Here is an interesting story:
Hackers blind quantum cryptographers
http://www.nature.com/news/2010/100829/full/news.2010.436.html
Basically, they found a really simple way to do a man-in-the-middle attack on a quantum encrypted link. You just intercept the photons and the "blind" the recipient by shining photons at him, so that he does not interfere with your decoding. Then you send a copy to the recipient using the blinding photons.
No doubt this will be patchable, but it suggests that quantum encryption in EP may have some potential for hacking despite its fundamental security. After all, the real security of a system is equal to the security of the weakest link, and the EP systems are very, very complex.
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