Secure communication using a chaos based signal encryption scheme

The large-scale proliferation of wireless communications both inside and outside the home-office environment has led to an increased demand for effective and cheap encryption schemes. Now a new chaos based signal encryption scheme is proposed to transmit digital information signals by using the conventional synchronization of chaos and digital encryption approaches. In this scheme, either a chaotic or hyperchaotic system is used to generate a digital key after thresholding a chaotic signal. This signal along with the information digital signal is used to generate the encrypted signal. Then the encrypted signal is masked by one of the chaotic signals of the transmitter and is transmitted through the channel to the receiver as well as used to drive the transmitter chaotic system using the concept of self-modulation. At the receiver end, a suitable feedback loop is constructed for unmasking and then the decryption rule is used to recover the information signal. By suitable combinations of the chaotic signals, the effect of additional nonlinear-keys has also been considered. The effect of typical perturbing factors, like channel noise and parameter mismatch, are included and their corresponding performance analysis is discussed. By considering an appropriate circuit configuration, simulation results are presented.