The finite-time synchronization for the high-dimensional chaotic system is studied. A method is derived from the finite-time stability theory and adaptive control technique. To show the wider applicability of our method, an illustration is given using four-dimensional (4D) hyperchaotic systems. Numerical simulations are also used to verify the effectiveness of the technique. Then, the synchronization is applied to secure communication through chaos masking. Simulation results show that the two high-dimensional chaotic systems can realize monotonous synchronization, and the information signal, which is masked, can be recovered undistortedly.