Latent Watermark: Inject and Detect Watermarks in Latent Diffusion Space

Watermarking is a tool for actively identifying and attributing the images generated by latent diffusion models. Existing methods face the dilemma of watermark robustness and image quality. The reason for this dilemma is that watermark detection is performed in pixel space, implying an intrinsic link between image quality and watermark robustness. In this paper, we highlight that an effective solution to the problem is to both inject and detect watermarks in latent space, and propose Latent Watermark (LW) with a progressive training strategy. Experiments show that compared to the recently proposed methods such as StegaStamp, StableSignature, RoSteALS and TreeRing, LW not only surpasses them in terms of robustness but also offers superior image quality. When we inject 64-bit messages, LW can achieve an identification performance close to 100% and an attribution performance above 97% under 9 single-attack scenarios and one all-attack scenario. Our code will be available on GitHub.