Paper:
Effective defense of deep neural networks against adversarial attacks remains a challenging problem, especially under white-box attacks. In this paper, we develop a new generative cleaning network with quantized nonlinear transform for effective defense of deep neural networks. The generative cleaning network, equipped with a trainable quantized nonlinear transform block, is able to destroy the sophisticated noise pattern of adversarial attacks and recover the original image content. The generative cleaning network and attack detector network are jointly trained using adversarial learning to minimize both perceptual loss and adversarial loss. Our extensive experimental results demonstrate that our approach outperforms the state-of-art methods by large margins in both white-box and black-box attacks. For example, it improves the classification accuracy for white-box attacks upon the second best method by more than 40% on the SVHN dataset and more than 20% on the challenging CIFAR-10 dataset.

Review:
This paper developed a method for defending deep neural networks against adversarial attacks based on generative cleaning networks with quantized nonlinear transform. The network is claimed to recover the original image while cleaning up the residual attack noise. The authors developed a detector network, which serves as the dual network of the target classifier network to be defended, to detect if the image is clean or being attacked. This detector network and the generative cleaning network are jointly trained with adversarial learning so that the detector network cannot find any attack noise in the output image of generative cleaning network. The experimental results demonstrated that the proposed approach outperforms the state-of-art methods by large margins in both white-box and black-box attacks. 
A few comments: 
1. It does not provide theoretical reasons why the prosed method can defend against those attacks. 
2. The experiments are a bit messy and the attacks' setup need to improve. 
3. The proposed defense showed only empirical results against the target attack. It seems to provide no theoretical / provable guarantees.