About five years ago, James “Jim” Shinn, a professor at Princeton University, was in the lunchroom of the School of Engineering & Applied Science quad with his former student, Andrew Choi, a promising young software engineer who was set to graduate in a few weeks. They were talking about an idea Shinn was working on, based on a concept he’d had while working as an intelligence officer—one he regarded as filling a critical weakness not only in government circles but other sectors as well,