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Quantum Computing Breakthrough in Japan
An anonymous reader writes "A research team funded by NEC and RIKEN, Japan's Institute of Physical and Chemical Research, are the first to demonstrate a Controlled NOT (CNOT) quantum gate. The CNOT gate when coupled with a rotational gate would create a universal gate. The universal gate would be the basis for quantum computing. ETA for the first quantum computers: 10 to 100 years." When quantum computers first come to fruition, the best part will be reminiscing about how terrible computers were "back in the day."
But does it run Linux?
We are already hitting the limits of how much code can work together without being riddled by bugs. I think we need a advance in programming first.
Yeah but encryption will catch up just as fast. You can break codes from WW2 now with what? A 486DX and 15 seconds of CPU time? It's all relative. Besides, we should all be using OTPs anyway ;)
Maybe distributed.net will be able to finish the new RC5 contest now ;)
I want peace on earth and goodwill toward man.
We are the United States Government! We don't do that sort of thing.
I think that modern encryption schemes could be broken really quickly.
Imagine what kind of encryption you could do with quantum computing. When the first computers were built, most of the standard methods of encryption became obsolete -- ones that usually involved simple letter-substitution. That wasn't the end of encryption; those same computers enabled new ways to encrypt messages.
So it stands to reason that the existence of quantum computers would lead to new quantum encryption methods, which would take millions of years for the best quantum computers to crack using brute-force.
Is it just me, or in the last few years (as a result of AMD vs Intel perhaps?) that hardware has generally outpaced software.
Sure, a lot of us (myself included) want the "bleeding edge" system, but in reality, even my (now three year old) AMD 750 is still a decent enough system. Whereas I recall "back in the day" being worried about system requirements everytime I bought a piece of software -- only six or nine months after I bought my first PC (a 486DX-4 100).
Does anyone see software catching up (in the consumer market)? How long until we have an end-user quantum computer? And how hard will it be to defeat the built in DRM ;)
I want peace on earth and goodwill toward man.
We are the United States Government! We don't do that sort of thing.
What if we really achieve breakthrough and can really make usable quantum computers, while we still couldn't break through the math bottleneck, and all crypto suddenly become irrelevant?
Now we have a computer that can break all crypto, and we have no new crytpo algo that would make even a quantum computer crack for millions of years, would the governments in the world allow manufacturing of such a beast?
Has anyone ever implemented one for a VPN? I had considered writing a quick one, mainly for the time honored reason of "Because we can", but in all seriousness, with DVD-Rs why isn't this feasible (assuming you can make a safe exchange of the media). 4 gigs is a _lot_ of data (hell, even an old fashion CD-R at 700 megs is). You could even get further mileage out of it by compressing the data before you encrypted it. Creating the code itself is child's play -- that's the beauty of OTPs.
What's the best way of generating the random data you need in the first place? How random does it truly have to be? I read somewhere that the way the Government does it is to use radio noise. I've never heard a better way (though I hope RIAA doesn't found out ;) that would be as easy to implement.
I want peace on earth and goodwill toward man.
We are the United States Government! We don't do that sort of thing.
Raw clock cycle rate has surprisingly little to do with processor speed, unless you only ever talk about a single platform. A quantum computer is so different from a modern CPU as to make the comparison nonsensical.
It's a bit like asking "how fast would my car go if I doubled the gas tank size?"
Endless arguments over trivial contradictions in books written by ignorant savages to explain thunder in the dark.
I'm not so sure one time pads will hold up to quantum mathematics where state or position are the key elements.
as long as a solution exists. not matter how improbable, it can be arrived at, as the gates in superposition go through all the possibilities simultaneously.
so, to my admittedly limited understanding, where brute forcing means it's statistically likely you'll crack conventional encryption after a certain limited number of iterations, and a certainty once you exhaust all the possibilities, unless the chance of brute forcing an OTP is exactly infinite then it's still going to be a snap to a machine that evaluates all states simultaneously.
But i don't pretend to have a deep understanding of the field.
So I promise not to get upset if someone now brutally demolishes my thinking
'There is a Light that never goes out.'
This is not the first controlled not gate. Controlled not operations have been implemented in quantum optical systems for a few years now. The problem with quantum optics is that you cannot make the systems with lithography.
As they say in the article, it is the first controlled not quantum gate in a solid state device.
It is very important to make that distinction, since quantum optical systems have much less decoherence then solid state devices, which makes them a better candidate from a fundamental point of view. Combining that with the electronic-optical hybrid chip that was discussed in a posting here a few days ago, I think that you cannot rule out the possibility that quantum computers will be implemented in such hybrid systems as well.
In case anyone has doubts about this think of a simple illustration. Suppose my key is "1" - as in the number 1 - as in one bit long. My cipher method is to add the key bit to the ASCII code, wrapping around. Hello becomes Ifmmp. That would take somebody reading the sunday paper all of 5 minutes to crack. Just using it one time wouldn't help.
On the other hand, suppose my key is 1,2,3,4,5 - making the message "Hello" turn into "Igopt". Now let me brute-force that - let's try 25,6,22,1,6. Whoa - lucky guess, the message was "Jason"! Boy, we sure cracked that system!
The whole point with a OTP is that you can find a key that will yield ANY message - and there is no way to know if it is right or not!
And the algorithm isn't all that importang - the simple alphabet-shift cipher is just fine when using OTP - although XOR tends to be more popular since it is easier to apply/reverse (assuming you have a calculator).