Anthony Etim

Anthony Etim, Jakub Szefer

Adversarial input image perturbation attacks have emerged as a significant threat to machine learning algorithms, particularly in image classification setting. These attacks involve subtle perturbations to input images that cause neural networks to misclassify the input images, even though the images remain easily recognizable to humans. One critical area where adversarial attacks have been demonstrated is in automotive systems where traffic sign classification and recognition is critical, and where misclassified images can cause autonomous systems to take wrong actions. This work presents a new class of adversarial attacks. Unlike existing work that has focused on adversarial perturbations that leverage human-made artifacts to cause the perturbations, such as adding stickers, paint, or shining flashlights at traffic signs, this work leverages nature-made artifacts: tree leaves. By leveraging nature-made artifacts, the new class of attacks has plausible deniability: a fall leaf stuck to a street sign could come from a near-by tree, rather than be placed there by an malicious human attacker. To evaluate the new class of the adversarial input image perturbation attacks, this work analyses how fall leaves can cause misclassification in street signs. The work evaluates various leaves from different species of trees, and considers various parameters such as size, color due to tree leaf type, and rotation. The work demonstrates high success rate for misclassification. The work also explores the correlation between successful attacks and how they affect the edge detection, which is critical in many image classification algorithms.

Anthony Etim, Jakub Szefer

Adversarial attacks on machine learning models often rely on small, imperceptible perturbations to mislead classifiers. Such strategy focuses on minimizing the visual perturbation for humans so they are not confused, and also maximizing the misclassification for machine learning algorithms. An orthogonal strategy for adversarial attacks is to create perturbations that are clearly visible but do not confuse humans, yet still maximize misclassification for machine learning algorithms. This work follows the later strategy, and demonstrates instance of it through the Snowball Adversarial Attack in the context of traffic sign recognition. The attack leverages the human brain's superior ability to recognize objects despite various occlusions, while machine learning algorithms are easily confused. The evaluation shows that the Snowball Adversarial Attack is robust across various images and is able to confuse state-of-the-art traffic sign recognition algorithm. The findings reveal that Snowball Adversarial Attack can significantly degrade model performance with minimal effort, raising important concerns about the vulnerabilities of deep neural networks and highlighting the necessity for improved defenses for image recognition machine learning models.

Anthony Etim, Jakub Szefer

Adversarial attacks on deep learning models have proliferated in recent years. In many cases, a different adversarial perturbation is required to be added to each image to cause the deep learning model to misclassify it. This is ineffective as each image has to be modified in a different way. Meanwhile, research on universal perturbations focuses on designing a single perturbation that can be applied to all images in a data set, and cause a deep learning model to misclassify the images. This work advances the field of universal perturbations by exploring universal perturbations in the context of traffic signs and autonomous vehicle systems. This work introduces a novel method for generating universal perturbations that visually look like simple black and white stickers, and using them to cause incorrect street sign predictions. Unlike traditional adversarial perturbations, the adversarial universal stickers are designed to be applicable to any street sign: same sticker, or stickers, can be applied in same location to any street sign and cause it to be misclassified. Further, to enable safe experimentation with adversarial images and street signs, this work presents a virtual setting that leverages Street View images of street signs, rather than the need to physically modify street signs, to test the attacks. The experiments in the virtual setting demonstrate that these stickers can consistently mislead deep learning models used commonly in street sign recognition, and achieve high attack success rates on dataset of US traffic signs. The findings highlight the practical security risks posed by simple stickers applied to traffic signs, and the ease with which adversaries can generate adversarial universal stickers that can be applied to many street signs.