一种基于交替密钥的分组结构彩色图像加密算法

基于循环迭代的加/解密机制，提出了一种新的彩色图像加密算法。该算法在彩色空间应用了仿射变换，将交替密钥生成算法与分组结构引入到彩色图像加密过程，采用二种混沌映射对彩色图像加密，在每一次交替加密过程中，通过对初始密钥循环移位生成相应的交替密钥并产生二种子密钥，用于二种混沌映射，从而增加了密钥空间，有效提高了彩色图像加密算法的安全性。实验结果表明，该彩色图像加密算法安全性好，免疫性强，效率高。

A packet structure color image encryption algorithmbased on alternant secret key

based on the encryption and decryption mechanism of iterative structure, a new encryption algorithm for color image is put forward. The proposed?algorithm applys affine transformation to the color space, takes the generation algorithm of alternant keys?and?packet structure?into?the procedure of color?image?encryption, adopts two different chaotic mapping encrypting images. The corresponding alternate key and two?different?subkeys?are generated by shifting of the initial secret key In each procedure of the iterate encryption, then the?generated keys are respectively used to different chaotic mapping, Thus, it enhances the key space, effectively improves the safety of the encryption algorithm for color image. The results show this encryption algorithm for color image has good safety, great immunity and high efficiency.