基于混合混沌系统和ECG信号的图像加密算法

Image Encryption Algorithm Based on Mixed Chaotic System and ECG Signal

为提高明文图像和密钥在加密算法的敏感性和不可预测性,设计了一种基于混合混沌系统和ECG信号相结合的图像加密算法;ECG信号因人而异且难以模仿和复制;首先利用wolf算法计算出随机性强的ECG信号特征值,以及生成明文图像的SHA-256哈希值,用于计算混合混沌系统和ZigZag变换的初始条件;其次利用改善的ZigZag变换对明文图像进行动态置乱,并进行DNA动态编码;最后对置乱的图像按照一定的方法完成扩散过程;通过理论分析和实验结果表明,该加密算法对明文图像和ECG信号高度敏感,具有密钥空间大的优点,能够有效地抵抗已知明文、选择明文攻击、抗穷举攻击和差分攻击。

In order to improve the sensitivity and unpredictability of plaint image and key in encryption algorithm.In the paper,an image encryption algorithm based on mixed chaotic system and electrocardiogram(ECG)signal is proposed.ECG signal vary from person to person,making it difficult to be imitated and duplicated.Firstly,characteristic value of the ECG signal with strong randomness was calculated by Wolf algorithm,and secure hash algorithm-256(SHA-256)hash function of the plain image is combined to comput the initial conditions for mixed chaotic system and ZigZag transformation.Then,the improved ZigZag transformation was used to image dynamic scrambling pixel position of the plain image,and dynamic deoxyribonucleic acid(DNA)standard rule coding was selected.Finally,getting the scrambling according to certain method or process which is encrypted exclusive image.The experimental and security analysis indicate that the encryption algorithm is highly sensitive to plain image and ECG signal,and has the advantages of large key space and can effectively risist known-plaintext and chosen-plaintext attacks、statistical attack and differential attack.