U.S. Military Turned GPS into a Global "Numbers Station"
3 hours ago
- #military communication
- #data privacy
- #GPS encryption
- The U.S. military has used public GPS to secretly broadcast encrypted messages for nearly 20 years, turning each satellite into a hidden 'numbers station.'
- A 176-bit sequence labeled 'Subframe 4, Page 17' contains encrypted material from the Pentagon's Over-the-Air Distribution (OTAD) network for distributing cryptographic keys to military personnel globally.
- Security expert Steven Murdoch discovered the encrypted data over a decade ago and recently confirmed its purpose by analyzing archived GNSS recordings and matching patterns with declassified military documents.
- A key-repeating 'sentinel' pattern observed in 2010 coincided with the rollout of military rekeying systems (OTAD/OTAR), providing strong evidence of the broadcast's purpose.
- The hidden rekeying operation went unnoticed in public GPS data for 11 years until 2022, when new message formats emerged, possibly indicating system modernization.
- The findings highlight that encrypted government signals have been openly available via GPS for years, suggesting more hidden data may exist for those willing to analyze public satellite transmissions.