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Creeping Toward 10 Qbits: Atomic Computing
RetroGeek points to this "New York Times article about a computer using atoms as switches. Give me twenty atoms and I'll break the RC5 contest." Going from 7 atoms to 10 is the order of the year, and if this keeps up maybe soon we'll need some slightly longer encryption keys, thanks.
After years of being behind, it looks like this might be the equalizer in the neverending battle between those who write and those who break crypto. Now all we need to know is how many atoms need to be manipulated so that users won't put their passphrase on a Post-It(TM) note and stick it to their computer screen.
[Insert the usual disclaimer here]
Not only does the incredible computational power of quantum computing render current encryption keys useless, but it also will provide enough computing power to run windows 2000.
Someone you trust is one of us.
Defeat NYTimes awesome password technology with...
user slashdot2000
pword slashdot2000
I'm sure the Czech crew who released the PGP advisory this week would love the same kind of computing. (more historical codebreaking)
Seems entirely over my head (the level of computing obviously) but here would be some nice uses for this level of computing.
I wonder how old I'll be before a computer like this is something like what a c64 is in nowadays. Just think scientists where developing this starting in 1994 (from what I saw on NYTimes), imagine when the level of computing in 20 years, or would it all come crashing down. Scary thought. Anyone care to reply with links to basic quantum computing information you care to share?
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360 degrees of Karma
So if I've understood the article correctly (possibly not, since it's 6am and I've been up all night), your QBIT (quantum bit) can be in 1 of 3 states:
1) up
2) down
3) dead kitten AND live kitten (superposition)
Does this mean that we'll use a new, post-boolean algebra on trinary computers, or will we be running a binary system which gets internally compiled down into operations involving QBITS?
Maybe the third state will be soaked up by the error correction mentioned in the article...
I actually think it would be cooler to have a binary computer, but the third state really did represent an unknown and mysterious simultaneously true and false state...
dim x as boolean
x=MyComplexMethod("goat",45,"all your base")
if x=true then
print "Yes- true"
else
if x=false then
print "No- false"
else
print "WTF is up with this?"
endif
endif
360 degrees of Karma
Introductory articles on quantum computation>
read on... quantum crypto
360 degrees of Karma
I don't mean to rain on anyone's parade. I really don't. Its just I think we may be getting a LITTLE ahead of ourselves, here. Contrary to a lot of posts on /., Quantum Computing is not so much a issue of EE as it is of good, old-fashioned AMO Physics - lasers (BIG lasers), nonlinear optics, RF Ion Traps and more lasers. This is not your granddad's transistor (which, even in its original form, probably could be safely operated at Johny and Susie's house in Peoria). From my experience as a research assistant in a quantum computing laboratory at a big academic institution, trapped-ion quantum computing is not the type of thing that'll be running your palm pilot 10, 30 or even 50 years down the road - the (absolutely crucial) electronics of the trap, alone, would make it insanely dangerous to have in your home, let alone your pocket (ions will still require the same EM containment fields 1,000 years down the road as they do now - its what makes 'em ions).
And no one has EVER gotten an Ion-Trap quantum computer to do ANYTHING. Not add two numbers. Not factor a number. Not multiply two numbers. The potential is there - the qubits - its just no one has ever tapped it in a feasible way.
I'm sure people said the same things about transistor based computer back in the day, but I really, really feel that the Ion Trapping method is not going to be the type of QC we'll see in practical use anytime down the road.
Ok, that's an overly inflammatory subject header. However, I once had a chat with a friend and we tried to work out what practical effect it would have on the world if you could solve NP problems reliably in polynomial time. I'm sure a lot of things would become slightly better, but neither of us could think of any revolutionary new applications that would become possible that weren't previously possible.
Remember that a lot of the problems that are in NP can be approximated pretty well. If you were actually routing travelling salesmen around the US, you might not mind a solution that's off by a few percent (particularly when there are going to be a whole pile of other sources of error; your salesmen getting stuck in traffic jams or dallying with housewives, etc.).
Can anyone offer some problem domains where quantum computing would offer more than an incremental improvement (discounting crypto, which seems to be a case of gain a little, lose a little)? I'm not claiming that such domains don't exist, btw. I'd be delighted if someone could point out a few.
Here is an article from Scientific American giving a good overview of the basics of quantum computing.
It's a bit dated (from 1998) but the principles are the same.
For more info on P vs. NP, see the classic Computers and Intractability: A Guide to the Theory of NP-Completeness by Garey and Johnson.
Note, by the way, that quantum computers are not generally thought able to solve NP-hard problems in P-time. They can solve in P-time a class of problems called QBP, which is believed to sit between P and NP in difficulty. Quantum computing suddenly got a lot of press when Peter Shor discovered that factoring is in QBP. However, factoring is probably not NP-hard.
Each bit is always a 1 or a 0. In a quantum computer they are represented by an elections spin, so if it is spinning clockwise it is a one, counter-clockwise is a zero. Because of all sorts of wierd arsed quantum stuff an electon can have multiple states, so it can represent a 1 and a 0 at once which is why in the article it says the quantum computer can perform multiple instructions at once. The electrons state is then manipulated using lasers, or radio waves.
The main problem which this article is saying they are closer to solving is that the state of an electron is very unstable and can be easily corrupted by all sorts of things, another passing electron for example.
I may be wrong about all of this, so if I am wrong please tell me, but this is how I think they are working.
There was a lecturer at my university who was working on quantum computers, I forget his name though. Here's what I understood of what he said: Quantum computers amke use of some of the peculiar quantum mechanical effects which occur is certain types of systems, like cold trapped atoms. One of these properties is superposition, whereby the spin of an atom in a quantum computer is not really up or down(1 or 0) but a superposition of both states at once, and it only has a probability of being in any one once one makes a measurement(at which point the wave equation collapses to a discrete value). A set of quantum bits(each an atom in this type of implementation, there are several kinds being pursued) can be an information storage vector. As long as one maintains the systems quantum coherence(whatever this means) one can have this set of qubits represent a real vector in a space with dimension equal to that of the number of qubits. ie an n bit array of qubits can represent a vector in an n dimentional vector space, not just 2^n discrete values, which n conventional bits can represent. When one makes there measurement, one gets values of one or zero for each value. The beauty is that until one makes their measurement, the system represents all possible values, so that one can perform their operations of a system which represents the vector to infinite precision(or as good as one maintains coherence), only reducing the answer to n bit precision when they make the final measurement. One interesting thing that the speaker said is that there aren't enough barionic particles(electron, protons, neutrons) in the known universe to construct a conventional computer which could simulate a 200 qubit quantum computer. Hope this has been helpful, and I hope I did not make too many glaring errors. empathogen
They were building structures measuring in the hundreds of cubits three thousand years ago.
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Not relevant.
Moore's Law is _not_ to do with computing power, but with gate size/density.
e.g. here is the first thing a web search provided:
http://www.webopedia.com/TERM/M/Moores_Law.html
THL
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Keeping
Windows already uses quantum effects. Just looking at it will make it crash....
</Humor>
www.eFax.com are spammers
Could you imagine a beowulf cluster of qubits in Natalie Portman's pants, running Linux?!
Keys based on biometric security can be tens of thousands of bytes long, have nothing crackable about them and are entirely consistent. and much more secure.
They'll also need 64-bit hardware. Goodbye 32-bits and that other unportable OS won't make it there will it?
MSBPodcast.com The opinions expressed here are my own. If you don't like 'em... Think up your own stuff.
this article was posted on slashdot before; that where I learned 'bout it. It's well written and covers the theory and a bit of the mechanics. Worth a read (and a re-read) if you're interested.
.... will be needed to write a CSS Decoder?
It ISN'T NP-hard. Remember that an NP-hard problem is one where, even if you had a proposed solution, you can't verify the answer in polynomial time. Verifying a factorization answer is easy: just multiply. That's polynomial time, therefore factoring isn't NP-hard.
That's as opposed to Travelling Salesman where even if you have a proposed path, you'd have to check all possible paths to decide if yours was the minimum.
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324006
Well, let's see:
10 atoms this year
20 atoms by early 2003
40 atoms by late 2004...
By the 22nd century, the entire universe will be a computer. Or is it already?
You are in a maze of twisty little passages, all alike.
"Nobody will ever need more than 640KB RAM." -- Bill Gates.
Maybe he meant 'more than 640 atoms' or 'more than 640KB RSA'?
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