Authenticated Galileo

Finally. Digital cryptography has been applied to a civil satellite positioning system.

Satellite positioning is one of the technologies that deeply influence our daily lives. Thousands of services rely on the fact that a mobile phone can instantly figure out where on Earth it is. Mobile maps are the first obvious example. 

But there are other less obvious. Time stamping voltage and current samples in power distribution grids to synchronize them. Arbitrage of high frequency trading on stock exchanges. Maintaining microsecond time slots in 5G networks. Weather forecasting. Seismic monitoring. Tracking and recovery of items that broadcast Bluetooth signals. Photo tagging. Drones. City rentals of electric scooters and bikes. And many more...

Then of course we have aircraft navigation, ship navigation, and many high value services.

Disruption of satellite signals has been an easy target. There are several methods to do this. Brute-force jamming is the most straightforward. But there are more sophisticated and dangerous methods, that rely on sending a fake signal. This can be easily seen when flying from Europe to Asia - most flights cross the Black Sea and if you sit by a window, you can easily catch the "satellite" signal using a smart watch or a phone. The device will show you that you are over Crimea, while you are far from it. This is to fool autonomous weapons so they miss the targets. An autonomous drone could detect the signal is jammed and continue flying using other navigation subsystems (like inertial). But if they receive a proper satellite signal, they would trust it. Even if the signal indicates a spoofed position. 

So how to distinguish a fake signal from the real one? Authentication of course. The bread ad butter of cryptography. But somehow the civil signals were not authenticated at all. Until recently.

I blogged about the authentication in the European Galileo back in 2018: https://headworx.slupik.com/2018/08/gnss-authentication.html. That was before the war.

Now we finally start seeing the authenticated satellite positioning in civil applications. Two weeks ago the ESA announced the Galileo's first civil authenticated position fix under spoofing conditions. In Andøya, Norway at the Jammertest GNSS testing event people were testing the resilience of their GNSS systems against various attacks, including jamming, delayed retransmission, and spoofing. Using five Galileo satellites, the European Space Agency was able to obtain a stable lock on their receiver even during spoofing.