You can listen to spies coded messages

NY Daily News/Washington Post:

It turns out that anybody can tune in to the world's top spy agencies talking to operatives. All you need is a cheap shortwave-radio receiver, the kind available at any drugstore.

Tune it to 6855 or 8010 kHz.

On the hour, you might hear a girlish voice repeating strings of numbers monotonously in Spanish. "Nueve, uno, nueve, tres, cinco-cinco, cuatro, cinco, tres, dos . . .," went one seemingly harmless message heard last month on a Grundig radio.

It was the Cuban Intelligence Directorate or Russian FSB broadcasting coded instructions from Havana to spies inside the United States.

Turn the dial up to 11545 kHz, and you might hear a few notes of an obscure English folk song, "Lincolnshire Poacher," followed by a voice repeating strings of numbers. That's believed to be British Secret Intelligence Service, MI6, broadcasting from Cyprus.

On 6840 kHz, you may hear a voice reading groups of letters. That's a station nicknamed "E10," thought to be Israel's Mossad intelligence.

Chris Smolinski runs SpyNumbers.com and the "Spooks" e-mail list, where "number stations" hobbyists log hundreds of shortwave messages transmitted every month. "It's like a puzzle. They're mystery stations," explained Smolinski, who has tracked the spy broadcasts for 30 years.

...

"It's extremely effective," agreed a senior intelligence official. "If you have a one-time pad, the code can't be broken, and you can send out dummy broadcasts as much as you want to confuse your enemy."

A "one-time pad" is the key to unlocking coded shortwave messages that the CIA calls "one-way voice link."

It is low-risk because it's known only to the sender and the recipient and used just once before being destroyed, said retired CIA officer Tony Mendez.

...

One-time pads and coded radio began in World War I, said Thomas Boghardt, a historian at the International Spy Museum. Little has changed since, judging by recent espionage cases involving shortwave radios, including that of a man detained in Canada last month and accused of being a Russian spy.

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I guess if you assume other people are listening anyway, why not broadcast it since the authorities will not have a line to trace. It is interesting that this ancient spy craft is still used after almost 100 years.