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Quantum Random Numbers

Soulskill posted about 2 years ago | from the randomly-kills-cats dept.

Math 167

tqft writes "What the world needs is more truly random sources of numbers. Researchers from Australian National University have found a brilliant way to make one: 'We do this by splitting a beam of light into two beams and then measuring the power in each beam. Because light is quantised, the light intensity in each beam fluctuates about the mean. Those fluctuations, due ultimately to the quantum vacuum, can be converted into a source of random numbers. Every number is randomly generated in real time and cannot be predicted beforehand.' So if you need some really random numbers, just use their generator service."

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dead link (0)

Anonymous Coward | about 2 years ago | (#39673549) []

503 error!

Re:dead link (2)

game kid (805301) | about 2 years ago | (#39673675)

The site and its images randomly (appropriately enough) bobble between working and 503 at the moment. Not quite down, but taking heavy fire.

Re:dead link (2)

dna_(c)(tm)(r) (618003) | about 2 years ago | (#39674109)

The site and its images randomly (appropriately enough) bobble between working and 503 at the moment. Not quite down, but taking heavy fire.

Probably the cleaning lady using the left beam of light to read the instructions on the detergent bottle, thereby generating a whole string of identical 503 numbers.

Will last (0)

Anonymous Coward | about 2 years ago | (#39673559)

Until we can calculate the wave, its the wave not the particle that makes the pseudo quantum state.

Generator Service down (1)

Anonymous Coward | about 2 years ago | (#39673575)

That seems pretty random after a /. post

well that was quick (0)

Anonymous Coward | about 2 years ago | (#39673587)

3mins and the site dies...

site is slashdotted..so... (3, Funny)

Anonymous Coward | about 2 years ago | (#39673589)

..feel free to use these...

1 1 1 1 1 1 1 1 1 1 1 1

Re:site is slashdotted..so... (4, Funny)

Anonymous Coward | about 2 years ago | (#39673735)

I'll only use them if you can assure me that they were chosen by fair dice roll..

Re:site is slashdotted..so... (0)

Anonymous Coward | about 2 years ago | (#39674069)

I'll only use them if you can assure me that they were chosen by fair dice roll..

[citation provided [thedailywtf.com]]

of course (1)

Anonymous Coward | about 2 years ago | (#39673591)

Random numbers are not useful in programs that need repeatable results

Re:of course (0)

Anonymous Coward | about 2 years ago | (#39673653)

I had a random component to all my calculations

x = x +1 + 0 * rand()

Re:of course (1)

game kid (805301) | about 2 years ago | (#39673765)

The big problem with a true RNG is that you can't really "seed" a given sequence of random numbers—unless you or the server pre-record a block of them and choose that block, you'll almost certainly get a whole new one.

If you do want a whole new block, of course, this is a wish-come-true.

Re:of course (1)

Opportunist (166417) | about 2 years ago | (#39674465)

As hard as it may be to believe with someone who grew up with Windows, it is terribly hard with normal computers to generate true randomness. These machines WILL always generate the same output for the same input (again, can the bad Windows jokes). Normal pseudo-random generators usually use something like the clock cycles since turn-on as a seed to generate numbers that seem random, but if you somehow start the program exactly after the same amount of cycles you get exactly the same "random" numbers.

I studied statistics. A whole semester was pretty much "wasted" on the question how to get good randomized sample sets (e.g. to compare your result with the expected result from a certain distribution system to prove that reality follows it). It is insanely complicated and I guess it doesn't really belong here now just what hoops we tried to jump through. In that light, this could well be a breakthrough for statistics. Or any science that relies heavily on "real" random numbers.

I still claim, though, that any source of "good" static noise can serve as a seed for a random generator. I created a random number generator using the static noise from radio, tuned to an "empty" channel. The problem here is to make sure that you're really using a channel where nobody sends any signal, or at least that any signal is drowned out in white noise.

Service Temporarily Unavailable (0)

Anonymous Coward | about 2 years ago | (#39673623)

What a jip!

Re:Service Temporarily Unavailable (1)

Anonymous Coward | about 2 years ago | (#39673761)

The term is 'gyp' as in 'gypsy' as in 'That dirty gypsy ripped me off again. What a gyp!'

Re:Service Temporarily Unavailable (0)

Anonymous Coward | about 2 years ago | (#39673773)

That's "gyp". As in "gypsy".

There's no such thing as random (4, Interesting)

ShieldW0lf (601553) | about 2 years ago | (#39673633)

The quest to find random numbers is the quest to entangle our locality to ever more distantly related things in weirder and weirder ways... which, if you ask me, is far more interesting to think about.

Re:There's no such thing as random (0)

Anonymous Coward | about 2 years ago | (#39673787)

This is fundamentally wrong. Quantum systems are things that are actually random. True randomness does exist in QM and comes into play with the collapse of the wavefunction.

Re:There's no such thing as random (1)

Impy the Impiuos Imp (442658) | about 2 years ago | (#39673965)

This itself may be fundamentally wrong. QM could itself be built on a deterministic substrait, but that would be an even greater violation of Einstein's concept of reality, AKA there exist real objects out there with real, measurable properties. Basically our reality would be pushed off two levels deeper to below QM, rather than just one, to QM.

Re:There's no such thing as random (1)

TexVex (669445) | about 2 years ago | (#39674031)

Determinism is one way to explain so-called spooky action at a distance without using hidden variables or violation of causality.

Re:There's no such thing as random (4, Interesting)

Anonymous Coward | about 2 years ago | (#39673981)

There is no such thing is the "collapse" of the wavefunction. The observer just gets entangled with the experiment.

Re:There's no such thing as random (4, Interesting)

Anonymous Coward | about 2 years ago | (#39673991)

Well, not so fast...

The modern view of quantum mechanics is that the wavefunction never collapses. This isn't purely a matter interpretation (as many people claim): theoretical work over the last ~20 years on decoherence [wikipedia.org] has shown that you can explain everything in QM with a deterministic wavefunction and no ad-hoc collapse axiom. Experimental work has been demonstrating quantum superposition of ever-large systems: there is no experimental evidence for collapse, which suggests that arbitrary large systems (cats, people, galaxies, the entire universe) can be in superpositions. Of course, when you're 'inside' a superposition, you cannot get information from the other branches. Thus the simplest available theory that fits experimental data is consistent with the Everett ('many-worlds') interpretation [wikipedia.org].

In this paradigm, the evolution of the total wavefunction is deterministic and there is no global randomness. There is randomness at the level of the individual observer, since they lack the information/correlations necessary to probe other branches of the wavefunction. Whether or not you consider this 'true randomness' or just 'ignorance randomness' is as much a definitional and philosophical question as anything.

Re:There's no such thing as random (0)

Anonymous Coward | about 2 years ago | (#39674149)

I don't quite buy it. This reminds me of the creationist's "entropy on Earth" argument, where they argue that since entropy can only go one way and life seems to be going the other then something must have input something into life. They say that something was a God. The truth is that, yes, there is something putting energy into life, that something is called the Sun - and is outside this world.

Here the people who interprets QM, beause they're scientists and can't blame things on a God, are simply saying that there's nothing behind it, it's truly random. But just like the Sun is outside the Earth, the source of that randomness may simply be outside the Universe. QM only says the randomness can't come from within the Universe (without violating some principle).

Just because there's no way for us to use science to prove/disprove it doesn't mean it can't be true - technically there's nothing preventing the whole thing from being a computer simulation somewhere.

Re:There's no such thing as random (2)

ShieldW0lf (601553) | about 2 years ago | (#39676241)

The fact that there was a singularity in the first place makes it pretty obvious that entropy does not only go one way. Abiogenesis will eventually be accepted as fact, and this will provide strong evidence that the "heat death of the universe" hypothesis is wrong.

I wrote a rambling essay that I think relates and threw it in my journal for the trolls to rip apart... maybe it will provoke something.

http://slashdot.org/journal/281071 [slashdot.org]

Re:There's no such thing as random (1)

kipsate (314423) | about 2 years ago | (#39675543)

Indeed, and it would be even more interesting to see in how far the randomness of these numbers holds up when tested to extremes. It would be a huge result if these numbers can not be tested to be 100% pure random.

Re:There's no such thing as random (2)

Surt (22457) | about 2 years ago | (#39675675)

There's no proof of that. That's a commonly held belief, but that doesn't make it true. The bottom line is that we don't know whether there is any randomness in the universe, and there is certainly considerable evidence that there might be.

So much for random (2)

bulldog060 (992160) | about 2 years ago | (#39673649)

Just keeps spitting out 503 ... >.>

Re:So much for random (1)

residieu (577863) | about 2 years ago | (#39673685)

doesn't mean it's not random.

Re:So much for random (1)

Anonymous Coward | about 2 years ago | (#39673799)

Re:So much for random (0)

tom17 (659054) | about 2 years ago | (#39674051)

You spelled XKCD wrong, and the number was wrong too.

http://xkcd.com/221/ [xkcd.com]

I know, I know, the one predates the other. So what!

No thanks (5, Funny)

Anonymous Coward | about 2 years ago | (#39673661)

The generation of random numbers is too important to be left to chance.
- Robert R. Coveyou, Oak Ridge National Laboratory

Re:No thanks (1)

Darth Snowshoe (1434515) | about 2 years ago | (#39673695)

This. Why, if you really needed actual random numbers, would you leave the generation of them to someone else?

Re:No thanks (0)

Anonymous Coward | about 2 years ago | (#39673763)

If you want random, why not? Ask a dog. A person on the street. Your dead uncle.

Quantum (0)

Anonymous Coward | about 2 years ago | (#39673753)

Does anything with the word 'quantum' gets published on slashdot?

Re:Quantum (3, Informative)

jawtheshark (198669) | about 2 years ago | (#39673867)

In this case, it doesn't matter. Random number generation is in itself interesting and a very important part of computer science... or better said, the problem that with a finite state machine, like a computer, we cannot generate truly random numbers. Computers can generate pseudorandom numbers, but they are only random within the constraints set, are repeatable and will have a periodicity. Getting "true" random numbers only is possible from physical processes.

There have been several articles about random number generation on slashdot. On the top of my head, random numbers generated from a lava lamp, or from a CCD with a (disassembled?) smoke detector (which contains Americum, a radioactive element). Let's just say that random numbers are interesting unto themselves. That's they're generated by quantum fluctuations is just an added bonus.

Win - Win (0)

Anonymous Coward | about 2 years ago | (#39673759)

Maybe they could pipe these random numbers to US cloud storage providers. Problem solved.

Raas!? (2, Insightful)

turbidostato (878842) | about 2 years ago | (#39673779)

Randomness as a Service?

I don't know if out will work, but I know it certainly shouldn't.

In two words: MiM attack.

Re:Raas!? (0)

Anonymous Coward | about 2 years ago | (#39673871)

One acronym: SSL.

Re:Raas!? (0)

Anonymous Coward | about 2 years ago | (#39673949)

SSL handshake requires a random nonce. Anything you transmit over SSL can only be as secure as the nonce you started off with. Hence, any random data you get from this site can only be at most as secure as whatever source of randomness you had before you connected, making the whole thing pretty useless from a security standpoint! Really randomness is only good when it's generated locally.

Re:Raas!? (0)

Anonymous Coward | about 2 years ago | (#39674019)

Except you could bootstrap a small amount of local randomness into a larger amount of randomness. There are already cryptographic tools to do this i.e. leftover hash lemma, but this is another option. Said lemma also allows for the input randomness to be public (known to the adversary) while still retaining full security, so this service could spit out signed randomness and it would work great. However, there is already a service by NIST that is doing this and they have a lot more resources so the only novelty in this approach is the method they use to generate entropy.

Re:Raas!? (0)

Anonymous Coward | about 2 years ago | (#39674135)

You might have a good source of randomness which just produces very little data (say, one bit per minute or so). In that case, it would be worthwhile to use that source to get your initial random data for the SSL connection to the service delivering random numbers at a much higher rate.

However this doesn't save you from the possibility that the generating party might be compromised. After all, who tells you that nobody had introduced some trojan on their system which reads all the bits sent to you and sends them to the attacker as well?

Re:Raas!? (3, Insightful)

rapidmax (707233) | about 2 years ago | (#39674059)

The random service alone as cryptographic source raises questions about thrust. But if you use it as an additional source to mix into you entropy pool, it won't hurt and probably improve the quality and data rate of your random source.


actually, I'm NOT referring to /b/ (1)

Thud457 (234763) | about 2 years ago | (#39674119)

That's a fine idea, until you get sued [google.com] because the "random" numbers you're providing turn out to be inadequately random.

503 (0)

Anonymous Coward | about 2 years ago | (#39673791)

It is only generating the number 503, not that random.

Memory quota warning (1)

Anonymous Coward | about 2 years ago | (#39673911)

If you guys keep entangling shit in there, the simulator will run out of memory.

Is that what you want?

Radioactive decay (3, Interesting)

mbone (558574) | about 2 years ago | (#39673943)

This was done using radioactive decay to generate random numbers (i.e., something like counting geiger counter clicks), I believe first in the 1950's.

I also seem to remember that the first units weren't entirely random, due to dead times in the counters or something similar. Random in theory does not mean random in practice, and I am not sure I would trust a billion dollar deal relying on a one-time-pad generated by the ANU quantum random number generator, at least until it had been through a lot of testing.

Re:Radioactive decay (2)

rapidmax (707233) | about 2 years ago | (#39674279)

I also seem to remember that the first units weren't entirely random, due to dead times in the counters or something similar. Random in theory does not mean random in practice, and I am not sure I would trust a billion dollar deal relying on a one-time-pad generated by the ANU quantum random number generator, at least until it had been through a lot of testing.

Having build my own random generator I can confirm this discrepancy between theory and practice. You have to be very cautious to eliminate externals noise and oscillation of the random source. As it's not possible to measure the true randomness but only guess it, additional filtering like bias elimination and mixing may improve the entropy, but may be still not true random.

Re:Radioactive decay (0)

Anonymous Coward | about 2 years ago | (#39674353)

And I can't tell how either are better than the antenna model of randum number generation. Stick an antenna on an input line, no filter, just pick an arbitrary way of reading the clutterred static of the entire spectrum that the antenna can recieve.
Sure, a problematic third party can theoretically blast the area with an oppressive known signal, but proper antenna choice can make sure that such an activity would be very obvious and grounds for switching back to classic psuedo-randoms until the kill-team gets to the jammer.

I Just Do This (0)

Anonymous Coward | about 2 years ago | (#39673957)

int rand = 4; // Guaranteed to be random.

For sale cheap - used random numbers (0)

Anonymous Coward | about 2 years ago | (#39674035)

Random numbers. You know what the series is. Are they still random? What if the only difference is whether you know the series or not. Does that change the randomness of the numbers?

My brain hurts.

Don't think so (0)

Anonymous Coward | about 2 years ago | (#39674045)

They're not truly random unless inifinitely long numbers can be returned.

If 2^129929120912238723948732984732897439287^2938923982 is just as likely to be returned as 42, then maybe.

Re:Don't think so (1)

Surt (22457) | about 2 years ago | (#39675857)

That's incorrect. For true randomness, it need only be possible (and equally probable), that the prior number can be generated as a series of smaller numbers glued together, as that 424242424242..... (a string of equal length) would be generated.

A cheap non-quantum option (2)

wonkey_monkey (2592601) | about 2 years ago | (#39674227)

When I needed some very random numbers, I read the low bit of samples from my soundcard without a source connected. Connecting a mic may have better, to use ambient rather than electrical noise, but it worked well for me, and always had a "fair" average (but that was the only criteria I knew how to test). I'd be interested to hear what's wrong with doing it that way from those more knowledgeable than myself.

Re:A cheap non-quantum option (0)

Anonymous Coward | about 2 years ago | (#39675549)

Connecting a mic may have better

No, ambient acoustic noise is way less random than electrical noise, which is pretty much thermal, though in the case of the soundcard it may be mixed with repetitive electrical interference.

Re:A cheap non-quantum option (4, Informative)

canajin56 (660655) | about 2 years ago | (#39675891)

How "very random" do you need, that a Mersenne Twister is not good enough, but an untested signal is? And if you only looked at the 1 bit word mean, you basically didn't test it at all. If you don't care about specifics, you can just use the Testu01 [umontreal.ca] suite of tests. If you care about specifics and want to do your own tests...you should do the same bias test for various word lengths. So besides making sure the 0 and 1 appear about 50% of the time, you should make sure that 00,01,10,11 appear about 25% of the time, 000,001,etc are all uniform for 3 bit words, and so on until at least several hundred bit words (yes, it will take you a long time to sample enough words!) Besides those simple "fair dice" tests, you can also pick a dimension, (2 or more) and sample a lot of points (using whatever bit words you like) and then find the minimum distance between two points. With repeated tests this minumum distance should follow an exponential distribution, with the parameters describing that distribution depending on the range of possible values and the number of dimensions. Similarly, if you treat your n bit words as floats from [0,1) (by dividing by 2^n), then sampling a large number and adding them together should get you a normal variable, where the mu and sigma depend on n and how many you are adding together. There's also a 'pigeon hole' test where you have 2^n bins and sample n bit words and put them in the bin, and then take the maximum occupancy. Again, statistically this value should have a known distribution and you can test against that. A related one is called a "parking lot" test, where you sample in 2 dimensions and treat points as circles of some radius, and you only place a circle if it doesn't overlap with other circles already placed. After 10,000 samples you should have less than 10,000 placed, and the number you actually placed should be normally distributed, with the mu and sigma depending on the size of the lot, the number of attempts, and the radius of the circles used. There are plenty of such tests. They all revolve around using your generator to simulate a simple statistical system where the distribution of the result is known by you, so you can see how consistent your repeated simulations are with the expected distribution. A 1-bit mean test is just simulating coin tosses, while a 2-bit mean test is simulating 4 sided die tosses, etc.

But a Mersenne Twister does quite well on Testu01, so you have to ask yourself why a software generator can't possibly be sufficient.

As for the mechanical "what's wrong" side of things, if you don't know the physical mechanism, you can't know what conditions are required for your tests to remain valid. Where is the line noise coming from? Just noise from the physical components, or is there a radio wave factor? Will a new tower broadcasting alter the behavior of the noise in a meaningful way? What about wifi devices? I know of sound cards that pick up the signal sent when a cellphone rings so you can tell moments before it actually rings. (You can get a TARDIS for your keychain that lights up when a nearby cellphone is being rung, which works by the same mechanism but on purpose).

Twitter Feeds (1)

baynham (874879) | about 2 years ago | (#39674491)

I read somewhere that twitter feeds were being used as seeds for random number generators. Found the page here http://pyevolve.sourceforge.net/wordpress/?p=631 [sourceforge.net] This seems like a great approach. Could someone explain the benefits of this over the above, why it is needed and how can we be sure they are truly random.

Re:Twitter Feeds (1)

baynham (874879) | about 2 years ago | (#39674531)

Just read the abstract..."We demonstrate up to 2 Gbps of real time random number generation that were verified using standard randomness tests". A twitter RNG could not do this :)

Re:Twitter Feeds (1)

atisss (1661313) | about 2 years ago | (#39675455)

That would be predictable generator, as access to source code and algorithms would allow you to do the same calculations and predict random numbers generated by it.

There is no need for this new method at all (4, Informative)

gweihir (88907) | about 2 years ago | (#39674595)

Zener-noise at 5V6 or NPN transistor EB noise is already about half quantum effect noise. Just use that, plenty of recipes on the web. Cost is at a few USD/EUR for the raw generator and you can get it as an USB stick.

http://www.cryogenius.com/hardware/isarng/ [cryogenius.com]
http://www.tonbandstimmen.de/evpmaker/random-bit-generator/index_e.htm [tonbandstimmen.de]
http://www.entropykey.co.uk/ [entropykey.co.uk]

Seems to me the quantum folks are getting a bit desperate to prove they actually are doing something worthwhile.

My RNG algorithm... (5, Funny)

Iniamyen (2440798) | about 2 years ago | (#39675069)

I tell my dog to go get a toy. I've preassigned a numerical value between 1 & 10 to each of her toys. Whichever one she brings me, I cube the resulting number, and then divide by today's date (1 thru 31), and then floor the result. I get my yellow pages and turn to this page. I take the time of day as a percentage of 24-hour time (so 0700 would be 29.2%) and go that percentage down either the left or right column on that page, depending on the phase of the moon (left column for waxing, right column for waning.) Whichever phone number is there, I call. I then ask whoever picks up to think of a number.

Re:My RNG algorithm... (1)

zeugma-amp (139862) | about 2 years ago | (#39675271)

I'm sorry, but the algorithm you described above is patented. You'll have to cease using it until proper royalties are paid.

Actually, you were doing just fine until that last step. Humans are notoriously bad at picking random numbers.

Re:My RNG algorithm... (2)

atisss (1661313) | about 2 years ago | (#39675715)

As the rest of variables are known for each individual point in time, your choice is limited by 1/10 preference of dog (your precision to measure percentage in page is cancelled out by fact that dog probably has some favourite toys is probably ).

Given call centre with 50 employees I could constantly dial to the numbers you have chance to choose and ask if you have called and what number have the person told you. That would give 2/3 advantage to find out the number (If the person would lie, or hangup, he probably wouldn't told you the number in first place).

So, that's not random

Quantum Randomness (0)

Anonymous Coward | about 2 years ago | (#39675391)

"Build a Noise-Based Random Number Generator" by Terry Mayhugh which
          appeared in the May 1981 BYTE Magazine (pages 452-456).

Based on quantum tunneling in a Zener diode

Arguably the Silvania 6D4 Tube used for random number generation in the 40's was based on quantum emmision statistics.

Calculator as a service (1)

WaffleMonster (969671) | about 2 years ago | (#39675567)

Creating a random number generator is even easier than designing useful circuits. Just ignore your noise margins. There is no need for quantum laser bullshit.

Little need now (1)

Sara Chan (138144) | about 2 years ago | (#39675811)

Some way to generate random numbers is really important, for certain applications. Intel's next generation of CPUs, based on Ivy Bridge [wikipedia.org] and due out within a month, addresses that. The CPUs support a new instruction: RdRand [wikipedia.org]. RdRand generates random numbers based on noise in the hardware. For almost all purposes, it should be adequate.

Just use a sample of climate science data. NT (0)

Anonymous Coward | about 2 years ago | (#39675821)

That seems about as random as you can get. :)

What if (1)

starfishsystems (834319) | about 2 years ago | (#39675993)

What if it turns out that quantum randomness is only pseudo-random?

What if our entire reality is just a carrier wave for some other civilization's spread-spectrum communications network?

(Completely pointless speculation, I know. Still, I have to do something with my first coffee buzz of the morning.)

Who needs quantum stuff... (0)

Anonymous Coward | about 2 years ago | (#39676367)

just take a poll and use these numbers, you'll never get the same answer twice, at not long as our current boob ( president) continues his erratic actions...

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