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Reordering image pixels to defend against adversarial attacks

Reordering image pixels to defend against adversarial attacks

Supervisor(s): Ching-Yu Kao
Status: finished
Topic: Others
Author: Mohamed Amine Ben Hamouda
Submission: 2023-02-15
Type of Thesis: Bachelorthesis
Thesis topic in co-operation with the Fraunhofer Institute for Applied and Integrated Security AISEC, Garching

Description

Researchers have demonstrated that deep neural networks are vulnerable to 
adversarial instances, namely maliciously perturbed inputs that are 
indistinguishable from benign data and yet mislead models at test-time [1, 2]. 
In this work, we propose two novel adversarial defense augmentation methods based 
on pixel reordering to boost the model’s robustness. The proposed methods utilize 
a Hilbert curve-based block-wise reordering method [3] and an image-wide random 
shuffling. The experiments are carried out on 3 different datasets with both adaptive 
and non-adaptive maximum-norm bounded white-box attacks. Results show increased accuracy 
against various adversaries, specifically FGSM [4] and PGD [5].The proposed methods can be 
employed as low-overhead augmentations against possible attacks, and can further be investigated 
as pre-processing techniques against adversarial input or in combination with other defenses.