CHAOS-BASED IMAGE ENCRYPTION APPROACH USING BAKER‘S MAP

Abstract

Data Encryption Standard (DES), International Data Encryption Algorithm (IDEA), and (RSA) appear not to be ideal for image related areas, due to some internal features of images such as bulk data capacity and high redundancy, which are troublesome for traditional encryption, computational time and high computing power. Most of the these encryption schemes require extra operations on compressed image data, thereby demanding long computational time and high computing power. The chaotic cryptography is obtaining more attention than the others because of its lower mathematical complexity & better Security. It also avoids the data spreading hence reduces the transmission cost & delay. The digital image cryptography which is based on chaotic systems utilizes the discrete non-linear system dynamics generally called chaotic mapping. By combining them a large number of cryptographic techniques could be designed in this paper presents a chaotic baker 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. Diffusion template is also created by random number generator based on Gaussian distribution. The technique is using Bakers map and it is capable to provide the key length of 128 bits although it’s length can be extended further. The proposed technique is simulated using Matlab and the results will prove its robustness with all type of cryptanalytic tests and faster execution.