A strategy is presented for detecting spoofing attacks against cryptographically-secured GNSS signals. The strategy is applicable both to military GPS signals and to proposed security-enhanced civil GNSS signals, whose trustworthiness is increasingly an issue of national security. The detection strategy takes the form of a hypothesis test that accounts for the statistical profile of a replay-type spoofing attack. A performance and robustness evaluation demonstrates that the detection test is both powerful and tolerant of some uncertainty in the threat model. The test is validated by experiments conducted on a spoofing testbed.  

Cite and download the paper:
Humphreys, T.E, "Detection Strategy for Cryptographic GNSS Anti-Spoofing," IEEE Transactions on Aerospace and Electronic Systems, 49(2):1073-1090, 2013.