A jump-diffusion model is introduced to describe proton diffusion in cubic perovskites. It is solved using both an analytical matrix approach and kinetic Monte Carlo simulations. The model is applied to In-doped BaZrO3 and we use first-principles calculations to determine binding energies and diffusion barriers. We find that dopants act as traps and reduce the diffusion coefficient with about one order of magnitude at T=600 K. (c) 2005 Elsevier B.V. All rights reserved.