GPS Spoofing

BACKGROUND

In global navigation satellite systems (GNSS), a spoofing attack attempts to deceive a GNSS receiver by broadcasting fake GNSS signals, structured to resemble a set of normal GNSS signals, or by rebroadcasting genuine signals captured elsewhere or at a different time. Spoofing attacks are generally hard to detect as adversaries generate counterfeit signals. These spoofed signals are challenging to recognize from legitimate signals, thus confusing ships' calculation of positioning, navigation, and timing (PNT). This means that 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. One common form of a GNSS spoofing attack, commonly termed a carry-off attack, begins by broadcasting signals synchronized with the genuine signals observed by the target receiver. The power of the counterfeit signals is then gradually increased and drawn away from the genuine signals.