Chaotic communication systems in the presence of parametric uncertainty and mismatch

Abstract

SUMMARYA recently developed synchronization scheme in (Phys. Lett. A 2007; 361:108-114) is applied to design a secure communication system with parametric uncertainties and mismatches in this paper. Based on the bounds of the uncertainties and mismatches and a pre-specified bound of the synchronization error, a scheme is given to determine an upper bound of impulsive intervals. With the scheme, the synchronization error is ensured to approach to and stay within the given pre-specified bound and this in turn guarantees that signals can be decoded accurately. To further enhance system security, it is also proposed to transmit functions of the chaotic states at impulsive instants, instead of the states directly. The designed system is tested and verified with text, audio and image encryption and transmission with comparisons to some existing schemes.

Spiral periodic structure inside chaotic region in parameter‐space of a Chua circuit

“…Further, we find two connected sequences aligned in specific directions in parameter-space, organized in period-adding cascades. Finally, we point out that the results reported in this letter may be useful to the experimentalists who work with applications of chaotic circuits, and that depend on the existence of wide regions of chaos, such as secure communication [7,[15][16][17][18][19].…”

Chaotic Secure Communication Systems with an Adaptive State Observer

“…. ., is a series of digital sequences that will be delivered, ( ) is a continuous carrier signal obtained from the signal modulation method, and this signal is taken to be the chaotic parameter of the unified system as described in (5) to achieve the chaotic encryption, ( ) is the measurable output signal that contains only partial information of states,̂1( ),̂2( ), and̂3( ) produced by an adaptive state observer are the estimates of chaotic states, respectively,̂( ) is then the decrypted signal for , and the recovered digital sequencê( ) will eventually be obtained after executing certain demodulation method. In the following subsections, we introduce the detailed descriptions for signal modulation, modified chaotic decryption, and signal demodulation.…”

“…Over the past two decades, a large number of researches regarding chaotic systems and their related applications have successively been proposed and developed. One of them is about the chaotic secure communication [1][2][3][4][5][6][7][8][9][10][11][12]. Chaos synchronization that was initially proposed by Pecora and Carroll in [13] is the important factor to achieve the security.…”

Study on Chaotic Fault Tolerant Synchronization Control Based on Adaptive Observer

“…The characteristics of chaos have been attracting researchers' attention since 1990s. The realization of OGY (Ott-Grebogi-Yorke) chaos-control method [ 1 ] and PC synchronization method (Pecora and Carroll's method) [ 2 ] had greatly promoted the application of chaos theory. As the key technology for secure communications, chaotic synchronization research has made some progress [ 3 – 14 ].…”