本文提出一种基于最高有效位（MSB）构造密钥的零水印算法，先将二值水印图像置乱并拓展为载体图像的大小，再将其像素值与载体像素的MSB进行对应比较，当比较结果为真时，用一个零矩阵来标记载体像素的位置，被标记过的零矩阵作为密钥来检测水印。由于水印信息遍布载体图像的MSB而且不改变载体图像的信息，使得算法表现出较好的抗攻击性能。实验表明了该算法的有效性。

This paper presents a nonwatermarking algorithm based on the most significant bits to construct the key. Firstly, the binary watermarking image is scrambled and extended to the size of the main image.Then the value of every pixel of the watermarking image is compared with that of the corresponding MSB (Most Significant Bit) of the main image. When the compared value is true,the location of the main image is marked by a zero matrix, and the marked zero matrix is a key that can be used to detect the watermarking image later. Good performance can be achieved due to the watermarking information which is relatively in the most high bitplane and is scattered to the whole of a main image. The experimental results show the validity of the method.