An image encryption scheme based on generalized synchronization theorem for discrete chaos system

A constructive theorem of generalized synchronization for discrete chaos systems is established. Based on the theorem, a generalized chaotic synchronization discrete system was constructed. Combining this system with the Henon chaotic mapping designs a digital image encryption scheme, which can successfully encrypt and decrypt gray-scale images without any lost. The scheme is sensitive to perturbations of the parameters and initial conditions of the chaos system. Any perturbations which are larger than 10-15 will make corresponding decryptions become impossible. The key space of the scheme is as large as 1076. The analysis of key space and key parameter sensitivity shows that the scheme has sound security. Numerical simulations reveal that the scheme is effective in network communication.