PCDiff: Watermark-Compatible Active Control of Diffusion Model Ownership

PCDiff redefines model authorization by regulating generation quality, providing active access control and intellectual property protection for text-to-image diffusion models. It integrates a trainable fuser module and hierarchical authentication into the decoder, so that only those holding valid encrypted credentials can generate high-fidelity images; without a valid key, output quality is actively degraded, and the decoupled design is compatible with existing watermarks. Experiments across multiple attack scenarios show that credential verification is strongly correlated with image quality, and it also performs well when combined with conventional watermarks and post-processing.