Reversible data hiding in permutation encrypted images using sorting and histogram shifting

• Main Authors: Chih-Wei Shiu, 許志維
• Other Authors: Gwoboa Horng
• Format: Others
• Language: en_US
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/22613030823002357207

博士 === 國立中興大學 === 資訊科學與工程學系 === 102 === This dissertation presents a new reversible data hiding in encrypted image (RDHEI). Cover image are segmented along a space filling curve, and segments are permuted to encrypt the image. Since the segments are scrambled, the encrypted image reveals no information about the original one. Since the pixel sequence in a segment is preserved before and after embedding, data embedment can be done using this characteristic. Experimental results show that when the averaged payload is 0.12bpp, the image quality is 50.85 dB. Moreover, many existing methods might encounter a privacy problem. This is because in the image recovery stage, the receiver must both have encryption key and data-hiding key. This means that in the recovery stage, receiver can obtains a decrypted image via encryption key. Therefore, the privacy of the content owner is threatened. In the proposed method, image decryption, message extraction and image recovery are controlled by encryption and data-hiding key separately and therefore, the privacy problem can be solved.