Abstract: In order to protect digital images information, a chaotic image encryption algorithm based on slider and matrix rotation is proposed. Firstly, in the process of pixels position global scrambling, these parameters to control the chaotic system are generated base on the characteristics of the plaintext image, and therefore it is closely related to the plaintext image. Secondly, the image sub-matrix block is rotated to scramble the entire image so that all pixels are uniformly distributed. Finally, in the process of pixel value substitution, the slider encryption method allowes the encryption result of each pixel to affect several other pixels within the slider, which ensures the encryption results of all pixels are interrelated, and improves the security of encrypted image. The experimental results show that the encryption algorithm can not only effectively resist the statistical attack and differential attack, but also achieve high security and good encryption effect.

Key words: chaotic systems, image encryption, chaotic sequence, Kent map

摘要： 针对当前混沌图像加密算法存在的安全缺陷问题，提出了一种基于滑块与矩阵旋转的混沌图像加密算法。在像素位置置乱过程中根据明文图像自身特点，产生与明文图像紧密相关的混沌系统控制参数；旋转图像子矩阵块来打乱整个图像，使所有像素点均匀分布。最后，在像素值替代过程中，利用滑块加密方法，使每一个像素点的加密结果都会影响滑块内的其他若干像素点，从而使加密图像所有像素点的加密结果相互关联，提高了加密图像的安全性。实验仿真结果表明，该加密算法能够有效的抵抗统计特征攻击、差分攻击，具有较高的安全性和良好的加密效果。

关键词: 混沌系统, 图像加密, 混沌序列, Kent映射