Is there anyone else reluctant to open a pdf from the NSA?
(a) It's from their museum facility (if you ever get the chance to visit the National Cryptologic Museum in Maryland TAKE IT TAKE IT TAKE IT )[1], not the NSA itself. (b) It's a scan of a 30-year-old report on a completed project, redacted heavily. Nothing more. (c) If they want your inside leg measurement they've got better ways to find it without feeding you a PDF they overtly created. [1] Where else will you find…
Seconded. I went midweek around noon and it was pretty quiet so I got a personal 90 minute tour by an NSA retiree. He was very knowledgeable about crypto history, esp. as used in the cold war and WWII. They had Turing's "bombe", multiple Enigma variants, many lesser-known crypto machines, historic correspondence, a Cray YMP, codetalkers exhibit, spy satellites, and tons of other good stuff. Everything is free - except merchandise in the gift shop, which is also pretty unique.