大容量的密文域图像可逆信息隐藏算法

High-Capacity Reversible Data Hiding for Encrypted Images

提出了一种新的用于加密图像的可逆信息隐藏算法.使用同一密钥对原始图像中每个不重叠分块中的像素进行加密,在保证原始图像内容安全的同时,利用块内相邻像素相关性特征和游程编码在加密图像中嵌入秘密信息.对于嵌入信息后的加密图像可直接用加密密钥解密,得到与原始图像视觉上相似的解密图像;也可以通过嵌入密钥正确地提取嵌入信息;在拥有这两个密钥的条件下,既可以正确地提取嵌入信息,又可以完全无误地恢复原始图像.实验结果表明:与已有方法相比,该方法不仅提高了加密图像的信息嵌入量,而且实现了原始图像的可逆恢复.

In this paper, we propose a novel scheme of reversible data hiding in encrypted image. By using the same encryption key to encrypt the pixels in each non-overlapping block of original image, the contents of original image can be effectively masked by the content owner. The data-bider can realize data embedding in the encrypted image by exploiting the continuity characteristic of the pixels in each encrypted block and using run-length coding. After receiving the encrypted image containing extra data, with the encryption key, the receiver can obtain a directly-decrypted image which is similar to the original image; with the data-hiding key, the receiver can extract the embedded data correctly; with both encryption and data-hiding keys, the receiver can extract extra data and recover original image. Experimental results demonstrate that the proposed scheme can not only increase the hiding capacity in encrypted image, but also recover the original image without error.