Digital Information Transmission using Discrete Chaotic Signal

Chaos, Solitons & Fractals, 2005

This paper presents a secure digital communication system based on chaotic modulation, cryptography, and chaotic synchronization techniques. The proposed system consists of a Chaotic Modulator (CM), a Chaotic Secure Transmitter (CST), a Chaotic Secure Receiver (CSR) and a Chaotic Demodulator (CDM). The CM module incorporates a chaotic system and a novel Chaotic Differential Peaks Keying (CDPK) modulation scheme to generate analog patterns corresponding to the input digital bits. The CST and CSR modules are designed such that a single scalar signal is transmitted in the public channel. Furthermore, by giving certain structural conditions of a particular class of chaotic system, the CST and the nonlinear observer-based CSR with an appropriate observer gain are constructed to synchronize with each other. These two slave systems are driven simultaneously by the transmitted signal and are designed to synchronize and generate appropriate cryptography keys for encryption and decryption purposes. In the CDM module, a nonlinear observer is designed to estimate the chaotic modulating system in the CM. A demodulation mechanism is then applied to decode the transmitted input digital bits. The effectiveness of the proposed scheme is demonstrated through the numerical simulation of an illustrative communication system. Synchronization between the chaotic circuits of the transmitter and receiver modules is guaranteed through the Lyapunov stability theorem. Finally, the security features of the proposed system in the event of attack by an intruder in either the time domain or the frequency domain are discussed.

In recent years, synchronization of chaotic systems and its potential application to secure digital communications have received ever increasing attention.

2006

In this paper, synchronization of two chaotic signals is studied and analyzed. A nonlinear recursive backstepping scheme is utilized to design an appropriate control input signal that achieves synchronization between the two chaotic signals. For the sake of comparison, an alternative master-slave synchronizing controller is designed and the two controllers are compared. Numerical simulations are used to demonstrate the effectiveness of the designed control signals in synchronizing the two chaotic systems. The study demonstrates a promising technique which can be applied in secure communication applications, whereby a chaoticallytransmitted information-bearing signal can be faithfully recovered via synchronization.

m-hikari.com

The nonlinear chaotic non-autonomous fourth order system is algebraically simple but can generate complex chaotic attractors. In this paper, non-autonomous fourth order chaotic oscillator circuits were designed and simulated. Also chaotic non-autonomous attractor is addressed suitable for chaotic masking communication circuits using Matlab ® and MultiSIM ® programs. We have demonstrated in simulations that chaos can be synchronized and applied to signal masking communications. We suggest that this phenomenon of chaos synchronism may serve as the basis for little known chaotic non-autonomous attractor to achieve signal masking communication applications. Simulation results are used to visualize and illustrate the effectiveness of non-autonomous chaotic system in signal masking. All simulations results performed on non-autonomous chaotic system are verify the applicable of secure communication.

Nonlinear Analysis: Theory, Methods & Applications, 2009

In this work we present a thorough investigation of the effect of noise (internal or external) on the synchronization of a drive-response configuration system (unidirectional coupling between two identical systems). Moreover, since in every practical implementation of a communication system, the transmitter and receiver circuits (although identical) operate under slightly different conditions it is essential to consider the case of the mismatch between the parameters of the transmitter and the receiver. In our work we consider the non-autonomous 2nd order nonlinear oscillator system presented in [G. Mycolaitis, A. Tamasevicious, A. Cenys, A. Namajunas, K. Navionis, A. N. Anagnostopoulos, Globally synchronizable non-autonomous chaotic oscillator, in: Proc. of 7th International Workshop on Nonlinear Dynamics of Electronic Systems, Denmark, July 1999, pp. 277-280] which is particularly suitable for digital communications.

Chaos, Solitons & Fractals, 2003

In this paper we propose some secure digital communication schemes using discrete chaotic systems. In our approach a message is encrypted at the transmitter using chaotic modulation. Next, the driving signal synchronizes the receiver using discrete observer design or drive-response concept. Finally, by reverting the coding procedure the transmitted message is reconstructed. To demonstrate the efficiency of our communication schemes a modified H e enonÕs map is considered as an illustrative example.

Nonlinear Dynamics, 2013

We develop an experimental system for secure communication with nonlinear mixing of information signal and chaotic signal of a time-delay system. The proposed scheme is based on programmable microcontrollers with digital transmission line. The scheme allows one to transmit and receive speech and musical signals in real time without noticeable distortion. A high quality of extraction of hidden information signal is achieved due to the use of digital elements in the scheme, which ensures identity of the parameters and high stability to noise. We study a possibility of hidden message extraction from a chaotic carrier by a third party in the case of mismatch of the receiver and transmitter parameters.

Chaotic systems are characterized by sensitive dependence on initial conditions, similar to random behavior, and continuous broad-band power spectrum. Chaos is a good potential to be used in secure communications system. In this paper, in order to show some interesting phenomena of three-order Jerk circuit with modulus nonlinearity, the chaotic behavior as a function of a variable control parameter, has been studied. The initial study in this paper is to analyze the phase portraits, the Poincaré maps, the bifurcation diagrams, while the analysis of the synchronization in the case of unidirectional coupling between two identical generated chaotic systems, has been presented. Moreover, some appropriate comparisons are made to contrast some of the existing results. Finally, the effectiveness of the unidirectional coupling scheme between two identical Jerk circuits in a secure communication system is presented in details. Integration of theoretical physics, the numerical simulation by using MATLAB 2010, as well as the implementation of circuit simulations by using MultiSIM 10.0 has been performed in this study.

2010

In this work, the synchronization of two indirectly coupled discrete-time chaotic systems is first demonstrated. Next, the result is then applied for presenting a secure communication system. The novelty of the proposed method lies on the generation of encryption keystream for discrete-time chaotic systems using indirect coupled synchronization. Simulation is performed for the proposed synchronization and communication system and it is shown that the message can be successfully recovered. Moreover, security analysis of the proposed method is also carried out to show that the technique is indeed potentially secure.

Physics Letters A, 2005

This letter analyzes the security weakness of a recently proposed communication method based on chaotic modulation and masking using synchronization of two chaotic systems with different orders. It is shown that its application to secure communication is unsafe, because it can be broken in two different ways, by highpass filtering and by reduced order system synchronization, without knowing neither the system parameter values nor the system key.