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Could packet round-trip times be an analog to qubits?

  1. May 30, 2013 #1
    I'm a programmer who is trying to figure out if there is any possible way to implement a pseudo-quantum cryptography algorithm without quantum computers, or is Bell's Inequality something that is going to get in the way of that goal? Or if I am anywhere in the ballpark. I wouldn't be surprised if I were way off on everything.

    The reason I'm looking at packet round-trip times is because it seems like an analog to a qubit. It doesn't have a certain value until you measure it.

    This may be good for cryptography since an eavesdropping party couldn't measure it and see what you would see, and the eavesdropping would affect the value you end up with. For example, the owner of megaupload figured out that authorities were eavesdropping on his internet connection due to a decline in his connections performance, he then noticed an extra hop when running a trace route.

    Compromised computers or routers on a local network could do similar things and not be nearly as noticeable. It still takes a cpu tick to process, it could be almost impossible to notice or measure in that circumstance, but it still changes the round-trip time, a very subtle change.

    Oh and this is my first post here. Hello :-)
  2. jcsd
  3. May 30, 2013 #2


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    It is not the same thing. The fact that a qubit can be in a superposition of 0 and 1 has nothing as such to do with measurements, it simply means that it is in state which does not have a classical analouge. It has nothing to do with our inability to measure it.

    There are many ways one could eavesdrop on a classical connection, both in theory and practice. Anyone with physical access to the cables could just eavesdrop on the lines directly by putting current clamps around the wires in an electrical cable, or insert a splitter if it is a fibre.

    Hence, your method does nothing to prevent someone from a "physical" attack where someone can directly access your physical connection, whereas QC does.

    Hello. Welcome to PF :tongue2:
  4. May 30, 2013 #3
    No. That's the point. See Gilder's Age of Entanglement. Bell's Theorem shows that there is "No Way" to duplicate the features of QM in a "Local Real" Cryptographic Setting:

    "So it happened that Eckert, in the quiet of Clarendon's library, sat back in shock when he read for the first time the famous EPR definition of "an element of reality: if, without in any way disturbing a system, we can predict with certainty the value of a physical quantity, then there exists an element of reality corresponding to this physical quantity. "It just clicked in my brain: wow - this is about eavesdropping!"...
    ""Local Realism", Eckert realized, "allows you somehow to incorporate the definition of perfect eavesdropping into the formulation: "Ha! - but I know it was refuted!" An entangled code would be an un-eavesdroppable code..."

    AoE, p. 314.

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