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

Spin-off company

[Anonymous Coward]

Was it a spin-off company, or perhaps just a spin-up or spin-down company?

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.

The RIAA Should Fund Quantum Research

[PhysicsGenius]

I like my free MP3s, so don't spread this too widely: I've figured out a fool-proof method that the RIAA can use to "digitally manage" their intellectual property by using quantum computers.

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

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.

We must thank the cat

[r_j_prahad]

Schroedinger's cat may have sacrificed its life to make this product a reality. Or maybe not. Only Heisenberg knows for sure.

So Funny!

[sweatyboatman]

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