A novel chaotic system with suppressed time-delay signature based on multiple electro-optic nonlinear loops

Abstract

We present a novel time-delay chaotic system by adopting multiple electro-optic nonlinear loops. The dynamic characteristics of the proposed chaotic system are investigated by means of the bifurcation diagram and the permutation entropy. The security performance of the system is analyzed in detail by using autocorrelation function, delayed mutual information, and the permutation information approach. The simulation results show that the time-delay signature is suppressed under certain simple conditions. Moreover, a synchronization scheme on basis of the proposed system is analyzed. Both the security and the feasibility are verified. The proposed chaotic system can be used in secure communications and also has potential applications in random number generation or chaos computing.

Security-Enhanced Electro-Optic Feedback Phase Chaotic System Based on Nonlinear Coupling of Two Delayed Interfering Branches

“…The extremum value at the delay time T in ACF and DMI with their background (i.e., Q A CF and Q D M I ) as a function of β are shown in Fig. 1, the ACF, DMI, Q A CF and Q D M I are defined as follows [26]:…”

“…11(b) shows that to ensure the correctness of demodulation, the detuning of corresponding time-delay between the transmitter and the receiver should lower than sever picoseconds (5 ps for BPSK modulation format, 3 ps for QPSK and 1 ps for 8PSK). Fortunately, the precision of time-delay can be maintained at femtosecond level by a commercial tunable optical delay line [26]. These two factors make the parameters of time-delay are appropriate for encryption as a secret key.…”

Enhancing optical-feedback-induced chaotic dynamics in semiconductor ring lasers via optical injection

“…Particularly for chaos-based communications, early works on chaotic lasers with feedback showed that even when the TD signature is concealed in the intensity dynamics I(t) [8], it may in some cases still be inferred by applying the same identifiers to the optical phase dynamics ϕ(t) [9]. For these reasons, novel approaches for suppressing the TD signature in chaotic sources have been reported [10][11][12][13][14][15][16][17][18][19]. Optical injection has been shown as a possible way to generate enhanced chaotic signals, exhibiting suppressed TD signatures, improved chaos bandwidth and dynamical complexity.…”

Two‐dimensional electro‐optic delayed feedback system with electrical and optical coupling

“…Chaotic optical signal can be generated based on the inner non-linear effects of semiconductor lasers [1][2][3], and can be generated based on the non-linear effects of external non-linear device as well [4][5][6]. Among all kinds of chaotic optic systems, the electro-optic delayed feedback system based on Mach-Zehnder (MZ) modulator has large Lyapunov dimension, high modulation speed, and good stability, which has been widely investigated [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20].…”

“…All these models are based on only one semiconductor laser, and can conceal the time-delay more effectively than the original model. Another kind of method is based on coupling multiple chaotic systems [11][12][13][14][15][16][17][18]. Liu et al [11] coupling a digital logistic chaotic map with electro-optic chaotic system to suppress the time-delay signature.…”