To realize the safe transmission of images, a chaotic image encryption algorithm based on Latin square and random shift is proposed. The algorithm consists of four parts: key generation, pixel scrambling, pixel replacement, and bit scrambling. Firstly, the key is generated from the plain image to improve the sensitivity of the encryption method. Secondly, each pixel in each row of the image matrix is moved cyclically to the right, in turn, to change the position of the image pixel and realize pixel position scrambling. Then, a 256-order Latin square matrix composed of a chaotic sequence is used as a lookup table, and the replacement coordinates are calculated based on the image pixel value and the chaotic sequence value, replacing the corresponding coordinate elements in the image matrix. Finally, decompose the bitplane of the image matrix and combine it into two-bit matrices, scramble the two bit matrices, respectively, with the Latin square matrix, recombine the scrambled two-bit matrices, and convert them into decimal to obtain the ciphertext image. In the proposed encryption method, all the Latin square matrices used are generated by chaotic sequences, further enhancing the complexity of the generated Latin square matrix and improving the algorithm’s security. Experimental results and security analysis show that the proposed algorithm has good security performance and is suitable for image encryption.

中文翻译：

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一种新的基于拉丁方和随机移位的混沌图像加密算法

为实现图像的安全传输，提出了一种基于拉丁方和随机移位的混沌图像加密算法。该算法由四部分组成：密钥生成、像素加扰、像素替换和比特加扰。首先，从明文图像中生成密钥以提高加密方法的敏感性。其次，将图像矩阵每一行的每个像素循环向右移动，依次改变图像像素的位置，实现像素位置加扰。然后，以一个由混沌序列组成的256阶拉丁方阵作为查找表，根据图像像素值和混沌序列值计算替换坐标，替换图像矩阵中对应的坐标元素。最后，将图像矩阵的位平面分解并组合成两位矩阵，将两个位矩阵分别用拉丁方阵打乱，将打乱后的两位矩阵重新组合，并转化为十进制得到密文图像。在所提出的加密方法中，所有使用的拉丁方阵都是由混沌序列生成的，进一步提高了生成的拉丁方阵的复杂度，提高了算法的安全性。实验结果和安全分析表明，该算法具有良好的安全性能，适用于图像加密。在所提出的加密方法中，所有使用的拉丁方阵都是由混沌序列生成的，进一步提高了生成的拉丁方阵的复杂度，提高了算法的安全性。实验结果和安全分析表明，该算法具有良好的安全性能，适用于图像加密。在所提出的加密方法中，所有使用的拉丁方阵都是由混沌序列生成的，进一步提高了生成的拉丁方阵的复杂度，提高了算法的安全性。实验结果和安全分析表明，该算法具有良好的安全性能，适用于图像加密。