Spoofing, It’s About Time Too.
The effects of GNSS spoofing on position are well known but did you know it can also affect time? ?A GNSS receiver produces precise position AND time outputs and often, the time is accepted as gospel by dependent systems. Wrong times and timestamps can create all sorts of effects, most of them unpleasant.
One of the more pernicious is its effects on security certificates. These often have beginning dates and ending dates. If time is out of this range, perhaps because of spoofing, the security certificate will be regarded as invalid. This in turn can lead to all sorts of havoc and in some cases, can brick equipment or throw it into a slow recovery cycle. I first saw this in the wild in 2017 at a navigation conference where an accidental spoofing event caused numerous phones to brick or act really strangely ( report is available at:? https://www.gpsexpert.net/chimera-specification ) . Now, I’m reading about this happening with aircraft to whit:
“One of the areas that I was surprised at that gets affected is CPDLC and FANS, because they have date and time stamps. Once the GPS time stamps are compromised, then systems that use that information can be compromised as well. If applications that have a license key that expires at a certain date, if a GPS date is shifted to a point where a license becomes invalid, then those applications potentially could not be available to the pilots.” ?Mitesh Patel, L3 Harris, via AIN article
The only surprise to me is the surprise. Time should be one of the most protected items in any security architecture. Procedures for setting clocks should be extremely cautious in what constitutes a valid time. Otherwise, dependent systems are open to diverse exploits.
#GPS #GNSS #Galileo #spoofing #security
Resilient Time, Sync & Timing Systems | Sharing Knowledge | Helping business understand & deploy resilient time & timing solutions, Chair of the International Timing & Sync Forum (ITSF)
1 周Thanks Logan! Chronos has been highlighting this issue for over a decade now. I still remember playing with the Coherent Navigation simulator in 2013 and the surprise/not-surprise that all the GPS-based timing receivers we had in our labs blindly followed the time from the simulator, no matter how subtle or obvious the step/slope of time offsets we dialled in.
Board Member at National Space Based Position, Navigation and Timing Advisory Board
1 周I agree
A good report. Thank you for this, Logan!
Director (CEO) of the Royal Institute of Navigation. Director of Studies and Bye-Fellow at Queens' College, University of Cambridge. NED and Tech-Founder Mentor to various startups in the UK and USA.
3 周If you haven't seen this already it's a little gold mine. On the 737 max there is no other time other than GPS time (!!) 58min51 secs https://youtu.be/j1tNd3FcHNI?si=eOxTEB50VR4VT8kF