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Internet of things (IoT) coupled with mobile cloud computing has made a paradigm shift in the service sector. IoT-assisted mobile cloud based e-healthcare services are making giant strides and are likely to change the conventional ways of healthcare service delivery. Though numerous approaches for preventing unauthorized access to information exchanged between a mobile phone and cloud platform do exist, but there is no security mechanism to prevent unauthorized access by the cloud administrators. With an aim to ensure security of client data such as Electronic Patient Records (EPR), we propose a novel high-capacity and reversible data hiding approach for securely embedding EPR within the medical images using Optimal Pixel Repetition (OPR). OPR converts every pixel of the input image to a 2 × 2 block to facilitate reversibility by ensuring all the pixels in a 2 × 2 block to have different values. Since a 2 × 2 block is comprised of 4-pixel elements, which could be arranged in sixteen possible ways; we generate a lookup table corresponding to sixteen possible positions of pixels. EPR hiding in each block is achieved by permuting the pixels of a block according to the four-bit word of secret data, resulting in a histogram invariant stego image. The histogram invariance improves the robustness of the proposed scheme to statistical attacks. A stego image is said to hide embedded data securely, when it provides better imperceptivity for an appreciably high payload. Thus, while using information embedding approach for securing client data on a mobile-cloud platform, high imperceptivity is a desirable feature. Experimental results show that average PSNR obtained is 42 dB for payload 1.25 bpp by our scheme, showing its effectiveness for preventing unauthorized access to client’s sensitive data.  相似文献   
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对结构化文档的字体视觉冗余进行研究,利用CSS修改字体外观实现信息嵌入。该思路将加密和隐藏结合,载体应用范围广,隐藏密度大,安全性高,易于软件实现,所提出的嵌入方式对格式文本信息隐藏都具有指导意义。  相似文献   
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图像信息隐藏是近些年快速发展起来的一种新型信息安全技术,本文在对已有的二值图像隐写方法比较分析基础上,设计了一种通过二值原始图像与隐写图像和隐写图像与二次隐写图像的游程特性变化差值不同,分类确定相应阈值来检测隐秘信息的统计分析方法。实验结果证明这种方法能够成地检测出分块跳转中心像素和分块非跳转中心像素的信息隐藏,并有很高的检测率,实现了对二值图像隐写的盲检测。  相似文献   
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LSB密写技术是目前一种应用最为广泛的数据隐藏技术。本文通过对LSB密写算法的分析,指出了对载体图像进行LSB密写会引起图像统计特性改变的原因,并在此基础上提出了一种基于记忆特性的LSB密写算法。该算法记录下载体已经进行密写部分的统计特性,如果被嵌入的秘密比特与原始像素值的最低位相同,就不作改动;否则就根据该统计特性进行增1或减1的调整;在接收方,提取信息时只需要将载体图像的最低比特位提取、解密即可恢复秘密信息。该算法具有较高的隐蔽性,能够有效地抵抗统计分析方法。  相似文献   
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