基于广义Feistel结构的分组图像加密算法

Adaptive Block Image Encryption Algorithms Based on Generalized Feistel Structure

为了提高加密信息的安全性等要求,提出了一种广义拟feistel结构分组加密算法。首先利用三角混沌映射产生混沌序列并将明文分块,然后将三角混沌映射和灰度扩散机制相结合依次对明文进行替换,最后将三角混沌作为密钥用于广义拟feistel结构分组加密算法对替换后的明文加密。通过对加密后图像相邻像素所对应的共生矩阵特性分析表明,加密图像具有良好的空间随机均匀分布特性。

In order to improve the security of the image encryption algorithms,the generalized quasi-feistel structure block cipher algorithm for image encryption is proposed.Firstly,the triangular chaotic sequence generated by triangular chaotic map and plaintext is segmented into four equal sub-blocks.Secondly,the triangle chaotic map combined with gray-scale diffusion mechanism is used to replace the gray values of plaintext.Lastly,the improved encryption algorithm based on quasi-feistel structure and triangle chaotic sequence is applied to realize the encryption of the replaced plaintext.Analyzing the encrypted image by means of gray level co-occurrence matrix（GLCM）,it shows that the neighborhood pixels of encrypted image has good performance of space random uniform distribution.