A new secure communication technique using a novel chaos-based nonlinear cryptography function

A new secure communication technique is proposed using a novel chaotic encryption method. A chaotic system with a single adjustable parameter, which has a structure that is similar to the Rikitake model, is used to construct the communication link between the receiver and the transmitter. The nonlinear function used for the encryption/decryption of the message utilizes a single time series of the receiver system along with a synchronization-based states observer and an adaptive parameter identifier. A Lyapunov function is used to design the parameter identifier that functions as an embedded secret key. The proposed technique is demonstrated to have improved security as the signal could be efficiently retrieved only if the secret key is known, even when both the receiver and the transmitter are in perfect synchronization. In addition, the proposed technique is shown to be easily implementable using both analog and digital hardware while being capable of transmitting signals with variable bandwidth.