Action recognition has been heavily employed in many applications such as
autonomous vehicles, surveillance, etc, where its robustness is a primary
concern. In this paper, we examine the robustness of state-of-the-art action
recognizers against adversarial attack, which has been rarely investigated so
far. To this end, we propose a new method to attack action recognizers that
rely on 3D skeletal motion. Our method involves an innovative perceptual loss
that ensures the imperceptibility of the attack. Empirical studies demonstrate
that our method is effective in both white-box and black-box scenarios. Its
generalizability is evidenced on a variety of action recognizers and datasets.
Its versatility is shown in different attacking strategies. Its deceitfulness
is proven in extensive perceptual studies. Our method shows that adversarial
attack on 3D skeletal motions, one type of time-series data, is significantly
different from traditional adversarial attack problems. Its success raises
serious concern on the robustness of action recognizers and provides insights
on potential improvements.

文章研究了先进的行动识别器对抗性攻击的鲁棒性，并提出了一种基于 3D 骨架运动的攻击方法，该方法包含一种创新的感知丢失，保证攻击的不可察觉性，实证研究表明我们的方法对于白盒和黑盒情况均有效。

鲁棒性骨骼动作识别在对抗攻击下的理解

Understanding the Robustness of Skeleton-based Action Recognition under  Adversarial Attack

Adversarial attack has inspired great interest in computer vision, by showing
that classification-based solutions are prone to imperceptible attack in many
tasks. In this paper, we propose a method, SMART, to attack action recognizers
which rely on 3D skeletal motions. Our method involves an innovative perceptual
loss which ensures the imperceptibility of the attack. Empirical studies
demonstrate that SMART is effective in both white-box and black-box scenarios.
Its generalizability is evidenced on a variety of action recognizers and
datasets. Its versatility is shown in different attacking strategies. Its
deceitfulness is proven in extensive perceptual studies. Finally, SMART shows
that adversarial attack on 3D skeletal motion, one type of time-series data, is
significantly different from traditional adversarial attack problems.

提出了一种名为 SMART 的方法，通过创新的感知损失攻击依赖于 3D 骨架运动的动作识别器，该方法在白盒和黑盒场景中都很有效，且具有广泛的推广性和多样性，并且证明 3D 骨架运动的对抗攻击与传统的对抗攻击问题存在明显的差异。