关键词: 图像置乱, 位置交换, 均匀分布, 帐篷映射, 排序置乱

Abstract: Abstract: In order to efficiently scramble image, based on skew tent map, a fast random permutation procedure was firstly presented, and then a fast image scrambling algorithm, based on the preceding procedure, was designed. The main idea behind the fast random permutation was position interchange. Its implementation process was, based on geometrical meaning of probability, non-uniform distribution chaos sequence generated by skew tent map was transformed into uniform random sequence, which then drove image element to interchange position. Theory and experiments results demonstrate that the fast random permutation has better efficiency then sorting-based random permutation, the proposed image scrambling method has larger key space and higher running efficiency than sorting-based image scrambling.

Key words: image scrambling, position interchange, uniform distribution, skew tent map, sorting permutation