Image encryption based on synchronization of fractional chaotic systems

• Synchronization scheme for two fractional-order chaotic systems is applied in image encryption.
• We propose a new image encryption algorithm.
• The image encryption method has the higher security than some previous means.
• The results show that it is a good choice to apply fractional order chaotic signals into secure communication.

This paper deals with a synchronization scheme for two fractional chaotic systems which is applied in image encryption. Based on Pecora and Carroll (PC) synchronization, fractional-order Lorenz-like system forms a master–slave configuration, and the sufficient conditions are derived to realize synchronization between these two systems via the Laplace transformation theory. An image encryption algorithm is introduced where the original image is encoded by a nonlinear function of a fractional chaotic state. Simulation results show that the original image is well masked in the cipher texts and recovered successfully through chaotic signals. Further, the cryptanalysis is conducted in detail through histogram, information entropy, key space and sensitivity to verify the high security.