Researchers Devise a Way To Generate Provably Random Numbers Using Quantum Mechanics (newatlas.com)

No random number generator you've ever used is truly, provably random. Until now, that is. Researchers have used an experiment developed to test quantum mechanics to generate demonstrably random numbers, which could come in handy for encryption. From a report: The method uses photons to generate a string of random ones and zeros, and leans on the laws of physics to prove that these strings are truly random, rather than merely posing as random. The researchers say their work could improve digital security and cryptography. The challenge for existing random number generators is not only creating truly random numbers, but proving that those numbers are random. "It's hard to guarantee that a given classical source is really unpredictable," says Peter Bierhorst, a mathematician at the National Institute of Standards and Technology (NIST), where this research took place. "Our quantum source and protocol is like a fail-safe. We're sure that no one can predict our numbers." For example, random number algorithms often rely on a source of data which may ultimately prove predictable, such as atmospheric noise. And however complex the algorithm, it's still applying consistent rules. Despite these potential imperfections, these methods are relied on in the day-to-day encryption of data. This team's method, however, makes use of the properties of quantum mechanics, or what Einstein described as "spooky action at a distance." Further reading: Wired, LiveScience, and CNET.

Comments

Woo Quantum, must be better...

[lurcher]

I would have thought thermal noise in a resistor or semiconductor (which is in itself generated by subatomic so quantum, events) would be just as random.

Re:Woo Quantum, must be better...

[Baloroth]

It is, and that's exactly how Intel's hardware-based random number generator in their CPUs works (so, yes, we have used a truly provably random source of RNGs... that is, if Intel is telling the truth about how it works). Another source of RNG is radioactive decay, though that's not terribly commonly used thanks to the hardware requirements. In this case, the article doesn't describe the source of randomess (aside from "correlations in superpositions", which could be anything from completely random to completely unrandom). It might not even be as random as they think it is (just being quantum is very much not enough), especially because they "improved their data" by only looking at sequences where the bits were almost perfectly uniformly 50/50 1 and 0, which is precisely not the right way to ensure good randomness: true random sequences usually don't obey uniformity, except in the limit as the length of the sequence goes to infinity, and requiring uniformity (or near-uniformity) in a "random" sequence reduces the entropy. That tells me they don't really understand randomness, which does not bode well for their claims.

Re:Woo Quantum, must be better...

[TechyImmigrant]

>It is, and that's exactly how Intel's hardware-based random number generator in their CPUs works

Indeed, it is. I happen to know this well because I'm one of the designers of it.

Quantum proven randomness is proven by showing a violation of Bell's theorem, showing a correlation that exceeds whats could be achieved by unentangled particles and therefore showing that they were a part of a random quantum process.

The form of every mathematical proof is of the form "If this is true, then [blah blah blah], so that it true".
The form of this particular proof is "If the rules of quantum physics are true, then [blah blah blah] so 'the output is random' is true".

Re:First post

[alvinrod]

In this case TFS seems to define provably random as that which cannot be predicted in advance given sufficient knowledge of how the number is generated and some initial conditions. Supposedly they have proven that this is the case, though I have not verified the correctness of their proof. However, this is really no different than other mathematical proofs. Either the proof is correct or it is not, but a lack of understanding of the proof does not change its correctness.

Re:Very Different from Maths Proof

[swillden]

Mathematical proofs are far more fundamental in that they are true regardless of the properties of the universe you happen to be in at the time.

This is deeply wrong.

Mathematical proofs are true if and only if the assumptions (axioms) on which they're based are true. When you apply mathematics to real things, you're making a critical unproven and unprovable assumption: That the mathematical structure maps perfectly onto the real-world structure. That this works quite well isn't surprising, because we work hard to craft mathematical structures that map as closely as we can, and because the universe appears to have consistent structure. That said, the fact that it has always worked well in no way proves that the mapping will always hold, and it says nothing about the "truth" of reality other than we observe that it consistently appears to behave according to a certain pattern.

The map is not the terrain. And when you posit a universe with a different properties (different terrain!) then there is no reason to expect the map even to be useful.