Reply to post: Re: What's the Point?

European Space Agency wants in on quantum comms satellites

Anonymous Coward
Anonymous Coward

Re: What's the Point?

Arse-backwards. I would rather trust QM, which has never been proved holey (indeed, is the most solid book on physical law ever( than the assurance that factorization is not in P.

One of the most fundamental truths of the state of physics at the moment is that we know we do not have a complete description of How the Universe Works. The lack of unification of quantum mechanics and general relativity, both fine theories in their own right with a ton of supporting experimental data, is a big hint that there's stuff we don't know.

Now, "stuff we don't know" simply means that there's no public papers giving a better description of QM and GR. For quantum cryptography to be secure, you have to guarantee that there is no one out there who has made a breakthrough but has chosen to keep that information to themselves.

Can you give that guarantee? Like, really guarantee it? No, you can't. You can take a good bet, but you're unable to guarantee it.

Ok, so the same is true of factorisation, but at least that is in a realm of mathematics where we do all know what the rules are. Plus, fast factorisation is not a fundamental threat to all encryption schemes; if you have physical key exchange methods (eg paper tape is still commonly used) instead of a PKI then it really does come down to how long does it take to brute force guess a very long number. That's very easy to be confident about.

POST COMMENT House rules

Not a member of The Register? Create a new account here.

  • Enter your comment

  • Add an icon

Anonymous cowards cannot choose their icon

Biting the hand that feeds IT © 1998–2022