Public key watermarking for reversible image authentication

In this paper, we propose a new public key watermarking scheme for reversible image authentication where if the image is authentic, the distortion due to embedding can be completely removed from the watermarked image after the hidden data has been extracted. This technique utilizes histogram characteristics of the difference image and modifies pixel values slightly to embed more data than other lossless data hiding algorithm. We show that the lower bound of the PSNR(peak-signal-to-noise-ratio) values of watermarked images are 51.14 dB. Moreover, the proposed scheme is quite simple and the execution time is rather short. Experimental results demonstrate that the proposed scheme can detect any modifications of the watermarked image.