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Quantum Cryptography

  1. May 31, 2004 #1
    Quantum Cryptography is the process of encrypting information with polarised photons. This makes a theoretically and practically unbreakable code that would ensure good communication forever. You can run the photons by fibre optic cables but not in the air because the signal dissipates. The point is that we can do it right now, but there is no need to because our current assymetric RSA ciphers would take the NSA about 500 billions years to decipher. I have no contention, i just think this is cool. The ultimate achievement would be to invent a quantum computer that could break an RSA cipher instaneously due to superposition. however then we could just use the quantum cipher. :smile:

    Any Questions?
    Last edited: May 31, 2004
  2. jcsd
  3. May 31, 2004 #2
    Hawking radiation derived as a consequence of quantum information in curved spacetime

    What is spooky action at a distance?

    Now Robert Gingrich and Christoph Adami of the Jet Propulsion Laboratory in Pasadena, California say that a boost can actually create spin or momentum entanglement, or both, between two particles that had neither to begin with. The speed change can also enhance entanglement in spin at the expense of momentum entanglement, or reduce them both. "If you can create [entanglement] just by moving with respect to what you're measuring, then seemingly you've created something from nothing," says Gingrich.


    Any comments?

    I just wanted to let you know, as well as slyboy, that I have been interested in this topic for a while.

    http://www.superstringtheory.com/forum/partboard/messages20/139.html [Broken] Action At a Distance

    When I refer to LIGO, some might understand why :confused:
    Last edited by a moderator: May 1, 2017
  4. Jun 1, 2004 #3
    .............o....k...apart from that having nothing to do with quantum cryptography
  5. Jun 1, 2004 #4
    okay......your reasons why?

    "Obvious though this commonsense description may seem, it is seriously at odds with modern physics. Albert Einstein famously expressed this point when he wrote to a friend, "The past, present and future are only illusions, even if stubborn ones." Einstein's startling conclusion stems directly from his special theory of relativity, which denies any absolute, universal significance to the present moment. According to the theory, simultaneity is relative. Two events that occur at the same moment if observed from one reference frame may occur at different moments if viewed from another."--Dr. Paul Davies


    [B]Exorcising Spooky[/B]
    [I]Now Karl Hess and Walter Philipp of the University of Illinois at Urbana-Champaign provide evidence that Einstein may have been right to be sceptical - there may indeed be another set of rules underlying quantum theory1[/I].


    [B]Mesons violate Bell’s inequality[/B]
    [I]Quantum mechanics predicts that "non-local" correlations can exist between the particles. This means that if one photon is polarized in, say, the vertical direction, the other will always be polarized in the horizontal direction, no matter how far away it is. However, some physicists argue that this cannot be true and that quantum particles must have local values - known as "hidden variables" - that we cannot measure. [/I]

    Last edited by a moderator: May 1, 2017
  6. Jun 1, 2004 #5
    What does this have to do with Quantum Cryptography?

    What does this have to do with Quantum Cryptography?
    This information, while interesting, does not seem to relate to my subject, Quantum Cryptography.
    Last edited by a moderator: May 1, 2017
  7. Jun 1, 2004 #6
    Teleportation and cryptography are very close to me, but I could be wrong.

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