Title: PersGuard: Preventing Malicious Personalization in Text-to-Image Diffusion via Model Backdoors
Primary area: alignment, fairness, safety, privacy, and societal considerations
Keywords: Privacy Protection, Backdoor Attack, Diffusion Model, Personalization

Abstract: Diffusion models (DMs) have achieved remarkable success in text-to-image (T2I) generation, yet their personalization capabilities pose serious privacy and copyright risks. Existing protection methods primarily rely on adversarial perturbations, which are impractical in realistic settings and can be easily bypassed when inputs are mixed with clean or transformed data. In this work, we propose PersGuard, a novel model backdoor-based framework to prevent unauthorized personalization of pre-trained T2I diffusion models. Unlike perturbation-based approaches, PersGuard embeds protective backdoors directly into released models, ensuring that fine-tuning on protected images triggers predefined protective behaviors, while unprotected images yield normal outputs. To this end, we formulate backdoor injection as a unified optimization problem with three objectives, and introduce a backdoor retention loss to withstand downstream personalized fine-tuning. Extensive experiments across comparative and gray-box settings, as well as multi-identity scenarios, demonstrate that PersGuard delivers stronger and more reliable protection than existing methods.

TL;DR: We propose backdoor-based framework that embeds protective triggers into diffusion models to prevent unauthorized personalization while preserving normal generation quality.