knightly the Sneptaur

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Cake day: July 5th, 2023

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  • But can you detect the link being broken by someone other than your intended communication partner?

    Yes, because breaking the entanglement destroys the link between the photons received at either end.

    Observing an entangled photon requires extremely precise timing, the lightspeed lag on the line has to be known down to the nanosecond to ensure that the photon received is paired with the photon at the other end. Even if a MitM wanted to try retransmitting the quantum states it observes on the line, they wouldn’t be able to do so without introducing enough lag to desync the connection.

    Alternatively, if M tried sending their own random data in sync with the expected timing, then the bits received by B would only have a 50-50 chance of matching the bits sent from A. Any encryption based on that data would almost immediately begin to suffer a 100% error rate.



  • Nope, quantum entanglement can’t enable FTL communication. “Real time” still involves lightspeed lag.

    What it does is allows random bits of information to be transmitted in an entangled state. You send an entangled pair of photons, and find out afterwards who got a 1 or a 0 when the photons are observed at either end. They call it ‘quantum teleportation’ because both ends know what the other got, and the information about who got what can’t be intercepted without disrupting the enganglement.

    Once they can figure out how to preserve that uncertainty through repeaters, switches, and routers, then we can have a quantum internet that uses encryption based on shared quantum random numbers. It’s likely to be necessary soon since quantum computers might only be a few years from breaking current common encryption techniques.



  • knightly the SneptaurtoTechnology@lemmy.worldruh roh
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    3 days ago

    A “fediverse” version of Youtube already got made and subsequently killed, PopcornTime.

    The Bittorrent backbone already has plenty of media and can handle more bandwidth than we’d ever need to throw at it. Encrypted Onion Routing provides a degree of insurance against copyright cops, too. The only problems left to solve are automating the discovery of user-relevant content and avoiding the legal system long enough to write and popularize an open source app that puts it all together with a couch-friendly front-end.