基于小波变换与LDPC码的图像加密

Image encryption based on wavelet transform and LDPC code

为提高图像的安全性,提出将小波变换、混沌以及LDPC码相结合的图像加密方案。即利用小波变换、混沌对图像进行加密处理,经过小波变换后的系数通过混沌系统产生的序列进行扩散、置乱、组合系数,以显示出加密后的图像,再由LDPC码嵌入水印。利用Matlab进行仿真,结果发现,相较于单一混沌加密而言,该加密方案有着很大的密钥空间,不容易被破解,也能够抵御一些攻击,安全性有所提高。

To improving the security of the image,an image encryption scheme combining wavelet transform,chaos and LDPC codes is proposed. That is,use wavelet transform chaos to encrypt the image.The process is to diffuse the coefficients after wavelet transform through the sequence generated by the chaotic system,scramble,and combine the coefficients to display the encrypted image. Then embed the watermark by the LDPC code. Using Matlab for simulation,it was found that compared with a single chaotic encryption,there is a large key space,which is not easy to be cracked;it can also resist some attacks,and the security is improved.