A new chaotic secure communication system

This paper proposes a digital chaotic secure communication by introducing a concept of magnifying glass, which is used to enlarge and observe minor parameter mismatch so as to increase the sensitivity of the system. The encryption method is based on a one-time pad encryption scheme, where the random key sequence is replaced by a chaotic sequence generated via a Chua's circuit. In our system, we make use of an impulsive control strategy to synchronize two identical chaotic systems embedded in the encrypter and the decrypter, respectively. The lengths of impulsive intervals are piecewise constant and as a result, the security of the system is further improved. Moreover, with the given parameters of the chaotic system and the impulsive control law, an estimate of the synchronization time is derived. The proposed cryptosystem is shown to he very sensitive to parameter mismatch and hence the security of the chaotic secure communication system is greatly enhanced.