云与用户之间交互式抗屏摄密文水印协议  

Interactive screen-shooting resilient ciphertext watermarking protocol between the cloud and the user

作　　者：董晓娟 张卫明[1] 方涵 俞能海[1] Xiaojuan DONG;Weiming ZHANG;Han FANG;Nenghai YU(Key Laboratory of Electromagnetic Space Informnation,Chinese Academy of Sciences,University of Science and Technology of China,Hefei 230026,China)

机构地区：[1]中国科学技术大学中国科学院电磁空间信息重点实验室

出　　处：《中国科学：信息科学》2022年第7期1272-1286,共15页Scientia Sinica(Informationis)

基　　金：国家自然科学基金(批准号:62072421,62002334,62121002);国家重点研发计划项目(批准号:2018YFB0804100);安徽省自然科学基金(批准号:2008085QF296);中国科学技术大学探索类基金(批准号:YD3480002001)资助项目。

摘　　要：现有的云存储服务普遍推出了浏览文件的功能,这为用户通过拍摄屏幕上的文件来窃取信息带来极大的便利,同时也加重了信息泄露的风险.因此,用户通过拍照窃取信息对云存储服务来说是一个潜在的安全性问题.现有的办法是云端在推送图像至用户端前,先嵌入与用户身份相关的抗屏摄水印,那么云端能从拍摄的图像检测到水印,发现用户身份.然而云端和用户端都有含用户水印的图像,我们无法确认被泄露的图像是从云端流出的还是从用户端流出的.为了消除泄露源的二义性,使用密文水印,云端将用户的密文水印嵌入到明文图像,生成含用户水印的密文图像.只有用户端能将之解密,获得相应的明文图像.一旦该图像被偷拍泄露,我们可断定该图像一定是从用户端流出的.但是目前的抗屏摄水印算法不支持上述功能,仅支持明文水印的嵌入.为此,本文提出一个云与用户之间的抗屏摄密文水印协议,旨在保护版权用户对其图像的版权,防止使用图像的用户通过偷拍窃取图像.通过理论分析和仿真实验,本文验证了所提出协议在实施过程中的安全性和有效性.The current cloud storage services generally launch the function of browsing files, which brings great convenience for users to steal information by shooting files on the screen, and also increases the risk of information leakage. As a result, users taking photos to steal information poses a potential security risk for cloud storage services. The existing method is for the cloud to embed a screen-shooting resilient watermark associated with the user’s identity in an image before sending it to the user. Then the cloud can detect the user’s watermark from the captured image and discover the user’s identity. Both the cloud and the user have the image embedded with the user’s watermark, so the leaked images cannot be confirmed to be from the cloud or from the user. To eliminate the ambiguity of the leakage source, ciphertext watermark is utilized, that is, the user’s ciphertext watermark is embedded into a plaintext image in the cloud to generate the ciphertext image containing the user’s watermark,which can only be decrypted by the user to obtain the plaintext image. Once this image is secretly shot and leaked, it must flow out from the user. However, the current screen-shooting resilient watermarking algorithm does not support the above functions and only supports the embedding of the plaintext watermark. This paper proposes a screen-shooting resilient ciphertext watermarking protocol between the cloud and users, which aims to protect the copyright users’ ownership of their images and prevent other users who use the images from stealing images by taking pictures secretly. This paper verifies the security and effectiveness of the proposed protocol through theoretical analysis and simulation experiments.

关 键 词：云存储 密文水印协议 抗屏摄水印 版权保护 泄露追踪 

分 类 号：TP309.7[自动化与计算机技术—计算机系统结构]