基于小波变换的抗退化混沌图像加密算法

针对图像加密普遍存在高复杂度和安全性差的问题,结合抗退化混沌系统和小波变换,设计一种图像加密算法。利用Lorenz混沌系统,进行抗退化处理,生成混沌序列;使用小波变换,通过混沌序列对各子带系数进行置乱处理,同时对低频子带系数做扩散处理,小波逆变换后得到初始加密图像;对初始加密图像进行像素值的扩散和像素间耦合加密得到最终加密图像。仿真结果表明,该算法的密钥空间大,密钥敏感性强,可以抵抗各种攻击,具有较高的安全性和实用性。

ANTI-DEGRADATION CHAOTIC IMAGE ENCRYPTION ALGORITHM BASED ON WAVELET TRANSFORM

Aiming at the problem of high complexity and poor security of image encryption,an image encryption algorithm is designed based on anti-degeneration chaotic system and wavelet transform.It used the Lorenz chaotic system to perform anti-degeneration processing and generated chaotic sequences.Then,using wavelet transform,the sub-band coefficients were scrambled by chaotic sequence,and the low-frequency sub-band coefficients were diffused.The initial encrypted image was obtained after inverse wavelet transform.The initial encrypted image was subjected to pixel value diffusion and inter-pixel coupling encryption to obtain a final encrypted image.The simulation results show that the algorithm has large key space,strong key sensitivity,and can resist various attacks.It has high security and practicability.