Digital Chaotic Synchronized Communication System

Abstract

The experimental study of a secure chaotic synchronized communication system is presented. The synchronization between two digital chaotic oscillators, serving as a transmitter-receiver scheme, is studied. The oscillators exhibit rich chaotic behavior and are unidirectionally coupled, forming a master-slave topology. Both the input information signal and the transmitted chaotic signal are digital ones.Keywords: Nonlinear circuits, Chaotic circuits, Digital chaotic oscillator, Synchronization. Nonlinear oscillator synchronization is a process that is frequently encountered in nature, explaining relevant phenomena. A significant property that nonlinear dynamical systems possess is their ability to be synchronized. As a consequence, chaotic system synchronization is encountered in a variety of scientific fields, from astronomy and electronic engineering to social sciences. Chaotic deterministic signals exhibit several intrinsic features, beneficial to secure communication systems, both analog and digital ones. Two key features of deterministic chaos are the "noise-like" time series and the sensitive dependence on initial conditions [1,2]. Both of them grant to chaotic signals low probability of detection in chaotic transmissions and low probability of decoding, in case of interception [3]. Journal of EngineeringDue to their possible application for secure internet communications, a number of promising non-linear circuits, demonstrating chaotic behavior, have been presented in the last decade [4][5][6][7][8]. There are two main issues in studying the control of chaotic electronic circuits suitable for secure communications [9]. The first one is the way a non-linear circuit begins to operate in chaotic mode (route to chaos) [2, 10, 11] and the second one is the achievement of synchronization between transmitter-receiver [12,13].Since the discovery by Pecora and Carroll that chaotic systems can be synchronized [12], the topic of synchronization of coupled chaotic circuits and systems has been studied intensely [14] and some interesting applications such as broadband communication systems or cryptographic systems have come out of this research [15][16][17][18].In this paper the system synchronization properties of a chaotic communication system, suitable for secure communication, are examined. Scheme and Circuit descriptionA very interesting electronic circuit exhibiting chaotic behavior and with potential applications in secure communications, was proposed and numerically examined in [19], while its transmitter has been experimentally studied in [20]. The circuit, of the system under question, is presented in Fig 1. Both the transmitter and receiver, of this chaotic communication system, are second order non-linear non-autonomous electronic circuits, with their mode of operation depending on the externally applied driving frequency. It has already been found that the transmitter circuit exhibits the period doubling [21,22] and the intermittency [23,24] routes to chaos as well as internal crisis [25], in differ...

Real-World Chaos-Based Cryptography Using Synchronised Chua Chaotic Circuits

“…In our approach, two channels are utilized, one for achieving synchronisation and another for transmitting information. The signal produced by the chaotic circuits is digitised and processed according to the method described in [3], [4]. After being processed, this signal is used to encrypt a message, by performing an XOR operation.…”

Stochastic Computing Implementation of Chaotic Systems

“…As a result, there exist numerous proposals in this sense, usually ubiquitous ones; one such promising option seems to lean towards using chaotic-based encoder-decoder schemes to secure and/or authenticate data transmission in general [13][14][15][16]. There are examples of such secure-communication systems, analog [17,18], and digital [19,20] ones demonstrating merits like low-cost, circuit simplicity, low-power operation etc. [9,10,21,22].…”

Stochastic Computing Implementation of Chaotic Systems

“…As a result, there exist numerous proposals in this sense, usually ubiquitous ones; one such promising option seems to lean towards using chaotic-based encoder-decoder schemes to secure and/or authenticate data transmission in general [13][14][15][16]. There are examples of such secure-communication systems, analog [17,18], and digital [19,20] ones demonstrating merits like low-cost, circuit simplicity, low-power operation etc. [9,10,21,22].…”