Countermeasure against Backdoor Attack on Neural Networks Utilizing Knowledge Distillation

Abstract

A backdoor attack is a well-known security issue facing deep neural networks (DNNs). In a backdoor attack against DNNs for image classification, an adversary creates tampered data containing special marks ("poison data") and injects them into a training dataset. A DNN model that is trained with the tampered training dataset can achieve a high classification accuracy for clean (normal) input data, but the inference on the poisonous input data is misclassi-fied to the adversarial target label. In this work, we propose a countermeasure against the backdoor attack by utilizing knowledge distillation in which the DNN model user dis-tills a backdoored DNN model with clean unlabeled data. The distilled DNN model can be trained with clean knowledge on the backdoored model because the backdoor is not activated by clean data. Experimental results showed that the distilled model achieves high performance equiva­ lent to that of a clean model without a backdoor.