Abstract

Some two-dimensional chaotic maps are used for scrambling in image encryption. However, the encryption is often unsafe without destroying image statistical characteristics. Moreover, they can only process square image. Here, it designs a bit-level rectangular image encryption algorithm using three-dimensional chaotic maps to solve the problems. The process can permute and confuse images at the same time. Firstly, a plain image is splitted into eight layers according to the value of pixels, then the eight layers are stretched and connected to a new 8-fold image. Secondly, it introduces and improves a new two-dimensional chaotic map that can deal with rectangular images. Every pixel of a column is placed between two adjacent pixels of corresponding row one by one. When the row is longer than the column, the extra pixels are arranged in the original order. After the process, all the pixels are stretched and connected into a row of pixels. Introducing folding mechanism, the line is further mapped to a new image that is not recognized. Lastly, it uses the maps to permute the bigger image. Finally, the cipher image is combined into an original size cipher image. The process shuffles the pixels’ positions and changes the values. Simulation results validate encryption algorithm has large keys space, no statistical characteristics and fast encryption speed above 1 MB/S. It can achieve enough security requirements in public network.

中文翻译：

---

一种利用新混沌映射的位级三维矩形图像加密算法

摘要

一些二维混沌映射用于图像加密中的置乱。然而，在不破坏图像统计特性的情况下加密往往是不安全的。而且，它们只能处理方形图像。这里，设计了一种利用三维混沌图的比特级矩形图像加密算法来解决该问题。该过程可以同时排列和混淆图像。首先，将原始图像根据像素值分割为八层，然后将八层拉伸并连接成新的八倍图像。其次，引入并改进了一种新的可以处理矩形图像的二维混沌图。一列的每个像素依次放置在相应行的两个相邻像素之间。当行长于列时，多余的像素按原始顺序排列。经过该处理后，所有像素都被拉伸并连接成一行像素。引入折叠机制，将线条进一步映射到无法识别的新图像上。最后，它使用贴图来排列更大的图像。最后，将密码图像组合成原始尺寸的密码图像。该过程会打乱像素的位置并更改值。仿真结果验证了加密算法具有密钥空间大、无统计特性、加密速度快(1MB/S以上)的特点。能够满足公网的足够的安全要求。它使用贴图来排列更大的图像。最后，将密码图像组合成原始尺寸的密码图像。该过程会打乱像素的位置并更改值。仿真结果验证了加密算法具有密钥空间大、无统计特性、加密速度快(1MB/S以上)的特点。能够满足公网的足够的安全要求。它使用贴图来排列更大的图像。最后，将密码图像组合成原始尺寸的密码图像。该过程会打乱像素的位置并更改值。仿真结果验证了加密算法具有密钥空间大、无统计特性、加密速度快(1MB/S以上)的特点。能够满足公网的足够的安全要求。