This document describes a method of processing data which consists in detecting and storing in a device the stream of navigation messages and the physical parameters of the signals received in a receiver originating from the satellite-based or terrestrial navigation systems and its comparison with the original data transmitted by the navigation system with respect to a time reference common for all the signals. The stream recorded generates a signature which is unique for each instant and each position over the whole service area (Earth or other planet or celestial body). The result of the processing of the data for a particular point of the Earth serves to validate and authenticate the position and the time reference that are delivered by the navigation receiver as well as the quality and authenticity of the signal received.