Generalized switched synchronization and dependent image encryption using dynamically rotating fractional-order chaotic systems

Abstract

This paper presents a generalization, attractor control and multi-scroll generation method for fractional-order chaotic systems through rotation transformation. A novel synchronization-dependent colored image encryption and secure communication scheme is also proposed. The systems with dynamic rotation angle fit successfully in a generalized dynamic switched synchronization scheme. Dynamic control switches specify whether the system acts as a master or slave. Dynamic scaling factors determine whether the master is a single system or a combination of two or more systems. Simulation results validate successful synchronization when rotating fractional-order systems act as slave or master or both. The proposed synchronization is suitable for one-to-one, one-to-many, mutual interconnection and role switching communication applications. The proposed synchronization-dependent image encryption scheme performs rotation angle modulation using the plaintext and XOR logic operation for plaintext image substitution. The performance of the chaotic systems as Pseudo-Random Number Generators (PRNGs) is validated using National Institute of Standards & Technology (NIST). Three synchronization scenarios are tested using Lena image. The performance of the scheme is evaluated through the encrypted image, histogram and its uniformity through chi square test, pixel correlation, Mean Squared Error (MSE), entropy, Peak Signal-to-Noise Ratio (PSNR), key sensitivity, resistance to brute force, differential and other security attacks.