Perturbation-Induced Linearization: Constructing Unlearnable Data with Solely Linear Classifiers
Jinlin Liu, Wei Chen, Xiaojin Zhang
TL;DR
Unlearnable examples aim to protect data by imperceptible perturbations, but existing approaches rely on costly deep surrogates. This paper introduces Perturbation-Induced Linearization (PIL), which uses a bias-free linear surrogate to craft perturbations under $\|\bm{\delta}_i\|_\infty \le \epsilon$ with $\epsilon = 8/255$ and a two-term loss to induce semantic obfuscation and a perturbation–label shortcut, producing an unlearnable dataset $\mathcal{D}_u = \{ (\bm{x}_i - \bm{\delta}_i^*, y_i) \}$. PIL achieves comparable or better protection than deep-surrogate methods while dramatically reducing compute time, and experiments show it generalizes across architectures/datasets and remains robust under augmentations and adversarial training. The paper also provides a theoretical partial-perturbation analysis and empirical evidence that unlearnable perturbations induce stronger linear behavior in DNNs, offering practical data protection and mechanistic insight.
Abstract
Collecting web data to train deep models has become increasingly common, raising concerns about unauthorized data usage. To mitigate this issue, unlearnable examples introduce imperceptible perturbations into data, preventing models from learning effectively. However, existing methods typically rely on deep neural networks as surrogate models for perturbation generation, resulting in significant computational costs. In this work, we propose Perturbation-Induced Linearization (PIL), a computationally efficient yet effective method that generates perturbations using only linear surrogate models. PIL achieves comparable or better performance than existing surrogate-based methods while reducing computational time dramatically. We further reveal a key mechanism underlying unlearnable examples: inducing linearization to deep models, which explains why PIL can achieve competitive results in a very short time. Beyond this, we provide an analysis about the property of unlearnable examples under percentage-based partial perturbation. Our work not only provides a practical approach for data protection but also offers insights into what makes unlearnable examples effective.
