On the Robustness of “Robust Reversible Data Hiding Scheme Based on Two-Layer Embedding Strategy”

In the paper “Robust reversible data hiding scheme based on two-layer embedding strategy” published in INS recently, Kumar et al. proposed a robust reversible data hiding (RRDH) scheme based on two-layer embedding. Secret data was embedded into the most significant bit-planes to increase robustness, and a sorting strategy based on local complexity was adopted to reduce distortion. However, Kumar’s reversible data hiding (RDH) scheme is not as robust against joint photographic experts group (JPEG) compression as stated and can not be called RRDH. This comment first gives a brief description of their RDH scheme, then analyzes their scheme’s robustness from the perspective of JPEG compression principles. JPEG compression will change pixel values, thereby destroying auxiliary information and pixel value ordering required to extract secret data correctly, making their scheme not robust. Finally, the changes in both bit-plane and pixel value ordering after JPEG compression are shown and analyzed by different robustness-testing experiments.