🤖 AI Summary
This study addresses the security vulnerability of existing diffusion model-based generative image steganography (DM-GIS) methods, which are susceptible to detection due to perturbations in the noise distribution. The authors systematically analyze the security of such approaches and identify the noise space as the critical embedding domain, theoretically proving that any steganographic operation that disrupts the noise distribution inherently compromises security. Building on this insight, they propose NS-DSer, the first steganalysis framework specifically designed for the noise space, which formally establishes the intrinsic relationship between diffusion-based steganography security and noise distribution fidelity. Experimental results demonstrate that NS-DSer effectively detects stego images generated by various state-of-the-art DM-GIS methods across multiple scenarios, significantly outperforming existing detectors and thereby validating both the theoretical foundation and practical utility of the proposed framework.
📝 Abstract
Generative image steganography is a technique that conceals secret messages within generated images, without relying on pre-existing cover images. Recently, a number of diffusion model-based generative image steganography (DM-GIS) methods have been introduced, which effectively combat traditional steganalysis techniques. In this paper, we identify the key factors that influence DM-GIS security and revisit the security of existing methods. Specifically, we first provide an overview of the general pipelines of current DM-GIS methods, finding that the noise space of diffusion models serves as the primary embedding domain. Further, we analyze the relationship between DM-GIS security and noise distribution of diffusion models, theoretically demonstrating that any steganographic operation that disrupts the noise distribution compromise DM-GIS security. Building on this insight, we propose a Noise Space-based Diffusion Steganalyzer (NS-DSer)-a simple yet effective steganalysis framework allowing for detecting DM-GIS generated images in the diffusion model noise space. We reevaluate the security of existing DM-GIS methods using NS-DSer across increasingly challenging detection scenarios. Experimental results validate our theoretical analysis of DM-GIS security and show the effectiveness of NS-DSer across diverse detection scenarios.