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Yes, sure...

zackers 6th Sep 2010

@i2fun@... Actually, the distance between the two ends is now in the 10 kilometer range, and probably will get much longer over time. The whole point of using secure systems is precisely because the data will be traveling through unsecure areas.

The method proposed by the hackers uses a woman-in-the-middle (traditionally named "Eve") attack (see http://www.nature.com/nphoton/journal/vaop/ncurrent/full/nphoton.2010.214.html ). While the whole point of quantum cryptography is that when you do so the entanglement is broken and the message is lost, as the article above implies this requires special properties of the detectors at both ends. The hack overpowers these special properties, and in addition happens to allow Eve to send whatever signals she wants to both ends without being detected. Thus Eve can copy the messages from one end to the other, including the key exchanges, and decode the messages.