Biblio

Based on the Lyapunov stability theory, a novel adaptive synchronization method is proposed for three chaotic systems with different orders. Then the proposed method is applied to secure communication. This paper designs a novel multistage chaotic synchronized secure communication system in which the encrypted information signal is transmitted to the receiver after two chaotic masking, and then recovered at the synchronized receiver. Numerical results show the success in transmitting a continuous signal and a discrete signal through three synchronized systems.

As a result of increasing the interest in developing the communication systems that use public channels for transmitting information, many channel problems are raised up. Among these problems, the important one should be addressed is the information security. This paper presents a proposed communication system with high security uses two encryption levels based on chaotic systems. The first level is chaotic scrambling, while the second one is chaotic masking. This configuration increases the information security since the key space becomes too large. The MATLAB simulation results showed that the Segmental Spectral Signal to Noise Ratio (SSSNR) of the first level (chaotic scrambling) is reduced by -5.195 dB comparing to time domain scrambling. Furthermore, in the second level (chaotic masking), the SSSNR is reduced by -20.679 dB. It is also showed that when the two levels are combined, the overall reduction obtained is -21.755 dB.