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Theoretical Breakthrough For Quantum Cryptography
KentuckyFC writes "Quantum cryptography uses the quantum properties of photons to guarantee perfect secrecy. But one of its lesser known limitations is that it only works if Alice and Bob are perfectly aligned so that they can carry out well-defined polarization measurements on the photons as they arrive. Physicists say that Alice and Bob must share the same reference frame. That's OK if Alice and Bob are in their own ground-based labs, but it's a problem in many other applications, such as ground-to-satellite communications or even in chip-to-chip communications, because it's hard to keep chips still over distances of the order of the wavelength of light. Now a group of UK physicists have developed a way of doing quantum cryptography without sharing a reference frame. The trick is to use entangled triplets of photons, so-called qutrits, rather than entangled pairs. This solves the problem by embedding it in an extra abstract dimension, which is independent of space. So, as long as both Alice and Bob know the way in which all these abstract dimensions are related, the third provides a reference against which measurements of the other two can be made. That allows Alice and Bob to make any measurements they need without having to agree ahead of time on a frame of reference. That could be an important advance enabling the widespread use of quantum cryptography."
One thing, with quantum crypto, the code changes when you look at it. In other words, you have to know the key before seeing it.
Two, it kills a LOT of cats! You get the code right, and BAM! dead cat.
PETA will be against this!
Especially when dealing with entangled triplets.
cute tits or quit its?
Paying taxes to buy civilization is like paying a hooker to buy love.
I think this is engineering, not theory. Theory was the original idea of using entanglement for cryptography. Now they're applying the technology to make it practical, and that's engineering. They're adding a bit of steel or another entanglement to make it more usable. If nobody has built this device yet, it's theoretical engineering.
Boy am I glad I didn't pursue that physics major. The only thing I got out of that is that Alice and Bob needed a marriage counselor to reconcile their differences.
Anyone mind converting that attempt in layman's terms to something useful, like a car analogy?
"This solves the problem by embedding it in an extra abstract dimension, which is independent of space."
Has it occurred to anyone else how UNBELIEVABLY FRIGGIN' COOL it is that a line like that shows up in an article that is talking about building an actual, physical device?
Technoli
Glap glar photons biddle doo-vack triple photon vajmu double photon zirreyzoo-zah picture frame powlat pweegoo paparazzi photos of Alice and Bob.
Sorry about the mess.
Would this system still allow alice/bob to know if someone's evesdropped? What's the difference between a hostile evesdropper and just some other part of the infrastructure for getting data from alice to bob? Without that, quantum cryptography is just another encryption system, and there are nothing wrong with the current ones. Right? (It would arouse me if replies to this post started simply "Wrong.")
Why cant they simply open a sub space channel and use a Tachyon pulse to synchronize the two frames ?
I, for one welcome our new quantum overlords.
(It would arouse me if replies to this post started simply "Wrong.")
Not to judge your lifestyle choices, but I'm pretty sure that the reason no one has replied as such has to do with the collective will of the community not to see you aroused.
Now that I think about it, I'm pretty sure everything I just said is completely wrong.
Oh... so that's what the kids are calling it these days... ??