Synchronizations and secure communication applications of second and third degree systems with chaotic flow

Key Words: Chaos, Chaotic Systems, Chaotic Circuits, Synchronization, Chaotic Masking, Secure Communication Chaos and chaotic systems have many fields of applications. One of the popular practical application is secure communication. Chaotic signals depend very sensitively on initial conditions, have unpredictable features and noise like wideband spread spectrum. So, it can be used in various communication applications because of their features of masking and immunizing information against noise. Chaos-based secure communication systems have been alternative of the standard spread-spectrum systems, since they are able to spread the spectrum of the information signals and simultaneously encrypt the information signals with chaotic circuitry which is simple and inexpensive. In secure communication field, like Lorenz, Chua, Rossler, Duffing etc., classical systems are widely used. This thesis` aims are; introducing new chaotic systems which could be used alternatively to classical chaotic systems; simulating their electronic circuit models, simulating their synchronization circuit models using Pecora-Carroll method, simulating their chaotic masking communication circuit models, and showing that these chaotic systems could be used in secure communication area. Towards these aims, firstly chaotic systems from different science disciplines were investigated. From these investigated systems, Sprott97a and Malasoma2000 systems were chosen. These chaotic systems are topologically simple but their dynamical behaviours are very rich and their synchronization and secure communication applications were not seen in literature. Using Matlab-Simulink program, their modelings, synchronization and secure communication applications were realized respectively. Results obtained in this study have been discussed and evaluated in the last chapter.