Application of megastable system with $2$-$D$ strip of hidden chaotic attractors to secure communications

Many real dynamical systems are characterized by the presence of a coexisting attractors set. This property of systems is called multistability. In multistable systems, a sudden transition to unwanted or unknown attractors can occur. Such a transition can lead to catastrophic events. It turned out that multistability is also associated with the emergence of unpredictable attractors, which are called hidden attractors. One of the defining reasons for studying multistable chaotic systems with different characteristics is a wide range of their potential engineering applications - synchronization of the receiver and transmitter, masking and recovery of messages, noise filtering, recovery of information signals, as well as the development of decoding and coding algorithms that allow you to present an arbitrary digital message through the symbolic dynamics of a chaotic system.
This paper proposes not only a mathematical model of a secure communication scheme based on adaptive synchronization between a pair of identical megastable systems with a 2-D band of hidden chaotic attractors, but also its numerical simulation using the MATLAB & Simulink environment. The use of synchronization in communication systems is of fundamental importance, since it forces systems to simultaneously output the same output data and, in turn, leads to accurate restoration of information signals. Meanwhile, on the receiver side, information can be successfully recovered using adaptive technology. The presented method is stable with respect to various levels of additive white Gaussian noise. The scheme used for synchronization made it possible to overcome the well-known difficulties presented in the works of a number of specialists that arise in the problem of synchronizing in the case of multistability and coexistence of hidden oscillations, with the wrong choice of the form of the control signal.
Numerical simulations are given to verify the feasibility of proposed synchronization and better performance of image encryption technique in terms of histogram, robustness to noise and visual imperceptibility. Three types of masked messages (text, grayscale image and audio signal) are considered as test examples.