New Symmetrical Cryptosystems Based on a Dynamic Optimization Model : two-Dimensional non-Uniform Cellular Automata

Today, computer networks are complex and illegal wiretapping is possible. This poses a real problem for the security during transmission of data. For ethical reasons, the transfer of sensitive data cannot be done with such a danger and must protect themselves. Protection best suited for this type of communication is the cryptography. However, despite all its developments, it is still hampered by some flaws citing in particular the key size and resistance against advanced attacks. Thus, in this paper we present two new cellular automata-based optimization algorithms aiming to solve problems of images encryption: S2CA, Symmetrical Cellular Automata-based Ciphering Algorithm, and S2CA-EX, Symmetrical Cellular Automata-based Ciphering Algorithm Extension. The main idea is to operate on the pixels positions or pixels RGB coding positions in order to alter the original image so as to have the maximum of disorder in the corresponding encrypted image. The proposed algorithms were tested on images of different sizes where they have shown a good confusion level and resistibility against the most advanced attacks. A comparison between these algorithms and the best-known cryptographic standards conclude this work.