Posted on 02/09/2007 11:28:07 AM PST by US admirer
Twenty years before most scientists expected it, a commercial company has announceda quantum computer that promises to massively speed up searches and optimisation calculations.
D-Wave of British Columbia has promised to demonstrate a quantum computer next Tuesday, that can carry out 64,000 calculations simultaneously (in parallel "universes"), thanks to a new technique which rethinks the already-uncanny world of quantum computing. But the academic world is taking a wait-and-see approach.
D-Wave is the world's only "commercial" quantum computing company, backed by more than $20 million of venture capital (there are more commercial ventures in the related field of quantum cryptography). Its stated aim is to eventually produce commercially available quantum computers that can be used online or shipped to computer rooms, where they will solve intractable and expensive problems such as financial optimisation. It has been predicted that quantum computing will make current computer security obsolete, cracking any current cryptography scheme by providing an unlimited amount of simultaneous processing resources. Multiple quantum states exist at the same time, so every quantum bit or "qubit" in such a machine is simultaneously 0 and 1. D-Wave's prototype has only 16 qubits, but systems with hundreds of qubits would be able to process more inputs than there are atoms in the universe.
Scientists in the world's many quantum science departments are looking anxiously at whether the demonstration - linked to a computer museum in Mountain View California, will vindicate their work or cast doubt upon it.
"This is somewhat like claims of cold fusion," said Professor Andrew Steane of Oxford University's Centre for Quantum Computing. "I doubt that this computing method is substantially easier to achieve than any other."
Others are more enthusiastic: "I'll be a bit of a sceptic till I see what they have done," said Professor Seth Lloyd of MIT. "But I'm happy these guys are doing it." Lloyd is one of the scientists who helped develop the "adiabatic" model of quantum computing which D-Wave's system exploits - a method which D-Wave believes will sidestep the problems which have restricted progress in quantum computing so far.
Current SSL is 128-bit, and it'll be a LONG time before a quantum computer is made that can crack that quickly (you'd need about a 129 qubit quantum computer). If we get close to that, make SSL 1024 bits and the quantum computer builders will have to catch up again. But when the time comes, quantum physics solves the problem it creates, using quantum encryption.
Dr. Heisenberg..
Can I have my cat back now ??
As a programmer, I've gone from 1KB RAM to 1GB RAM - 6 orders of magnitude in just two decades.
We're at 16 qbits right now.
16Mqb 20 years from now is not an unreasonable prediction.
1024 bit SSL will be a cute anachronism then.
Heck, 1024 bit SSL may be a cute anachronism some time next year (that would only need a 32x32 qbit quantum computer, and we're at 4x4 now).
LOL!
We can control it by looking at it, or looking away.
I'm totally uncertain about what you meant!
I think I've got it!
Can I have my cat back now ?
Yes and No.
The operation you're doing is an exclusive or, XOR. If you XOR x with y to get z, then XOR z with y again, you get x back. The problems with one-time pads are the distribution system, the security of the pads, and synching-up the key usage in a secure manner.
Also, one-time-pads are not usually used to authenticate, which is also an important part of online banking. But I guess your system could say to the bank "I'm user X and I'm about to use pad ID #19782356" and then send some known data, like the user account name, and then authentication passes if what you send comes out when decrypted at the other end.
It means that it when it crashes you get the blue screen of death really really fast.
"How else could Santa deliver so many presents to so many kids all over the world in one single night? Parallel universes."
Quanta Claus, lol.
A quantum computer might be able to decrypt messages but what a lot of people seem worried about, which is silly, is password cracking. The computer could run through nearly infinite combinations of passwords in a second and find the right sequence of letters and numbers.
The good thing about password or access cracking is that there's no way for the quantum computer to know the right answer - it would have to send the password to whatever program it was trying to access, and you can only do that so fast. Shoot ten quadrillion possible passwords at the CIA's computer system and see what happens. It'll crash, and the men in black will start looking for you.
The solution to encryption cracking, I think, isn't better encryption but preventing the criminal with the quantum computer from getting an encrypted message in the first place. That's where the interesting technology challenges will be.
You are saying that the real problem will be to know when you have the right or correct answer. True. In the traveling salesman problem you can put values on the connections and then look at the sum of the values in order to choose the correct solution from the multitude of solutions given by the computer. However if you use the computer to model global warming, which of the answers is the correct one? Only a proponent of the current whacko stuff on it (read AlGore) would know.
Fun stuff.
For going through the interface it would never work, especially since accounts are usually locked out or logins suspended for a short time after only a few tries.
This comes into play when someone has the password file with the hashes of the passwords. A quantum computer can compute the correct inputs very quickly.
Ford? There's an infinite number of monkeys outside who want to talk to us about this script for 'Hamlet' they've worked out
Until you observe it; then its either one or the other.
Sub-Space relays
You have to get beyond 3 dimensions to get that to work...
CA....
That's an interesting thought. If a list of totally random numbers is encrypted, even with a weak encryption scheme and weak key, could it ever be decrypted by an eavesdropper? Doesn't the ability to crack something require patterns in the data? If there are no patterns to exploit I can't see how it could be cracked. If they stumbled upon the key how would they even know it? If this is true then we can live without public key cryptography in the future should it become crackable (though it should be assumed the NSA has already cracked it).
Does that mean we can find out what our universe would be like without Hillary?
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