4 ms·

If I was still a student, I would definitely go in quantum computing. So much opportunities for innovation on a very cool subject. I often wonder what will hap

by d0m 10y ago

If I was still a student, I would definitely go in quantum computing. So much opportunities for innovation on a very cool subject. I often wonder what will happen at the 0-day quantum machine where it's not just a few qbit but the real deal.. I think anyone in possession of such technology will be able to crack any SSL certificate, and thus gain access to almost anything online. I wonder if criminal organisations aren't secretly investing in such thing? And, not to be paranoid, but we're almost certain it will be possible to build them, wouldn't it be prudent to start investing in the defense against such things? What kind of security could we have to counter a quantum computing? Would it only be possible to use quantum computing to defend against quantum computing?

munin 10y ago
https://en.wikipedia.org/wiki/Post-quantum_cryptography https://en.wikipedia.org/wiki/Post-quantum_cryptography
dcosson 10y ago
> Would it only be possible to use quantum computing to defend against quantum computing? Not at all. As it is believed currently, there are a few problems (BQP space) such as the discreet logarithm that quantum computers can solve quickly. But lots of other hard problems, probably including all NP problems, cannot be solved exponentially faster by a quantum computer. See also http://security.stackexchange.com/questions/48022/what-kinds-of-encryption-are-not-breakable-via-quantum-computers http://security.stackexchange.com/questions/48022/what-kinds...
- ikeboy 10y ago
  You mean NP-complete, right?
  - PeCaN 10y ago
    No, he means all problems without a (known) polynomial time solution.
    - ikeboy 10y ago
      That's still not NP, that's NPI+NP-complete.
    - lorenzhs 10y ago
      As ikeboy implied, NP does not stand for non-polynomial, but for non-deterministic polynomial. Thus the open question whether the two are equal. In particular, it is clear that P is a subset of NP, as any problem that is polynomially computable with a deterministic machine is immediately also polynomially computable with a non-deterministic one by just not using the non-determinism
  - dcosson 10y ago
    Yeah, NP-complete.
digler999 10y ago
> If I was still a student, I would definitely go in quantum computing Timing the market would be hard. I remember seeing an article in 1999 talking about quantum computing, as if it were "just around the corner". Tons of advances have been made in the field since then, but we could still be 10-20 years out from QC being available/ubiquitous.
- marvy 10y ago
  20 years sounds optimistic for "ubiquitous". Consider: it took over a century to go from Maxwell's equations (1861 and 1862) to modern cell phones. It took over a century from the time that Babbage proposed his analytical engine to the first working general purpose computer. The dawn of quantum computing can be traced back to, maybe, at earliest, the early 1960s. (Based on cursory Wikipedia browsing.) It took several decades to get Shor's algorithm, which finally got people to take quantum computing seriously. If we have quantum computers comparable to ENIAC by 2060, I'll be pretty impressed.
  - davnicwil 10y ago
    I really don't want to just bang the 'exponential progress' drum but you're probably not accounting for it enough with these examples. The ubiquity of computers and phones isn't just a consequence of the theory underpinning them being developed into industrial applications, but of the myriad related ways that industrial engineering, society, and the economy had to develop to support and necessitate their existence. Those last two were indeed probably the most viscous factors in the way of technological progress, up to this point, more so than the science and engineering challenges involved, though they are clearly all interlinked. Now, however, it's probably the case that the scientific and engineering challenges are the biggest hurdles - we already have the society and economy hungry for more computing power. Assuming the necessary breakthroughs can be made to make quantum computing a reality in the next 10-15 years (obviously a big assumption, and not intending at all to sweep that aside, it could take decades, but just let's make that assumption) it's not at all difficult to see how it could rapidly find its way into production and then ubiquitous industrial application, and 20 years then does not sound outlandish at all.
Retra 10y ago
By "opportunities" do you mean "funding?"

by d0m 10y ago

munin 10y ago

https://en.wikipedia.org/wiki/Post-quantum_cryptography https://en.wikipedia.org/wiki/Post-quantum_cryptography

dcosson 10y ago

> Would it only be possible to use quantum computing to defend against quantum computing? Not at all. As it is believed currently, there are a few problems (BQP space) such as the discreet logarithm that quantum computers can solve quickly. But lots of other hard problems, probably including all NP problems, cannot be solved exponentially faster by a quantum computer. See also http://security.stackexchange.com/questions/48022/what-kinds-of-encryption-are-not-breakable-via-quantum-computers http://security.stackexchange.com/questions/48022/what-kinds...

ikeboy 10y ago
You mean NP-complete, right?
- PeCaN 10y ago
  No, he means all problems without a (known) polynomial time solution.
  - ikeboy 10y ago
    That's still not NP, that's NPI+NP-complete.
  - lorenzhs 10y ago
    As ikeboy implied, NP does not stand for non-polynomial, but for non-deterministic polynomial. Thus the open question whether the two are equal. In particular, it is clear that P is a subset of NP, as any problem that is polynomially computable with a deterministic machine is immediately also polynomially computable with a non-deterministic one by just not using the non-determinism
- dcosson 10y ago
  Yeah, NP-complete.

digler999 10y ago

> If I was still a student, I would definitely go in quantum computing Timing the market would be hard. I remember seeing an article in 1999 talking about quantum computing, as if it were "just around the corner". Tons of advances have been made in the field since then, but we could still be 10-20 years out from QC being available/ubiquitous.

marvy 10y ago
20 years sounds optimistic for "ubiquitous". Consider: it took over a century to go from Maxwell's equations (1861 and 1862) to modern cell phones. It took over a century from the time that Babbage proposed his analytical engine to the first working general purpose computer. The dawn of quantum computing can be traced back to, maybe, at earliest, the early 1960s. (Based on cursory Wikipedia browsing.) It took several decades to get Shor's algorithm, which finally got people to take quantum computing seriously. If we have quantum computers comparable to ENIAC by 2060, I'll be pretty impressed.
- davnicwil 10y ago
  I really don't want to just bang the 'exponential progress' drum but you're probably not accounting for it enough with these examples. The ubiquity of computers and phones isn't just a consequence of the theory underpinning them being developed into industrial applications, but of the myriad related ways that industrial engineering, society, and the economy had to develop to support and necessitate their existence. Those last two were indeed probably the most viscous factors in the way of technological progress, up to this point, more so than the science and engineering challenges involved, though they are clearly all interlinked. Now, however, it's probably the case that the scientific and engineering challenges are the biggest hurdles - we already have the society and economy hungry for more computing power. Assuming the necessary breakthroughs can be made to make quantum computing a reality in the next 10-15 years (obviously a big assumption, and not intending at all to sweep that aside, it could take decades, but just let's make that assumption) it's not at all difficult to see how it could rapidly find its way into production and then ubiquitous industrial application, and 20 years then does not sound outlandish at all.

Retra 10y ago

By "opportunities" do you mean "funding?"