Mutual Information-Optimized Steganalysis for Generative Steganography

Mingzhi Hu, Hongxia Wang

Abstract: Coverless generative steganography is a highly secure method of information hiding. With the advent of the AI-generated content (AIGC) era, the widespread dissemination of generative content on the internet provides an excellent hiding environment for generative steganographic images. Generative steganographic images do not require the participation of carrier images, making existing steganalysis methods expired. However, there are currently no detection methods specifically targeting generative steganographic content. To address this gap, we propose a steganalysis method for generative steganographic images. Our approach focuses on the intrinsic differences between generative steganographic images and ordinary generative images. Through comparative analysis, we propose optimizing the detection model using mutual information estimation. We hypothesize about the distribution characteristics of steganographic signals and design a feature discrimination loss function to further guide the model’s optimization. In addition to designing a feature extraction network to extract features from different image regions, we also incorporate an image classification model pretrained on a large dataset to extract classification features for the final classification. Experimental results in various training and testing scenarios demonstrate that the proposed model not only possesses excellent detection capability but also exhibits reliable generalization compared to other models. Furthermore, we provide necessary descriptions and analysis to validate the rationale behind the network design.