Every engineer has stories of bugs that they discovered through clever detective work, but nothing compares with the story of how an electrical engineer at the NSA uncovered an elaborate — and ingenious — scheme by Soviet engineers to intercept communications in the American embassy in Moscow. It was during the Cold war in the late 1970s, when American spies were being arrested and U.S. intelligence was trying to figure out how they were being identified. The first break came with the accidental discovery of a false chimney cavity that housed an antenna that could be raised and lowered with pulleys. Electrical engineer Charles Gandy investigated the matter, but was issued a “cease and desist” letter by the CIA, which had authority over security at the embassy. Finally, President Ronald Reagan took decisive action and authorized Gandy to proceed with his investigation. 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. Gandy found that keystroke information from the typewriter was stored and sent in encrypted burst transmissions that hopped across multiple frequencies. The NSA developed a plan over the next few months to remove and examine all information processing and telecommunications equipment at the U.S. embassy in Moscow. They then replaced all of the equipment and began monitoring for future bugs.
