Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Practical No-box Adversarial Attacks with Training-free Hybrid Image
  Transformation   In recent years, the adversarial vulnerability of deep neural networks (DNNs)
has raised increasing attention. Among all the threat models, no-box attacks
are the most practical but extremely challenging since they neither rely on any
knowledge of the target model or similar substitute model, nor access the
dataset for training a new substitute model. Although a recent method has
attempted such an attack in a loose sense, its performance is not good enough
and computational overhead of training is expensive. In this paper, we move a
step forward and show the existence of a \textbf{training-free} adversarial
perturbation under the no-box threat model, which can be successfully used to
attack different DNNs in real-time. Motivated by our observation that
high-frequency component (HFC) domains in low-level features and plays a
crucial role in classification, we attack an image mainly by manipulating its
frequency components. Specifically, the perturbation is manipulated by
suppression of the original HFC and adding of noisy HFC. We empirically and
experimentally analyze the requirements of effective noisy HFC and show that it
should be regionally homogeneous, repeating and dense. Extensive experiments on
the ImageNet dataset demonstrate the effectiveness of our proposed no-box
method. It attacks ten well-known models with a success rate of
\textbf{98.13\%} on average, which outperforms state-of-the-art no-box attacks
by \textbf{29.39\%}. Furthermore, our method is even competitive to mainstream
transfer-based black-box attacks.

36
The categories of this paper are: cmp-lg
22
The categories of this paper are: chao-dyn
35
The categories of this paper are: mtrl-th
18
The categories of this paper are: econ
7
The categories of this paper are: hep-th
2
The categories of this paper are: math
21
The categories of this paper are: adap-org
15
The categories of this paper are: nucl-ex
26
The categories of this paper are: bayes-an
14
The categories of this paper are: math-ph
29
The categories of this paper are: funct-an
25
The categories of this paper are: patt-sol
31
The categories of this paper are: ao-sci
12
The categories of this paper are: nucl-th
33
The categories of this paper are: plasm-ph
6
The categories of this paper are: astro-ph