CIF: A Constrained Inversion Framework for Reliable Message Extraction in Diffusion-Based Generative Steganography
Yuqi Qian, Yun Cao, Meiyang Lv, Haocheng Fu
TL;DR
This work addresses unreliable message extraction in diffusion-based generative steganography by diagnosing two core inversion errors: dynamic structural error and numerical integration error. It introduces CIF, a constrained inversion framework with Path Consistency Inversion (PCI) to enforce linear, velocity-aligned trajectories and Adaptive Hybrid-Order Solver (AHOS) to adapt integration order to local stability. Empirical results show CIF reduces latent reconstruction error by over 35% and achieves top extraction accuracy under various distortions, including JPEG compression and resizing, while maintaining security against steganalysis and a high hiding capacity. The approach offers practical, robust, end-to-end extraction reliability for high-capacity steganography in real-world transmission scenarios.
Abstract
Generative image steganography aims to conceal secret information in generated images without arousing suspicion. However, in practical scenarios involving high-capacity embedding or lossy transmission, existing methods still suffer from limited extraction accuracy. The main challenge lies in accurately recovering the secret-embedded latent vectors from stego images. To address this issue, we propose CIF, a constrained inversion framework designed to achieve accurate message extraction. Specifically, CIF reduces dynamic structural errors by enforcing linear consistency in the latent space, meanwhile reduces numerical integration errors by adaptively adjusting the integration order according to local trajectory stability. Experimental results show that our method reduces latent reconstruction error by more than 35\% and achieves higher message extraction accuracy than existing approaches.
