

BB84 – A quantum key distribution scheme - flowerpot
http://en.wikipedia.org/wiki/BB84

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gnuvince
I took an introduction to quantum computing with Gilles Brassard at Université
de Montréal 2-3 years ago: it was a really fun class given by a great
lecturer. If you're an undergrad or grad student at UdeM, consider taking a
class with Gilles (he also teaches introduction to algorithms, IFT2125 or
something), you won't regret it.

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mazork
Thanks, I'm gonna be attending UdeM next semester so I'm noting this down.
Does this class require much CS education ? I'm going to be studying
Mathematics but I have a good base of C#.

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gnuvince
You'll need to know algorithms, asymptotic complexity, probably have some
knowledge of classical theory of computation. Mathematical maturity and linear
algebra and complex numbers are important too. If you're curious, you can of
course contact the prof and discuss your situation with them.

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whitewhim
While all of these are required, none of the besides linear algebra are needed
in great detail. I think someone who is Studying mathematics should be able to
handle it.

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bradhe
I'm a dumb dumb, but it seems this is the SSL triple handshake with another
dimension?

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mileswu
Quantum Key distribution is different from classical ones in that it allows
Alice and Bob to detect Eve. This is because a measurement in Quantum
mechanics disturbs the state. In particular for BB84, a measurement by Eve in
the wrong basis destroys the correlation of Alice and Bob in the correct
basis.

Unlike classical key distribution, these guarantees derive from fundamental
physics laws as opposed to, say, RSA that can be broken given enough computing
power/time, and so are unbreakable.

Unfortunately there can be flaws in actual implementations of the BB84 scheme,
such as side-channel attacks. E91 [1] (a newer scheme) addresses these flaws
and prevents these attacks.

[1]
[http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.67....](http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.67.661)

