A Novel 2D Hyperchaotic with a Complex Dynamic Behavior for Color Image Encryption

Abstract

The generation method of the key stream and the structure of the algorithm determine the security of the cryptosystem. The classical chaotic map has simple dynamic behavior and few control parameters, so it is not suitable for modern cryptography. In this paper, we design a new 2D hyperchaotic system called 2D simple structure and complex dynamic behavior map (2D-SSCDB). The 2D-SSCDB has a simple structure but has complex dynamic behavior. The Lyapunov exponent verifies that the 2D-SSCDB has hyperchaotic behavior, and the parameter space in the hyperchaotic state is extensive and continuous. Trajectory analysis and some randomness tests verify that the 2D-SSCDB can generate random sequences with good performance. Next, to verify the excellent performance of the 2D-SSCDB, we use the 2D-SSCDB to generate a keystream for color image encryption. In the encryption algorithm, the encryption algorithm scrambles and diffuses simultaneously, increasing the cryptographic system’s security. The horizontal correlation, vertical correlation, and diagonal correlation of ciphertext are −0.0004, −0.0004 and 0.0007, respectively. The average information entropy of the ciphertext is 7.9993. In addition, the designed encryption algorithm reduces the correlation between the three channels of the color image. Security analysis shows that the color image encryption algorithm designed using 2D-SSCDB has good security, can resist standard attack methods, and has high efficiency.