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Quantum Cryptography: 100km Barrier Broken

Posted by timothy on from the speaking-of-crypto dept.

jdfox writes "Toshiba Research Europe have just demonstrated quantum crypto over 100km fibre links. Sounds like there's still a fair bit of work to be done before it leaves the lab, but it's amazing that they've got as far as they have. There's another article about it, though still not much technical detail, here on the BBC and here on The Register."

4 of 194 comments (clear)

  1. assumptions by Photon01 · · Score: 4, Insightful

    From the Register article:

    Ultimately, quantum cryptography seeks to deliver a method of communication whose secrecy does not depend upon any assumptions.

    Dosent quantum cryptography depend on the assumption that it is impossible to copy this stream of encoded photons without leaving a trace?

    1. Re:assumptions by djpig · · Score: 4, Insightful

      Hmm, physical laws are actually not facts...

      They are more best explanations for which no counterevidence exists yet or explanations that describe the problem as good as needed

  2. Re:The US Gov is going to LOOOVE this! by jez9999 · · Score: 3, Insightful

    Actually, I think this means fuck all for the individual citizen's privacy. As it requires an unbroken fibre all the way from party A to party B, it would indeed only be appropriate for things like banks to use. Big deal. Think the government wants to spy on the minutia of your bank account? Think that, if they did, they'd have to hack the bank's network to do so, rather than just requiring it in law?

    Where it may have helped is over something like the internet... if an 'unhackable' transport method could be developed, privacy would greatly be benefitted. But as the internet inherently requires data streams to be intercepted and forwarded, usually many times over, this method will do nothing to help regular privacy.

    --
    == Jez ==
    Do you miss Firefox? Try Pale Moon.
  3. Re:Sounds like the press hasn't thought this throu by Ryan+Amos · · Score: 3, Insightful

    Barring what the other poster said, you can also predict transmission times over fiber VERY accurately. Any time spent processing the photon information to create a new photon to retransmit would be longer than the total transmission time. This would be easily detected.

    I have another interesting question though.. Would it be possible to combine this with the "laser teleportation" technology demonstrated earlier this year to have a REALLY secure wireless link? If so, 30 years from now, all communications might be so secure that we wouldn't have to worry about eavesdroppers.