILB) for approximating computation. Moreover, to quantitatively evaluate mutual information, we utilize the Mutual Information Neural Estimator (MINE) to perform a thorough analysis. Our experiments on the ImageNet dataset well demonstrate the efficiency and scalability of IBTA and derived MILB. Our code is available at https://github.com/Biqing-Qi/Enhancing-Adversarial-Transferability-via-Information-Bottleneck-Constraints.
