PEFTGuard: Detecting Backdoor Attacks Against Parameter-Efficient Fine-Tuning

Fuente: arXiv
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Main Authors: Sun, Zhen, Cong, Tianshuo, Liu, Yule, Lin, Chenhao, He, Xinlei, Chen, Rongmao, Han, Xingshuo, Huang, Xinyi
Format: Preprint
Published: 2024
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author Sun, Zhen
Cong, Tianshuo
Liu, Yule
Lin, Chenhao
He, Xinlei
Chen, Rongmao
Han, Xingshuo
Huang, Xinyi
author_facet Sun, Zhen
Cong, Tianshuo
Liu, Yule
Lin, Chenhao
He, Xinlei
Chen, Rongmao
Han, Xingshuo
Huang, Xinyi
contents Fine-tuning is an essential process to improve the performance of Large Language Models (LLMs) in specific domains, with Parameter-Efficient Fine-Tuning (PEFT) gaining popularity due to its capacity to reduce computational demands through the integration of low-rank adapters. These lightweight adapters, such as LoRA, can be shared and utilized on open-source platforms. However, adversaries could exploit this mechanism to inject backdoors into these adapters, resulting in malicious behaviors like incorrect or harmful outputs, which pose serious security risks to the community. Unfortunately, few current efforts concentrate on analyzing the backdoor patterns or detecting the backdoors in the adapters. To fill this gap, we first construct and release PADBench, a comprehensive benchmark that contains 13,300 benign and backdoored adapters fine-tuned with various datasets, attack strategies, PEFT methods, and LLMs. Moreover, we propose PEFTGuard, the first backdoor detection framework against PEFT-based adapters. Extensive evaluation upon PADBench shows that PEFTGuard outperforms existing detection methods, achieving nearly perfect detection accuracy (100%) in most cases. Notably, PEFTGuard exhibits zero-shot transferability on three aspects, including different attacks, PEFT methods, and adapter ranks. In addition, we consider various adaptive attacks to demonstrate the high robustness of PEFTGuard. We further explore several possible backdoor mitigation defenses, finding fine-mixing to be the most effective method. We envision that our benchmark and method can shed light on future LLM backdoor detection research.
format Preprint
id arxiv_https___arxiv_org_abs_2411_17453
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle PEFTGuard: Detecting Backdoor Attacks Against Parameter-Efficient Fine-Tuning
Sun, Zhen
Cong, Tianshuo
Liu, Yule
Lin, Chenhao
He, Xinlei
Chen, Rongmao
Han, Xingshuo
Huang, Xinyi
Cryptography and Security
Fine-tuning is an essential process to improve the performance of Large Language Models (LLMs) in specific domains, with Parameter-Efficient Fine-Tuning (PEFT) gaining popularity due to its capacity to reduce computational demands through the integration of low-rank adapters. These lightweight adapters, such as LoRA, can be shared and utilized on open-source platforms. However, adversaries could exploit this mechanism to inject backdoors into these adapters, resulting in malicious behaviors like incorrect or harmful outputs, which pose serious security risks to the community. Unfortunately, few current efforts concentrate on analyzing the backdoor patterns or detecting the backdoors in the adapters. To fill this gap, we first construct and release PADBench, a comprehensive benchmark that contains 13,300 benign and backdoored adapters fine-tuned with various datasets, attack strategies, PEFT methods, and LLMs. Moreover, we propose PEFTGuard, the first backdoor detection framework against PEFT-based adapters. Extensive evaluation upon PADBench shows that PEFTGuard outperforms existing detection methods, achieving nearly perfect detection accuracy (100%) in most cases. Notably, PEFTGuard exhibits zero-shot transferability on three aspects, including different attacks, PEFT methods, and adapter ranks. In addition, we consider various adaptive attacks to demonstrate the high robustness of PEFTGuard. We further explore several possible backdoor mitigation defenses, finding fine-mixing to be the most effective method. We envision that our benchmark and method can shed light on future LLM backdoor detection research.
title PEFTGuard: Detecting Backdoor Attacks Against Parameter-Efficient Fine-Tuning
topic Cryptography and Security
url https://arxiv.org/abs/2411.17453