FUZZY OBSERVER DESIGN WITH n-SHIFT MULTIPLE KEY FOR CRYPTOGRAPHY BASED ON ۳D HYPERCHAOTIC OSCILLATOR

A fuzzy observer based scheme for synchronizing two hyperchaoticoscillators via a scalar transmitted signal for cryptographic application isproposed. The Takagi-Sugeno fuzzy model exactly represents chaotic systems.Based on the general fuzzy model, the fuzzy observer of a chaotic system isdesigned on the basis of the n-shift multiple state based key encryption algorithm.The scalar transmitted signal is designed in such a way that the hyperchaoticcarrier masks the encrypted signal, which in turn hides the message signal.Simulation results show that the proposed scheme gives a better performanceeven when a small additive stochastic noise is present in the channel.