基于整数非线性耦合混沌模型的图像加密算法

Image Encryption Algorithm Based on Integer Nonlinear Coupled Chaotic Model

以耦合映像格子模型为原型,Arnold猫映射作为空间格点间的耦合方式,选用整数化的Tent映射作为非线性函数,构造了一种整数非线性耦合混沌模型。该模型能快速、并行地产生多维混沌伪随机序列,多维序列具有均匀分布及相互独立的特征,从而克服了混沌伪随机序列发生器设计中存在的根本性缺陷。基于此设计了一种比特级图像置乱加密算法,利用该模型能产生相互独立序列的优势,实现8列图像灰度值并行混淆,并采用猫映射按比特位分块的方式对像素点位置进行置乱处理。最后对图像加密算法的加密效果进行仿真实验评估。

An integer nonlinear--coupled chaotic model based on coupled tent map lattices is structured, which uses Arnold cat map as the coupling method between lattices and the integral Tent function as the nonlinear function. The model can generate multiple-output multidimensional chaotic pseudorandom sequence, which has the features of uniform distribution and independent of each other, to overcome the fundamental flaws existing in designing of chaotic pseudo-random sequence generator. A bit-level image scrambling encryption algorithm based on the model is proposed, and 8 columns gray value been confused parallel come true, depending on the advantage that the model can generate independent sequence. By using the method of cat map and bit-level block, the position of the pixels is set randomly. At last, the simulation experiment evaluation of the encryption effect of image encryption algorithm is carried out.