Secure communication via partial synchronization of nonlinear systems

It is well known that due to their sensitive dependence on initial conditions, the chaotic systems are capable of producing unpredictable outputs, characteristically, with a widely spread power spectrum. The idea of using them in secure data transmission have been studied extensively over the past decades and various chaotic communication schemes have been proposed. However, their performance in data transmission have been marginally superior at best compared to the conventional approaches. In this study, a novel method to design a secure communication system based on the cluster synchronization in networks of chaotic oscillators has been proposed. Cluster synchronization is observed when the nodes of the network synchronize in groups but there is no synchronization in between the groups. In the proposed system, one or more controllable parameters allow the cluster synchronization of different node groups. The symbols to be transmitted are represented by the cluster synchronization modes. The system is divided into two as transmitter and receiver, the change of cluster synchronization mode also changes the dynamics in the receiver side and hence the presence or the absence of the symbols are signified by the synchronization mode in the corresponding cluster. The basic concept and functioning of the proposed system have been illustrated through numerical simulations.