An Image Encryption Approach Using Chaotic Map in Frequency Domain

This paper presents a chaotic map based cryptography technique, in the proposed technique; confusion and diffusion applied on spectral domain (on DCT(Discrete Cosine Transform) coefficients) hence the encryption can be achieved quickly without applying the large number of confusion and diffusion cycle as it is needed in spatial domain. Also the diffusion template is created by random number generator based on Gaussian distribution. The technique uses Bakers map and capable of providing the key length of 128 bits although it’s length can be extended further. The proposed technique is simulated using Matlab and the results prove its robustness with all type of cryptanalytic tests and faster execution.