Quantum Computing Closer Than You Think

[Skami Pilno]

Step inside D-Wave's ground-floor office suite and you're greeted by bland meeting rooms, offices, and cubicles. But open the correct door off the main corridor and you emerge into a bright white lab space dominated by four black monoliths—D-Wave's computers. Roughly cube-shaped, and around 10 feet tall, they emit a rhythmic, high-pitched sound as supercooled gases circulate inside. Each of the machines has a door on the side and is mostly empty, with what looks like a ray gun descending from the ceiling, a widely spaced stack of five metal discs of decreasing size held together with cables, struts, and pipes plated with gold and copper. It is actually a cold gun: the structure is a chilly -259 °F (4 °Kelvin) at the wide end and a few thousandths of a degree above absolute zero at its tip, where D-Wave's inch-square chip can be found. Not even the deepest reaches of space are this cold, or so shielded from magnetic fields as this chip, which is etched at a plant in Silicon Valley from a niobium alloy that becomes superconducting at ultralow temperatures.

The processor in every computer you've used is made from silicon and patterned with transistors that create logic gates—switches that are either on (represented by a 1 in the computer's programming) or off (a 0). D-Wave's processors are also made up of elements that switch between 1 and 0, but they are loops of niobium alloy—there are 512 of them in the newest processor. These loops are known as qubits and can trap electrical current, which circles inside the loops either clockwise (signified by a 0) or counterclockwise (1). Smaller superconducting loops called couplers link the qubits so they can interact and even influence one another to flip between 1 and 0.

http://www.technologyreview.com/news...tum-computing/

[Riverdance]

It looks pretty cool but it sounds like they haven't actually proven much yet, like whether it's actually quantum, and even if it is, whether it's any faster than a normal computer. Do you know more about this? I don't actually know much about computing. (Except in reference to how the human brain works. I do know some stuff about that, but it's not very relevant.)

[Skami Pilno]

The D-Wave claim is interesting. There's a lot to understand about it, so I'll try to do a quick run through. The D-Wave processor has been shown to be incredibly fast and accurate, through repeated observation. However, the D-Wave processor is not a general purpose processor, but is one that is designed to handle a very specific type of problem. The concern that many have over the technology is that it is not true quantum technology, but merely a weird, highly specialized processor.

Now for just a bit of history breakdown. D-Wave originally made the claim to have a quantum processor back in 2007. The scant bit of math they released didn't quite add up and they were largely criticized by the community of professionals. However, that was not enough to deter investors. in 2012 they have released more information on their improved design. The new information is not enough to prove that it is a true quantum processor, but it does point in that direction. Many are still concerned that it is not a real quantum processor as D-Wave has yet to release proof of quantum entanglement within the processor.

The issue is further complicated by the value of information regarding the processor: the more information they release, the more likely that someone else may be able to reconstruct their work or create a competing product. So you now have a group of professionals asking for proof, and a company that seems to barely understand what's happening in the processor at all, but they can't provide too much information in case it would hurt their market standing.

It's an interesting situation, but if you look at who the big investors are, it seems like this is either legit, or the closest thing in existence right now. Even Google has purchased the use of this chip and has been frequently sending it problems to solve.

This is very exciting because for the last decade or two quantum processors have been 10 years in the future, and for the previous few decades they were always 15 or 20 years in the future, but now, now they may actually be 10 years in the future.

If you read this and you think "Quantum computing = faster computers" you are quite wrong. Quantum computing will not just be an upgrade in speed, but in capability of computers, moving them forward by light years. Calculations that would have taken thousand upon thousands of years to solve with today's supercomputers can be solved with a quantum computer instantly. If that doesn't either terrify you or fill you with hope, you have either no fear or no understanding.

Just for fun, here's some articles about it ( nothing heavy or scientific): 1, 2

[EDIT]
But perhaps you wanted to know how quantum computing works. Here is a good thread that discusses quantum computing a non-mathematical level.

[Coidzor]

Don't the horrible, horrible security problems of quantum computers outweigh the projected benefits still at this point or have they started making progress on some kind of security protocol that isn't a complete joke?

[tyckspoon]

Originally Posted by Coidzor

Don't the horrible, horrible security problems of quantum computers outweigh the projected benefits still at this point or have they started making progress on some kind of security protocol that isn't a complete joke?

I would imagine security on the first actual quantum computers would be primarily physical, with access controls on who gets to use it and what they're allowed to put in it. I would not expect it to have any sort of outside access connection such that poor or non-existent system security would even be a potential avenue of attack.

Edit: That or the quantum computer would be behind a security layer of established traditional computer security.

[Flickerdart]

Does people not being able to know whether or not it's a quantum computer make it a quantum computer?

[Skami Pilno]

Originally Posted by Coidzor

Don't the horrible, horrible security problems of quantum computers outweigh the projected benefits still at this point or have they started making progress on some kind of security protocol that isn't a complete joke?

This is the area of quantum computing with which I am much more familiarized. Yes, quantum computing will break most modern encryption creating absolute catastrophe in the world of cyber-security and, consequentially the financial sector. At least, this is true if quantum computing appears out of nowhere and proliferates at unprecedented speed. As it stands, quantum computing resistant algorithms are being developed and will most likely be ready for incorporation by the time quantum computing becomes a significant threat. The only remaining issue is how quick will companies be to guard against their new vulnerabilities? History shows us the answer is "not very." Quantum computing will require the re-issuing of all credit cards and many internal financial systems used by banks among other financial institutions. In short, the extent of the disaster is exactly, directly proportional to how slow major financial institutions are to change their algorithms and existing software/hardware. It will be bad, but the potential of quantum computing to advance research in many fields (not the least of which are physics and chemistry) by leaps and bounds far outweighs the disaster that financial institutions will bring by being slow to update their systems.

[EDIT]
@flickerdart: lol

[Heliomance]

Originally Posted by tyckspoon

I would imagine security on the first actual quantum computers would be primarily physical, with access controls on who gets to use it and what they're allowed to put in it. I would not expect it to have any sort of outside access connection such that poor or non-existent system security would even be a potential avenue of attack.

Edit: That or the quantum computer would be behind a security layer of established traditional computer security.

Not the point. The point is that quantum computing immediately and utterly obsoletes all current cryptography methods. Against a quantum computer, the encryption keeping, eg, your bank details secure might as well not exist.

[leafman]

I would think how well a quantum computer can decrypt current security algorithms really only is a concern when they aren't super expensive chips in 10ft supercooled cubes anymore. Even if the chip itself becomes easy/cheap to produce, I bet the cooling system is what will restrict this to being accessible only in research facilities for a long time to come.

[Taliesin]

Originally Posted by Heliomance

Not the point. The point is that quantum computing immediately and utterly obsoletes all current cryptography methods. Against a quantum computer, the encryption keeping, eg, your bank details secure might as well not exist.

Not quite true. It is true that factoring (a thing generally hard on classical computers) can be done fast via Shor's algorithm - they are even making scary progress, I heard that recently they managed to factor a number as large as 15 (correct in 48% of the cases! link to article). It is big, I know, but maybe it can be achieved somehow without quantum computing too.

Second, not all cryptographic systems are known to be weak against quantum algorithms. Generally, as my quantum crypto professor told me, cryptosystems based on groups and their properties e.g. discrete logarithm tend to be vulnerable to quantum algorithms.And groups are really popular in modern crypto. However, lattice-based crypto has not shown any weakness yet. True, lattice-based crypto is in baby-shoes and is rather complex but it is also rather in vogue at the moment. So, quantum computers might break the crypto-systems that are currently used, but it doesn't mean that when they arrive, we will be completely powerless because maybe we will have worked out, for example, lattice-based crypto (it's good for other stuff too! can be fully homomorphic! (which means that you can essentially cipher your data, for example two numbers, you give it to an untrusted party who computes on it , gives the resulting ciphertext back to you, you decrypt it, and voila! - you have the sum of your two numbers in our example- fully homomorphic means that you can both add and multiply))


Third, I am not sure about how fast the efficiency of quantum computing grows. If it is slow there is no significant threat since we can just increase our security parameters so that it would be enough.

Fourth, there is such a thing called quantum cryptography, which use the properties of quantum mechanics (namely - you can't observe stuff without altering it) to do crypto stuff).

Fifth, while the leap down from exponential time to polynomial time is a really fundamental thing, it does not automatically mean that stuff can be solved polynomial time is not secure. Shors algorithm takes cubic time in input length as bits - so, if you want to factor a number that consists of a million bits, then it takes about 10**18 "time" on a quantum computer- and if they grow slowly, then it is probably infeasible.

[GnomeFighter]

Originally Posted by Skami Pilno

The only remaining issue is how quick will companies be to guard against their new vulnerabilities? History shows us the answer is "not very." Quantum computing will require the re-issuing of all credit cards and many internal financial systems used by banks among other financial institutions.

Don't forget with financial institutions they are very very good at using tech when they need to, they are just very poor at updateing stuff they think works.

Take a look at the stock markets and banks. Your local banks infrastructure is probably creaking with age because the bank thinks "well it works". Then take a look at stock exchanges. The computers they use are really cutting edge stuff. They pay vast sums of money to get there servers a few feet closer to the exchanges servers, because the slight difference in delay due to longer cables matters to them. The programing they use on there trading software is really efficient stuff. They just need to have a good business case for spending the cash.