Steganalysis of a PVD-based content adaptive image steganography

Pixel-value-differencing (PVD) is a well-known technique for content adaptive steganography. By this technique, secret data are embedded into the differences of adjacent pixels. Recently, a new PVD-based steganographic method is proposed by Luo et al. Besides realizing adaptive embedding using PVD, the new method also exploits a pairwise modification mechanism to reduce the distortion. In this work, a targeted detector is devised to detect the new PVD-based steganography. We show that although content adaptive approach may enhance the stego-security, Luo et al.'s PVD-based scheme is not a good choice for realizing adaptive embedding since it contains a serious design flaw in data embedding procedure and this flaw can lead to possible attacks. More specifically, by counting the differences of adjacent pixels in both vertical and horizontal directions, a folded difference-histogram is generated and we show that Luo et al.'s PVD-based method may arise significant artifact to this histogram which can be exploited for reliable detection. Experimental results verify that Luo et al.'s PVD-based method can be detected by the proposed detector even at a low embedding rate of 0.05 bits per pixel.

•PVD is a well-known technique for content adaptive steganography.•A targeted detector is devised to detect a recently proposed PVD-based method.•The PVD-based method can be detected even at a low ER of 0.05 bpp.•A theoretical analysis of the proposed method is provided.