512-qubit Quantum Computer

[HappyBitCoinUser]

http://www.infowars.com/skynet-rising-google-acquires-512-qubit-quantum-computer-nsa-surveillance-to-be-turned-over-to-ai-machines/

Forget for a second that if you are mainstream, that you love Obama and Alex Jones / InfoWars.com is crazy.

So we have 512-qubit Quantum Computer now. After realizing how powerful that is, what affect would that have on BitCoin mining? Would this even make ASIC miners obsolete?

[ktttn]

Fuck Alex Jones.
Quantum encryption will come online before Quantum cracking becomes remotely viable.
SHA256 does not fear current quantum computers.
Edit: Sorry for knee jerk nonanswer.
Quantum computers are not as well suited to btc hashing due to difficulty increases.
http://bitcoin.stackexchange.com/questions/6062/what-effects-would-a-scalable-quantum-computer-have-on-bitcoin
http://cs.stackexchange.com/questions/586/could-quantum-computing-eventually-be-used-to-make-modern-day-hashing-trivial-to

[ElectricMucus]

Alex Jones / InfoWars.com is crazy.

Bullshit!

[ElectricMucus]

A QC is either useless for hashing (if it is too small) or can determine the right nonce for any hash (if it is large enough).
There might be some indeterminate use but since it makes difficulty increases a linear problem out of an exponential one once it is useful it would make difficulty useless soon after.

[HappyBitCoinUser]

Alex Jones / InfoWars.com is crazy.

Bullshit!

Great, take Alex Jones out of context and make a lol video.

Ok back on topic, what affect would this new computer have on mining?

[HappyBitCoinUser]

A QC is either useless for hashing (if it is too small) or can determine the right nonce for any hash (if it is large enough).
There might be some indeterminate use but since it makes difficulty increases a linear problem out of an exponential one once it is useful it would make difficulty useless soon after.

Try to explain in plain English for those of us still thumbing through Win95 for Dummies.

[ElectricMucus]

A QC is either useless for hashing (if it is too small) or can determine the right nonce for any hash (if it is large enough).
There might be some indeterminate use but since it makes difficulty increases a linear problem out of an exponential one once it is useful it would make difficulty useless soon after.

Try to explain in plain English for those of us still thumbing through Win95 for Dummies.

Well with traditional computers you would count this way to 1000:
1, 2, 4, 5, ... , 996, 997, 998, 999, 1000

With a quantum computer you would do

(1-9), (10-99), (100-999), 1000

(It's not exactly right since it is bits vs. qbits and I used the decimal system for the example but in principle.)

[moocowpong1]

Quantum computers don't just turn exponential time into linear time. There are certain problems where they're known to be able to do that, but there are a lot of problems where that's not known. Finding a suitable nonce is a lot like reverse phonebook search, and Grover's algorithm operates in order sqrt(N) guesses, instead of the classical N guesses. Assuming this is in fact the best way to use a quantum computer for mining, this has a curious effect. It means that if the difficulty quadrupled, it would take only twice as long to find a suitable nonce – which is effectively twice the hashpower, but still finding blocks slower. The effective hashpower of a quantum computer increases with increasing difficulty, but it still falls behind. The difficulty would still be able to increase to keep up with hashpower, so there's no existential threat to Bitcoin mining.

[johnyj]

Pre-order Quavalon mining rig that do 1PH/s on USB power  

It's time to collect interests for a Quantum mining rig project

[ElectricMucus]

Finding a suitable nonce is a lot like reverse phonebook search, and Grover's algorithm operates in order sqrt(N) guesses, instead of the classical N guesses. Assuming this is in fact the best way to use a quantum computer for mining, this has a curious effect. It means that if the difficulty quadrupled, it would take only twice as long to find a suitable nonce

Doubt it.
How I understand QC its just a matter of what kind of tradeoff you have to take to solve a problem with a computer of a particular size. And if you can even make such a trade-off (currently we can not)
As quantum computers get larger the trade-off can be reduced to the point where it is none existent.

[Kluge]

A QC is either useless for hashing (if it is too small) or can determine the right nonce for any hash (if it is large enough).
There might be some indeterminate use but since it makes difficulty increases a linear problem out of an exponential one once it is useful it would make difficulty useless soon after.

Try to explain in plain English for those of us still thumbing through Win95 for Dummies.

Well with traditional computers you would count this way to 1000:
1, 2, 4, 5, ... , 996, 997, 998, 999, 1000

With a quantum computer you would do

(1-9), (10-99), (100-999), 1000

(It's not exactly right since it is bits vs. qbits and I used the decimal system for the example but in principle.)

Is there a good resource for the totally uninformed pointing out why this is superior to binary calculations, or what the benefits and drawbacks are in using qubits?

When I try to learn about it, I either get


which I completely lack foundational knowledge to understand,

or

"It grabs answers from another dimension."

[ElectricMucus]

"It grabs answers from another dimension."

I think that is as good an explanation as any. But I'm no a physicist.
What works for me is thinking of a quantum computer as an analogue computer with infinite signal/noise ratio.

[notme]

"It grabs answers from another dimension."

I think that is as good an explanation as any. But I'm no a physicist.
What works for me is thinking of a quantum computer as an analogue computer with infinite signal/noise ratio.

Can you give some simple examples of algorithms for quantum computers?  What kinds of questions can I ask this magic ball?

[ElectricMucus]

"It grabs answers from another dimension."

I think that is as good an explanation as any. But I'm no a physicist.
What works for me is thinking of a quantum computer as an analogue computer with infinite signal/noise ratio.

Can you give some simple examples of algorithms for quantum computers?  What kinds of questions can I ask this magic ball?

Sorry I can't.

[notme]

Can I ask it 1 + 2?

[johnyj]

In my understanding, Quantum computer might not be suitable to do general purpose computing but it is very suitable to solve one specific problem, that's exactly what bitcoin mining requires, to find a correct nonce that match certain criteria

Move the hashing function in ASICs into a Quantum computer and you will reduce the hash time for several magnitudes (And increase the difficulty to same degree )

There will be some companies provide ASIC to Quantum chips conversion in future, and I don't think there will be much difference, the functional design is the same, and the underlying implementation is invisible

In principle, the first Quantum miner will immediately command 99.99% of the network hashing power, this is very dangerous so better we have several loyal bitcoin hardware companies start to deploy those miners at the same time

[favelle75]

But can it play Crysis?

[Odalv]

"It grabs answers from another dimension."

I think that is as good an explanation as any. But I'm no a physicist.
What works for me is thinking of a quantum computer as an analogue computer with infinite signal/noise ratio.

Can you give some simple examples of algorithms for quantum computers?  What kinds of questions can I ask this magic ball?

Look like this magic ball can be able to answer question  "Here is public key. What is PRIVATE one ?"

[Kluge]

I guess I'm just missing where a superposition would be useful. Why would I want 0, 1, AND 2? How does "both" make for more efficient code, and why wouldn't it be incorporated in instruction sets where it could be useful in general purpose? I guess just a sample of simple instructions, like maybe for an adder, and how it would look, mechanically, in binary logic and quantum - would help.

Right now, I'm thinking of a truth table with "AND" in it, and now there's "yes," "no," and the useless (or I'm just unimaginative) "both." Do there need to be new operators to work with "both," or does "both" just replace "AND" to simplify?

Edit: Or maybe it doesn't log a "2" (some potential state between 0 and 1) but is instead a whole slew of possibilities between 0 and 1? - But it has to compute the probabilities, right? Dammit. Now I need this to click.

Okay, so what exactly's happening here -- something's trying to record the probability of something being on or off, because we can't measure it in certain cases with certain materials. How can it do this without tons of calculations going into determining whether something's "on" or "off" - how could something possibly measure that?

[dexX7]

This thing is not a quantum computer, but a computer which uses quantum effects for faster problem solving and has significant differences.

http://arstechnica.com/science/2013/05/d-waves-quantum-optimizer-pitted-against-traditional-computers/

I'm not sure, what the implications are, though.