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Qutrits Bring Quantum Computers Closer
KentuckyFC writes "To do anything useful with quantum logic gates, you need dozens to hundreds of them, all joined together. And because of various errors and problems that creep in, that's more or less impossible with today's technology. Now an Australian group has built and tested logic gates that convert qubits into qutrits (three-level quantum states) before processing and then convert them back again. That makes them far more powerful. The group says that a quantum computer that might require 50 conventional quantum logic gates can now be built with just 9 of the new gates. What's more, the gates process photons using nothing more than standard linear optical components (abstract on the physics arxiv)."
I don't understand any of that. Except the word "gates"... unless it means something different in this context.
Throughout the heyday of personal encryption, when Zimmerman was maintaining PGP and Bruce Schneier's Applied Cryptography was released, we kept hearing about how it would take thousands or millions of years to crack just one PGP message. Now we hear that computers that could break these messages might be relatively just around the corner. It's got to be a real disappointment and source of worry to people who did use PGP to encode the secrets that they are desparate to hide.
Does it run linux?
Naturally, I read that as "qutits" the first time.
How can I believe you when you tell me what I don't want to hear?
Give the computer a nice cup of hot tea. From Douglas Adams "The Hitchhiker's Guide to the Galaxy" "If he thought to himself, such a machine is a virtual impossibility, then it must logically be a finite improbability. So all I have to do in order to make one is to work out exactly how improbable it is, feed that into the finite improbability generator, give it a fresh cup of really hot tea...and turn it on!"
Laters Sol "Have you found the secrets of the universe? Asked Zebade "I'm sure I left them here somewhere"
What this is basically saying is that instead of operating a quantum computer with 2 levels, 0 and 1, they are operating with 3, 0,1,2 lets say. According to my computer architecture prof 3 levels is the most efficient way of making computers, from a number of components standpoint. Its hard thinking in base-3, because things like inverters become meaningless. AND and OR gates still work with a reasonable amount of understanding. Things like multiplexers and decoders make sense. If you can get into the macroscopic level of design its pretty understandable. You can use 3 trit words to do base-27 in a similar way to using 4 bit words and hex.
All I know is, my gut says "maybe"...
I am not a quantum computer researcher or mathematician but doesn't this put extra work in for less outcome? If you start with info in qubits then convert it to qutrits (extra work) then process it (normal work) then convert it back to qubits (extra work) aren't you essentially doing twice as much work for only a 50% (qutrits vs qubits) increase in processing? Wouldn't it make a hell of a lot more sense just to use qutrits to begin with and not use qubits or convert anything?
Finally some games coming out for the quantum computers. I can't wait to see what Alexey Pajitnov would have done with this hardware.
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So does this mean that quantum computing will be based entirely on trinary code? Will those conceptual/theoretical trinary programming languages finally get some time in the sun?
don't be silly, no one gives a shit what 99.99% of people here sent using PGP. Governments, banking system, financial markets, megacorps will be the ones to worry.
Yes and no. I mean, the problem that you point out is only exists because a quantum computer is cracking an encryption that had to run in reasonable time on today's computers. But quantum computers don't have to be just one way like that... now you would have at your disposal a computer that can run encryption that would take thousands or millions of years on todays machines, on your data.
"When life gives you lemons, don't make lemonade. Make life take the lemons back!" -- Cave Johnson
Somewhat. Private key schemes are still secure.
The real power of quantum computing will be in factoring primes. Which most certainly will affect public key crypto, but public key was never the FULL solution. Like anything in crypto different problems have different solutions.
Public key crypto is great in the web age because you can use it for establishing connections, exchanging private keys, etc.
One of the first things you learn in any crypto grad class is that creating the crypto schemes is only part of the problem. Creating the usage scheme is the other. Most man in the middle and other such attacks can defeat the algorithms by which we use crypto far easier than we can defeat the encryption itself. (or just social engineer your way past it)
While it does suck a bit that the heyday of public key crypto might come to an end because of quantum computing, some other scheme will take its place. Perhaps someone will come up with a key gen scheme that doesn't rely on the difficulty of factoring large primes and instead some other mathematical relationship that quantum computing won't be able to stop.
Perhaps the optimal solution will be a mix. Perhaps each public key will in fact be 2 operations. One large prime factor to defeat traditional systems, combined with some as yet created scheme that stops quantum systems (but may be easy to beat on a tradition system).
As with all things, crypto will adapt. Perhaps one day we'll figure out a way using quantum mechanics to create true OTP encryption. Maybe 2 entangled particles or something (I know technically this is impossible, but just making the point maybe there's something we don't know yet that will help us in the future implement todays theoretically impossible/infeasible crypto)
What I want to know is... when do we get a quantum computer based on Quatloos?! And can you imagine a Beowu... never mind!
Bruce Lane, KC7GR,
Blue Feather Technologies
So that I can hook it up to my network, along with my phantom console. Does anyone know if it will play duke nukem forever? Its also awesome because i'll be getting my wimax connection any day now.
> Perhaps the optimal solution will be a mix. Perhaps each public key will in fact be 2 operations. One large prime factor to defeat traditional systems, combined with some as yet created scheme that stops quantum systems (but may be easy to beat on a tradition system).
So then the attacker uses a quantum system to get past part A, and a traditional system to get part B.
This is exactly the point of QKD; http://en.wikipedia.org/wiki/Quantum_cryptography
Does. . .not. . .compute. . .
What's a Qutrit?
(Emphasis added)
You might die tomorrow. Hurricanes might devastate the western world. Aliens might show up and blow the planet to bits for housing such a greedy, self-centred species. Any number of progressively unlikely things might happen.
There's no real substance to the rumours of encryption-defeating quantum computers - it's a hypothesis somebody proposed a few years ago, which has never been proved or disproved. We don't know anything about it yet.
As for quantum computing: don't get your hopes up. There's no proof of concept that shows that QC will ever scale up to practicality. Every 6 months someone announces a "breakthrough" and gains plenty of funding, but in the final analysis, nothing ever comes of it. I'm convince that there are some fundamental things that we don't understand here, and that all we're going to get out of QC is a better understanding of how to scale down existing computational engineering models (which is a good thing, but not the promise of QC).
Qutrits with optics is cool, but is the quantum computer just around the corner? Most definitely not! Optics are great for communicating quantum information, not so much for storing them. Quantum memory needs solid state technology, and while some promising results have been reported using diamonds by researchers at Harvard and other places, the quantum computer is still many many years, maybe even decades away. TFA is overhyped, as seems to be the case with all articles reporting quantum computing breakthroughs!
The limit for quantum computing is currently space, the number of qubits you can keep at the same time is still very limited and AFAIK current QCs don't have the space to store a 2048 bit key.
Justice is the sheep getting arrested while an impartial judge declares the vote void.
I'm a visionary!
3-State Bit
Asin trinary? 0, 1, dead cat?
www.isoHunt.com
Does this mean that quantum computing is just bring us back to analog computers?
(Actually, I guess, if my elliptical thinking here is anywhere close to meaningful, I guess the idea would be that a quantum processor would allow building complex reprogrammable filters (amplifiers) that don't require iterations. (Not talking about the simple analog filters, of course.)
My son seems enamored of analog computing these days. I remember when I was, as well. Maybe, the babbling above being completely wrong notwithstanding, it's a little early to dismiss analog computing as just a failed path in the problem tree.
I really wish I understood what I am not talking about.
Computer memory is just fancy paper, CPUs just fancy pens with fancy erasers; the 'net is just a fancy backyard fence.
Bah! Back when I was a kid we had only two logic states and we were happy to have them!