Switching Chaotic Encryption and Decryption Circuits Design

This paper presents a two-mode switching secure communication system design based on linear unknown input filtering. In the transmitter design, a two-mode encryption method through unknown inputs switching is developed to enhance the security of transmitted message. Specifically, the feedthrough matrix of unknown inputs in the output equation is properly chosen to facilitate the design. In the receiver design, a new two-mode switching derivative-distributed unknown input filtering (DDUIF) is developed to decrypt the encrypted message. In this method, a two-mode switching reformed transmitter system is first designed to simplify the receiver circuit design. Then, the previously proposed DDUIF is used to recover the transmitted message. Next, to compensate for synchronization error, a delayed transmitted message and a delayed decrypted message annihilating signal are proposed to correctly recover the transmitted message. Finally, the usefulness of the proposed method is verified using an illustrative example.