Observer design for cryptography based on hyperchaotic oscillators

The authors describe a combination of cryptography and hyperchaos synchronisation in order to obtain a secure communications scheme. The transmitter and the receiver, which are based on a 4D hyperchaotic oscillator, are synchronised by exploiting the concept of the observer from control theory. The scalar transmitted signal is designed so that the hyperchaotic carrier masks the encrypted signal, which in turn hides the message signal. The approach leads to communication systems with higher security