Random numbers, Persian code: A mysterious signal transfixes radio sleuths

Original Article ↗ Hacker News Discussion ↗

A mysterious shortwave “numbers station” transmitting coded messages in Persian, likely from a U.S. military base in Germany, has drawn attention from radio enthusiasts and raised questions about modern spycraft. Commenters explore why intelligence agencies still use old-school shortwave broadcasts and one-time pads instead of satellite or internet channels, citing anonymity of reception, resilience during internet blackouts, and resistance to decryption. Others delve into the technical challenges of locating such transmitters and point to analysis suggesting the CIA may be targeting assets in Iran during wartime conditions.

Alternative sources & background

  • Several commenters prefer the RFE/RL article over the Wired piece, citing trust concerns with the latter.
  • The linked Priyom.org analysis is highlighted as a detailed technical and attribution deep-dive on the station (V32).

Why shortwave numbers stations?

  • Argued advantages:
    • Simple, robust, and cheap; small shortwave receivers are common enough (“world band radios,” ham gear).
    • Broadcast is one-to-many and inherently anonymous: you can’t easily tell who is listening.
    • One-time pads (OTP) remain information-theoretically secure if used correctly and distributed offline.
  • Alternatives debated:
    • Phones/satellite: seen as more traceable and attackable, though some argue satellite downlinks are also broad and receivers can’t easily be located.
    • Internet steganography and covert web channels are mentioned, but depend on functioning connectivity, which may be absent in war/blackout conditions.

Receiver hardware availability

  • Some say shortwave-capable radios are niche in the US; others say they’re still readily available as “world radios.”
  • Ham handhelds are mentioned but clarified as typically VHF/UHF-only, not shortwave.

Triangulation & propagation challenges

  • Direction-finding HF sources is portrayed as non-trivial:
    • Ionospheric reflections, skip zones, multipath, and terrain complicate locating the true source.
    • Highly directional antennas at HF must be large and are hard to move; precise long-range triangulation requires expensive distributed arrays.
  • Others note ham “fox hunts” as evidence that locating transmitters is possible, but concede HF is harder than VHF/UHF.
  • Consensus: local search is easy; long-range precision is difficult.

Location, attribution & possible intent

  • Multiple posts claim the transmitter is at a shortwave facility on a US military base near Böblingen/Stuttgart, Germany, with coordinates supplied and map imagery discussed.
  • Priyom’s writeup is cited suggesting a likely CIA-operated station targeting Iran, possibly as a last-resort channel for assets during an Internet blackout.
  • Alternative interpretations:
    • Psychological operation to make Iranian authorities suspect internal traitors.
    • A potential decoy to waste foreign SIGINT resources.
    • Some assert numbers stations don’t need hidden locations and can be in defended bases.

Crypto, steganography & history

  • Discussion covers:
    • OTP basics, the danger of ever broadcasting the pad itself, and confusion between OTPs and book ciphers.
    • Ideas for pseudo-OTP using books, irrational numbers, or arbitrary data, with warnings about statistical attacks.
    • Historical use of BBC “personal messages” and code phrases in WWII and the 1953 Iran coup.
    • Steganographic techniques in regular broadcasts (PSK on carrier, RDS manipulation) as theoretical alternatives.

Culture & side notes

  • The Conet Project is mentioned as a canonical collection of numbers station recordings.
  • There is meta-discussion of nominative determinism around cryptography-related surnames, and light joking around fox-hunting, AM radios, and conspiracy fodder.