Improving Local Effectiveness for Global robust training
This addresses the problem of expensive robust training for deep neural networks, offering a more efficient approach that is incremental over existing methods.
The paper tackles the high computational cost of generating strong adversaries for robust training by proposing a method that focuses on local robustness around weak adversaries, achieving similar robust accuracy to state-of-the-art methods on MNIST, CIFAR-10, and CIFAR-100 while reducing training time.
Despite its popularity, deep neural networks are easily fooled. To alleviate this deficiency, researchers are actively developing new training strategies, which encourage models that are robust to small input perturbations. Several successful robust training methods have been proposed. However, many of them rely on strong adversaries, which can be prohibitively expensive to generate when the input dimension is high and the model structure is complicated. We adopt a new perspective on robustness and propose a novel training algorithm that allows a more effective use of adversaries. Our method improves the model robustness at each local ball centered around an adversary and then, by combining these local balls through a global term, achieves overall robustness. We demonstrate that, by maximizing the use of adversaries via focusing on local balls, we achieve high robust accuracy with weak adversaries. Specifically, our method reaches a similar robust accuracy level to the state of the art approaches trained on strong adversaries on MNIST, CIFAR-10 and CIFAR-100. As a result, the overall training time is reduced. Furthermore, when trained with strong adversaries, our method matches with the current state of the art on MNIST and outperforms them on CIFAR-10 and CIFAR-100.