Time scaling of chaotic systems: Application to secure communications

The paper deals with time-scaling transformations of dynamical systems. Such scaling functions operate a change of coordinates on the time axis of the system trajectories preserving its phase portrait. Exploiting this property, a chaos encryption technique to transmit a binary signal through an analog channel is proposed. The scheme is based on a suitable time-scaling function which plays the role of a private key. The encoded transmitted signal is proved to resist known decryption attacks offering a secure and reliable communication.