基于复合混沌映射与连续扩散的图像加密算法

摘要

To solve the problem such as low efficiency and obvious chaos periodicity in current image encryption algorithm based on high dimension chaotic system,the image encryption algorithm based on composite low dimensional chaotic maps and nonlinear continuous diffusion was proposed.The complex low dimensional chaotic system was constructed by introducing three onedimensional chaotic maps and combining with the pixels number of plain,and the integer transform rule was used to disturb the pixels position of plain for effectively reducing the periodicity.The random sequence optimization function was designed to optimize the output sequence of the composite low dimensional chaotic system,and the continuous diffusion mechanism was established based on the nonlinear theory to diffuse the pixels of the permutation cipher.The output data were optimized by introducing the imperial competition mechanism,as well as taking the entropy and the correlation degree between adjacent pixels.Experimental results show that compared with the current high dimensional chaotic encryption technology,the proposed algorithm has the same level of security,and its encryption efficiency is higher.%为解决当前基于高维混沌系统的图像加密算法存在效率低以及明显的混沌周期性的不足,提出复合低维混沌映射与连续扩散的图像加密算法.引入3个一维混沌映射,联合明文像素数量,构造复合低维混沌系统,利用其整数变换规则,对明文像素位置进行扰乱,有效削弱周期性;设计随机序列优化函数,对复合低维混沌系统的输出序列进行优化,建立连续扩散机制,对置乱密文进行扩散;引入帝国竞争机制,以密文的熵值和相邻像素间的关联度为目标函数,对输出数据实施优化.实验数据表明,与已有高维混沌加密机制相比,该技术具有同等水平的安全度,加密效率更高.