Information encryption and decryption using hyperchaotic systems in delayed nonlinear feedback systems

The possibility of using chaos for the encryption and decryption of message signals in communication systems has been widely used and accepted. Hyperchaotic dynamics of high dimensionality is featured in chaos generated by systems with delayed nonlinear feedback. An efficient and fast encryption and decryption scheme exploiting hyperchaotic regimes of a nonlinear oscillator with time delay feedback is proposed. Information is transmitted by adding a small amplitude message signal to a large chaotic carrier, the latter effectively hiding the former. The message is extracted at the receiver by subtracting the chaos created in the receiver from the transmitted chaos-plus-message signal. The cryptographic systems demonstrated here is based on chaotic devices with delayed nonlinear feedback, which features a high robustness of the chaos synchronization and a very good performance in terms of stability and information recovery.