数字图像的随机置乱加密及其与Arnold变换技术的比较

提出了一个用于图像加密的随机置乱算法。该算法首先将代表数字图像的二维数组按列扫描转换为一维向量，然后对该向量中的元素进行随机置乱，最后将经置乱的一维向量转换为二维数组，得到置乱后的图像。与Arnold变换相比较，该算法无需迭代，一般只需执行1，2次置乱就能达到较理想的置乱效果，效率明显提高且算法简单，易于软硬件实现，置乱度相当稳定，也不存在周期性恢复的安全问题。

A Random Scrambling Method for Digital Image Encryption and Comparison with the Technique Based on Arnold Transform

A random scrambling method was proposed for digital image encryption. The two dimension matrix of image was changed to a one dimension vector by column directional scanning, which was performed by a random scrambling algorithm. After scrambled, the vector was returned to an encrypted image. Compared with Arnold transform, this method is very simple for realizing by software or hardware. It doesn＇t require iterative computation, and can bring a better result after being executed one time or twice. Experiments show that the algorithm is effective and has better efficiency and steady scrambling degree than Arnold transform.