During the 1990s, I had been working on a book, Crypto, which dove deep into cryptography policy, and it took me years — years! — to get an interview with an employee crucial to my narrative. I couldn’t quote him, but he provided invaluable background on the Clipper Chip, an ill-fated NSA encryption runaround that purported to strike a balance between protecting personal privacy and maintaining national security.
Oh, and I was not permitted to interview my Crypto source at the agency’s headquarters in Fort Meade, Maryland. I was crushed; I had grown obsessed with the vaunted triple fence surrounding the restricted area and had climactic hopes that I’d get inside. Instead, the meet occurred just outside the headquarters’ heavily guarded perimeter, at the National Cryptologic Museum. (I did buy a cool NSA umbrella in the gift shop.)