That the NSA picked the magic DES S-boxes in order to defend against differential cryptanalysis (which they'd discovered first), and that the NSA picked the Dua

That the NSA picked the magic DES S-boxes in order to defend against differential cryptanalysis (which they'd discovered first), and that the NSA picked the Dual EC DRBG constants to backdoor it in a NOBUS type operation are both established facts. Yes, curves in the Web PKI are largely P curves right now, but ed25519 is also standardized. You're certainly free to trust the NIST curves, but my point still stands: there is no good reason not to pick such constants using a nothing up my sleeve algorithm, and the fact they didn't do that means they either know something we don't, they backdoored it, they wanted people to suspect they backdoored it, or they're idiots and decided to ignore established best practice for no reason. It's entirely possible the answer is the latter, of course :)