像素位置与比特双重置乱的混沌图像加密算法

Chaotic image encryption algorithm based on dual scrambling of pixel position and bits

分析当前流行的一类基于混沌序列置乱像素位置和像素值加密的混沌算法的安全性的不足,提出了一种抗选择明(密)文攻击的图像加密新算法。采用Kent混沌系统,根据明文像素值的特征和输入的密钥共同产生混沌系统的参数和预迭代次数,首先用混沌序列实现图像像素位置的全局置乱;其次,用另一个混沌序列实现对图像像素值中0、1比特位置乱。混沌序列的产生都与图像本身的内容自适应。仿真实验结果表明,该算法既克服了以往算法不能抵抗选择明(密)文攻击的缺陷,又具有良好的图像加密性能。

We analyze the safety of a chaotic encryption algorithm which is very popular nowadays,based on chaotic sequences scrambling pixel position and pixels encryption,and propose a new image encryption algorithm which is resistant to known-plain-text and chosen-plaintext attacks.The algorithm uses Kent chaotic system to produce the parameters of the chaotic system and the iteration times based on the features of plaintext pixel and input key.Firstly,the global position scrambling is achieved with the chaotic sequence image pixels.Second,the other chaotic sequence is used to scramble the 0,1 bit position of image pixels. Chaotic sequence is produced adapting to the image.Simulation results show that the algorithm is not only resistant to known-plaintext and chosen-plaintext attacks,but also has good image encryption performance.