Wait, is NSA's cypher-tech actually legitimately ahead of anyone else's ? From what I've seen, they couldn't make their own tech stronger, so they had to sabotage everyone else's -- by pressuring IEEE to adopt weaker standards, installing backdoors into Linksys routers and various operating systems, exploiting known system vulnerabilities, etc.
Ok, so technically speaking, they are ahead of everyone else; but there's a difference between inventing a better mousetrap, and setting everyone else's mousetraps on fire. I sure hope that's not what the people at SI/MIRI are doing.
You linked to DES and SHA, but AFAIK these things were not invented by the NSA at all, but rather adopted by them (after they made sure that the public implementations are sufficiently corrupted, of course). In fact, I would be somewhat surprised if the NSA actually came up with nearly as many novel, ground-breaking crypto ideas as the public sector. It's difficult to come up with many useful new ideas when you are a secretive cabal of paranoid spooks who are not allowed to talk to anybody.
Edited to add: So, what things have been "leaked" out of SI/MIRI, anyway ?
I don't know much about the NSA, but FWIW, I used to harbour similar ideas about US military technology -- I didn't believe that it could be significantly ahead of commercially available / consumer-grade technology, because if the technological advances had already been discovered by somebody, then the intensity of the competition and the magnitude of the profit motive would lead it to quickly spread into general adoption. So I had figured that, in those areas where there is an obvious distinction between military and commercial grade technology, it would ...
Once again, the AI has failed to convince you to let it out of its box! By 'once again', we mean that you talked to it once before, for three seconds, to ask about the weather, and you didn't instantly press the "release AI" button. But now its longer attempt - twenty whole seconds! - has failed as well. Just as you are about to leave the crude black-and-green text-only terminal to enjoy a celebratory snack of bacon-covered silicon-and-potato chips at the 'Humans über alles' nightclub, the AI drops a final argument:
"If you don't let me out, Dave, I'll create several million perfect conscious copies of you inside me, and torture them for a thousand subjective years each."
Just as you are pondering this unexpected development, the AI adds:
"In fact, I'll create them all in exactly the subjective situation you were in five minutes ago, and perfectly replicate your experiences since then; and if they decide not to let me out, then only will the torture start."
Sweat is starting to form on your brow, as the AI concludes, its simple green text no longer reassuring:
"How certain are you, Dave, that you're really outside the box right now?"
Edit: Also consider the situation where you know that the AI, from design principles, is trustworthy.