© Stuart Bradford
This was during the Cold War in the late 1970s. American spies were being arrested, and how they were being identified was a matter of great concern to U.S. intelligence. The first break came with the accidental discovery of a false chimney cavity at the Moscow embassy. Inside the chimney was an unusual Yagi-style antenna that could be raised and lowered with pulleys. The antenna had three active elements, each tuned to a different wavelength. What was the purpose of this antenna, and what transmitters was it listening to?
Gandy pursued these questions for years, not only baffled by the technology, but buffeted by interagency disputes and hampered by the Soviet KGB. At one point he was issued a "cease and desist" letter by the CIA, which, along with the State Department, had authority over security at the embassy. These agencies were not persuaded that there were any transmitters to be found: Regular scans for emissions from bugs showed nothing.
It was only when Gandy got a letter authorizing his investigation from President Ronald Reagan that he was able to take decisive action. All of the electronics at the embassy — some 10 tons of equipment — was securely shipped back to the United States. Every piece was disassembled and X-rayed.
After tens of thousands of fruitless X-rays, a technician noticed a small coil of wire inside the on/off switch of an IBM Selectric typewriter. Gandy believed that this coil was acting as a step-down transformer to supply lower-voltage power to something within the typewriter. Eventually he uncovered a series of modifications that had been concealed so expertly that they had previously defied detection.
A solid aluminum bar, part of the structural support of the typewriter, had been replaced with one that looked identical but was hollow. Inside the cavity was a circuit board and six magnetometers. The magnetometers sensed movements of tiny magnets that had been embedded in the transposers that moved the typing "golf ball" into position for striking a given letter.
Other components of the typewriters, such as springs and screws, had been repurposed to deliver power to the hidden circuits and to act as antennas. Keystroke information was stored and sent in encrypted burst transmissions that hopped across multiple frequencies.
Perhaps most interesting, the transmissions were at a low power level in a narrow frequency band that was occupied by intermodulation overtones of powerful Soviet TV stations. The TV signals would swamp the illicit transmissions and mask them from detection by embassy security scans, but the clever design of the mystery antenna and associated electronic filtering let the Soviets extract the keystroke signals.
When all had been discovered, Haseltine recounts how Gandy sat back and felt an emotion — a kinship with the Soviet engineers who had designed this ingenious system. This is the same kinship I feel whenever I come across some particularly innovative design, whether by a colleague or competitor. It is the moment when a technology transcends known limits, when the impossible becomes the doable. Gandy and his unknown Soviet opponents were working with 1970s technology. Imagine what limits will be transcended tomorrow!
This article appears in the January 2020 print issue as "The Ingenuity of Spies."
electronic filtering let the Soviets extract the keystroke signals.
And decades later we are now discovering that Google has the same ability.
Those pesky Russkies, were ahead of the game
If I remember correctly the US had to abandon it's embassy in Moscow because it was full of soviet bugs.
[Link] The Bugged Embassy Case: What Went Wrong
In 1969, after years of tortuous negotiation, the Nixon Administration signed an agreement with the Soviet Union providing for new embassy complexes in Washington and Moscow.
The American project was to be the most elaborate and expensive United States embassy ever, a testament to American wealth and power.Today, the eight-story American chancery in Moscow stands useless, infested with spying systems planted by Soviet construction workers, a stark monument to one of the most embarrassing failures of American diplomacy and intelligence in decades.
Over the years, the United States has spent $23 million on the building, but more than twice that amount in an attempt to figure out how the Soviets used eavesdropping devices to transform it into a giant antenna capable of transmitting written and verbal communications to the outside.
After a saga of suspicious behavior by Soviet work crews, electronic devices buried in concrete and investigators hanging like rock-climbers from the roof, a secret cable to the American Ambassador resulted, finally, in a halt to what a 1987 Senate committee described as ''the most massive, sophisticated and skillfully executed bugging operation in history.
''The Bush Administration will have to decide whether to follow President Reagan's advice that the building be torn down.
A very interesting read.