Encryption of Analog and Digital signals through Synchronized Chaotic Systems

2011 ◽  
pp. 415-438
Author(s):  
Kehui Sun
Keyword(s):  
Secure Communication ◽  
Communication Systems ◽  
Chaotic Sequence ◽  
Digital Signals ◽  
Encryption Schemes ◽  
Shift Keying ◽  
Chaos Shift Keying ◽  
Sequence Generator ◽  
Chaotic Secure Communication ◽  
Spreading Spectrum

Chaos is characterized by aperiodic, wideband, random-like, and ergodicity. Chaotic secure communication has become one of the hot topics in nonlinear dynamics since the early 1990s exploiting the technique of chaos synchronization. As distinguished by the type of information being carried, chaos-based communication systems can be categorized into analogy and digital, including four popular techniques such as Chaos Masking, Chaos Shift Keying, Chaos Modulation, and Chaos Spreading Spectrum. In this chapter, the principles of these schemes and their modifications are analyzed by theoretical analysis as well as dynamic simulation. In addition, chaos-based cryptography is a new approach to encrypt information. After analyzing the performances of chaotic sequence and designing an effective chaotic sequence generator, the authors briefly presented the principle of two classes of chaotic encryption schemes, chaotic sequence encryption and chaotic data stream encryption.

scholarly journals Efficient error correcting scheme for chaos shift keying signals

2019 ◽  
Vol 9 (5) ◽  
pp. 3550
Author(s):  
Hikmat N. Abdullah ◽  
Thamir R. Saeed ◽  
Asaad H. Sahar
Keyword(s):  
Error Correction ◽  
Logistic Map ◽  
Chaotic Sequence ◽  
Chaos Communication ◽  
Shortest Distance ◽  
Correction Scheme ◽  
Shift Keying ◽  
Minimum Delay ◽  
Modified Logistic Map ◽  
Chaos Shift Keying

An effective error-correction scheme based on normalized correlation for a non coherent chaos communication system with no redundancy bits is proposed in this paper. A modified logistic map is used in the proposed scheme for generating two sequences, one for every data bit value, in a manner that the initial value of the next chaotic sequence is set by the second value of the present chaotic sequence of the similar symbol. This arrangement, thus, has the creation of successive chaotic sequences with identical chaotic dynamics for error correction purpose. The detection symbol is performed prior to correction, on the basis of the suboptimal receiver which anchors on the computation of the shortest distance existing between the received sequence and the modified logistic map’s chaotic trajectory. The results of the simulation reveal noticeable Eb/No improvement by the proposed scheme over the prior to the error- correcting scheme with the improvement increasing whenever there is increase in the number of sequence N. Prior to the error-correcting scheme when N=8, a gain of 1.3 dB is accomplished in E<sub>b</sub>/N<sub>o</sub> at 10<sup>-3 </sup>bit error probability. On the basis of normalized correlation, the most efficient point in our proposed error correction scheme is the absence of any redundant bits needed with minimum delay procedure, in contrast to earlier method that was based on suboptimal method detection and correction. Such performance would render the scheme good candidate for applications requiring high rates of data transmission.

DCSK performance analysis of a chaos-based communication using a newly designed chaotic system

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Namrata Biswas ◽  
Raja Mohamed I
Keyword(s):  
Chaotic System ◽  
Secure Communication ◽  
Chaotic Signal ◽  
Coherent Detection ◽  
Phase Portraits ◽  
Modulation Scheme ◽  
Threshold Control ◽  
New Chaotic System ◽  
Shift Keying ◽  
Chaos Shift Keying

Abstract In this paper, a new chaotic system has been introduced and the fundamental properties of the system were investigated and presented using a bifurcation diagram, max Lyapunov exponent (LE) and phase portraits. The synchronization of the drive and response system has been done using the threshold control parameter. Later the differential chaos shift keying (DCSK) modulation scheme has been carried out for the system as it is the most efficient modulation scheme. The demodulator detects the data without the use of chaotic signal phase recovery, as it uses the non-coherent detection technique. The results were compared with other modulation schemes using the bit error rate (BER) graph. It reveals that the proposed chaos-based system could be used for secure communication. The system has been implemented using the MATLAB Simulink technique.

scholarly journals A Novel Chaotic System with a Line Equilibrium: Analysis and Its Applications to Secure Communication and Random Bit Generation

Telecom ◽  
2020 ◽  
Vol 1 (3) ◽  
pp. 283-296
Author(s):  
Lazaros Moysis ◽  
Christos Volos ◽  
Ioannis Stouboulos ◽  
Sotirios Goudos ◽  
Serdar Çiçek ◽  
...  
Keyword(s):  
Chaotic System ◽  
Secure Communication ◽  
Three Dimensional ◽  
Equilibrium Analysis ◽  
Modulation Method ◽  
Secure Communications ◽  
Information Signal ◽  
Shift Keying ◽  
Binary Information ◽  
Chaos Shift Keying

In this study, a novel two-parameter, three-dimensional chaotic system is constructed. The system has no linear terms and its equilibrium is a line, so it is a system with hidden attractors. The system is first studied by computation of its bifurcation diagrams and diagram of Lyapunov exponents. Then, the system is applied to two encryption related problems. First, the problem of secure communications is considered, using the symmetric chaos shift keying modulation method. Here, the states of the chaotic system are combined with a binary information signal in order to mask it, safely transmit it through a communication channel, and successfully reconstruct the information at the receiver end. In the second problem, the states of the system are utilized to design a simple rule to generate a bit sequence that possesses random properties, and is thus suitable for encryption related applications. For both applications, simulations are performed through Matlab to verify the soundness of the designs.

PERFORMANCE OF FREQUENCY-MODULATED DIFFERENTIAL-CHAOS-SHIFT-KEYING COMMUNICATION SYSTEM OVER MULTIPATH FADING CHANNELS WITH DELAY SPREAD

2005 ◽  
Vol 15 (12) ◽  
pp. 4027-4033 ◽  
Author(s):  
YONGXIANG XIA ◽  
CHI K. TSE ◽  
FRANCIS C. M. LAU ◽  
GÉZA KOLUMBÁN
Keyword(s):  
Fading Channels ◽  
Communication System ◽  
Communication Systems ◽  
Multipath Fading ◽  
Equivalent Model ◽  
Delay Spread ◽  
Error Performance ◽  
Multipath Fading Channels ◽  
Shift Keying ◽  
Chaos Shift Keying

Multipath performance is an important consideration for chaos-based communication systems. In this letter, the performance of the FM-DCSK communication system over multipath fading channels is evaluated by computer simulations. Both Rayleigh fading and Ricean fading are considered, and the low-pass equivalent model of the FM-DCSK system is used in the simulation. Based on this model, we analyze the bit error performance of the system and the effects of system parameters on the bit-error performance.

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