Intelligence services in several countries continue to use Cold War radio stations to transmit encrypted messages to agents, according to Bloomberg.
The so-called numbers radio stations broadcast sequences of numbers in different languages, Morse code, or music snippets. Signals reflect off the ionosphere to reach thousands of kilometers, and most stations operate on strict timetables.
Authorities almost never confirm the existence of numbers stations, but amateur radio operators have repeatedly located broadcast sources using direction-finding equipment. Signal locations have been traced to military bases, embassies, and government facilities, including a station linked to a British Royal Air Force base in Cyprus that broadcast from the 1970s until 2008.
Recent broadcasts and secret operations
New stations continue to emerge, including one that broadcast a male voice reading numbers in Farsi in February 2026, hours after US and Israeli strikes on Iran began. Matt Blaze, head of the computer science department at Georgetown University, said major intelligence services likely all use this method because open-frequency transmissions make it impossible to determine who receives the message.
The British Government Communications Headquarters (GCHQ) declined to comment to Bloomberg, and the US National Security Agency (NSA) did not respond to a request for comment. Separately, the UVB-76 radio station, known as the Doomsday radio, aired a new coded message at 11:39 a.m. Moscow time on July 27 after a four-day pause.
