三维可逆混沌映射的图像加密算法

Image encryption approach based on invertible chaotic three-dimensional map

提出了一种三维可逆混沌映射图像加密算法。基于Line map二维混沌可逆映射,推导了该三维可逆映射的数学表达式。将灰度图像用一个三维矩阵数据描述,并按照所提出的算法将其组成一个二维的二进制图像。首先对此图像应用Line map二维混沌可逆映射进行像素置乱处理,然后再将置乱后的二进制图像还原成十进制的灰度图像,这样就得到了加密后的图像。所提出的方法可以通过一次三维可逆混沌映射同时实现图像加密的两个步骤,即像素置乱和像素混淆。仿真实验结果表明了该算法的有效性,且加密速度快、安全性高、简单易行。

A image encryption approach based on invertible chaos three-dimensional （3D） map is proposed. It is based on invertible chaotic two-dimensional （2D） map which is called line map. A gray-level image is firstly described as a 3D matrix, using binary format to represent the pixel values of the image. Then the 3D matrix is mapped to a 2D matrix according to the algorithms proposed. Line map is used to permute the elements of the 2D matrix. The permuted matrix is mapped back to a same sized gray-level image. Therefore, image encryption is completed. The proposed approach realizes both pixel permutation and substitution at the same time. Experiments are carried out and the results prove that the encryption scheme is valid, and has high security simple and is easy to implement, its encryption speed is fast.