关键词: 二维离散分数阶Fourier变换, 双混沌, 辅助密钥矩阵, 置乱

Abstract: In order to solve the shortcomings of the fractional Fourier transform and the traditional chaotic encryption, this paper proposes a new algorithm, two dimensional chaotic image encryption algorithm, based on two-dimensional discrete fractional Fourier transform. In this algorithm, the chaotic sequence is obtained by the input key and the combination of the auxiliary key matrix with the help of the clear text image information, and then the generated intermediate cipher is used as the input of the two-dimensional discrete fractional Fourier transform. At last, through making the scrambling operation, so that the text information is very good hidden. The experimental simulation shows that this algorithm not only can effectively resist statistical attack, differential attack, but also can greatly improve the traditional fractional Fourier transform image histogram smoothing shortcomings, achieve good encryption effect.

Key words: two dimensional discrete fractional Fourier transform, double chaos, auxiliary key matrix, scrambling