Research

Anti-Spoofing

A GPS spoofing attack attempts to "deceive" a GPS receiver by broadcasting counterfeit GPS signals, structured to resemble a set of normal GPS signals, or by rebroadcasting genuine signals captured elsewhere or at a different time. These spoofed signals may be modified in such a way as to cause the receiver to estimate its position to be somewhere other than where it actually is, or to be located where it is but at a different time, as determined by the attacker.

Anti-spoofing graphic image

Spoofing attacks have become increasingly common since 2023. One of the earliest suspected cases was the capture of a Lockheed RQ-170 drone aircraft in northeastern Iran in December 2011, that likely was the result of such an attack. Currently, multiple spoofing events are detected daily using ADS-B reports from aircraft.

For a number of years, Stanford has been performing research on how to make GPS and GPS receivers more robust against spoofing attacks. Current research includes the following techniques:

  • Using WAAS message authentication
  • Time of arrival techniques
  • Use of antenna to distinguish direction of arrival
  • Using and comparing encrypted P(Y) code

The FAA has supported Stanford's research in this area.

For More Information