A SYSTEM INVERSION APPROACH TO CHAOS-BASED SECURE SPEECH COMMUNICATION

A new approach to real-time secure speech communication is proposed based on the inversion theory of nonlinear discrete-time dynamical systems. The proposed approach uses an observable minimal-phase nonlinear discrete-time dynamical system, particularly with chaotic zero-dynamics, as the drive system to generate encrypted speech signals for transmission. The receiver is the minimal left-inverse system of the drive system. The receiver decrypts the received signal and recovers the original message in real-time. The effectiveness of the proposed approach and design is demonstrated via examples for secure speech signal transmission. Performance evaluation of the designed secure communication system is discussed. Both analysis and simulation show that the new scheme is relatively secure but simple, accurate and robust, suitable for some civil and commercial voice-communication applications.