BulletTrain: Accelerating Robust Neural Network Training via Boundary Example Mining

TL;DR

BulletTrain is a boundary example mining method that significantly accelerates robust neural network training by focusing on the most beneficial examples, reducing computational costs without sacrificing accuracy.

Contribution

It introduces a dynamic boundary example mining technique that improves training efficiency for robustness algorithms without accuracy loss.

Findings

Achieves 2.1× speed-up for TRADES and MART on CIFAR-10.

Achieves 1.7× speed-up for AugMix on CIFAR-10-C and CIFAR-100-C.

Maintains both clean and robust accuracy during acceleration.

Abstract

Neural network robustness has become a central topic in machine learning in recent years. Most training algorithms that improve the model's robustness to adversarial and common corruptions also introduce a large computational overhead, requiring as many as ten times the number of forward and backward passes in order to converge. To combat this inefficiency, we propose BulletTrain $-$ a boundary example mining technique to drastically reduce the computational cost of robust training. Our key observation is that only a small fraction of examples are beneficial for improving robustness. BulletTrain dynamically predicts these important examples and optimizes robust training algorithms to focus on the important examples. We apply our technique to several existing robust training algorithms and achieve a 2.1$\times$ speed-up for TRADES and MART on CIFAR-10 and a 1.7$\times$ speed-up for AugMix on CIFAR-10-C and CIFAR-100-C without any reduction in clean and robust accuracy.