Harnessing the Vulnerability of Latent Layers in Adversarially Trained Models
This addresses the problem of improving robustness in neural networks against adversarial attacks for security-critical applications, but it is incremental as it builds on existing adversarial training methods.
The paper tackled the vulnerability of latent layers in adversarially trained models to adversarial attacks, revealing that these layers are highly susceptible to small perturbations, and introduced Latent Adversarial Training (LAT) which achieved state-of-the-art adversarial accuracy against PGD attacks on MNIST, CIFAR-10, and CIFAR-100 datasets.
Neural networks are vulnerable to adversarial attacks -- small visually imperceptible crafted noise which when added to the input drastically changes the output. The most effective method of defending against these adversarial attacks is to use the methodology of adversarial training. We analyze the adversarially trained robust models to study their vulnerability against adversarial attacks at the level of the latent layers. Our analysis reveals that contrary to the input layer which is robust to adversarial attack, the latent layer of these robust models are highly susceptible to adversarial perturbations of small magnitude. Leveraging this information, we introduce a new technique Latent Adversarial Training (LAT) which comprises of fine-tuning the adversarially trained models to ensure the robustness at the feature layers. We also propose Latent Attack (LA), a novel algorithm for construction of adversarial examples. LAT results in minor improvement in test accuracy and leads to a state-of-the-art adversarial accuracy against the universal first-order adversarial PGD attack which is shown for the MNIST, CIFAR-10, CIFAR-100 datasets.