基于有限域与Arnold映射结合的医学图像快速加密算法

FAST MEDICAL IMAGE ENCRYPTION ALGORITHM BASED ON COMBINATION OF FINITE FIELD AND ARNOLD MAPPING

为了快速且高效地对医学图像加密,设计一种对医学图像的快速加密算法。运用Tent映射迭代的序列中随机选4位数字作为超混沌Lorenz系统的初始值;运用超混沌Lorenz系统产生混沌序列,并生成有限域加法运算表,运用混沌序列对明文图像进行2次扩散加密,得到第一次加密图像;运用混沌序列作为优化后Arnold映射的参数向量,对扩散后的图像进行置乱,从而得到密文图像。从加密结果可以看出,该加密算法具有较好的加密效果,加密后的图像具有随机性效果较好、相邻像素之间相关性较小、安全性更高等特征,并且所需加密时间较短。

In order to encrypt medical images quickly and efficiently,this paper designs a fast encryption algorithm for medical images.The initial values of hyperchaotic Lorenz system were selected randomly from the iterative sequence of Tent mapping.The hyperchaotic Lorenz system was used to generate chaotic sequence and finite field addition operation table.Chaotic sequence was used to encrypt plaintext image twice to obtain the first encrypted image.The chaotic sequence was used as the parameter vector of Arnold mapping after optimization to scramble the diffused image,so as to obtain the ciphertext image.The encryption results show that the encryption algorithm has good encryption effect,the encrypted image has better randomness,less correlation between adjacent pixels,higher security,and requires shorter encryption time.