For more than half a century, governments all over the world trusted a single company to keep the communications of their spies, soldiers and diplomats secret. The company, Crypto AG, got its first break with a contract to build code-making machines for U.S. troops during World War II. SNIP The Swiss firm made millions of dollars selling equipment to more than 120 countries well into the 21st century. Its clients included Iran, military juntas in Latin America, nuclear rivals India and Pakistan, and even the Vatican. But what none of its customers ever knew was that Crypto AG was secretly...