Methods and systems for cryptographically-secure autonomous detection of spoofed GNSS signals is provided. A method is provided that includes the steps of: generating a cryptographic code, controlling a motion of at least one antenna of a Global Navigation Satellite System (GNSS) receiver system according to the cryptographic code, detecting a plurality of satellite signals during the controlled motion of the at least one antenna, and determining, based on carrier phase variations of the detected plurality of satellite signals, whether the plurality of satellite signals originated from a spoofer transmitter.