Papers › T2IShield: Defending Against Backdoors on Text-to-Image Diffusion Models

T2IShield: Defending Against Backdoors on Text-to-Image Diffusion Models

5 Jul 2024arXiv:2407.04215archive 2025-07-28

Zhongqi Wang, Jie Zhang, Shiguang Shan, Xilin Chen

While text-to-image diffusion models demonstrate impressive generation capabilities, they also exhibit vulnerability to backdoor attacks, which involve the manipulation of model outputs through malicious triggers. In this paper, for the first time, we propose a comprehensive defense method named T2IShield to detect, localize, and mitigate such attacks. Specifically, we find the "Assimilation Phenomenon" on the cross-attention maps caused by the backdoor trigger. Based on this key insight, we propose two effective backdoor detection methods: Frobenius Norm Threshold Truncation and Covariance Discriminant Analysis. Besides, we introduce a binary-search approach to localize the trigger within a backdoor sample and assess the efficacy of existing concept editing methods in mitigating backdoor attacks. Empirical evaluations on two advanced backdoor attack scenarios show the effectiveness of our proposed defense method. For backdoor sample detection, T2IShield achieves a detection F1 score of 88.9% with low computational cost. Furthermore, T2IShield achieves a localization F1 score of 86.4% and invalidates 99% poisoned samples. Codes are released at https://github.com/Robin-WZQ/T2IShield.

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binary_search_helper robin-wzq/t2ishield/backdoor_localization/locate_clip_rickrolling.py official repository unverified MIT (permissive) · a68c381b7719889b · report
binary_search_trigger robin-wzq/t2ishield/backdoor_localization/locate_clip_rickrolling.py official repository unverified MIT (permissive) · e9260bd77c9e3df8 · report
compute_similairy robin-wzq/t2ishield/backdoor_localization/locate_clip_rickrolling.py official repository unverified MIT (permissive) · a705996c5d120e82 · report

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Diffusion

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