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."

Comments

Commercially Available Product Link

[slugfro]

The conclusion of the article states that the system is currently commercially available. Here is a link to the QKD System.

What exactly IS quantum cryptography?

[Hemos (editor)]

I found a site that explains why classic cryptography suffers when compared to the benefits of quantum cryptographic methods.

The site is located at http://www.qubit.org/intros/crypt.html, and is part of the Center for Quantum Computation (Oxford University).

Here's a nice basic overview of QC from the site mentioned above: "While classical cryptography employs various mathematical techniques to restrict eavesdroppers from learning the contents of encrypted messages, in quantum mechanics the information is protected by the laws of physics. In classical cryptography an absolute security of information cannot be guaranteed. The Heisenberg uncertainty principle and quantum entanglement can be exploited in a system of secure communication, often referred to as "quantum cryptography". Quantum cryptography provides means for two parties to exchange a enciphering key over a private channel with complete security of communication."

Linux > Help > About

A little background on QC

[guest]

Quantum Cryptography can be a bit hard to get your head around, if you're interested at all in the topic you can take a look at this page for the some of the basic ideas and history behind QC.

Re:A little background on QC

[curb]

or this

What's quantum cryptography/key distrobution?

[moniker_21]

Well, I wasn't too sure, so I dug up some links to try and help myself and others understand this:
http://research.microsoft.com/~gottesma/QKD.html
http://www.qubit.org/intros/crypt.html
http://www.ecst.csuchico.edu/~atman/Crypto/quantum /quantum-index.html

The last link is particularly +1 insightful about the basics of quantum cryptography.

Re:All I have to say "neato"

[zer0vector]

Some ideas called quantum cryptography, such as using polarized photons (quanta of light) rely on the quantum mechanical properties of the photons, but not necessarily quantum computing. A good overview of how this works is included in The Code Book, by Simon Singh, I suggest you give it a look. Without going into the detail here, I can tell you that if the quantum cryptography he describes ever works it would not only be absolutely secure (this can be mathematically proven) but by its nature you could tell if someone was eavesdropping on the line.

The company is:

[Alien54]

The Company is: ID Quantique.

Home Page here:

www.idquantique.com/index.html

Re:All I have to say "neato"

[tomstdenis]

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

Re:Not secure

[sfeinstein]

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.

more reading here...

[bje2]

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...