Image encryption algorithm based on DFRCT
基于离散分数余弦变换的图像加密算法研究*

In order to improve the efficiency and security of image encryption,this paper constructed a new discrete fractional cosine transform(DFRCT) with arbitrary period by the method of linear combination, with its well orthogonal performance, the fractional and period parameters, and proposed a new image encryption algorithm based on discrete fractional cosine transform.It adopted the method of image block (image element) in the encryption algorithm. Divided original image into different sizes of image elements first, and then used the discrete fractional cosine transform to encrypt each image element by rows and by columns, the image encryption achieved at last. The analyzed results of the simulation show that the encryption algorithm effectiveness, efficiency and ability to resist brute-force attack are satisfactory.