'Track from one DeviceZone to whomever originally signed the zone
(the zone creator--either the central server, or a device)
Returns an (ordered) list of dictionaries (Device, DeviceZone), defining the chain of trust.'

def _compute(self):

    return self.__class__.compute_one_way(zone=self.zone, from_device=self.device, to_device=self.zone_owner)
