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BB84 – A quantum key distribution scheme (wikipedia.org)
12 points by flowerpot on April 18, 2015 | hide | past | favorite | 6 comments

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.

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#.

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.

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.

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

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....

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