摘要： 目前的差值直方图平移算法多数存在嵌入容量偏低的缺点，因此，在信息隐藏算法的基础上，提出一种大容量的密文域可逆信息隐藏算法。利用单同态加密在加密域内直接对图像进行操作，将图像分成大小相同的块，每块图像的像素根据位置关系进行分组，通过对互不重叠的4个相邻像素作差建立分块差值直方图，再选取两侧边缘值作为嵌入位置以提高嵌入容量。实验结果表明，该算法在提高信息嵌入率的同时可保证直接解密后的图像具有较高的PSNR值，并且能够完全恢复载体图像。

关键词: 信息隐藏, 可逆信息隐藏, 同态加密, 差值直方图, 密文域

Abstract: The embedding capacity of the current difference histogram shifting algorithm is low.To cope with this problem,we propose a large-capacity reversible data hiding algorithm in encrypted domain.First,we use the single homomorphic encryption to enable a direct operation on the images in the encryption domain.Then,we divide the images into blocks of the same size and group the pixels of each image according to their positions.Finally,we establish a block difference histogram through the difference of four adjacent non-overlapping pixels,and choose the edge value of both sides as the embedding location to improve the embedding capacity.Experimental results show that the proposed algorithm can ensure that the directly decrypted image has a higher PSNR value when the information embedding rate is improved,and the carrier images can also be restored completely.

Key words: information hiding, reversible information hiding, homomorphic encryption, difference histogram, encrypted domain

中图分类号: 

• TP309