Controlling the ultimate state of projective synchronization in chaos: Application to chaotic encryption

The ultimate state of projective synchronization is usually considered to be hardly controllable due to its close dependence on the initial conditions of both drive and response systems. In this letter, we show that the scaling factor of projective synchronization can be controlled to be proportional to a given scalar function with respect to time even without the knowledge of the initial conditions of response system. Further, we apply it to the chaotic encryption. Comparing with some existing implementations, it is found that the present scheme owns several remarkable advantages. To our knowledge, it is for the first time that the projective synchronization is applied to chaos-based encryption.