Method and system to optimise the authentication of radio-navigation signals

The current invention introduces a system and method for the authentication of radio-navigation signals from several senders, whereby all senders transmit the same or related cryptographic information at a certain interval, and a receiver is able to authenticate the data of all or some senders by receiving the cryptographic from a single sender, increasing the availability of an authenticated position even in degraded reception environments. The invention also relates to the optimal transmission of authentication information so as to minimize the signal predictability time and the increase of robustness against replay attacks.

THE MAIN APPLICATION AREAS

• Global Navigation Satellite Systems (GNSS)
• location-based services (lbs)
• road
• aviation
• rail
• maritime
• agriculture
• surveying
• timing & synchronisation

THE MAIN INNOVATIVE ASPECTS AND ADVANTAGES

An advantage of the invention is the performance improvement in radio-navigation services by the use of a single key, or keys from the same chain, from several radio-navigation signal transmitters. A further advantage is that the system can authenticate the radio-navigation data and signal of a certain sender by using the data and MAC from such a sender, while using the key from the said sender or any other sender, if the key from the said sender is not properly demodulated from the radio-navigation signal. A consequent advantage is to drastically reduce the authentication error rate (AER) in degraded reception conditions: by allowing all the satellites to be authenticated through the same key or the same chain, a user needs to receive only a correct key from one satellite every sub-frame to authenticate all satellites. This reduces dramatically the amount of bits required for a position and time fix computed using authenticated senders.