Even if you’re not a Cuban spy, you too can receive secret messages sent by Havana to its spooks in Miami, Washington and around the world.
Every week, one short wave radio station in Cuba broadcasts 97 messages coded in fax-like tones. A computer program easily available to the public changes the tones into numbers, and the Cuban spies then decode the numbers into words.
A second Cuban spy station transmits 16 messages per week in the dots and dashes of the 175-year-old Morse code – secret messages to Havana spies who may be older or less technologically savvy.
Sixteen years after the arrests in Miami of five Cuban spies who got their secret orders by short wave transmissions, Havana is still using a system that fell out of favor in the cloak-and-dagger world with the end of the Cold War.
There are many more modern and efficient ways of communicating secrets by using satellites, burst transmissions, one-time emails and other means, said Chris Simmons, a retired Pentagon counter-intelligence officer who specialized on Cuban affairs.
“But these Cuban transmissions may be for old spies, dinosaurs who have been listening to (short wave) for so long, long term agents, that they are comfortable with it and don’t want or need a change,” Simmons added.
The busiest Cuban station these days, and the only spy station in the world that uses the fax-like tones, has been baptized as HM01 by amateur eavesdroppers who run Web pages like Spooks List, Spynumbers, ShortwaveSchedule and Enigma2000.
It transmits 11 to 14 messages per day, a total of 96 per week, on the same schedule each week but using a dozen different short wave frequencies, said Chris Smolinski, 41, a Maryland software engineer who monitors the spy stations as a hobby.
Each message almost always has 150 five-digit groups, so that eavesdroppers cannot measure the true length of the text. And some of the 10-minute transmissions are phonies, designed to mask the real number of spies receiving them.
Anyone can hook up a radio receiver to a computer, where the DIGTRX program – widely used by ham radio aficionados to send and receive lengthy texts, turns the tones into numbers. Spies then use secret computer programs to turn numbers into text.
“HM01 is an ideal system because you don’t have to teach any to anybody. The computer does all the work,” said Smolinski.
For the less computer-savvy spooks there’s the M08a station, which broadcasts 16 messages in Morse code, developed for the telegraph in 1836, on a set weekly schedule and on many of the same frequencies as Hm01.
Smolinski says Morse code indeed is easier to understand in difficult atmospheric conditions than voice transmissions. Simmons, who played a key role in the 2001 arrest of Pentagon analyst and Cuban spy Ana Belen Montes, said “it’s probably an old-spy thing.”
Walter Kendall Myers, 76, a retired State Department official, and his wife Gwendolyn, both convicted in 2009 of spying for Cuba for nearly 30 years, received their messages from Havana in the Morse code that Myers learned in the U.S. military.
The Cuban broadcasts are transmitted from different locations on the island and, although there’s no way of determining how many real spooks are listening, they can provide hints to the spies’ general locations.
The frequencies and footpaths of the most active Cuban spy station in the 1990s indicated it was transmitting mostly to two areas: Florida, home to the five Havana spies convicted in a 2001 trial; and a footpath that started in North Carolina, — home of the 82nd Airborne and several Special Forces units — and covered Washington and New York, monitors said.
During the heyday of the Cold War in the 1970s there were scores of short wave spy stations, known as “numbers stations” because they used blocks of numbers to broadcast coded messages, although some used music or tones, said Smolinski.
The United States ran several of the stations, and so did the Soviet Union, East Germany, Britain, Israel, France and China. But many went off the air with the end of the Cold War and the arrival of new technology and today Cuba, Russia, Vietnam and North Korea are the main users of the coded short-wave stations, Smolinski said.
Cuba’s most famous numbers station, known as “Atención” because of the opening line of the deadpan female voice in Spanish that started its transmissions, went off the air just late last year, Smolinski.
The five spies convicted in Miami typed the numbers into a secret decryption program on their home computers to read the texts. The FBI surreptitiously broke into their homes, copied the program and was reading their messages long before their arrests in 1998.
Montes, a Defense Intelligence Agency expert on Cuba, received her marching orders from Atención on its Tuesday and Thursday evening broadcasts. She pleaded guilty to spying for Cuba in 2002 and is serving a 25-year sentence.
The lack of any accent in the voice of the Atención station was explained in December by Jorge García Vázquez, a Cuban in Berlin who has been researching the links between Havana and the STASI, the former East Germany’ intelligence service.
A Jan. 10 1977 letter in the STASI archives shows Cuban intelligence Maj. Eddy Herrera had requested the equipment for a numbers station, preloaded with the Spanish words for one through zero, Attention, Goodbye and Final, Garcia Vasquez reported.
Smolinski says he laughs when he talks about the Atención station because it was infamous as one of the worst-run spy stations in the spook world. Its transmissions often started late, its signal drifted across frequencies and a buzz would make the messages unintelligible, he said.
The station once mistakenly broadcast part of a regular Radio Havana program, a no-no for a spy station trying to conceal its country’s identity, Smolinski said. In another broadcast, a rooster could be clearly heard in the background.
“I guess most things there don’t run very well,” he chuckled.