DTAMS: High-Capacity Generative Steganography via Dynamic Multi-Timestep Selection and Adaptive Deviation Mapping in Latent Diffusion
Yuhao Xue, Jiuan Zhou, Yu Cheng, Zhaoxia Yin
TL;DR
DTAMS tackles the challenge of high-capacity generative steganography by integrating dynamic multi-timestep embedding, global interval deviation mapping, and multi-dimensional deviation compensation into a diffusion-based framework. It preselects embedding timesteps via a transition-cost model, maps modifications to pixel-intervals to constrain deviations, and jointly regularizes pixel, latent, and semantic representations to enhance robustness and anti-steganalysis performance. Experiments show embedding capacities up to 12 bpp with extraction accuracy above 99% and strong perceptual quality, while reducing average extraction errors by approximately 59% over state-of-the-art methods under common distortions. The approach offers practical, robust, high-capacity steganography for diffusion-generated imagery with effective defenses against standard steganalysis attacks.
Abstract
With the rapid development of AIGC technologies, generative image steganography has attracted increasing attention due to its high imperceptibility and flexibility. However, existing generative steganography methods often maintain acceptable security and robustness only at relatively low embedding rates, severely limiting the practical applicability of steganographic systems. To address this issue, we propose a novel DTAMS framework that achieves high embedding rates while ensuring strong robustness and security. Specifically, a dynamic multi-timestep adaptive embedding mechanism is constructed based on transition-cost modeling in diffusion models, enabling automatic selection of optimal embedding timesteps to improve embedding rates while preserving overall performance. Meanwhile, we propose a global sub-interval mapping strategy that jointly considers mapping errors and the frequency distribution of secret information, converting point-wise perturbations into interval-level statistical mappings to suppress error accumulation and distribution drift during multi-step diffusion processes. Furthermore, a multi-dimensional joint constraint mechanism is introduced to mitigate distortions caused by repeated latent-pixel transformations by jointly regularizing embedding errors at the pixel, latent, and semantic levels. Experiments demonstrate that the proposed method achieves an embedding rate of 12 bpp while maintaining excellent security and robustness. Across all evaluated conditions, DTAMS reduces the average extraction error rate by 59.39%, representing a significant improvement over SOTA methods.
