Concurrent Weight Encoding-based Detection for Bit-Flip Attack on Neural Network Accelerators

Qi Liu, Wujie Wen, Yanzhi Wang

Abstract: The recent revealed Bit-Flip Attack (BFA) against deep neural networks (DNNs) is highly concerning, as it can completely mislead the inference of quantized DNNs by only flipping a few weight bits in hardware memories through manners like DRAM rowhammer. A key question before applying any BFA mitigation solutions, such as retraining or model reloading, is how to quickly and accurately detect such an attack without impacting the normal inference. In this paper, we propose a weight encoding-based framework to concurrently detect BFA by leveraging the spatial locality of bit flipping in BFA and a fast encoding of sensitive weights only. Extensive experimental results show that our method can accurately differentiate the malicious fault models under BFA and the random bit flipping that could also occur in weight memories but does not impact accuracy as that of BFA, with very low overhead across various DNNs on both CIFAR-10 and ImageNet datasets. To the best of our knowledge, this is the first real-time detection framework for BFA attack against quantized DNNs that are widely deployed in hardware accelerators.