Increasing the security of image encryption based on intertwining logistic map and elementary cellular automata

Due to the rapid advances in technology and the increasing exchange of information through communication systems such as satellite and internet, crating secure channels is very important. One of the important steps in establishing security in different fields such as medical, industrial and military is image encryption. This paper presents a system of image encryption based on intertwining logistic map and cellular automata. The proposed method is performed in three steps. In the first step, an intertwining logistic map is used as the primary key, and then, in the second step, the attractors of cellular automata are used as the second key, and finally, in the third step, the encryption key is generated through combining the first and second keys. Different criteria such as histogram, space key, correlation coefficient between adjacent pixels and the amount of difference in encrypted image with the original image in this system are calculated. Experimental results showed that, because of the three steps in the generation of the encryption key, the proposed method is able to bring the system to a higher security level than did the previous schemes even after one performing encryption.