[Carlhole]

FT

A new photonic chip that works on light rather than electricity has been built by an international research team, paving the way for the production of ultra-fast quantum computers with capabilities far beyond today’s devices.

Future quantum computers will, for example, be able to pull important information out of the biggest databases almost instantaneously. As the amount of electronic data stored worldwide grows exponentially, the technology will make it easier for people to search with precision for what they want. An early application will be to investigate and design complex molecules, such as new drugs and other materials, that cannot be simulated with ordinary computers. More general consumer applications should follow.

Jeremy O’Brien, director of the UK’s Centre for Quantum Photonics, who led the project, said many people in the field had believed a functional quantum computer would not be a reality for at least 25 years.

They have arrived. How many years early was that?

[tridentblack]

Sweet! The problem is that these computers, through Shor's algorithm, can factor large integers in "polynomial" rather than "non-polynomial" time. All the encryption currently used to protect financial data on the Internet uses the fact that this cannot be done, so the widespread availability of Quantum computers would actually be a threat to the financial security of the country, as all the current codes could be all be cracked.

I think there are plans for new quantum encryption schemes that they can't break, but it will be awhile from what I hear.

[Carlhole]

Sweet!

Actually, I read down through the links and found that you won't be able to buy a quantum computer from WalMart inside of about 10 years. But QCs were here in theory but now they are here in fact, if only as prototypical proof.

Another article knocked me back a few months ago. It was this one: Most Efficient Quantum Memory for Light Developed

"Light entering the crystal is slowed all the way to a stop, where it remains until we let it go again," explains lead researcher Morgan Hedges. "When we do let it go, we get out essentially everything that went in as a three-dimensional hologram, accurate right down to the last photon.

"Because of the inherent uncertainty in quantum mechanics, some of the information in this light will be lost the moment it is measured, making it a read-once hologram. Quantum mechanics guarantees this information can only be read once, making it perfect for secure communication."

The same efficient and accurate qualities make the memory a leading prospect for quantum computing, which has the potential to be many times faster and more powerful than contemporary computing.

In addition, the researchers say the light storage will allow tests of fundamental physics, such as how the bizarre phenomenon of quantum entanglement interacts with of the theory of relativity.

Wow! Just wow!

[tridentblack]

Amen to that, WOW.

I'm a comp sci. guy buy education, and the paradigm shift this represents is really exciting to me. I've been dying to find a simple math model (like the Turing machine is for today's computers) for Quantum machines, but I haven't found one yet I can wrap my head around. But I know that things will be fundamentally different. Just the way light acts in Holograms, where you cut it in half and each half has copy of the information of the whole with less quality:
http://www.metacafe.com/watch/1035719/t ... holograms/
I saw that and it blew my mind, it tells me we are REALLY in for a new world as far as computers go with this stuff finally gets out there.

[Pretorian]

ok so how much does this thing cost---also, why exactly us military allows this to go public. shouldnt this be classified, or they already did what they had to do

[Expatriot]

Oh gawd, more nonsense passed off as game changing.

1st, let's start with this. There is one, and only one difference between electron/transistor computing and light/quantum computing - efficiency. At the end of the day, you can't do anything with a quantum computer that you couldn't do with a punch card computer - the only difference is how efficiently you could do it.

In short, transistors have 2 states. In a quantum computer, each transistor-like element could have more than two states. Ergo, you need many fewer transistor-like elements in a quantum computer than you would in a regular computer.


So, no need to get too excited - efficiency will go up and you'll be able to do . . . whatever . . . more quickly.

Have a need to have instant-on computers? They'll be here.
No lag in your photoshop? Done.

And so on.

Regarding encryption, there is only one thing that the non-cryptologist needs to get his arms around to understand the power of encryption.

There is a practical limit to cracking a password - that limit exists because it takes energy to "guess" at a password.

So, while it is theoretically true that a quantum computer operating at 100 times the speed of a Pentium 5 COULD be used to guess a 30 character password in a 1024 bit RSA system, how much energy will that consume?

Point is, at some point of encryption, even if each "guess" only takes a bit of energy, the amount of energy required to guess the password is more than can be allocated.

Keeping it in perspective, energy required to crack a password increases exponentially as you add encryption bits.

For example - if you have a one digit code, it will require 10 guesses to crack, maximum (0-9). But if you have a two digit code, then it's 100. Three digits is a 1,000, and so on. Add enough digits, and you become, within practical limits, unbreakable.

To conclude, unless they figure out how to perform computations using no energy, encryption technology will become bulletproof in the near future, and I'd argue that some applications are, for practical purposes, already bulletproof, notwithstanding any gains in computing efficiency.

See, for example, this link (FBI couldn't break encryption after 18 months of trying - gotta figure they'll make encryption illegal soon):
http://www.theregister.co.uk/2010/06/28 ... _lock_out/