NOVEL METHOD FOR REAL-TIME END-TO-END SECURE VOICE COMMUNICATION FOR LOW BIT RATE SYSTEMS

DJAMAL E BERRAKI

Algeria, dberraki@googlemail.com

Abstract:  This work proposes a solution to provide end-to-end real-time secure voice communication by introducing embedded hardware, combined with proper software. Before injecting the speech straight into the communication system, a low rate codec is used to compress the speech. The bit stream is then encrypted using a pseudo-random sequence generated from the comparison of two chaotic logistic maps. The encrypted bits are then double secured by a phase modulation of a chaotic carrier. A special care is given to the generation of the chaotic carrier to be able to pass through the voice channel. The final noise-like waveform is then injected into the communication system instead of the original speech. At the receiver side, the reverse functions are implemented in order to regenerate the clear speech. The use of chaotic encryption guaranties that the original signal cannot be recovered from the noise-like received signal without the right algorithm and the correct key of encryption