The pervasiveness of neural networks (NNs) in critical computer vision and image processing applications makes them very attractive for adversarial manipulation. A large body of existing research thoroughly investigates two broad categories of attacks targeting the integrity of NN models. The first category of attacks, commonly called Adversarial Examples, perturbs the model's inference by carefully adding noise into input examples. In the second category of attacks, adversaries try to manipulate the model during the training process by implanting Trojan backdoors. Researchers show that such attacks pose severe threats to the growing applications of NNs and propose several defenses against each attack type individually. However, such one-sided defense approaches leave potentially unknown risks in real-world scenarios when an adversary can unify different attacks to create new and more lethal ones bypassing existing defenses. In this work, we show how to jointly exploit adversarial perturbation and model poisoning vulnerabilities to practically launch a new stealthy attack, dubbed AdvTrojan. AdvTrojan is stealthy because it can be activated only when: 1) a carefully crafted adversarial perturbation is injected into the input examples during inference, and 2) a Trojan backdoor is implanted during the training process of the model. We leverage adversarial noise in the input space to move Trojan-infected examples across the model decision boundary, making it difficult to detect. The stealthiness behavior of AdvTrojan fools the users into accidentally trusting the infected model as a robust classifier against adversarial examples. AdvTrojan can be implemented by only poisoning the training data similar to conventional Trojan backdoor attacks. Our thorough analysis and extensive experiments on several benchmark datasets show that AdvTrojan can bypass existing defenses with a success rate close to 100% in most of our experimental scenarios and can be extended to attack federated learning as well as high-resolution images.
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Stochastic Computing as a Defence Against Adversarial Attacks
Abstract- Neural networks (NNs) are increasingly often employed in safety critical systems. It is therefore necessary to ensure that these NNs are robust against malicious interference in the form of adversarial attacks, which cause an NN to misclassify inputs. Many proposed defenses against such attacks incorporate randomness in order to make it harder for an attacker to find small input modifications that result in misclassification. Stochastic computing (SC) is a type of approximate computing based on pseudo-random bit-streams that has been successfully used to implement convolutional neural networks (CNNs). Some results have previously suggested that such stochastic CNNs (SCNNs) are partially robust against adversarial attacks. In this work, we will demonstrate that SCNNs do indeed possess inherent protection against some powerful adversarial attacks. Our results show that the white-box C&W attack is up to 16x less successful compared to an equivalent binary NN, and Boundary Attack even fails to generate adversarial inputs in many cases.
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- Award ID(s):
- 2006704
- PAR ID:
- 10518941
- Publisher / Repository:
- IEEE
- Date Published:
- ISBN:
- 979-8-3503-2543-0
- Page Range / eLocation ID:
- 191 to 194
- Format(s):
- Medium: X
- Location:
- Porto, Portugal
- Sponsoring Org:
- National Science Foundation
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