Deep Neural Networks for image classification have been found to be
vulnerable to adversarial samples, which consist of sub-perceptual noise added
to a benign image that can easily fool trained neural networks, posing a
significant risk to their commercial deployment. In this work, we analyze
adversarial samples through the lens of their contributions to the principal
components of each image, which is different than prior works in which authors
performed PCA on the entire dataset. We investigate a number of
state-of-the-art deep neural networks trained on ImageNet as well as several
attacks for each of the networks. Our results demonstrate empirically that
adversarial samples across several attacks have similar properties in their
contributions to the principal components of neural network inputs. We propose
a new metric for neural networks to measure their robustness to adversarial
samples, termed the (k,p) point. We utilize this metric to achieve 93.36%
accuracy in detecting adversarial samples independent of architecture and
attack type for models trained on ImageNet.