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  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>Robustness with Black-Box Adversarial Attack using Reinforcement Learning</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Soumyendu Sarkar</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Ashwin Ramesh Babu</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Sajad Mousavi</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Vineet Gundecha</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Sahand Ghorbanpour</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Alexander Shmakov</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Ricardo Luna Gutierrez</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Antonio Guillen</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Avisek Naug</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Adversarial Sample</institution>
          ,
          <addr-line>RLAB</addr-line>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>Hewlett Packard Enterprise</institution>
          ,
          <country country="US">USA</country>
        </aff>
      </contrib-group>
      <abstract>
        <p>A measure of robustness against naturally occurring distortions is key to the safety, success, and trustworthiness of machine learning models on deployment. We investigate an adversarial black-box attack that adds minimum Gaussian noise distortions to input images to make deep learning models misclassify. We used a Reinforcement Learning (RL) agent as a smart hacker to explore the input images to add minimum distortions to the most sensitive regions to induce misclassification. The agent employs a smart policy also to remove noises introduced earlier, which has less impact on the trained model at a given state. This novel approach is equivalent to doing a deep tree search to add noises without an exhaustive search, leading to faster and optimal convergence. Also, this adversarial attack method efectively measures the robustness of image classification models with the misclassification inducing minimum 2 distortion of Gaussian noise similar to many naturally occurring distortions. Furthermore, the proposed black-box 2 adversarial attack tool beats state-of-the-art competitors in terms of the average number of queries by a significant margin with a 100% success rate while maintaining a very competitive 2 score, despite limiting distortions to Gaussian noise. For the ImageNet dataset, the average number of queries achieved by the proposed method for ResNet-50, Inception-V3, and VGG-16 models are 42%, 32%, and 31% better than the state-of-the-art "Square-Attack" approach while maintaining a competitive 2. Demo: https://tinyurl.com/2p8pnjn6 Figure 1: An example of adversarial perturbations driven by the learnt policy of RLAB agent. The image "" classified as Panda, an adversarial sample generated with RLAB (ours) " +  " has been classified as dolphin where  represents the noise added to the image.</p>
      </abstract>
      <kwd-group>
        <kwd>eol&gt;Reinforcement Learning</kwd>
        <kwd>Robustness</kwd>
        <kwd>Trustworthy AI</kwd>
        <kwd>Adversarial Attack</kwd>
        <kwd>Black-box attack</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1. Introduction</title>
      <p>
        Deep learning models have yielded impressive results
in numerous applications, but research on adversarial
attacks has shown that these models sufer from a
vulnerability where small distortions could lead to wrong
predictions. Specifically, naturally occurring distortions that
afect the inputs are of greater concern in safety-critical
applications such as self-driving cars, facial recognition,
and image-based authorization [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ][2]. Measuring
robustness, i.e., how resilient these machine learning models are
against distortions, is key to discovering vulnerabilities
of poorly trained models.
      </p>
      <p>Literature has provided us with two major paths to
identify the sensitivity of the deep learning models,
White box attacks [3][4] and Black box attacks [5][6].
Even though recent works have introduced eficient
white-box approaches targeting a specific region or very
minimum distortion to fool the Convolutional Neural
Network (CNN) models, it requires complete visibility of
the network architecture and the parameters. In general,
and with a 100% success rate while maintaining other
metrics like distortion at a minimum. The motivation for
using RL is to learn an optimum policy that incrementally
adds noise to deceive a model, unlike the hand-crafted
heuristics that are used in State-of-the-art adversarial
attacks. Our method includes a dual action RL agent,
which makes parallel addition and removal of distortions
to image regions, based on the image region sensitivity at
the current state and the history of progression of added
distortion as shown in Figure 1. The goal is to cause a
misclassification with minimum number of queries In
an extensive evaluation of un-targeted attacks with
ImageNet and CIFAR-10 datasets on CNN architectures such
as ResNet-50, Inception-V3, and VGG-16, RLAB
outperforms the state-of-the-art methods for 2 threat model
on the number of queries while achieving competitive
2 norm as shown in figure 2. The main contribution of
the work can be summarized as follows.</p>
    </sec>
    <sec id="sec-2">
      <title>2. Related Works</title>
      <p>Some of the established metrics to evaluate the
performance of a machine learning model include accuracy,
precision, recall, and F1 score. With the recent advances
in adversarial attacks, the models that showed excellent
performance on static test sets with the above metrics
were easily misclassified with adversarial examples. For
example, work done by Szegedy et al. [3] was one of the
ifrst works to introduce adversarial attacks. White-box
attacks showed great results with one of the initial works
from Goodfellow et al. in their work [4] introducing
Fast Gradient Sign Method (FGSM) based attack where
a small vector whose elements are equal to the sign of
the elements of the gradient of the cost function with
respect to the input changed the classification outcomes.
Following this work, there were other incremental works
based on gradients-based distortion that could flip the
model [7][8][9]. Papernot et al. [10] generated an
indication map representing the right area on the input
that can be attacked. Similarly, DeepFool by Moosavi et
al. [11] proposed a simple yet efective approach to add
perturbations to the input to fool the machine learning
models.</p>
      <sec id="sec-2-1">
        <title>2.1. Black-box attacks</title>
        <sec id="sec-2-1-1">
          <title>In Black-box attacks, there is only partial visibility to no</title>
          <p>visibility into the model. In a partially visible black-box
attack, information about the loss function, the
prediction probabilities, or top-K sorted labels could be
available based on which the attack is executed in a query
access approach. Work done by Michel et al. [12] and
Chakraborty et al. [13] provides a detailed survey on the
current trends in adversarial attacks on neural networks.</p>
          <p>Further, Ilyas et al. [14] in their early work approached
1. A novel Reinforcement Learning agent, that beats this problem with multiple level of restrictions including
the state-of-the-art un-targeted black-box 2 at- limited visibility, limited query access and so on. Some
tack models in terms of an average number of of the most popular black-box attack in recent times
queries by a wide margin with a 100% success that has been acknowledged by the research community
rate while keeping the 2-norm minimum. include Square attack [5], SimBA [15], and LeBA [16],
2. This RL approach learns a policy to form an op- which achieved significant results in breaking
Convolutimum adversarial attack agent that can outper- tional Neural Network based models. Guo et al. [15] in
form the engineered heuristic approach of the their work proposed a simple approach where they
iteraprevailing SOTA adversarial attacks by the above tively and randomly sample a vector from a predefined
metrics. orthonormal basis such that it can be added or subtracted
3. A high-performance adversarial attack agent that from the target image. Similarly, Andriushckenko et al.
limits the distortions to Gaussian noise, which [5] proposed an approach where square-shaped updates
is one of the naturally occurring real-life non- are added at random positions such that at each iteration,
malicious distortions, unlike most adversarial at- the total budget constraint is still preserved. Furthermore,
tacks. some of the most recent works in the black-box attack
include EigenBA [17], Pixle [18], Querynet [19], advFlow
[20], and CG attack [21] producing state-of-the-art
results.</p>
          <p>Reward
ΔProb Dilution for GT</p>
          <p>/ ΔL2-Distance</p>
          <p>Altered vs Previous image
Adds Distortion Removes Distortion</p>
          <p>CNN Classifier
*Image
Cleanup</p>
          <p>Adversarial</p>
          <p>Sample
Misclassified
* Takes out distortions, without flipping
classification back to Ground Truth</p>
        </sec>
      </sec>
      <sec id="sec-2-2">
        <title>2.2. Reinforcement learning for adversarial attacks</title>
        <p>Distorted Image
Probability of classes, L2 Distortion - Last N</p>
      </sec>
      <sec id="sec-2-3">
        <title>3.2. RLAB Overview</title>
        <sec id="sec-2-3-1">
          <title>In our approach, the image is divided into squared</title>
          <p>
            Reinforcement Learning has solved problems that clas- patches and sensitivity of the ground truth probability
sic machine learning struggles in various domains and  , to addition and removal of distortion, is computed
applications such as healthcare, energy [22, 23], medical for each patch. Based on the sensitivity information,
imaging, etc. Their unique ability to learn a policy for the RL decides the patches to which Gaussian noise is
action is a key attribute of their success. Reinforcement added or removed at every step. This process is done
learning for adversarial attacks has not been explored iteratively until the model misclassifies the image. To
furmuch. Sun et al. [24] in their work use reinforcement ther reduce 2, we perform an iterative image cleanup
learning to target graph neural networks via node in- as a post-processing step while maintaining the
misclasjections. Similarly, work done by Yang et al. [16](Patch sification. The overall flow of the proposed method is
Attack) applies reinforcement learning to attack CNN represented in the figure 3.
models by superimposing textured patches on the input
image. Unlike the previous approach, our RL agent uses 3.3. Image Sensitivity Analysis
a comprehensive state representation that captures the
model’s sensitivity to various image regions and imple- In our proposed approach, we limit all distortions to
ments a patch-based process with natural distortions. Gaussian noise, as it is a commonly encountered and
natThis enables our approach to significantly outperform urally occurring distortion. During the image sensitivity
state-of-the-art adversarial attacks, including RL-based analysis, we generate a fixed number of noise masks of
methods in terms of minimum distortion measured by same noise level, of size  ×  sampled from a normal
L2-norm, query eficiency, and success rate. distribution as represented in the equation 1.
  (× ) =  (0,  _)
(1)
3. Proposed Method At every step during the training and validation, one
mask is randomly chosen from the generated noise masks
3.1. Reinforcement Learning/problem and applied across all image patches to evaluate the drift
formulation in the ground truth classification probability  . A
The Deep Neural Network (DNN) model under test/e- lower noise level is chosen as it helps more granular
valuation can be represented as  =  (;  ), where  addition of noise in successive steps to specific regions
denotes the input image,  represents the prediction and that create maximum drift with the  , while keeping
 represents the model parameters. The motivation is to 2 minimum. The noise mask is generated such that
generate a perturbation  such that,  ̸=  ( +  ;  ). The they have the same efect on change in 2 distance. The
objective is to minimize  which represents a measure of perturbations ˆ −  are constrained to the values [
            <xref ref-type="bibr" rid="ref1">0, 1</xref>
            ].
robustness. Note that the size of the patch is fixed throughout the
experiment and is chosen as a hyper-parameter based on
the performance-cost trade-of. Table 6 provides detailed
experiments on diferent patch sizes.
          </p>
        </sec>
      </sec>
      <sec id="sec-2-4">
        <title>3.4. Alternative to Tree Search</title>
        <p>Generating adversarial examples for image classification
through multiple steps is similar to board games. For
board games, the most efective moves or actions are
figured out through a Deep Tree Search (DTS) of multiple
layers to determine the efectiveness of an action taken
at the current step on a longer time horizon as the game
evolves. DTS is computationally expensive, even with
approximations like Monte Carlo Tree Search (MCTS).
But unlike a board game, in this problem, there is a
possibility to reset the earlier moves when we realize that
we have made a less optimized move a few steps back.
In RLAB this is done by removing distortions from some
patches and adding distortions to some other patches,
considering the state of the modified image at any given
step (equivalent to position on the board). This is
equivalent to replaying all the moves in one step while keeping
the sensitivity analysis restricted to the current state of
the image without a tree search.</p>
        <p>Our method reduces the complexity from ( ) to
( ) where N represents the computation complexity
of one level of evaluation and corresponds to the image
size, and d represents the depth of the tree search, which
translates to how many queries and actions we would
like to look ahead if we were doing a tree search. d=[1,
max_steps].</p>
        <p>RL Test
Agent
Agent for Image
Classifier Test
(Dueling DQN)</p>
        <p>States
Sensitivity of classification probability to
Gaussian noise for various image tiles
Probability of various classes
L2 distance for last N steps</p>
        <p>Action
Distortion and Restoration mask for adding
and / or removing noise to image tiles</p>
        <p>Reward
Calssification probability change for Ground
Truth normalized by change in L2 distance
of the image
Environment
Image Classifer
Model Analytics</p>
        <p>Image
Transformations</p>
        <sec id="sec-2-4-1">
          <title>To keep the number of actions limited and discrete,</title>
          <p>we define RL action as the number   , where
RLAB adds distortion to the top (  + 1) patches
from the  in the state and removes distortion
from the top   patches from  
as represented in Figure 4.  ∈ [1, ] where
3.5. Reinforcement Learning  is a hyperparameter and is set to 8 for ImageNet
The decision of which patches to choose for adding or re- (224 × 224) image size with 2 × 2 patch size), to
balmoving distortion has multiple dependencies and needs ance efectiveness and computation. Note that the net
to be adaptive for the most eficient generation of adver- diference is one square patch where distortion is added,
sarial examples. Mapping this adversarial sample genera- keeping the change in the 2 distance approximately
tion as a Reinforcement Learning (RL) problem requires bound to what we would have got if we had added
disdefining the states, actions, and rewards. The state-space tortion to just one patch. However, there is a possibility
is constructed such that the environment becomes ob- that the patch where we are removing the distortion may
servable in a way it enables the RL agent to learn the have distortion added to it multiple times, which will
optimum policy to take actions while maximizing the only lower the net increase of 2 distance.
reward. We used the Dueling DQN Reinforcement Learn- 3.5.3. RL Reward
ing (RL) based agent in RLAB. Algorithm 1 represents the
overall flow of the proposed method. Figure 6 represents
the steps involved in adding and removing distortion by
the RL agent.
3.5.1. RL States
We define a probability dilution (PD) metric, which
measures the extent to which the classification probability
shifts from the ground truth to the other classes. The
diference between the PD of the altered image and the
original image as a result of an action (∆ PD) is a measure
of the efectiveness of the action. Moreover, the change in
2-distance (∆ 2) as a measure of the distortion added
is the cost for an action. The reward is defined by the
normalized PD as represented in equation 2.</p>
          <p>We designed a state space that gives required
observability to the RL agent but is simple enough and of lower
dimension such that the agent could be trained eficiently
as shown in Figure 5. The image sensitivity analysis acts
as a feature extractor where the the top ordered square
patch locations are ordered both based on the change
in  for adding and removing distortion in the state
vector. Also included are the classification probabilities
and 2 distance progression.
 = ∆   = − ∆  /∆ 2</p>
          <p>(2)</p>
        </sec>
        <sec id="sec-2-4-2">
          <title>However, there is a dependence on   and 2 for the optimum action to achieve the best eficiency in terms of both minimizing the 2 distance and</title>
          <p>= − ∆ 2/∆  
(3)</p>
        </sec>
      </sec>
      <sec id="sec-2-5">
        <title>3.7. Nature of Distortions</title>
        <p>We developed a Dueling DQN algorithm-based Reinforce- Most state-of-the-art competitive solutions use unnatural
ment Learning (RL) agent for RLAB as an adversarial modifications as shown in Figure 7. The only other RL
attack agent [6, 7], which also evaluates the CNN image method used for a similar adversarial attack, Patch
Atclassification models for robustness, as shown in Figure 8. tack, has completely unnatural squared patches placed
The Dueling DQN algorithm splits the Q-values into two on the images. In contrast, our proposed method
preparts: the value function V(s) and the advantage function serves the true nature of the image with barely
percepA(s, a). As shown in Figure 8, the same neural network tible Gaussian noise. Moreover, Patch Attack’s
distorsplits its last layer into two parts, one of them to estimate tion measured in 2-norm of 191 is significantly higher
the state value function for states (V(s)) and the other one than our RLAB’s 2-norm of 4.03 for ImageNet. Also,
to estimate state-dependent action advantage (A (s, a)). It as shown in Figure 7, the state-of-the-art high-eficiency
then combines both parts into a single output, estimating Square Attack has unnatural colors of red and green all
the Q-values. This change is helpful because sometimes over the cougar, unlike our RLAB method. In RLAB, any
it is unnecessary to know the exact value of each action. distortion is barely perceptible because of low Gaussian
So just learning the state-vlue function can be enough noise.
in some cases. The main benefit is generalizing
learning across actions without imposing specific changes to 4. Experiments
the underlying reinforcement learning algorithm. The
Dueling DQN model fits well with the discrete action
space of a limited number of   and has the
suitable complexity to predict   efectively with a
reasonably bounded training.</p>
        <p>In this section, we discuss the efectiveness of our
proposed method with the same experimental setup as our
competitors. We evaluate on two popular image
classification datasets ILSVRC2012 [ 31] and CIFAR-10. 80
percent of the validation set was used to train our RL
3.6. Post-processing noise removal agents, and 20 percent of the validation set was used
for evaluation. We performed our attacks on three
maOnce an adversarial sample is generated using RL fol- jor Convolution-based Neural Network architectures:
lowing the initial misclassification we perform a final ResNet, Inception-V3, and VGG-16. We used three
metnoise removal process. This iterative process maintains rics to evaluate the performance of our approach. 2
the misclassification while attempting to remove noise distance which is a measure of distortion, the average
Original
Image</p>
        <p>Queries : 22500
L2-Norm: 191
Square
Attack</p>
        <p>Square Attack</p>
        <p>Difference</p>
        <p>Queries : 180
L2-Norm: 4.87</p>
        <p>RLAB
(ours)</p>
        <p>RLAB (ours)</p>
        <p>Difference
number of queries to make a model miss-classify a
correctly classified sample, and the average success rate.</p>
        <p>For validation, we had an overall average 2 of 4.03
with the values of pixels ranging between 0 and 1 and
setting a maximum query budget of 3500 evaluated over
1000 samples from imagenet dataset on ResNet-50
architecture. A failure case is when the proposed method
could not fool the victim model within the given budget,
and failure cases were not included in any of the metrics
calculated except for the success rate. All experiments
were performed for a patch size of 2 × 2 and with the
noise level of 0.005 as we got the best results for this
configuration. pipeline.</p>
        <p>The computation for the complete pipeline is GPU- It is worth mentioning that the proposed
robustdependent and is eficiently batched, and scaled on GPUs. ness measure in Deep Fool [4] involves minimizing
Caching techniques were used for pre-computed infor- the amount of distortion needed for misclassification,
mation such as the noise masks for improved eficiency. which is defined by ∆( ; ˆ) := min ‖‖2 subject to
Apollo servers with 8 ×  100 32 GB GPUs were used ˆ( + ) ̸= ˆ(), where min ‖‖2 = min 2 and
for training and validation. We processed 16(images per ∆( ; ˆ) is the robustness of classifier ˆ for input x. As
GPU) x 8(GPUs) = 128 images in a batch for the complete we can see, this is consistent with our goal, which is
Attack
Q-Fool [26]
NES (2018) [14]
 (2018) [27]
HopSkipJumpAttack [28]
Subspace(2019) [29]
P-RGF (2019) [30]
LeBA (2020) [16]
Square (2020) [5]
SimBA-DCT (2021) [15]
querynet (2021) [19]
AdvFlow (2021) [20]
EigenBA (2022) [17]
Pixle (2022) [18]
CG-Attack (2022)[21]
Patch Attack (2022) [16]
RLAB (ours)
4.1. Evaluation on Imagenet Both approaches were evaluated on the ResNet-50 model.
It can be observed that the success rate of our proposed
Table 1 aggregates the proposed method’s results com- method is the same as the competitors which is 100
pared to other state-of-the-art black-box algorithms on percent while the average queries of the proposed
apImagenet dataset for ResNet-50 architecture. The com- proach outperform every state-of-the-art technique.
Expetitors’ results were generated with the best parame- cept EigenBA [17] and CG-Attack[21] which are close
ters described in their papers. The average Success Rate to our results, our approach beats the competitors by a
(ASR) and Average Query (AVG.Q) were calculated for large margin.
each victim model while the average L2 for most of the
competitors were presented in their paper. It can be
observed that our proposed approach beats state-of-the-art 4.3. Ablation study on diferent noise
algorithms for average queries and success rate by a sig- intensities
nificant margin while maintaining competitive 2. It is
also worth mentioning that the proposed approach was One of the key hyperparameters for RLAB is the quantity
able to achieve 100% success rate for a maximum query of Gaussian noise that it adds for distortion. Experiments
set to 3500 while the competitors have experiments per- showed that higher noise levels increased the final 2 of
formed with a maximum query set to 10000. Similarly, the adversarial sample, while too less of noise impacted
from table 2 our proposed approach outperforms com- the average number of queries. We performed an
evalpetitors for Inception-v3 for average number of queries uation of diferent noise levels and their impact on the
while maintaining competitive queries for VGG-16. Fur- metrics as represented in table 4. We applied the same
thermore, we have achieved a 100 % success rate for both noise level for evaluation on both datasets (ImageNet,
Inception-v3 and VGG-16 models. Figure 9 shows the CIFAR-10) and all three victim models. We observed that
comparison of RLAB with the competition RL method the chosen noise level gave the best results across all
and Square attack. datasets and victim models.</p>
      </sec>
      <sec id="sec-2-6">
        <title>4.2. Evaluation on CIFAR-10</title>
        <p>Queries : 1500
L2-Norm : 119</p>
        <p>Queries : 44
L2-Norm: 5</p>
        <p>Queries : 111
L2-Norm: 2.94
and remove (N) at each step. This decision is based on
a learned policy (Dynamic) or based on a tuned
hyperparameter baseline. From the table 5, it can be observed
that the results improved when the RL learned policy
made the decision than the baseline for the number of
patches to which noise was added and removed</p>
      </sec>
      <sec id="sec-2-7">
        <title>4.5. Performance vs Complexity</title>
        <p>In our proposed work, we generated all our results with
the patch of size 2 × 2 for best results. It can be observed
from table 6 that as the patch size increases, the number
of queries decreases while the 2 increases.
Furthermore, we observed similar pattern with other models
such as VGG-16 and Inception-V3. This could be due
to that fact that the computation for sensitivity
analysis primarily depends on the size of the image and can
be accelerated, scaled, and batched on the GPU, there
is a smaller variation based on the number of patches
due to the post-processing overhead which is typically
around 20% of the total computation for 224x224 images
with 2 × 2 patch sizes. Depending on the use case, our
approach allows using diferent patch sizes at diferent
levels of performance which are represented in table 6.</p>
      </sec>
    </sec>
    <sec id="sec-3">
      <title>5. Conclusion</title>
      <sec id="sec-3-1">
        <title>RLAB outperforms the state-of-the-art adversarial at</title>
        <p>tacks in query eficiency by a significant margin and
achieves a highly competitive 2-norm indicative of
Patch Size
2x2
4x4
8x8
16x16
32x32
very low distortion with 100% success rate for
missclassification. But as RLAB only uses Gaussian noise,
the distortions are similar to real-life deployment. This
makes it valuable for a more appropriate test for
nonmalicious distortions and an efective measure of
robustness, which is a key attribute of trustworthiness with a
positive social impact.</p>
        <p>Also, Reinforcement Learning proved to be very
efective in learning the optimum policy to make the complex
decision of choosing the square patches for changing
distortion and making RLAB adaptive, as compared to
hand-crafted heuristics. This is by far the best RL
implementation of this type of Black-Box adversarial attack
considering both the results achieved and the flexible
nature of the optimization approach. This RL design will
be extended to include other types of distortions as part
of future work. Also, this RL approach is generic enough
to extend to a wide variety of adversarial attack agents
beyond image classifiers.</p>
        <p>The adversarial samples generated by RLAB can be used
to augment the train data set to retrain the model and
enhance its robustness.
itations for securing facial authentication, in: Pro- [15] C. Guo, J. Gardner, Y. You, A. G. Wilson, K.
Weinceedings of the 2022 ACM on International Work- berger, Simple black-box adversarial attacks, in:
shop on Security and Privacy Analytics, 2022, pp. International Conference on Machine Learning,
2–12. PMLR, 2019, pp. 2484–2493.
[2] M. Ozdag, S. Raj, S. L. Fernandes, A. Velasquez, [16] J. Yang, Y. Jiang, X. Huang, B. Ni, C. Zhao, Learning
L. Pullum, S. K. Jha, On the susceptibility of black-box attackers with transferable priors and
deep neural networks to natural perturbations, in: query feedback, Advances in Neural Information
AISafety@ IJCAI, 2019. Processing Systems 33 (2020) 12288–12299.
[3] C. Szegedy, W. Zaremba, I. Sutskever, J. Bruna, D. Er- [17] L. Zhou, P. Cui, X. Zhang, Y. Jiang, S. Yang,
Adverhan, I. Goodfellow, R. Fergus, Intriguing properties sarial eigen attack on black-box models, in:
Proof neural networks, arXiv preprint arXiv:1312.6199 ceedings of the IEEE/CVF Conference on Computer
(2013). Vision and Pattern Recognition, 2022, pp. 15254–
[4] I. J. Goodfellow, J. Shlens, C. Szegedy, Explain- 15262.</p>
        <p>ing and harnessing adversarial examples, arXiv [18] J. Pomponi, S. Scardapane, A. Uncini, Pixle: a fast
preprint arXiv:1412.6572 (2014). and efective black-box attack based on rearranging
[5] M. Andriushchenko, F. Croce, N. Flammarion, pixels, arXiv preprint arXiv:2202.02236 (2022).</p>
        <p>M. Hein, Square attack: a query-eficient black-box [19] S. Chen, Z. Huang, Q. Tao, X. Huang, Querynet:
adversarial attack via random search, in: European Attack by multi-identity surrogates, arXiv e-prints
Conference on Computer Vision, Springer, 2020, pp. (2021) arXiv–2105.</p>
        <p>484–501. [20] H. Mohaghegh Dolatabadi, S. Erfani, C. Leckie,
Ad[6] J. Su, D. V. Vargas, K. Sakurai, One pixel attack for vflow: Inconspicuous black-box adversarial attacks
fooling deep neural networks, IEEE Transactions using normalizing flows, Advances in Neural
Inforon Evolutionary Computation 23 (2019) 828–841. mation Processing Systems 33 (2020) 15871–15884.
[7] A. Kurakin, I. Goodfellow, S. Bengio, et al., Adver- [21] Y. Feng, B. Wu, Y. Fan, L. Liu, Z. Li, S.-T. Xia,
Boostsarial examples in the physical world, 2016. ing black-box attack with partially transferred
con[8] A. Kurakin, I. Goodfellow, S. Bengio, Adversar- ditional adversarial distribution, in: Proceedings of
ial machine learning at scale, arXiv preprint the IEEE/CVF Conference on Computer Vision and
arXiv:1611.01236 (2016). Pattern Recognition, 2022, pp. 15095–15104.
[9] Y. Dong, F. Liao, T. Pang, H. Su, J. Zhu, X. Hu, J. Li, [22] S. Sarkar, V. Gundecha, S. Ghorbanpour,
Boosting adversarial attacks with momentum, in: A. Shmakov, A. R. Babu, A. Pichard, M.
CoProceedings of the IEEE conference on computer cho, Skip training for multi-agent reinforcement
vision and pattern recognition, 2018, pp. 9185–9193. learning controller for industrial wave energy
[10] N. Papernot, P. McDaniel, S. Jha, M. Fredrikson, Z. B. converters, in: 2022 IEEE 18th International
ConCelik, A. Swami, The limitations of deep learning in ference on Automation Science and Engineering
adversarial settings, in: 2016 IEEE European sym- (CASE), IEEE, 2022, pp. 212–219.
posium on security and privacy (EuroS&amp;P), IEEE, [23] S. Sarkar, V. Gundecha, A. Shmakov, S.
Ghor2016, pp. 372–387. banpour, A. R. Babu, P. Faraboschi, M. Cocho,
[11] S.-M. Moosavi-Dezfooli, A. Fawzi, P. Frossard, A. Pichard, J. Fievez, Multi-agent reinforcement
Deepfool: a simple and accurate method to fool learning controller to maximize energy eficiency
deep neural networks, in: Proceedings of the IEEE for multi-generator industrial wave energy
conconference on computer vision and pattern recog- verter, in: Proceedings of the AAAI Conference on
nition, 2016, pp. 2574–2582. Artificial Intelligence, volume 36, 2022, pp. 12135–
[12] A. Michel, S. K. Jha, R. Ewetz, A survey on the 12144.</p>
        <p>vulnerability of deep neural networks against ad- [24] Y. Sun, S. Wang, X. Tang, T.-Y. Hsieh, V. Honavar,
versarial attacks, Progress in Artificial Intelligence Adversarial attacks on graph neural networks via
(2022) 1–11. node injections: A hierarchical reinforcement
learn[13] A. Chakraborty, M. Alam, V. Dey, A. Chattopadhyay, ing approach, in: Proceedings of the Web
ConferD. Mukhopadhyay, Adversarial attacks and de- ence 2020, 2020, pp. 673–683.
fences: A survey, arXiv preprint arXiv:1810.00069 [25] M. Sewak, Deep q network (dqn), double dqn, and
(2018). dueling dqn, in: Deep Reinforcement Learning,
[14] A. Ilyas, L. Engstrom, A. Athalye, J. Lin, Black-box Springer, 2019, pp. 95–108.</p>
        <p>adversarial attacks with limited queries and infor- [26] J. Chen, M. I. Jordan, M. J. Wainwright,
Hopmation, in: International Conference on Machine skipjumpattack: A query-eficient decision-based
Learning, PMLR, 2018, pp. 2137–2146. attack, in: 2020 ieee symposium on security and
privacy (sp), IEEE, 2020, pp. 1277–1294.
[27] A. Ilyas, L. Engstrom, A. Madry, Prior convictions: systems 32 (2019).</p>
        <p>Black-box adversarial attacks with bandits and pri- [31] O. Russakovsky, J. Deng, H. Su, J. Krause,
ors, arXiv preprint arXiv:1807.07978 (2018). S. Satheesh, S. Ma, Z. Huang, A. Karpathy,
[28] A. Rahmati, S.-M. Moosavi-Dezfooli, P. Frossard, A. Khosla, M. Bernstein, et al., Imagenet large scale
H. Dai, Geoda: a geometric framework for black- visual recognition challenge, International journal
box adversarial attacks, in: Proceedings of the of computer vision 115 (2015) 211–252.
IEEE/CVF Conference on Computer Vision and Pat- [32] Y. Dong, T. Pang, H. Su, J. Zhu, Evading defenses
tern Recognition, 2020, pp. 8446–8455. to transferable adversarial examples by
translation[29] Y. Guo, Z. Yan, C. Zhang, Subspace attack: Ex- invariant attacks, in: Proceedings of the IEEE/CVF
ploiting promising subspaces for query-eficient Conference on Computer Vision and Pattern
Recogblack-box attacks, Advances in Neural Information nition, 2019, pp. 4312–4321.</p>
        <p>Processing Systems 32 (2019). [33] J. Du, H. Zhang, J. T. Zhou, Y. Yang, J. Feng,
Query[30] S. Cheng, Y. Dong, T. Pang, H. Su, J. Zhu, Improving eficient meta attack to deep neural networks, arXiv
black-box adversarial attacks with a transfer-based preprint arXiv:1906.02398 (2019).
prior, Advances in neural information processing</p>
      </sec>
    </sec>
  </body>
  <back>
    <ref-list>
      <ref id="ref1">
        <mixed-citation>
          [1]
          <string-name>
            <given-names>S.</given-names>
            <surname>Joos</surname>
          </string-name>
          , T. Van hamme,
          <string-name>
            <given-names>D.</given-names>
            <surname>Preuveneers</surname>
          </string-name>
          , W. Joosen,
          <article-title>Adversarial robustness is not enough: Practical lim-</article-title>
        </mixed-citation>
      </ref>
    </ref-list>
  </back>
</article>