For over 50 years, starting from the years following the end of the Second World War, more than 120 countries trusted Swiss firm, Crypto AG, to keep the communications of their spies, soldiers and diplomats secret.

The technology company got its first break with a contract to build code-making machines for U.S. troops during World War II. It later became a dominant maker of encryption devices for decades, navigating waves of technology from mechanical gears to electronic circuits and, finally, silicon chips and software.

However, a new report written by Washington Post’s Greg Miller alleged that the CIA used Crypto AG as a front to spy on U.S. allies.

The report explained that the CIA rigged Crypto AG’s devices so they could easily break the codes that countries used to send encrypted messages.

The CIA’s West German counterpart, the BND, were also involved in the scheme but came to believe the risk of exposure was too great and left the operation in the early 1990s, possibly shortly after the unification of West and East Germany. But the CIA bought the Germans’ stake and kept going until 2018, when the agency sold off the company’s assets, according to current and former officials.

According to details of the classified report described as “the intelligence coup of the century” by the CIA, “foreign governments were paying good money to the U.S. and West Germany for the privilege of having their most secret communications read by at least two (and possibly as many as five or six) foreign countries.”

Nigeria was one of the U.S. allies that bought equipment from Crypto AG, but the equipment may have never been used.

The report did not say when and who bought “a large shipment of Crypto machines” on behalf of Nigeria. It, however, said two years later, when there was still no corresponding payoff in intelligence, a company representative was sent to investigate but, according to a BND document, “he found the equipment in a warehouse still in its original packaging.”

U.S. Cold War rivals, China and the now-defunct Soviet Union were not Crypto AG’s customers because they were suspicious of the company’s ties to the West.

However, the Americans were able to still learn “a great deal” from other countries’ interactions with the Chinese and the Soviets.

