Deep neural networks (DNNs) have shown phenomenal success in many real-world applications. However, a concerning weakness of DNNs is their vulnerability to adversarial attacks. Although there exist some methods to detect adversarial attacks, they often suffer from high computational cost and constraints on certain types of attacks, and ignore external features that could aid during attack detection. In this article, we propose fast confidence detection method (FCDM), an innovative method for fast confidence detection of adversarial attacks based on measuring the integrity of sensor pattern noise fingerprinting embedded in input examples. We note that the existing adversarial detectors are often designed as a binary classifier to differentiate clean or adversarial examples. However, the detection of adversarial examples can be much more complicated than such a scenario. Our key insight is that the confidence level of detecting an input sample as an adversarial example is a more useful info for the system to properly take an action to resist potential attacks. The experimental results show that FCDM is capable to give a confidence distribution model of the most popular adversarial attacks. And, using the confidence distribution model, FCDM can quickly determine the confidence level of the input sample. Based on different properties of the confidence distribution models associated with these adversarial attacks, FCDM can provide early attack warning including even the possible attack types of the adversarial attack examples. FCDM also has the following advantages: 1) it is effective for both a white-box attack and black-box attack; 2) it do not depend on the class of adversarial attacks and can be used as both known attack defense and unknown attack defense; and 3) it does not need to know the details of the DNN model and does not affect the functionality of the DNN. Since fast confidence detection method (FCDM) is a computationally heavy task, we propose an FPGA-based accelerator based on a series of optimization techniques, such as the quantization, data reuse and operation replacement, etc. We implement our method on an FPGA platform and achieve a system clock frequency of 279 MHz with a power consumption of the only 0.7626 W. Moreover, in the real system performance test, we obtain a high efficiency of 29.740 IPS/W and a low latency of just 44.1 ms with very marginal accuracy loss.

Deep Neural Networks (DNNs) have shown phenomenal success in a wide range of real-world applications. However, a concerning weakness of DNNs is that they are vulnerable to adversarial attacks. Although there exist methods to detect adversarial attacks, they often suffer constraints on specific attack types and provide limited information to downstream systems. We specifically note that existing adversarial detectors are often binary classifiers, which differentiate clean or adversarial examples. However, detection of adversarial examples is much more complicated than such a scenario. Our key insight is that the confidence probability of detecting an input sample as an adversarial example will be more useful for the system to properly take action to resist potential attacks. In this work, we propose an innovative method for fast confidence detection of adversarial attacks based on integrity of sensor pattern noise embedded in input examples. Experimental results show that our proposed method is capable of providing a confidence distribution model of most of popular adversarial attacks. Furthermore, our presented method can provide early attack warning with even the attack types based on different properties of the confidence distribution models. Since fast confidence detection is a computationally heavy task, we propose an FPGA-Based hardware architecture based on a series of optimization techniques, such as incremental multi-level quantization and etc. We realize our proposed method on an FPGA platform and achieve a high efficiency of 29.740 IPS/W with a power consumption of only 0.7626W.