Towards Adversarial Attack Resistant Deep Neural Networks (original) (raw)

Recent publications have shown that neural network based classifiers are vulnerable to adversarial inputs that are virtually indistinguishable from normal data, constructed explicitly for the purpose of forcing misclassification. In this paper, we present several defenses to counter these threats. First, we observe that most adversarial attacks succeed by mounting gradient ascent on the confidence returned by the model, which allows adversary to gain understanding of the classification boundary. Our defenses are based on denying access to the precise classification boundary. Our first defense adds a controlled random noise to the output confidence levels, which prevents an adversary from converging in their numerical approximation attack. Our next defense is based on the observation that by varying the order of the training, often we arrive at models which offer the same classification accuracy, yet they are different numerically. An ensemble of such models allows us to randomly swi...