| Session P2：網路犯罪與數位鑑識
論文作者：Jen-Chun Chang, Yun-Hong Chou, Cheng-Huai Ni, Hsin-Lung Wu
This work studies how to construct a reversible data hiding scheme for encrypted images. We propose a novel separable reversible data hiding method for pairwisely encrypted images. The input image is encrypted first via a novel pairwise encryption scheme. Then the data bits can be embedded into the pairwisely encrypted image by the well-known differenceexpansion technique. Our proposed scheme is separable in the following sense. When the receiver gets the marked encrypted image, he can extract the secret data bits by the data-hiding key and obtain the marked decrypted image by the encryption key where the marked decrypted image has small distortion compared to the original host image. Furthermore, the receiver can recover the original image and extract the secret data bits once he owns both encryption and data-hiding keys. In the experimental result, we compare our scheme with existing separable methods which do not pre-reserve space for embedding secret data. The experimental result shows that the proposed scheme obtains much better embedding capacity than previous schemes without pre-reserving embedding space. |
