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Practical Quantum Cryptography
Alien54 writes: "Saw this on Eureka Alert: A commercially available system for quantum key distribution and cryptography has been released by a spin-off company from the University of Geneva. The system has been tested over distances up to 70km (from Geneva to Lausanne) through standard optical fiber cables and connects to PCs via USB ports. Transmission rates of about 60 bits per seconds were achieved, sufficient for key distribution. You can see the original abstract here, which also has a link for download of the paper in PDF, Postscript, and other formats."
Was it a spin-off company, or perhaps just a spin-up or spin-down company?
As nice as this scheme might be compared to previous quantum cryptography schemes, there are still fundamental problemns with implementing quantum cryptography. First off, you need a single, otherwise unused optical fiber to connect the two boxes. This means running your own cable. There's really no way around that. You're not going to find unrepeated, unused fiber just lying around.
vi is my shepard, I shall not font.
The conclusion of the article states that the system is currently commercially available. Here is a link to the QKD System.
-- Find the Truth...
pw:secret
You probably recall how quantum computation works: essentially you shove all the extra computation off into parallel universes and then get the answer back when it comes. Why not expand on that idea and use quantum file storage? The RIAA can create CDs where only part of the audio track exists in our universe and the rest is retrieved from parallel universes by your quantum audio system. This makes file copying mathematically impossible.
Now someone is probably going to pop up and say "well, I can pirate the signal after it has been revirtualized from the quantum foam". I'm glad you brought that up because it leads right into phase two of my idea. In order to listen to music, all consumers would be have sound-decoding chips implanted in their brains. The music would be beamed directly into your head from your audio system.
Thus we see that file copying can be made impossible by those that are willing to pay the price of our freedom. The only solution is to keep quantum computers from becoming a reality
Great...all my encryption problems are solved!!! And not a moment too soon, either...
:-)
After all, I was getting a bit nervous with respect to my encryption needs in light of the retirement of further development of PGP and the possible inadequacies of GnuPG...
Beer is proof that God loves us and wants us to be happy. -- Benjamin Franklin
Well, I wasn't too sure, so I dug up some links to try and help myself and others understand this:m /quantum-index.html
http://research.microsoft.com/~gottesma/QKD.html
http://www.qubit.org/intros/crypt.html
http://www.ecst.csuchico.edu/~atman/Crypto/quantu
The last link is particularly +1 insightful about the basics of quantum cryptography.
I posted to
Home Page here:
www.idquantique.com/index.html
"It is a greater offense to steal men's labor, than their clothes"
Quantum Crypto is based on the transmission of photons or somesuch.
The jist is if I send from
A =====> B
and someone traps the bits in the middle
A ===/C/===> B
e.g. an eavesdropper than they will change the spin of the photons and B will know [and in turn A].
So with quantum crypto you can send from A to B without any real crypto and you will be assured that an eavesdropper cannot get the message.
The big problem is this all requires direct connections.
Tom
Someday, I'll have a real sig.
Actually, quantum physics protects key distribution from retransmission. One of the fundamental benefits of quantum cryptography is the reliance on the principle that measurement affcts that which is being measured. In short: it is possible for the sender / receiver to determine if their key was intercepted by using unsecure communication of other information that doesn't benefit anyone else that may happen to see it. For a great explanation of how to protect your key distribution in this way, see this article in the New Scientist.
"Whether or not you believe me, I'm right" -RWF
if anyone wants to read more look for this book which covers the history of cryptography from ancient egypt to quantum cryptography...i read it, and it was extremely interesting from a mathematical and computer point of view...it includes a whole section of the theories behind quantum computing and quantum cryptography...
"Facts are meaningless. You could use facts to prove anything that's even remotely true." - Homer Simpson
But how do you know who the recipient is? QC offers no authentication. If you have to use public key for authentication, what advantage is gained by using superior methods for confidentiality?
The only one I can think of is that, with conventional cryptography, you can capture the data stream and crack it "off-line". I suppose that this is significant: with QC you only have to worry about whether they've cracked your private key (that you will use for authentication) already, not whether they can in 100 years (because you've used it for encryption).
Another argument might be that it is easier to eavesdrop on a channel than to redirect it. But that seems like a dubious assumption, if the enemy is determined.
Thoughts?
The evaluation of an action as 'practical' . . . depends on what it is that one wishes to practice.
Schroedinger's cat may have sacrificed its life to make this product a reality. Or maybe not. Only Heisenberg knows for sure.
Man, you made my day. This may lead some to wonder how boring my day is. It's pretty boring.
"RIAA can create CDs where only part of the audio track exists in our universe..."
I would bet this appeals a lot to RIAA. But why stop there? From what I understand they're looking for a way to sell you the CD so that there's actually no music on it.
Perhaps just a recording of one of the executives in charge saying "Thank you for purchasing this digital music container device. We assume that you have a computer and have downloaded countless megabytes of our copyrighted material. Therefore, we have pre-removed the equivalent amount of data from this CD. Enjoy." Followed by 71 and 3/4 minutes of silence.
Sweat
It breaks my pluginses, my precious!