High-Capacity RDH in Encrypted Images Based on Interpolation Mechanism

This study presents a high-capacity reversible data hiding (RDH) method within encrypted images. The proposed method implements a three-pass encryption algorithm to ensure image security. To generate additional space for data embedding, an interpolation mechanism is used. Secret data is hidden within all interpolated pixels using an adaptive hiding method based on pixel differences. Experimental results demonstrated that our method substantially improves existing methods regarding embedding capacity, achieving a mean embedding rate of 4.06 bits per pixel (bpp) across standard test images. Pixel correlation and histogram analysis are employed in a security analysis, confirming the method's robustness against statistical attacks. The method allows for the full restoration of both the original image and the hidden data. Therefore, the proposed method is suited for applications requiring high embedding capacity and security, for instance, medical imaging and military communications.