Comment by aumerle

Proof! the entire field of cryptography can prove absolutely nothing other than that a single use of One time pad is secure. the rest is all hand waving, that boils down to no-one I know knows how to do this, and I cant do it myself, so I believe it's secure.

So the best we have in cryptography is trusting "human instincts/judgements" about various algorithms. Which then further reduces to trusting humans.