A mysterious shortwave radio broadcast in Farsi began on 28 February, about 12 hours after the United States and Israel started bombing Iran. On a scratchy signal almost twice daily, in the early morning and early evening, a man's voice reads out what appear to be random numbers.
The numbers are read out for varying stretches of time, followed by a pause in which the word tavajjoh, which translates as "attention", is spoken three times. The global community of amateur radio enthusiasts dubbed it V32 and began monitoring the signal intensely. What should have been a technical curiosity became something far more intriguing when Iran responded.
The transmission is called a numbers station, a Cold War-era tool that employs radio transmissions and old-school cryptology to transmit secret messages, usually to spies around the world. Using a random series of numbers generated by some mechanical or electronic device, a person can send a coded message to another person in possession of a decoder, often called a "one-time pad."
What makes this broadcast extraordinary is not just its existence but where it is coming from. Multilateration and triangulation efforts have pinpointed the origin of V32 to a shortwave transmission facility within a US military base in Böblingen, 15 kilometres southwest of Stuttgart, Germany, in the forest between Panzer Kaserne and Patch Barracks.
The mystery deepened when interference began. On 4 March, a bubble jammer started broadcasting noise on the same shortwave frequency as the V32 broadcast, rendering it difficult to understand. The V32 transmissions were interrupted briefly and then switched to another nearby frequency.
The significance of that jamming is striking. The bubble jammer being used is exactly the same kind used against Radio Farda, VOA Farsi, Iran International TV shortwave relay, and BBC Farsi. This is the same technique Iran has employed for years to block independent foreign news services from reaching its population. If Iran is jamming this broadcast, it suggests the signal threatens Iranian interests or poses a security concern to Tehran.
The ambiguity about who operates the station and who receives its messages remains the core of the puzzle. The global radio community has competing theories; many appear to focus on the United States as the originator, potentially sending coded messages to agents within Iran. Other theories focus on Israel or even Turkey. A former US intelligence officer argues the broadcasts likely come from the US or Israel to activate or protect assets during the war's opening phase.
Numbers stations have been used by intelligence services since World War I to communicate with agents in the field, but have become increasingly rare in the digital age. With the Internet shut down by authorities in Iran, this Cold War relic has found new life.
The encryption protecting these messages is mathematically elegant. Both the sender and receiver hold matching one-time pads, identical sheets of random numbers used to encode and decode each message. Once used, the sheet is destroyed. The encryption is considered unbreakable. This means that even if Iran intercepts and records every transmission, without access to the matching decryption key, the broadcasts remain meaningless noise.
Whether the signal represents clandestine operational support for intelligence assets, psychological warfare aimed at Iran's military or leadership, or something else entirely remains unknown. No government has officially acknowledged involvement. What is clear is that modern warfare in the digital age has driven parties back to analogue tools from decades past, tools that work precisely when digital infrastructure becomes a liability rather than an asset.