Improving Poisoning Efficiency in Backdoor Attacks Through Proxy Attack-Free Sample Selection

Core Concepts

Selecting efficient poisoning samples can significantly improve the poisoning efficiency in backdoor attacks, without relying on proxy attacks.

Abstract

The paper presents a novel Proxy attack-Free Strategy (PFS) for improving the poisoning efficiency in backdoor attacks. The key insights are:

The similarity between benign and corresponding poisoning samples is a critical factor influencing the efficiency of poisoning samples. Samples with high similarity tend to be more efficient for backdoor injection.

The diversity within the poisoning sample set is also an important factor. Overly constrained diversity can degrade the performance.

PFS leverages both the similarity and diversity to identify efficient poisoning samples, without the need for a proxy attack task. This addresses the limitation of prior methods that rely on proxy attacks, which can lead to performance degradation when the proxy attack settings differ from the actual attack.

Theoretical analyses based on active learning and neural tangent kernel are provided to explain the effectiveness of the proposed PFS.

Comprehensive experiments on CIFAR-10, Tiny-ImageNet, and CIFAR-100 datasets demonstrate that PFS consistently outperforms prior sample selection methods in terms of attack success rate and computational efficiency.

Stats

Poisoning samples with high similarity between benign and corresponding poisoning samples tend to have higher attack success rates compared to low-similarity samples.
Selecting the top 10% most similar samples and randomly sampling from them (PFS) achieves better performance than random sampling and prior proxy attack-based methods.
PFS is significantly faster than prior proxy attack-based methods, often by hundreds or even thousands of times.

Quotes

"Selecting the to-be-poisoned samples with high similarity between clean samples and their corresponding poisoning samples results in significantly higher attack success rates compared to using samples with low similarity."
"The combination of uncertainty (similarity) and diversity strategies has demonstrated significant success in active learning, and is also effective in improving the efficiency of backdoor attacks."

Key Insights Distilled From

A Proxy Attack-Free Strategy for Practically Improving the Poisoning Efficiency in Backdoor Attacks

by Ziqiang Li,H... at arxiv.org 04-29-2024

https://arxiv.org/pdf/2306.08313.pdf

Deeper Inquiries

How can the proposed PFS be extended to other security-critical applications beyond backdoor attacks, such as adversarial examples or data poisoning

The Proxy Attack-Free Strategy (PFS) proposed in the context of backdoor attacks can be extended to other security-critical applications, such as adversarial examples or data poisoning, by leveraging the fundamental principles of sample selection based on similarity and diversity.
In the case of adversarial examples, where small, imperceptible perturbations are added to input data to deceive machine learning models, the PFS approach can be adapted to select samples that are most likely to generate effective adversarial examples. By considering the similarity between clean and perturbed samples, as well as the diversity within the set of adversarial samples, the PFS method can help in identifying the most impactful adversarial examples for targeted attacks.
Similarly, in the context of data poisoning in security-critical applications, such as malware detection or fraud detection, the PFS approach can aid in selecting the most efficient poisoning samples to compromise the integrity of machine learning models. By focusing on samples with high similarity to clean data and ensuring diversity within the poisoning set, the PFS method can enhance the effectiveness of data poisoning attacks in these scenarios.
Overall, the principles of similarity-based sampling and diversity consideration embedded in the PFS approach can be applied to various security-critical applications beyond backdoor attacks, providing a systematic and efficient way to select impactful samples for adversarial attacks or data poisoning strategies.

What are the potential limitations or drawbacks of the PFS approach, and how can they be addressed in future work

While the Proxy Attack-Free Strategy (PFS) offers significant advantages in improving poisoning efficiency in backdoor attacks, there are potential limitations and drawbacks that should be considered for future work:

Dependency on Feature Extractor: PFS relies on a pre-trained feature extractor to compute similarity between samples. If the feature extractor is not robust or fails to capture relevant features, it may impact the effectiveness of the sample selection process. Future work could explore more advanced feature extraction techniques to enhance the accuracy of similarity measurements.

Limited Generalization: PFS may have limitations in generalizing to diverse datasets or complex models. The effectiveness of the method could vary based on the characteristics of the dataset and the model architecture. Future research could focus on enhancing the adaptability and generalizability of PFS across different domains.

Scalability: The efficiency of PFS in large-scale datasets or real-time applications needs to be further investigated. Scaling up the method to handle massive datasets while maintaining computational efficiency is crucial for practical implementation.

To address these limitations, future work could explore advanced feature extraction methods, optimization techniques for scalability, and robustness testing across diverse datasets and models to enhance the applicability and effectiveness of the PFS approach in various security-critical applications.

Given the connection between sample selection in backdoor attacks and active learning, are there any insights from the PFS approach that could be applied to improve active learning algorithms

The connection between sample selection in backdoor attacks and active learning provides valuable insights that can be applied to improve active learning algorithms. Here are some key insights from the Proxy Attack-Free Strategy (PFS) approach that could benefit active learning algorithms:

Uncertainty-Diversity Trade-off: PFS balances the uncertainty and diversity of data points in sample selection for backdoor attacks. This trade-off is crucial in active learning, where selecting informative yet diverse samples is essential for model improvement. Insights from PFS can guide the development of active learning strategies that effectively balance uncertainty and diversity in sample selection.

Feature Similarity for Informative Sampling: PFS emphasizes the importance of feature similarity between clean and poisoning samples in backdoor attacks. This concept can be leveraged in active learning to prioritize samples that are most similar to the decision boundary, as they are likely to provide the most informative data points for model training.

Efficient Sampling Strategies: PFS introduces an efficient sample selection strategy based on individual similarity and ensemble diversity. These principles can be integrated into active learning algorithms to enhance the efficiency and effectiveness of sample selection processes, leading to improved model performance with reduced annotation costs.

By incorporating insights from the PFS approach into active learning algorithms, researchers can develop more robust and efficient strategies for selecting informative samples and improving model performance in various machine learning tasks.