Attack-Resistant Chaotic Communication System in Non-ideal Physical Channel

Coherent chaos-based communication is a developing technique for secure data transmission based on synchronization of chaotic oscillators at the transmitter and receiver sides, which is treated as a more secure method than non-coherent communication, chaotic symbolic dynamics, and other approaches. Nowadays, digital implementation of such systems allows high precision in parameter matching and sophisticated message recovery algorithms, though challenges remain: first, in adapting chaotic signals for non-ideal physical media, e.g., acoustic channels with frequency-dependent attenuation and noise, while, second, still providing the high level of security. The current study provides the implementation of a coherent chaotic communication system based on the Sprott Case S chaotic oscillator that meets these challenges. We utilize the modulation technique, minimizing changes in chaotic dynamics that may be captured by an intruder, propose an optimization of chaotic oscillator parameters to match channel characteristics and establish a signal normalization procedure to neutralize attenuation at the receiver side. Applying spectral and return map attacks, we show that the measures taken to counteract distortion in the path do not reduce the security of the transmission. In an experiment with a physical acoustic path, we demonstrate the practical operability of our approach.