Image Encryption Algorithms With Chaotic Map And Discrete Fractional Angular Transform

Nowadays more and more image data are frequently distributed through Internet.Therefore,the secure transmission of confidential or private image data over public channels has become one of the hottest research topics.Recently,with the development of chaos theory,chaos-based image encryption technologies have been gradually developed.In order to enlarge the key space and reduce the correlation of adjacent pixels,two image encryption schemes combining chaotic map with discrete fractional angular transform are constructed.An image encryption algorithm is designed by combining Logistic map with DFr AT.The original image is encrypted by Logistic map as the first encryption,and then the resulting image is encrypted by the discrete fractional angular transform as the second encryption.Simulation results show the validity and the security of this algorithm with acceptable performance in histogram,key sensitivity,and anti-noise and anti-cutting.However,the correlation of adjacent pixels in encrypted images is still too high.A chaos-based image encryption algorithm is proposed based on bit plane transform and DFrAT.In this algorithm,the bit plane transform decomposes the original image into eight bit planes,and then the higher four bit planes are encrypted with the Arnold transform.The encrypted image is subsequently processed by the discrete fractional angular transform,where the double encryption makes the initial image become ciphertext.Simulation results demonstrate that the proposed algorithm can not only retain the advantages of the previous algorithm,but also increase the correlation of adjacent pixels.It is shown that these algorithms are effective,reliable and able to resist some potential attacks.