Grid multi-scroll chaotic attractors in hybrid image encryption algorithm based on current conveyor

Abstract

In this paper we propose a novel grid-scroll chaotic attractor generator based on the second generation current conveyor(CCII), which is used for hybrid image encryption of physical chaos encryption and advanced encryption standard (AES) encryption algorithm, because CCII has a higher speed and larger dynamic range than ordinary operational amplifier and can generate multiscroll physical chaotic signal with higher frequency and more complex dynamics properties. The hybrid encryption system of multiscroll physical chaos encryption and AES encryption based on the CCII, does not assure the relationship between plaintext and ciphertext, and the statistical characteristics of ciphertexts in this algorithm should be better than those of any other encryption system. The difference in statistical property of cipher text between the two cases is studied. One case is that the ciphertexts come from different schemes, i. e. the hybrid and the single stage ones, respectively, and the other is that the ciphertexts are generated by chaotic signals with different numbers of scrolls in the same algorithm. We design and implement the chaos circuit based on CCII, and simulat the encryption system. The results shown that they are in agreement with the theoretical analyses, and that the bigger number of scrolls chaotic system causes the weaker correlation of ciphertexts.