Re: The Elevator Problem

[s1113645@tesla.cc.uottawa.ca]

On Sun, 10 Dec 1995, Daniel Miskell wrote:

> I think i was misunderstood.  I was not referring to the actual use of light 
> in the communications process.  I was talking about the key generation method 
> suggested in that article.  Of course the use of light is impractical for most 
> - the need for direct fiberoptics aside, you have to be able to test a photon 
> for its polarized orientation.  In any case, i dig on.

I didn't read the Discover article, but I did see it in Applied Crypto, 
1st edition. The polarization thing was used for eavesdropper detection, 
rather than key generation (I think, and I may be quite wrong).

The paper was intended to show that you could have unconditional security
even if P=NP (I even think that was one of the paper titles), so the authors
used a one time pad (and used whatever key generation method is usually used
for OTPs, ie coin flips, real RNGs and whatnot). So nothing special or new 
with regards to key generation. (Of course they may have newer papers...Any 
hints folks?)

Incidentally, Brassard wrote a nice and very short intro to modern crypto
that's in the Springer-Verlag Lecture Notes in Computer Science series.
I think Applied Cryptology was the title. It had good coverage of his quantum
crypto scheme. It ought to be in any university library.