Chaotic on–off keying for secure communications

Abstract

We experimentally demonstrate a chaotic on-off keying method for secure communications by using chaos synchronization in two microchip lasers. The output of the microchip laser in the transmitter is externally modulated with an acousto-optic modulator at ~4 MHz . One encodes a digital message in the chaotic carrier by turning the modulation on and off at 100 kHz. Because the accuracy of synchronization for the slave laser in the receiver tends to be degraded in the presence of external modulation in the injection laser signal, one can distinguish two binary states. The digital message can be recovered as an envelope of the chaotic oscillation when the difference between the two laser outputs of the transmitter and the receiver is calculated.

Synchronized Laser Chaos Communication: Statistical Investigation of an Experimental System

“…From a communications perspective, a comparison of segment-sized lengths is most relevant, and scatter plot examples for 10,20, 50 N  are given in Fig. 10.…”

“…The shift-keying idea has been implemented in a in a variety of communication settings, including laser-based secure communication [7] and laser on-off communications [20]. The non-coherent antipodal version of chaos shift-keying differs from chaos shift-keying as described in the classification (chaos masking, chaos modulation, and chaos shift-keying), introduced in [15].…”

Extracting the phase information from atomic memory by intensity correlation measurement

“…Although these schemes stored complete information of a quantum state of light, sometimes only partial information is needed for storage in some applications. For example, some traditional optical communications [14,15] only need amplitude information. Furthermore, these schemes generally require two optical fields that satisfy the two-photon resonance condition, leading to an increased degree of complexity.…”

Chaos Communication Performance: Theory and Computation

“…The possibilities to generate an infinite number of sequences make for easy modelling and application of these signals in the single and multi-user cases. A wide overview of the general area can be obtained from the monographs [9], [15], [23], [14] and [27], although not yet reaching work in laser optics [28], [2]. The paper focuses on the multi-user chaos shift-keying system of communication with chaotic map spreading, emerging from [6], [11], [12] and [24].…”