In plain words: Tiny patterns humans can't see predict labels well but break under small changes, causing the failures when an image is slightly altered. They are everywhere in image sets, and a simple proof shows human ideas of robustness clash with the data's real structure.
Abstract
Adversarial examples have attracted significant attention in machine learning, but the reasons for their existence and pervasiveness remain unclear. We demonstrate that adversarial examples can be directly attributed to the presence of non-robust features: features derived from patterns in the data distribution that are highly predictive, yet brittle and incomprehensible to humans. After capturing these features within a theoretical framework, we establish their widespread existence in standard datasets. Finally, we present a simple setting where we can rigorously tie the phenomena we observe in practice to a misalignment between the (human-specified) notion of robustness and the inherent geometry of the data.
Andrew Ilyas, Shibani Santurkar, Dimitris Tsipras, Logan Engstrom, Brandon Tran, Aleksander Madry
arXiv:1905.02175 · stat.ML, cs.CR, cs.CV, cs.LG · submitted May 6, 2019 · updated Aug 12, 2019
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It's intriguing how much focus there is on adversarial examples. You don't need adversarial examples to make a deep network fail - in a sense that's overkill. Just point the poor deep network at a sequence of images from the real world -- images from a self driving car, security camera, or webcam. You'll see it make spontaneous errors. No matter how much training data you gave it.
The field will advance when/if practitioners recognize that classifying pixel patterns in isolation isn't sufficient for robust visual perception, and adopt alternative neural network designs that can interpret what they perceive in light of (no pun intended) context and physical expectations.
It worked for our prototype.[0]
[0] https://arxiv.org/abs/1607.06854