4 ms·

How can air-gapped computers keep time well?

• zozbot234 5y ago
  Use a GPS receiver, that will only get time reference and location from the GPS satellites, and not transmit anything. So you're still airgapped - see https://gpsd.gitlab.io/gpsd/gpsd-time-service-howto.html https://gpsd.gitlab.io/gpsd/gpsd-time-service-howto.html for reference.
  • onionisafruit 5y ago
    Is it really still airgapped if it accepts input from an outside system?
    • fprotthetarball 5y ago
      No data leaves the computer over GPS and the computer controls how it processes the data. It's no worse than a keyboard.
  • matthewmacleod 5y ago
    It's not really an air-gapped system if it accepts unauthenticated external radio signals and changes state in response, which is what would be happening in that case. You don't need much imagination to think of various attacks that a spoofed GPS signal could open up, if you were able to cause a system to have an incorrect time.