Quantum processes seem to allow for "programming" operant particles into a time point previous to the operation. And the grandfather paradox doesn’t apply:
Scientists have for some years been able to ’teleport’ quantum states from one place to another. Now Seth Lloyd and his MIT team say that, using the same principles and a further strange quantum effect known as ’postselection’, it should be possible to do the same backwards in time. Lloyd told the Technology Review: "It is possible for particles (and, in principle, people) to tunnel from the future to the past."