Prediction error and histogram shifting based reversible data hiding

Objective of this paper is to improve the security for multimedia files and to increase the volume of hidden data in an image. The technique of reversible data hiding is capable of recovering the data embedded and the original image from a stego image without distortion. For some applications such as satellite and medical images, reversible data hiding is the valuable solution to render copyright or authentication. Reversible data hiding scheme is done based on Modification of Prediction Error (MPE). In this proposed MPE method, the histogram of prediction errors modified to prepare vacant positions for data embedding based on the secret data length. So data hiding capacity of an image is increased. The PSNR and embedding capacity of the stego image produced by MPE is more when compared to other techniques. To increase security, the secret data is encrypted using chaotic encryption algorithm. The encrypted secret message is then hide into the image. The complexity of extracting the encrypted secret data from the stego image is more. It is impossible to decrypt the data even though it is hacked. The encryption key generated is based on secret data and chaotic sequence. This improves the security of the multimedia files.