基于伪随机序列的Arnold加密算法

Arnold变换是一种经典的图像置乱算法。由于其具有周期性,导致密钥量不够。提出了一种改进的Arnold变换方法,即引入伪随机序列并利用安全哈希算法产生随机参数序列,将数字图像分块,并对每个块图像分别进行Arnold变换,最终得到一幅置乱图像。该算法有效地增加了密钥量,可以克服通过穷举分析等手段进行的攻击,增加了图像的安全性。

Arnold Encryption Algorithm Based on PN Sequence

Arnold Cat transformation is a classical algorithm of image scrambling. But its periodicity restrains the times of image scrambling, so the number of the keys is not enough. This paper presented a modified Arnold method, which uses PN sequence and secure hash algorithm to generate a random parameter sequence, then divides an image into 4 pieces and carries out Arnold algorithm to the 4 pieces respectively. The Arnold algorithm effectively increases the number of the keys, and overcomes the attack via the exhaustive analysis, which enhances the security.