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Physicist Uses Laser Light As Fast, True-Random Number Generator 326

Posted by Soulskill
from the everything-is-better-with-lasers dept.
MrKevvy writes "An Ottawa physicist is using laser light to create truly random numbers much faster than other methods do, with obvious potential benefits to cryptography: 'Sussman's Ottawa lab uses a pulse of laser light that lasts a few trillionths of a second. His team shines it at a diamond. The light goes in and comes out again, but along the way, it changes. ... It is changed because it has interacted with quantum vacuum fluctuations, the microscopic flickering of the amount of energy in a point in space. ... What happens to the light is unknown — and unknowable. Sussman's lab can measure the pulses of laser light that emerge from this mysterious transformation, and the measurements are random in a way that nothing in our ordinary surroundings is. Those measurements are his random numbers.'"
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Physicist Uses Laser Light As Fast, True-Random Number Generator

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  • Finally a reason for socially inept people to buy diamonds!
    • by MobileTatsu-NJG (946591) on Tuesday November 29, 2011 @06:29PM (#38207874)

      Finally a reason for socially inept people to buy diamonds!

      I dunno about that. Diamond video cards were okay.

    • by Hentes (2461350) on Tuesday November 29, 2011 @06:34PM (#38207936)

      A lot of tools have diamond blades.

    • Finally a reason for socially inept people to buy diamonds!

      Industrial grade diamonds are cheap. They are already found in various consumer gadgets that geeks may already have. :-)

    • by blair1q (305137)

      Socially inept people are the only ones who ever had to buy diamonds.

      Think about it.

  • by waynemcdougall (631415) <slashdot@codeworks.gen.nz> on Tuesday November 29, 2011 @06:17PM (#38207718) Homepage

    9 9 9 9 9 9 9 9 9 ....

    You don't KNOW it's not random...

    • by epine (68316)

      Actually, we do know it's not random, within a very small margin of dithering. Given any chosen universal computer (one with an extremely small definition is best), if a sequence can be printed by a program whose length is less than the sequence, the sequence is not random.

      There is a small dependence on which universal machine you pick at the outset, but any two universal machines will never disagree on the length of the shortest program required by more than the shortest program by which one machine simul

      • by artor3 (1344997) on Tuesday November 29, 2011 @07:28PM (#38208574)

        That's nonsense.

        If a pick a truly random number from a set that includes 9, then there is a nonzero chance that it will be nine. If I then pick another number from that same set, there is an equal nonzero chance of it being 9. If I pick N numbers from that set, then the probability of them all being 9 is X^N, where X is my nonzero chance. Any nonzero number raised to any power will still be nonzero. Therefore there is a nonzero chance that you can generate a random list of numbers and have them all be 9.

        I suppose you could get extremely pedantic and say that the question is the probability of a list of 9s being random (as opposed to the probability of a random list containing all 9s), and then make the claim that there is no way to get a completely random list of numbers, but otherwise I don't see how you can ever look at a list of numbers and say with certainty that it wasn't randomly generated.

  • There. I said it.

    They lost me at "microscopic energy".

  • by stanlyb (1839382) on Tuesday November 29, 2011 @06:21PM (#38207778)
    I mean, what about a diamond in the middle attack? If you manage to replace it with well known and tweaked diamond, with known quantum effect (you see, i could use funny words too), then all the systems would be jeopardized.
    • by martas (1439879)
      Absolutely true -- if you replace the diamond with one that produces numbers following some other distribution than the original, even if it's slightly different, that could introduce a massive vulnerability for a dedicated attacker to exploit. The same holds without the attacker needing to replace anything, if he has a slightly better estimate of the distribution that the random number generator follows than the creator of the system (e.g. if the person using it thinks they're getting 0/1 with exactly 0.5
  • by stating_the_obvious (1340413) on Tuesday November 29, 2011 @06:24PM (#38207806)
    I just use the rand() function in Excel. Way less hassle than firing a laser through a diamond...
    • by X0563511 (793323) on Tuesday November 29, 2011 @06:26PM (#38207832) Homepage Journal

      ... only random if you are measuring whether Excel crashes or not when you do it.

    • I just use the rand() function in Excel. Way less hassle than firing a laser through a diamond...

      But not nearly as much fun. :-)

  • Nonsense (Score:3, Insightful)

    by Anonymous Coward on Tuesday November 29, 2011 @06:28PM (#38207862)

    "the measurements are random in a way that nothing in our ordinary surroundings is"

    Nonsense. They are random in precisely the same way that a good bouncy roll of the dice are. They are random in precisely the same way that a temperature measurement of a cup full of boiling water 10 seconds after it is poured is. They are random in precisely the same way that the sound coming out of a piezoelectric microphone taped to a car window travelling at 60 MPH is. They are random in precisely the same way that the noise of a reverse-biased silicon junction is.

    Perhaps the author meant to say "the measurements are random in a way that no pseudorandom number generator algorithm is."

    • "the measurements are random in a way that nothing in our ordinary surroundings is"

      Nonsense. They are random in precisely the same way that a good bouncy roll of the dice are.

      No. The bouncy dice are describable by classical physics. Our inability to predict is based upon our imprecise understanding of the path of the dice, their rotation, air density and movement, the geometry of the area landing in and bouncing about in, the understanding of the materials of the dice and objects it is bouncing against, etc.

      In contrast this new method utilizes effects of quantum physics. That is inherently far less measurable and predictable.

  • Not me, but the post. Why is it in IT/Management when it should be in Science?
  • by Vario (120611) on Tuesday November 29, 2011 @06:29PM (#38207878)

    The newspaper article is not giving any information that is not already included in the summary.

    The paper is published in Optics Express, the abstract can be read here [opticsinfobase.org]. The full article is behind a paywall unfortunately. The author claim that this concept could deliver random numbers at a rate of 100 GHz which is quite fast compared to other true random number generators out there that are based on thermal noise, radiation or other processes.

  • "An Ottawa physicist is using laser light to create truly random numbers much faster than other methods do, with obvious potential benefits to cryptography"

    Even faster, use neutrinos!

    http://blogs.discovermagazine.com/crux/2011/11/22/faster-than-light-neutrinos-confirmed-in-one-way-yes-in-another-no/ [discovermagazine.com]

    Or? Maybe the answer is random? Truly random!

  • WARNING! (Score:5, Funny)

    by SnarfQuest (469614) on Tuesday November 29, 2011 @06:32PM (#38207910)

    Do not look at random numbers with remaining eye.

  • A while back, the Simtec Entropy Key [entropykey.co.uk] was making the rounds among Debian Devs, and claims to be exploiting quantum effects in the P-N junctions to be a true RNG.

    They seem serious and I tend to trust paranoid Debian developers' opinions [entropykey.co.uk], but ultimately I don't have enough knowledge myself to make a confident judgment call. I'd be curious about more opinions.

    • by evanbd (210358) on Tuesday November 29, 2011 @06:49PM (#38208114)

      You can also use resistor noise [wikipedia.org], a good amplifier, and an ADC to make moderately high bandwidth true quantum RNG. I priced out a simple design with a microcontroller on a USB key footprint; looked like $50-100 in prototype quantities, less in large quantities, for 10 KB/s output (or so). Getting the entropy is looked like the easy part; it then needed a fair bit of CPU power (by microcontroller standards) to hash that into usable bits.

      You can also (with a lot more software work, and low bitrates) use the resistor noise present in audio input channels to good effect. Turbid [av8n.com] is a project that does just that. Note that when evaluating such projects, the hard part is not getting the numbers, but proving that they have enough entropy, and that they've been properly processed to preserve it. Turbid does an excellent job on this important documentation step.

    • by vlm (69642) on Tuesday November 29, 2011 @06:58PM (#38208198)

      claims to be exploiting quantum effects in the P-N junctions to be a true RNG

      Thats a wee bit of the wordy mumbo jumbo, like talking about the "maxwellian equation emitter controlled by polarization rotation human interface unit" I'm using to read this, instead of calling it a freaking monitor. Just call it a zener diode and be done with it. The Zener story is bizarre and this doesn't help. Clarence M. Zener came up with the theory for his diodes in the 30s, although they couldn't be built until the 50s when they thought it would be cool to name the diode after him, or maybe his physics equation, or both. Strange but true fact is that a "zener" diode operating below 5 volts uses the actual physics Zener effect and a "zener" diode operating above 5 volts uses the physics avalanche effect, which the Entropy Key claims to use.

      Note that USB does not provide more than 5 volts and a reasonable current limiter means its gonna be operating well into zener-land.

      So, A dude named Zener, invented Zener physics, leading to the theory of zener diodes, then someone else built one 20 years later and named it after him, and the key markets itself as using the closely related avalanche effect, but because only 5 volts is available without some sort of voltage multiplier or boost switching regulator, its probably actually using the low voltage Zener effect, regardless of the effect, devices using avalanche or zener effect are always marketed as zener diodes commercially, so I'm sure there is a Zener on the board. Which doesn't matter in the end, because zener noise is just as good as avalanche noise for crypto, as far as I know. In fact zener is probably better, less temperature dependence. Talk about abuse of proper nouns and trademarks... kinda like my Xerox machine at home was manufactured by Brother.

      This stuff is all from memory, I hope I didn't swap Zener and Avalanche effects, although either way its still a heck of a story.

    • Thanks for posting about the Simtec Entropy Key. At only $56 (Qty 1) for a FIPS-140-2 Level 3 compliance type device based on quantum tunnels is pretty amazing. Just the buzz words, are worth that for any system advertised as secure.
  • I agree that the numbers are random, in the sense that they're subject to chance, but how confident are they that they know the sampling distribution? That is, can you use this method to generate a random sample a with uniform distribution, or a gamma distribution, or anything else you'd like to use random numbers for?

    With quantum observation errors, I wonder if they're assuming the sampling distribution is normal, in which case they'd have to do some work to convert it to give the kind of output that rand

    • by martas (1439879) on Tuesday November 29, 2011 @07:31PM (#38208618)
      The full paper (link by "Vario" above) seems to indicate that they get random bits, i.e. coin tosses, and claim that they can get a uniform distribution (i.e. 0.5). They also say that "Any possible bias in the phase measurement is removed by post-processing using a fair bit extractor algorithm", citing two papers* (i.e. that though their measurements could lead to a slightly different distribution, they can correct for that). I'm not familiar with the technique, but I guess it's well established. They also show results and say that they did something called the "DIEHARD statistical test suite" (which is apparently a set of tests designed exactly for this problem, i.e. random number generation), and "confirm[ed] that the measured optical phase is a suitable source of random numbers", though I'll have to take them at their word because I'm not familiar with the theory behind this.

      * First:
      J. von Neumann, “Various techniques used in connection with random digits,” Nat. Bur. Stand., Appl. Math Ser. 12, 36–38 (1951).
      Second:
      A. Juels, M. Jakobsson, E. Shriver, and B. Hillyer, “How to turn loaded dice into fair coins,” IEEE Trans. Inf. Theory 46, 911 –921 (2000).)
  • 'Sussman's Ottawa lab uses a pulse of laser light that lasts a few trillionths of a second. His team shines it at a diamond. The light goes in and comes out again, but along the way, it changes. ... It is changed because it has interacted with quantum vacuum fluctuations, the microscopic flickering of the amount of energy in a point in space. ... What happens to the light is unknown — and unknowable.

    Sounds very much like xray crystallography which discovers all kinds of interesting things about the crystalline matrix.

    Would be hilarious if they discover via non-random results there is, after all, some inherent crystaline like order to the quantum vacuum. Or even funnier if they knew it all along, and some TLA agency paid them to try and pass it off as random, cloaked in a lot of new age zero point energy stuff.

  • Can it generate pi? Wow.

  • Obligatory (Score:2, Funny)

    by ajlitt (19055)

    Shine on you random diamond.

  • Genuinely random? (Score:4, Interesting)

    by overshoot (39700) on Tuesday November 29, 2011 @06:40PM (#38208000)
    Unlike easily predicted phenomena like radioactive decay and thermal noise?
  • When it comes to true random devices, I've coded some micro-controllers to add random numbers based on key-presses from humans, picture someone pressing the button when a 24 mhz timer runs mad, no human that I know of - can repeat press the button so accurately that it hits the same number at a 0.00001th of a second more or less.

    When no human interaction is required, I use an insanely accurate temperature sensor, no temperature, not even placed in a professional fridge with 0.01c accuracy can get the same r

  • by ameline (771895) <ian.ameline@nOSPAM.gmail.com> on Tuesday November 29, 2011 @06:52PM (#38208148) Homepage Journal
    The generation of random numbers is too important to be left to chance.
  • C64 (Score:4, Interesting)

    by jamesh (87723) on Tuesday November 29, 2011 @06:52PM (#38208150)

    The Commodore 64 could produce random numbers by sampling the white noise generator in the SID audio chip. They probably weren't as random as shining a laser through the diamond but I wonder if the difference is enough to matter...

  • by Hentes (2461350) on Tuesday November 29, 2011 @06:54PM (#38208174)

    Big advantages of this is that it requires no outside information source, inexpensive and could be miniaturized to fit on an extension card. Then we all could put a random card next to our graphics card in our machines.

  • "Matter is built on flaky foundations. Physicists have now confirmed that the apparently substantial stuff is actually no more than fluctuations in the quantum vacuum."
    http://www.newscientist.com/article/dn16095-its-confirmed-matter-is-merely-vacuum-fluctuations.html [newscientist.com]

    Everything is random.

    "The Higgs field is also thought to make a small contribution, giving mass to individual quarks as well as to electrons and some other particles. The Higgs field creates mass out of the quantum vacuum too, in the form of vir

  • Now we need a cool name for it. How about:
    Zero Point Entropy

  • What happens to the light is unknown — and unknowable.

    It's knowable or else we couldn't measure it to generate random numbers.

    Whether it's predictable is another matter entirely, and I'm almost positive that it isn't.

  • Finally! (Score:4, Funny)

    by SpacePunk (17960) on Tuesday November 29, 2011 @09:22PM (#38209680) Homepage

    I can put away that cup of really hot tea.

...when fits of creativity run strong, more than one programmer or writer has been known to abandon the desktop for the more spacious floor. - Fred Brooks, Jr.

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