差分编码和块压缩的密文域可逆信息隐藏算法  

Reversible Data Hiding Algorithm in Encrypted Images with Difference Encoding and Block Compression

作　　者：葛国庆 葛斌[1] 夏晨星 王智盟 GE Guoqing;GE Bin;XIA Chenxing;WANG Zhimeng(School of Computer Sci.and Eng.,Anhui Univ.of Sci.and Technol.,Huainan 232001,China;Anhui Purvar Bigdata Technol.Co.,Ltd.,Huainan 232001,China)

机构地区：[1]安徽理工大学计算机科学与工程学院,安徽淮南232001 [2]安徽璞华大数据技术有限公司,安徽淮南232001

出　　处：《工程科学与技术》2024年第4期307-315,共9页Advanced Engineering Sciences

基　　金：安徽理工大学研究生创新基金项目(2022CX2123);国家自然科学基金项目(62102003);国家重大专项(2020YFB1314103);安徽省自然科学基金项目(2108085QF258);安徽省高等学校自然科学研究项目(KJ2020A0299);安徽理工大学青年科学研究基金重点项目(QN2019102)。

摘　　要：随着数字信息与云存储技术的发展与成熟,密文域可逆信息隐藏算法正逐渐成为通信传输中数据隐私保护的研究热点。如何根据不同载体图像像素的分布特征,对局部区域内像素进行自适应识别编码,实现对载体更彻底的压缩以提升嵌入容量仍具有较大挑战。本文针对密文域可逆信息隐藏算法因载体图像冗余空间压缩不充分而导致嵌入容量较低的问题,提出一种基于差分编码和块压缩的密文域可逆信息隐藏算法。首先,根据自然图像局部区域内像素强相关性邻位作差,并基于块内最大差值对差值图像矩阵进行分类和自适应编码,同时设计分块置乱和块内像素扩散加密机制保证图像信息安全。然后,将自适应编码结果在对应的密文图像块上进行标记,压缩冗余空间。最后,通过位替换嵌入秘密信息。不同于其他算法,本算法对差分编码后的图像进行比特位重排列,从密文图像像素最低有效位开始,标记差值像素的符号位,其余各位面依次标记最小差值比特位。由于加密操作与自适应编码的可逆性,合法接收者可实现对原始明文图像的无损重构和秘密信息的无误提取。实验结果表明,与现有的几类算法相比,本文提出的算法具有更高的嵌入率和更好的安全性,在BOSSbase和BOWS-2两个数据集上的平均嵌入率达到3.027位/像素和2.937位/像素,在测试图像上平均嵌入率也均提高了0.57位/像素以上。With the development of digital information and cloud-computing technology toward maturity,reversible hiding of data in encrypted images is gradually becoming an area of intensive research for protection of data privacy in communications.Nonetheless,notable challenges still exist regarding achieving greater compression of carriers to enhance embedding capacity by adaptive-recognition coding of pixels in local areas based on the distribution characteristics of pixels in different cover images.To address the problem of the low embedding capacity of reversible information hiding due to insufficient utilization of redundant space in carrier images,herein,a cipher-text domain-reversible data-hiding algorithm is proposed based on difference coding and block compression.First,the difference-image matrix is classified and adaptively coded according to the maximum difference value within the block based on the differences of strong-correlation neighbors in local areas of the natural image.At the same time,the original image is chunked,disrupting the order between blocks and diffusing pixels within blocks to ensure the security of the image information.Then,according to the result of the adaptive coding of the difference-pixel blocks,the redundant space is compressed on the corresponding encrypted image blocks,and the secret data is finally embedded by bit replacement.In contrast to previous algorithms,this approach rearranges the bits of the differential-encoded image,starting from the least-significant bit of the cipher-text image pixel,marking the sign bit of the differential pixel,and marking the least-significant differential bit in each of the remaining planes in turn.Due to the reversibility of the encryption operation and adaptive coding,a legitimate receiver can achieve lossless reconstruction of the original plain-text image and error-free extraction of the secret data.The experimental results show that the proposed algorithm has a greater embedding rate and better security than several existing algorithms.The av

关 键 词：可逆信息隐藏 密文域 隐私保护 差分编码 块压缩 

分 类 号：TP309[自动化与计算机技术—计算机系统结构]