影子不可窜改的图像秘密分享技术研究

Research of secret image sharing scheme with tamper-resistant shadows

为了使得影子具有更好的伪装性,普遍的方法是选择一定数量的掩盖图像,然后在大体不影响掩盖图像视觉效果的前提下将份额缩小嵌入其中并作为最终的影子图像。这样的做法为攻击者从影子图像中提取原始的份额数据留下了隐患。针对这一问题,提出了一种新的图像秘密分享方案,其最大的特点是掩盖图像不再只简单作为份额数据的嵌入载体,而是参与影子图像生成及秘密图像重构等过程所涉及的所有运算。任意像素点被修改过的影子图像都无法参与秘密图像的有效重构,能在计算安全层面上有效提高图像秘密分享系统的安全性。

In order to make shadows being better camouflage, the usual practice method is to select a certain number of cover images, and embed reduced share data into these cover images under the premise that the visual effect would not be affected observably, and those cover images with embedded share data are final shadows. However, this approach has a defect that attackers can extract the original share data from the shadow image. Aiming at this problem, this paper proposed a new image secret sharing scheme, and the most significant feature of which scheme was that the cover image was not only a simple embedded vector as the share data, but be involved in all operations of the shadow image production and the secret image reconstruction as an integral part of the image secret sharing system. A shadow image with any tamper cannot reconstruct the secret image effectively, so it improves the computational security of the secret image sharing system.