Latin方阵和二维量子漫步相结合的图像加密

Color Image Encryption Combining Latin Matrix and Two-Dimensional Quantum Random Walk

针对数字图像在网络传输过程中容易受到攻击导致信息泄漏的问题,在Arnold置乱变换的基础上引入量子漫步和Latin方阵,设计了一种新型的彩色图像加密方案。首先把彩色图像的三通道分离,用Arnold变换来对图像像素点置乱,量子漫步和Latin方阵被用来处理置乱后图像的像素值,然后对处理之后的图像使用加取模扩散算法进一步改变图像的像素值,最后合并三通道加密图像得到彩色加密图像。量子漫步的作用是为该文的加密算法提供随机序列。该文对加密算法进行了实验仿真,在直方图、相关性、信息熵、噪声攻击、裁剪攻击等多个方面对实验结果进行了性能分析。仿真结果显示:加密图像的直方图均匀分布,像素点之间的相关性趋近于0,信息熵为7.9993,接近于8,说明该算法具有较不错的抵抗统计分析的能力;经过噪声攻击和裁剪攻击之后的加密图像经过解密之后,仍然可以看到原图像信息,表明该算法的鲁棒性是良好的;该加密算法的密钥空间足够大为1060且密钥敏感性良好,NPCR值接近于99.61%,UACI值接近于33.45%,证明该算法拥有抵抗差分攻击的能力。

Aiming at the problem that digital images are vulnerable to attacks during network transmission and cause information leakage.This paper introduces quantum walk and Latin square matrix on the basis of Arnold scrambling,and designs a new type of color image encryption scheme.In the new scheme,the three channels of the color image are separated at first and the Arnold transform is used to scramble the pixel points of the image.Then quantum walk and Latin square matrix are used to process the pixel values of the scrambled image,the modulus diffusion algorithm is used on the processed image to further change the pixel value of the image.Finally,the color encrypted image is obtained by merging the three-channels encrypted images.Quantum walk,as an excellent random sequence generation tool,provides random sequences for algorithms.We conducted experimental simulations on the encryption algorithm,and analyzed the experimental results in the histogram,correlation,information entropy,noise attack,cropping attack and other aspects.The results show that the histogram of the encrypted image is distributed evenly,the correlation between pixels is close to 0,and the information entropy is 7.9993,close to 8,indicating that the algorithm has a relatively good ability to resist statistical analysis.After decrypting the encrypted image after noise attack and cropping attack,the original image information can still be seen,indicating that the robustness of the algorithm is good.The key space of the encryption algorithm is large enough and the key sensitivity is good.The NPCR(normalized pixel contrast ratio)value is close to 99.61%,and the UACI(unified average changing intensity)value is 33.45%.It has the ability to resist differential attacks.