A secure image encryption scheme based on cellular automata and chaotic skew tent map

This paper presents a highly secure image encryption scheme for secure image communication and storage. The scheme is based on a chaotic skew tent map and cellular automata (CA). The chaotic skew tent map is used as the initial vector generator for the CA which needs a 128 bit initial bit sequence to generate pseudo random number sequence (PRNS). Using the PRNS, the plain image pixels are first permuted to remove the high correlation among the adjacent pixels in the image. Then the permuted image is encrypted based on a single random number generated by the chaotic skew tent map. The chaotic skew tent map has a very large key space, on the other hand, CA generates PRNS faster than a chaotic pseudo random number generator (PRNG). Therefore, a combination of both chaotic map and CA gives a system with higher key space and faster PRNS generator. The experimental results show a good encryption effects which are capable to resist any kind of known attacks. (C) 2019 Elsevier Ltd. All rights reserved.