基于复合混沌的鲁棒型医学图像加密算法

当前单一混沌图像加密算法的图像置乱程度低，导致加密结果易受到已知明文攻击，存在安全性低的问题。本文提出基于复合混沌的鲁棒型医学图像加密算法。设置图像密文反馈机制作为算法实现的理论支持，并读取鲁棒型医学原始图像。根据混沌模型的建立条件，构建复合混沌模型。选择Logistics混沌映射，生成复合混沌序列并进行多次迭代后，置乱加密鲁棒型医学初始图像像素值并进行替换与扩散，生成对应的密钥，从而实现鲁棒型医学图像的加密。通过与传统加密算法的对比，本文方法的置乱位数增加了886位，即置乱程度提升了8.7%，且明密文序列相关性较低、抗明文攻击能力较强，实验结果表明该鲁棒型医学图像加密算法的安全性较高。

Robust Medical Image Encryption Algorithm Based on Compound Chaos

Aiming at the low degree of image scrambling of the current single chaotic image encryption algorithm, which makes the encryption result vulnerable to known attacks and the problem of low security, a robust medical image encryption algorithm based on compound chaos is proposed. The feedback mechanism of image encryption is set as the theoretical support of algorithm implementation, and read the original image of robust medical. According to the establishment conditions of the chaotic model, a compound chaotic model is constructed. Choosing the Logistics chaotic map, generating a compound chaotic sequence and performing multiple iterations, scrambling and encrypting the pixels of the initial image of the robust medical image, replacing and diffusing, and generating the corresponding key to achieve the encryption of the robust medical image. Compared with the traditional encryption algorithm, the number of scrambling bits of the paper method is increased by 886 bits, that is, the degree of scrambling is increased by 8.7%, and the correlation of image sequences is low and the ability of anti attack is strong. The experiment results show that the security of this robust type of medical image encryption algorithm is high.