The wave of GPS jamming and spoofing now disrupting commercial flights and shipping has a root cause that is finally being engineered out. The civilian satellite navigation signal was never designed to prove it is genuine. A receiver has no built-in way to tell a real GPS transmission from a counterfeit, which is exactly what a spoofer exploits. Two lines of defense are now reaching the market at the same time: one authenticates the signal so a receiver can reject fakes, and the other replaces GPS entirely when the signal is denied.
Why spoofing beats jamming
Jamming and spoofing are different problems. A jammer floods the L1 band at 1575.42 MHz with noise until the receiver loses lock, which a crew notices right away. A spoofer transmits a counterfeit signal that the receiver accepts as real, quietly reporting a false position with no error flag. That is what makes spoofing the harder threat, because the cockpit or bridge may see nothing wrong at all.
The scale is no longer marginal. Reported jamming incidents rose 67 percent and spoofing reports rose 193 percent between 2024 and 2025, according to International Air Transport Association figures cited by NBAA. During the fighting in the Gulf earlier this year, maritime intelligence firm Lloyd's List Intelligence logged 1,735 interference events affecting 655 commercial vessels in about a week, CNN reported. Military receivers using the encrypted GPS M-code kept working through that interference. The civilian users who depend on the open, unauthenticated signal did not.
Authentication: making the signal prove itself
The most direct fix is to let a receiver verify that a navigation message truly came from the satellite and was not altered on the way. Europe's Galileo constellation did exactly that when its Open Service Navigation Message Authentication, or OSNMA, was declared operational on 24 July 2025, making Galileo the first civilian GNSS to broadcast cryptographically authenticated navigation data worldwide and free of charge. OSNMA attaches digital signatures to the navigation message using a delayed-disclosure scheme, so a receiver can confirm authenticity seconds after reception.
OSNMA authenticates the data in the message rather than the signal itself, and EUSPA has said it will be complemented by a Galileo Signal Authentication Service to close that remaining gap. The harder problem is the last mile. Authentication broadcast from orbit does nothing until the receiver in the aircraft, ship or phone is built to check it, and chipset support is still limited. GPS, for its part, offers authentication only through its encrypted military M-code, and a civilian equivalent has been promised for years without wide deployment. Until receivers implement authentication at scale, the protection largely sits unused.
Alt-PNT: navigating when the signal is gone
Authentication keeps a receiver from trusting a fake, but it does not help when the signal is jammed into silence. That is the role of alternative positioning, navigation and timing, and avionics makers are now shipping it. Honeywell's Alternative Navigation Architecture, or HANA, described this month in NBAA's Business Aviation Insider, is a software layer that fuses non-GPS sensors already on the aircraft: vision-based camera navigation, magnetic anomaly navigation that reads small variations in Earth's magnetic field, radar terrain-aided navigation that matches radar-altimeter returns to a terrain map, and low-Earth-orbit satellite signals. Because LEO satellites orbit roughly 400 to 1,200 miles up, their signals arrive far stronger than distant GPS, which makes them harder to jam or spoof.
A second approach puts resilience on a chip. Iridium's PNT ASIC, an eight-millimetre-square integrated circuit, pulls an encrypted signal from the Iridium LEO network to provide positioning and, just as important, precise timing when GPS is unavailable. Timing is not a side issue. GPS clocks synchronise power grids, financial trading and telecom networks, and a spoofed time reference can ripple through all of them. A growing set of dedicated LEO-PNT ventures is chasing the same goal of a jam-resistant service independent of the legacy GNSS bands.
Detection is part of the defense
Hardware is only half the answer. Operators also need to know an attack is under way and coordinate a response. The MITRE Corporation has been working with US airports on a concept of operations for GPS disruption that covers how to detect an event, build a shared picture of it and pass that information to controllers and crews. Regulators are moving the same way. The FAA issued an updated GNSS interference resource guide in March 2026, and EASA revised its jamming and spoofing safety bulletin in early July, both urging crews to report interference and to treat affected regions with added caution.
What ties the effort together is unglamorous: adoption. OSNMA has been broadcasting authenticated signals for a year, yet it protects only the receivers built to verify them, and HANA and comparable alt-PNT systems will reach most fleets gradually rather than at once. The signals and the silicon are arriving faster than the installed base that can use them.
Reporting drawn from NBAA's Business Aviation Insider, EUSPA, and Lloyd's List Intelligence.
