一种基于Hash函数的脆弱水印算法

当前空域脆弱水印算法存在安全性不高及不能有效抵抗矢量量化攻击的缺陷。针对该缺陷,提出一种用于数字图像完整性认证及内容篡改证明的脆弱水印算法。算法首先对图像进行8×8分块,利用Logistic混沌映射对图像分块进行置乱编号;再采用Hash函数生成基于图像分块内容和位置信息的水印信号;最后将水印信号嵌入到图像分块像素值的低两位平面。实验结果及理论分析表明,提出的脆弱水印算法在保证安全性的同时,有效地抵抗了矢量量化攻击。

Fragile Image Watermarking Algorithm Based on Hash Function

At present,the flaws of the airspace fragile image watermarking algorithm are the low security and lack of effective resistance to the vector attacks.To solve the problem,a fragile watermarking scheme is presented for tamper-proof digital authentication and content tamper testification.Firstly,dividing the image into blocks of 8×8,using the Logistic chaotic map generates the block watermark;Then create the fragile image watermarking based on image-blocking by Hash function;Finally,embedding the watermarking signals into the 2 bit LSB of the blocks of image.Experimental results indicate that the fragile image watermarking algorithm based on Hash function can not only ensure the security in system,but also efficiently resist the vector quantization attacks.