Iranian “numbers station” broadcasts highly encrypted messages in Persian from somewhere in Western Europe

Cold War era espionage and terrorism revisit Europe

A Mysterious Signal Transfixes Radio Sleuths -- And Intelligence Experts
The mysterious Persian-language transmission began about 12 hours after the start of the US-Israeli bombing campaign against Iran. It was jammed five days later. Is it a coded message for US agents in Iran? Iranian sleeper cells? Israeli operatives? That’s what experts are trying to decipher.
Is this coded radio message CIA instructions for agents in Iran?
When 47-year-old Roberto, from Milan, switched on his shortwave radio on Tuesday, he heard a ghostly voice reciting a string of numbers in Persian.
In an age of cyber spying, burner phones and digital surveillance, coded radio broadcasts may sound like a relic of the Cold War. ¶But they still offer one major advantage. While computers and phones leave a trail, codebooks can simply be burned. ¶'There is no way of tracing the recipient of a signal, they could be anyone with a radio, anywhere in the world,' Roberto told The Times.

A shortwave radio is technologically much more primitive, basic and reliable than cell phone or internet communications anywhere. It can actually be built from scratch by anyone reasonably knowledgeable. A cell phone cannot.