Comment by gwern
10 years ago
> that unbreakable encryption was impossible?
Isn't that still an open question? We have Shor's algorithm which disposes of a bunch of things on its own, and the existence of one-way functions at all remains an assumption rather than a known fact.
Information-theoretically secure encryption and authentication do exist, so in a sense unbreakable (authenticated) encryption is a fact. Outside of that, the existence of OWFs is indeed an assumption, but I doubt anyone's losing sleep over it.
The original argument didn't make sense to begin with: the SIGABA rotor machines used by the US during WW2 were never known to have been broken during actual use, so the only reasonable conclusion about cryptography to draw at the time was that Enigma was simply a poor instance of it.