Slashdot Mirror
Quantum Cryptography Gets Nanotube Boost
c1ay writes "In an article at the ScienceDaily News it is reported that two researchers at the University of Rochester have discovered a new property of carbon nanotubes, ideal photon emission. "The emission bandwidth is as narrow as you can get at room temperature," says Lukas Novotny, professor of optics at Rochester and co-author of the study. Such a narrow and steady emission can make such fields as quantum cryptography and single-molecule sensors a practical reality. RSA and Elliptic Curve wouldn't stand a chance against this unbreakable encryption."
So-called "quantum encryption" may be unbreakable, but it is ignorant to portray it as a competitor to something like RSA. Quantum encrypton is a link-layer technique - something one would use to prevent eavesdropping on a single fibre hop (which is hardly a problem anyway).
Worse, it is hardly practical for real networks anyway - with routers, repeaters, EBFAs or Raman amps everywhere. If it ever makes it out of the lab, it may be useful for military systems (where money is no object), but it won't help you pirate music anonymously.
RSA and elliptic curve are able to provide encryption safe from a man in the middle attack, as well as authentication of where a message came from (signing). This is far ahead of what quantum encryption offers.
The only security quantum encyption has is that the message can only be read by one viewer - this prevents covert surveillance of the message, but not a man in the middle attack, nor a total interception.
Pragmatically you bundle quantum encryption with other authentication techniques, but RSA on it's own is far more useful and secure than quantum encryption on its own.
It's not time to throw RSA and Elliptic curve out just yet.
And crackers don't really stand a chance against the algorithms we have now. Although I'm happy to see them inventing cool stuff and cryptography os definitely neat, will this makes us more secure? Sure computers keep getting better and you need to stay ahead of the curve if you are someone like the NSA, but are people the loosing the security game because their 128 bit RSA keys keep getting cracked ? No. They are insecure because they have nanotube-size brains and use their birthday for their password or they leave a laptop with the vice president's agenda at a convenience store.
What we normally mean by "encryption" is "the transformation of readable stuff into stuff that can be seen by evil people without them able to understand anything". Encrypted data are a stream of bits just like anything else. Thus you can store your encrypted message on a disk, or write it down, or transmit it over a wire, or broadcast it.
In this sense "quantum encryption" isn't encryption at all. Quantum encryption is something that can only happen as part of the act of transmission. There is no such thing as "quantum-encrypted data" that can be recorded or written down or transmitted over conventional media. The act of doing any of those things collapses the wave packet and destroys communication just as effectively as interception would.
I'm not going to argue that we should start calling quantum encryption something else, the name is too snappy and too useful for getting research grants, but let's not get confused into comparing it with public-key or even private-key encryption: they're completely different animals.