Discrete time-based chua chaotic generator

Abstract

Chaos theory describes the behavior of certain nonlinear deterministic systems. These systems with evolving state time-dependence variation, may exhibit dynamics that is highly sensitive to initial conditions. Generally, the chaotic generators are classified into two main classes; continuous and discrete time generators. Continuous time such as systems based on Chua’s circuit[1] or the Lorenz[2] and Rossler systems[3], while discrete time systems such as Henon map[4]. Many methods that use analog circuits have been proposed in the field of chaotic communication systems[5-10]. Because recovery characteristics are sensitive to parameter mismatch between the receiver and the transmitter, one deficiency of these systems is that it must have both the transmitter and the receiver with very high component accuracy, to ensure correct information recovery. However, in practical situations, it is difficult to build both the transmitter and the receiver with very high component accuracy, since the component values are affected by aging, temperature…etc. Therefore, the analog implementation seems very difficult. Software implementations provide powerful computing tools in which complex numerical simulations of nonlinear phenomena are possible. They offer several advantages such as precision and ease of use to change the parameter values. Despite these privileges, applications such as spread spectrum and cryptography systems need high level of security; this is achieved by using hardware implementations instead of software implementations. In this paper, discrete time generators representing a modification of analog generators will be described. The goal here is to overcome the problems which face the analog circuits.