Image Encryption with Discrete Fractional Cosine Transform and Chaos

We present a new method for image encryption with discrete factional cosine transform (DFrCT) and chaos. DFrCT holds the particular properties which the conventional discrete cosine transform (DCT) hasnpsilat, that is its fraction. Chaos functions have extreme sensitivity to the initial conditions. Logistic map is a simple equation of chaos functions. XOR is first operated between the original image and logistic map. Then the chaotic image is transformed with DFrCT two times using different keys successively by rows and by columns. Based on this method, the image can encrypted effectively, also, the transmission of the encrypted image with DFrCT and chaos is faster than with fractional Fourier transform (DFrFT) and chaos. The computer simulations are presented to verify the validity of the proposed method, such as the mean square error (MSE) between the original images and the decrypted images.