Detection-and Information-Theoretic Analysis of Steganography and Fingerprinting

First, from a detection-theoretic perspective, we quantify the detectability of commonly used information-hiding techniques such as spread spectrum and distortion-compensated quantization index modulation, and also the detectability of block-based steganography. We devise a practical steganalysis method that exploits the peculiar block structure of block-DCT image steganography. To cope with the twin difficulties of unknown image statistics and unknown steganographic codes, we explore image steganalysis based on supervised learning and build an optimized classifier that outperforms previously proposed image steganalysis methods.