  Although deep neural networks (DNNs) are known to be fragile, no one has
studied the effects of zooming-in and zooming-out of images in the physical
world on DNNs performance. In this paper, we demonstrate a novel physical
adversarial attack technique called Adversarial Zoom Lens (AdvZL), which uses a
zoom lens to zoom in and out of pictures of the physical world, fooling DNNs
without changing the characteristics of the target object. The proposed method
is so far the only adversarial attack technique that does not add physical
adversarial perturbation attack DNNs. In a digital environment, we construct a
data set based on AdvZL to verify the antagonism of equal-scale enlarged images
to DNNs. In the physical environment, we manipulate the zoom lens to zoom in
and out of the target object, and generate adversarial samples. The
experimental results demonstrate the effectiveness of AdvZL in both digital and
physical environments. We further analyze the antagonism of the proposed data
set to the improved DNNs. On the other hand, we provide a guideline for defense
against AdvZL by means of adversarial training. Finally, we look into the
threat possibilities of the proposed approach to future autonomous driving and
variant attack ideas similar to the proposed attack.
