A Novel Encryption and Extended Dynamic Histogram Shifting Modulation for Reversible Data Hiding in Encrypted Image

Recently, progressive interest is paid to reversible data hiding (RDH) in encrypted images, since it preserves the original cover can be recovered without any loss after embedded data is extracted to protect the confidentiality of image content’s.Earlier method used“vacate room after Encryption” in which data can be embedded by reversibly vacating room from the encrypted images. This might cause errors while data extraction or image restoration. However this provides less PSNR value when embedding messages in Images. To address this problem, a proposed method uses Extended Dynamic Histogram Shifting Modulation (EDHS) can be done on the image content by the content owner. This method shifts the pixels of histogram based on prediction errors and its neighborhood pixels. The data can be embedded based on the space provided by the proposed histogram shifting method. After reserving space for data hiding by self reversible embedding using EDHS, Image can be encrypted by using proposed novel encryption method. Finally the receiver can restore the image and extract data by using encryption key and data hiding key. Experimental result provides greater PSNR value when compare with the existing work. Keywords— Reversible data hiding, Image encryption, Extended dynamic histogram.