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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!
Applying the standard naming conventions would result in qutits. I much prefer qutits.
"That could be an important advance enabling the widespread use of quantum cryptography."
Please enlighten the Slashdot crowd about where quantum cryptography is USED at all.
Yours In Ashgabat,
Kilgore Trout
But Alice will share a frame with ANYBODY, knowwhatimsayin'?
Someone please correct me if I'm wrong here, and I haven't had time to read the entire article, but wouldn't this also bypass the conventional data transmission necessity for quantum communications?
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.
By 'theoretical breakthrough', does that mean we theoretically may have made a breakthrough in quantum cryptography? Quick, nobody observe the research process!
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
Does this not seem like the most wasteful project ever? Can I get my tax money spent a little more cogently?
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.
I was all set to sell crypto supplies and repair services in the alternate dimension. Do you have any idea what this is going to do to housing prices there?
Why cant they simply open a sub space channel and use a Tachyon pulse to synchronize the two frames ?
Will CPUs be measured by the Bob:Alice ratio from now on?
Something tells me that Alice and Bob are going to great lengths to keep their affair a secret...
?
I, for one welcome our new quantum overlords.
... quantum parity!
It's absolutely uber, leaving no question unanswered. Can I have children with you? '
Let's just create another dimension and send everything through there, FUCK YEAH!!!
Oh... so that's what the kids are calling it these days... ??
Bob sends Alice a super secret quantum message.
Michael in the middle intercepts it.
Michael reads all the same quantum security shit Alice was suppose to verify.
Michael sends a fake message with all the quantum security shit duplicated.
Quantum doesn't solve shit - if it can be read (to be verified) it can be recreated.
Until there is a 100% reliable network with no processing delay, man-in-the-middle attacks will be possible. Until then, Michael will be able to intercept a message, read it, send a spoofed message in it's place. So what if it came a little later than expected? There are plenty of routers and fuckups along the way to add latency.
All security boils down to a key sharing problem.
We can't get that shit right in real life.
Maybe I'm not up on my vocab as of late, but since when does the phrase "Theoretical Breakthrough" make any kind of sense?
I have a question:
If this arrangement enables the two sets of particles to see the state of the other ones with no interference of the frame or reference...
what will happen if i drop a pair of those ones in a black hole?
the remaining pair...what will measure? a ever increase rate of information? or what?
I just KNEW there was a third guy involved in there. Bob was never going to satisfy Alice all by himself, all these years.
Religous speak to God. Insane are spoken to by God. When all shut up, one can finally hear Shostakovich in peace
Nothing. What frame reference independence actually means is that they are encoding a reference frame in the particles themselves, so that you don't have to worry about external alignment. It does nothing about the communication channel, that does not exist through an events horizon.
entropy happens
So, this works for Alice and Bob. What about Homer and Jethro?
Polarization has a nasty habit of rotating when it travels through optical (telecom) fiber. To make matters worse, the degree of rotation depends on temperature and physical strain and can change quite rapidly. Of course, entangling three photons is much harder than entangling two.
So if this is the future...where's my jet pack?