GPS spoofing is the fabrication of GPS signals to deceive receivers about their actual location or the current time. An attacker transmits signals stronger than the real satellites, thereby taking control of the received position.
GPS spoofing affects more than navigation: many IT systems rely on GPS as a time source (NTP via GPS). Manipulated timestamps can corrupt log files, disrupt certificate validation, and undermine time-based security mechanisms. Countermeasures include multi-GNSS receivers (GPS + Galileo + GLONASS), signal-strength plausibility checks, and the use of multiple independent time sources. For drones and autonomous vehicles, GPS spoofing is a security risk with physical consequences.