Abstract: In this paper, a novel image blocks encryption algorithm based on Coupled Map Lattice (CML) system was presented to solve the parallel problem of the common image encryption algorithm. The basic idea is to divide the image into blocks，and then used the block number as the spatial parameter of CML to iterate the chaos system. The chaotic stream was used to conduct confusion operations with part of the image，the result of which was applied to encrypt the other part. The proposed method can encrypt image in parallel and can also satisfy color image encryption. The simulation process indicates that the algorithm is easy to realize with low computation complexity，high sensitivity，high speed，high security and other properties simultaneously.

Key words: Coupled Map Lattice (CML), parallelism, blocks, digital image, encryption

摘要： 针对一般图像加密算法不能并行化运行的缺陷，提出一种新的基于耦合映象格子（CML）和分组加密技术的图像加密算法。首先对图像一部分进行分组，并迭代混沌系统，产生与图像分组数相同数目的混沌序列。使用混沌序列值与图像分组部分进行混合操作，其操作结果用来对图像另一部分进行加密。所提算法能够并行地实现图像加密，并可用于彩色图像加密。实验表明该加密算法计算简单，易于实现，密钥敏感性强，在安全性和效率上也有很好的表现。

关键词: 耦合映象格子, 并行性, 分组, 数字图像, 加密