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To: ImaGraftedBranch; Jeff Winston; American in Israel; LibWhacker
    If I read the data stream by light leakage off of a fiber with a photodiode, it would not change the quantum data one bit. This is horse pucky.

      At the quantum level, merely measuring something affects it. You may have heard it said that you can know the location, but not the velocity, or the velocity but not the location?

This is well known as Heisenberg Uncertainty Principle aka Uncertainty Principle or Heisenberg Effect, or in layman's terms, object under observation changes its behaviour or state and is therefore unmeasurable, or as stated by Werner Heisenberg, "The more precisely the position is determined, the less precisely the momentum is known in this instant, and vice versa."

Ref: Heisenberg - Quantum Mechanics, 1925-1927: The Uncertainty Principle

They key exchange is a slight variation of or not that much different from PGP (Pretty Good Privacy) public-private/symmetric keys mechanism, developed and published by Phil Zimmermann in the early 1990s, except in this case it's fortified by the use of quantum mechanics to make even the key exchange impossible to tap without breaking communication.

Nothing here is revolutionary, the idea of the practical and inexpensive secure quantum net communications using fiber optics (or even "fixed wireless" lasers) has been around for more than 15 years. The scalability has been tested and established when Abilene Project gave way to Internet2 in 2007.


Pretty Good Privacy

Phil Zimmermann

32 posted on 05/07/2013 6:56:47 PM PDT by CutePuppy (If you don't ask the right questions you may not get the right answers)
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To: CutePuppy
While great in theory, the premise of the measurement changing the data stream thereby scrambling the key is just that, a theory. All fibers leak a percentage of light. If the light leakage does not scramble the key, then the reading of the leaked light that is no longer part of the data stream but does reflect the data will not change the initial data stream. A photo diode adsorbing a photon is no more or less a loss of that photon than a bit of black plastic sheathing material on the fiber.

So while I find the theory interesting, I also observe that theory does not over come the physical reality. This is why I chose the wording I prefer physics over meta physics.

It is easy to over think a problem. An interesting example, in the space race, it was found that in zero gravity a ball point pen ceases to work. America spent a million dollars developing a pressurized ball point pen to work in zero gravity. When one diplomat bragged about it to the Russians, the Russian just laughed and said “we just use pencils”.

I took that incident as a life lesson. But to give it a try at least, if I think of a quantum physic theory, and am able to prove it, it then becomes simply physics. Therefore the measurement of any quantum physic idea changes it so that it no longer is Quantum physics... How did I do? -grin-

33 posted on 05/08/2013 7:35:22 AM PDT by American in Israel (A wise man's heart directs him to the right, but the foolish mans heart directs him toward the left.)
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