Fast image encryption algorithm based on (n, m, k)-PCMLCA

Abstract

Cellular Automata (CA) can be implemented by hardware and processed in parallel unlike the conventional algorithm based on chaotic function. In this paper, we propose a fast encryption algorithm for color image using (n, m, k)-programmable complemented maximum length CA((n, m, k)-PCMLCA). This algorithm improves the speed of shuffling pixel positions in the color image encryption system. The encryption process of the proposed image encryption system consists of a substitution step and a shuffling step. In the substitution step, we design the (n, m, k)-PCMLCA which can generate nonlinear sequences whose lengths are longer than the lengths of sequences generated by complemented maximum length CA (C-MLCA), and use it as the key sequence generator. In the shuffling step, we improve the encryption/decryption speed by raising the domain processing the image to the row/column level rather than the pixel unit and processing the block unit using 1-D MLCA. With the advantage of these CA, we can improve the speed of encryption/decryption.