用于盗版追踪的格雷码加密域可逆水印研究  

Reversible watermarking in encrypted image based on Gray code for piracy tracing

作　　者：石慧[1] 冯斌 王相海[1] 李明楚[3] 宋传鸣[1] Shi Hui;Feng Bin;Wang Xianghai;Li Mingchu;Song Chuanming(Computer and Information Technology College,Liaoning Normal University,Dalian 116029,China;School of lnformation Science and Technology,TaiShan University,Taian 271000,China;School of Software Technology,Dalian University of Technology,Dalian 116621,China)

机构地区：[1]辽宁师范大学计算机与信息技术学院,大连116029 [2]泰山学院信息科学技术学院,泰安271000 [3]大连理工大学软件学院,大连116621

出　　处：《中国图象图形学报》2018年第11期1635-1651,共17页Journal of Image and Graphics

基　　金：国家自然科学基金项目(61601214;61401060;61771090;41671439;61572095)~~

摘　　要：目的现有水印算法大多是基于明文域的,很容易被入侵、窃取。为了保护用户隐私、提高安全性,本文提出了一种用于盗版追踪的基于格雷码加密域的可逆水印方法,该方法支持对密文直接操作。方法首先提出了基于格雷码的同态加密系统(HESGC),并以此加密载体图像;然后依据整数小波变换(IWT)和人类视觉系统(HVS)特性,将图像分区并合理分类;再依据新提出的算法完成嵌入、可逆恢复及提取工作;最后利用首次提出的水印追踪联合策略(JWT)来进行盗版追踪。结果为了验证本文方法,选取USC-SIPI图像库中的6幅经典图像作为标准测试图像,与其他可逆水印算法相比,本文方法具有更高的PSNR值,PSNR高达50 d B,而且SSIM值均为1,实现了可逆功能;本文新提出的HESGC将使原始载体图像膨胀为原来的8倍,故容量较大。理论上,本文最大容量为3. 75 bit/像素,目前大多可逆水印算法的最大容量不足1 bit/像素;本文方法不仅实现了盗版追踪功能,而且能够抵抗一些常见的攻击,如随机噪声、中值滤波、图像平滑和JPEG编码、LZW编码和卷积模糊等。通过比较原始追踪证明与攻击后图像的追踪证明可知,相似度在1左右的即为盗版,其他非盗版的相似度都远远低于1,大部分在0. 6左右。结论本文提出了一种基于密文域的可逆水印方案,首次提出了HESGC和JWT,实现了密文域可逆水印技术和盗版追踪功能。该方案直接采用灰度图像作为水印图像,解除了以往以二值图像作为水印图像,或者将灰度图像二值化后作为水印图像的限制,而且采用基于级联混沌技术提高了灰度水印图像的安全性。此外,本文成功消除了图像分区分类中纹理/平滑区域中的平滑/纹理孤岛,使分类结果更加准确、合理。实验结果表明,本方案不仅能够抵抗一些常见攻击,而且容量大、安全性高,很好地保护了用户隐私。本文实现了密�Objective The rapid evolution of cloud technology has provided users with convenience but still has securityrisks. Users＇ privacy （e. g. , personal photos, corporate user information, and electronic notes） will be exposed once the cloud data are inaccessible or corrupted. Owing to the existence of security vulnerabilities or internal staff illicit activity, data may be tampered, replaced, or distributed illegally. In such a case, protecting the user＇ privacy is crucial. Currently and in practice, protecting the users＇ privacy is achieved by watermarking technology, especially reversible watermarking technology. Reversible watermarking can not only extract data correctly but also completely restore the original carrier. This technique is used in the medical, military, and other fields. Therefore, reversible watermarking technology plays an impor- tant role in the privacy protection field. Most of the existing reversible watermarking algorithms are based on the plaintext domain, such that they can be easily pirated or tampered. Thus, we proposed a reversible watermarking scheme in the ho- momorphic encrypted domain on the basis of Gray code for piracy tracing to enhance security and protect privacy. The pro- posed scheme provides support for a direct operation in the homomorphic encrypted domain. The ultimate goal of the new proposed scheme in the encrypted domain is to protect the users＇ privacy. Method First, the ＂homomorphic encryption system based on Gray code＂ （HESGC） is proposed to encrypt the original carrier image. Gray code encryption converts the grayscale values of the original carrier image into binary values. Second, in accordance with integer homomorphic encryp- tion, the binary values are converted into different decimal grayscale values. Subsequently, region division and classifica- tion can be reasonably performed in accordance with the ＂integer wavelet transform＂ and ＂human visual system＂ character- istics. Region division is used to avoid conflicts between watermarking

关 键 词：隐私保护 可逆水印 盗版追踪 基于格雷码的同态加密系统 水印追踪联合策略 大容量 高安全性 

分 类 号：TP311[自动化与计算机技术—计算机软件与理论]