一种密文域医学图像可逆信息隐藏算法

鉴于图像的密文域可逆信息隐藏在安全云计算和隐私保护方面的重要作用，为了提高信息嵌入率，结合医学DICOM图像像素深度高、像素分布连续性高的特点，提出了一种结合两种压缩算法的密文域医学图像可逆信息隐藏算法。首先发送方对图像进行预处理，根据像素中高位比特连续为0的数量嵌入标记信息，腾出高位的冗余空间；然后用一种特殊设计的块加密算法进行加密，在保证明文信息不被泄露的同时保留了部分图像相关性；接着嵌入方根据标记信息，在对应位置嵌入额外信息；此外，为了进一步提高嵌入率，嵌入方还可以利用图像像素的相关性，在块内进行做差，并压缩实施信息嵌入。实验结果表明，该算法不仅具有较高的信息嵌入率，同时还有较好的安全性表现。

A reversible data hiding method for encrypted medical image

Reversible data hiding in encrypted images (RDH-EI) is important in secure cloud computing and privacy protection. In order to improve the embedding rate, the characteristics of high pixel depth and high pixel distribution continuity of medical DICOM image was considered, and a reversible data hiding method in encrypted images combining two compression strategies was proposed in this paper. Firstly, the sender preprocessed the image and embedded the mark according to the number of consecutive high-order bits in the pixel. Then a unique block encryption algorithm was used for encryption, which ensured the plaintext information was not leaked while some image correlations were retained. The data-hider embedded additional information in the corresponding position according to the mark. In addition, in order to further improve the embedding rate, the data-hider can also make difference in the block and compress the space for information embedding. Experiments show that the method not only has high information embedding rate, but also has good security performance.