Messages to Spies Are Coded but Not Hidden
Friday, December 29, 2006
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.
While hobbyists guess at the meaning of each cryptic message or which spy service sent it, it's no mystery to intelligence officials, who confirmed the purpose is espionage.
The signals are too strong to be made by amateurs and are often on licensed frequencies. The State Department once complained to the Israeli Embassy in Washington that "E10" was blocking a U.S. broadcast, a source said.
"I can't imagine who else would waste the time in front of a microphone reading numbers" but a spy, said James Bamford, who has written about intelligence. Bamford calls number stations "simple but effective" spycraft.
"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.
Mendez said he would often imprint the code on microfilm or even a cigarette paper. Once inside the target country, a CIA operative could make a shortwave receiver out of simple materials. "The voices are not real people," he added. "They're computer-generated."
A CIA spokeswoman declined to comment.
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.
In Miami last week, Carlos and Elsa Alvarez pleaded guilty to lesser charges after the United States accused them of spying for Cuba. A prosecutor alleged in a court hearing this summer that they received shortwave "messages in five-digit groupings." An FBI interview transcript shows Alvarez admitted going into his bathroom "on Fridays to listen at 11" for messages aimed at the couple, code-named "David" and "Deborah."