Novel encryption method based on optical time-delay chaotic system and a wavelet for data transmission

In this paper, a new encryption approach based on optical time-delay chaotic system and a wavelet is proposed for date transmission. The general principle of this method is to drown the image in the chaos before inserting it into the approximation of another image (watermarking) obtained using the discrete wavelet transform (DWT). At the receiver, we use a descriptor observer with an unknown input design to establish synchronization between the transmitter and the receiver and to recover the transmitted encrypted image. The received image is decrypted after being extracted the encrypted image by using the discrete wavelet transform (DWT) and a decryption function. The got results plainly show the effectiveness of the proposed method which can be used to secure transmission of medical images.