Study on Chaotic Cryptosystem for Digital Image Encryption

Nowadays many image cryptosystems have been shown to be insecure. In this paper we present a new cryptosystem based on the chaotic time delay feedback Chua circuit. It consists of two steps: the first step assures the transmitter/receiver synchronization while the second step focuses on the encryption/decryption procedure. The synchronization is performed through a nonlinear state observer design, driven by the transmitted signal, and the encryption/decryption procedure is ensured by using the chaotic masking method. A secure analysis proves that this cryptosystem is robust to some best-known attacks. This efficiency relies to the properties of the chosen chaotic generator and the efficiency of the nonlinear observer.