Two Level Encryption of Grey Scale Image through 2D Cellular Automata

Cryptography means to encrypt and decrypt data; data is changed into some other unreadable form, and then the encrypted data is transferred to receiver. Two levels of security is employed in this paper, first one is 2D cellular automata and another one is Arnold Cat Map transformation. 2D Cellular automata is an interesting and capable way of solving problems associated with Arnold Cat Map as it doesn't possess periodic nature and can work upon rectangular images too. Experimental study reveals that scrambling parameters like GDD (Gray difference and Degree) is better in case of combination of 2D cellular automata (Moore Neighborhood) with ACM; while Correlation Coefficient are better in case of combination of 2D Cellular automata (Von Neumann) with Arnold transform. (C) 2018 The Authors. Published by Elsevier B.V.