一种基于整数小波变换和混沌映射的图像加密算法

An Image Encryption Algorithm Based on IWT and Chaotic Mapping

由于标准混沌模型图像加密效果不佳及运行速度较慢,提出了一种基于整数小波变换和混沌映射的图像加密算法.首先利用整数小波变换算法简单、快速,适合于并行处理及占用内存少等优点将其用于图像分解,其次通过混沌弥散近似得到图像的近似和细节成分,利用整数小波重构得到加密图像.最后通过简单的加扰操作达到进一步混淆密文信息视觉的目的.仿真结果表明,本文所提图像加密算法在加密的模糊性和抗破译性等方面具有更好的性能.

Because of the poor result and slower operation of standard chaotic model for encrypting digital image,an image encryption algorithm is put forward based on integer wavelet transform(IWT)and chaotic mapping.Firstly,the integer wavelet transform is used for image decomposition because of its simplicity,speed,suitability for parallel processing and small memory footprint.Then,approximation and detail components of the image are obtained by chaos dispersion approximation,and the encrypted image is reconstructed by integer wavelet transform.Finally,visual effect of ciphertext information is further confused by simple scrambling operation.Simulations show that the proposed image encryption algorithm has better performance in encrypting fuzzy and resisting decryption.