一种篡改检测与篡改定位分离的图像认证方案

An Image Authentication Scheme Separating Tamper Detection from Tamper Location

针对脆弱水印认证算法的篡改定位精度及安全性问题,提出了一种将篡改检测和定位分离的图像认证方案:对图像进行单像素置乱并将其低两位置零,采用像素关联技术生成各个像素的篡改定位水印,并将其嵌入到自身的次低位;将图像逆置乱后并进行分块,生成各个分块的篡改检测水印,将篡改检测水印嵌入到各像素的最低位,进而生成含水印图像.理论分析和实验结果表明:该方案可以抵抗目前针对单像素认证算法的Oracle攻击及针对分块算法的量化攻击,在保证系统安全性的同时可将篡改定位到单个像素.

An image authentication scheme is proposed to locate tampered area on the watermarked image and improve the security of existing watermarking algorithms. In this scheme, the original image is permuted in pixel-level and the Hypo-LSB and LSB of each pixel are set to zero, the location watermark is embedded into the Hypo-LSB of each pixel, then, the image is inversely permuted and divided into blocks, afterwards, the detection watermark of each block is embedded into its LSB. Theoretical analysis and simulation results show that the proposed algorithm can not only resists all kinds of attacks including Oracle and VQ attack, but also locate tampered area in pixel-level accurately as well as ensure the security.