great...but does encryption prevent eavesdropping? (Score 1)

One-time pad through quantum encryption prevents Eve from listening into the conversation across the line or changing the signal. But it does nothing, as indeed it can't, to prevent her from capturing the unencrypted information on either Alice or Bob's end. Eventually, all cypher must be converted to plaintext, where it is susceptible to any number of attacks. Of course, Alice and Bob could be locked inside steel vaults, with no Internet connection and a room full of M-16s...