Third party demodulation of a chaotic communication scheme using adaptive estimation via parallel processing

The use of chaotic signals as a means of masking information to achieve highly secure transmission has been a popular research topic. Recently, we have proposed third party schemes by interceptors to decode the transmitted message where the message has been modulated at the transmitter end by chaotic-pulse-position-modulation. These proposed third party algorithms, proceed by first estimating the degree (order) of the chaotic map used at the chaotic-pulse-position modulation transmitter off-line, and then estimating the state of the chaotic map on-line. In this paper, we introduce a novel third party intrusion scheme that achieves the goal of simultaneously estimating the degree of the chaotic map and its state through the use of adaptive estimation via parallel processing. We evaluate the performance of our new design using various second and third order chaotic maps. The Bit error rate of these schemes is compared to that of the original chaotic-pulse-position modulation for different signal to noise ratios to show the vulnerability of the chaotic-pulse-position-modulation to third party attacks