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Programming Forum and web based access to our favorite programming groups.This topic comes up often enough in c.l.f that I thought this would be of interest. Regards, Mike Metcalf ======================================== ============ a.. "True Randomness Upon Request" Innovations Report (03/18/04) The University of Geneva's Group of Applied Physics and its Computer Science department have partnered with id Quantique, a company spun off from the university, to launch the first Web site where true random numbers can be generated and downloaded on demand. Users could request a specific sequence of random numbers from the site by specifying the sequence's parameters, and the numbers would be created by a quantum random number generator linked to the server. The first practical quantum random number generator was developed six years ago by the Group of Applied Physics, and the technology was commercialized by id Quantique. The device produces binary random numbers by harnessing the reflection or transmission of a photon on a semi-transparent mirror. "Quantum physics is the only physical theory predicting that the outcome of certain phenomena is random," explains Group of Applied Physics director Nicolas Gisin. "It is thus a natural choice to use it to generate true random numbers." The University of Geneva's Computer Science department has devised a server/client application that would allow researchers worldwide to download random numbers in the C, C+, Java, or Fortran codes employed for their simulations. The Web site, www.randomnumbers.info, is expected to evolve into the standard online resource on randomness and random numbers. Random numbers are essential in applications ranging from secure encryption of electronic communications to lotteries to scientific calculations, but generating them has always been a formidable challenge. For more: http://www.innovations-report.com/h...45.html
Post Follow-up to this messageThere is an enormous amount of confusion about the meaning of the term "random". Ask your friends for a definition, and consult a few books, and you will discover a great variety of proposed meanings for the word. I do not have a pet definition to promote, but I would like to point out some of the variety. 1. Random does not imply inteterministic. Indeed, dynamical chaos has been aptly described (by the late Joe Ford) as "deterministic randomness". 2. Usually, in statistics and in Monte Carlo simulations, "random" means that certain kinds of correlations are absent. Since there are an infinite number of correlations that can be defined, there are infinitely many degrees of statistical randomness. The Geneva process is indeterministic, but that does not guarantee any particular degree of statistical randomness. 3. In cryptography, "random" means "unpredictable". If you just ask me for a number, my reply will be just as random (unpredictable) as a number generated by the Geneva group. 4. A few decades ago, the Rand Corporation published a book of "random digits". In those days, people seemed to think that "randomization" gave an experimental design a kind of metaphysical virtue. That belief is no longer so common. 5. "Ranodmness" as "unpredicability" is often desirable. But now that the Rand Corp. book and the Geneva sequence have been published, they are no longer unpredictable. In conclusion, I doubt that the published Geneva "random" numbers have any significant value. I will certainly continue to use established random number subroutines in my Monte Carlo simulations. Leslie Ballentine Michael Metcalf <metcalfm@acm.org> wrote: : This topic comes up often enough in c.l.f that I thought this would be of : interest. : Regards, : Mike Metcalf : ======================================== ============ : a.. "True Randomness Upon Request" : Innovations Report (03/18/04) : The University of Geneva's Group of Applied Physics and its Computer Scien ce : department have partnered with id Quantique, a company spun off from the : university, to launch the first Web site where true random numbers can be : generated and downloaded on demand. Users could request a specific sequenc e : of random numbers from the site by specifying the sequence's parameters, a nd : the numbers would be created by a quantum random number generator linked t o : the server. The first practical quantum random number generator was : developed six years ago by the Group of Applied Physics, and the technolog y : was commercialized by id Quantique. The device produces binary random : numbers by harnessing the reflection or transmission of a photon on a : semi-transparent mirror. "Quantum physics is the only physical theory : predicting that the outcome of certain phenomena is random," explains Grou p : of Applied Physics director Nicolas Gisin. "It is thus a natural choice to : use it to generate true random numbers." The University of Geneva's Comput er : Science department has devised a server/client application that would allo w : researchers worldwide to download random numbers in the C, C+, Java, or : Fortran codes employed for their simulations. The Web site, : www.randomnumbers.info, is expected to evolve into the standard online : resource on randomness and random numbers. Random numbers are essential in : applications ranging from secure encryption of electronic communications t o : lotteries to scientific calculations, but generating them has always been a : formidable challenge. : For more: : http://www.innovations-report.com/h...45.ht ml
Post Follow-up to this message"Michael Metcalf" <metcalfm@acm.org> wrote in message news:c3nf9l$8hj$1@ngspool-d02.news.aol.com... > This topic comes up often enough in c.l.f that I thought this would be of > interest. > My last inquiry about this subject drew ZERO response (see below from Google archive)... Search Result 1 From: David Frank (dave_frank@hotmail.com) Subject: Is there a genuine random number routine? This is the only article in this thread View: Original Format Newsgroups: comp.lang.fortran Date: 2001-05-14 05:50:01 PST re: my 1999 subject "genuine random numbers" which was debated at length here in clf.. I'm curious, does anyone YET have any info about reading pentium 3's (and I assume pentium 4's) random number register? If so, pls list the routine's assy instructions and any related info about it, (timing restraints/etc.)
Post Follow-up to this message"David Frank" <dave_frank@hotmail.com> wrote in message news:XYV7c.305283$jH.4291081@twister.tampabay.rr.com... > My last inquiry about this subject drew ZERO response (see below from Google > archive)... Intel put the RNG on the chipset, not on the chip itself because verification of a chip with random characteristics can be rather awkward. You might want to have a look at: http://www.intel.com/design/chipsets/manuals/298029.pdf and see if you can get it to work. -- write(*,*) transfer((/17.392111325966148d0,6.5794487871554595D-85, & 6.0134700243160014d-154/),(/'x'/)); end
Post Follow-up to this messageJohn C. Bollinger <jobollin@indiana.edu> wrote: > Leslie Ballentine wrote: > > > Indeed. A glimpse at Webster's New Universal was enlightening, mostly > because it didn't include a statistical definition of the term. > Consultation of my nearest statistics text then surprised me when I > discovered that although it defined "random variable", "random number", > "random process", and a few other related terms, it never defined > "random" itself. Interesting. > > > I find that one clever because it seems so oxymoronic (to me), yet as > you say, it's very apt. "random" is a mathematical description and mathematical concept, like say, "continuously differentiable function". Physical things have properties, which in some limits, are best describable by mathematical laws, which humans have constructed to fulfill the axioms of probability theory. In that theory there are devices called 'random variables'. Reality is as reality is. > The fact that the value of each future output put bit is indeterministic > does not guarantee absence of correlation, true. Nevertheless the > underlying physical theory does not introduce such correlations, the > equipment is designed to avoid introducing correlations as much as > possible, and actual the self-correlation of the output has been > examined and found to be quite small. I am not well enough versed in > the theory or knowledgable enough about the experiment to determine > whether the observed tiny self correlations were in fact within the > range of the experiment's reasonable statistical error. Nevertheless, I > certainly would assert that the reported degree of [non-]correlation > should be at least as sufficient for statistical simulations as that of > any pseudorandom number generation algorithm could be. I would believe that any practical physical device would inevitably introduc e *more* correlation than a cryptographically strong, or even well-validated statistical, PRNG. It would be good to use a physical random number generator as a seed.
Post Follow-up to this messageDr Chaos <mbkennelSPAMBEGONE@NOSPAMyahoo.com> writes: > "random" is a mathematical description and mathematical concept, like > say, "continuously differentiable function". > > Physical things have properties, which in some limits, are best describabl e > by mathematical laws, which humans have constructed to fulfill the axioms > of probability theory. > > In that theory there are devices called 'random variables'. > > Reality is as reality is. Indeed. As someone who has worked a lot in the field of system identification, I find it critical to keep in mind the distinction between reality and mathematical models. Others have said it better than either you or I are likely to. A few relevant quotes that I used in the introduction to one of my reports. The writing style seems a little strange to modern ears, but if you adapt to the style, I think you'll see that these are pretty cogent comments. (You'll also need to overlook the sexist phraseology typical of the time). All retyped from scratch as I don't have original electrons, so I'm sure there are plenty of typos. From Bayes (1736), who did some "minor" work on statistics, as translated by Barnard(1958) "In is not the business of the mathematician to dispute whether quaantities do in fact ever vary in the manner that is supposed, but only whether the notion of their doing so be intelligible; which being allowed, he has a right to take it for granted, and then see what deductions he can make from that supposition....He is not inquiring how things are in matter of fact, but supposing things to be in a certain way, what are the consequences to be deduced from them; and all that is demanded of him is, that his suppositions be intelligible, and his inferences just from the suppositions he makes." Though as engineers rather than pure mathematicians, we might find ourselves more in line with Bayes' later statement in the same document "So far as Mathematics do not tend to make men more sober and rational thinkers, wiser and better men, they are only to be considered as an amusement, which ought not take us off from serious business." Quoting myself next, because I don't think I can seque into the next classic quotation any better now than I did in the report "A few words are necessary in defense of the probalistic approach, lest the reader decide that it is not worthwhile to pursue. The main issue here is the description of deterministic phenomena as random. This disagrees with common modern perceptions of the meaning and use of randomness for physical situations, in which random and deterministic phenomena are considered as quite distinct and well delineated. Our viewpoint owes more to the earlier philosophy of probability theory - that it is a useful tool for studying complicated phenomena which need not be inherently random (if anything is inherently random). Cramer (1946, p. 141) gives a classic exposition of this philosophy: [The following is descriptive of]...large and important groups of random experiments. Small variations in the initial state of the observed units, which cannot be detected by our instruments, may produce considerable changes in the final result. The complicated character of the laws of the observed phenomenon may render exact calculation practically, if not theoretically, impossible. Uncontrollable action by small disturbing factors may lead to irregular deviation from a presumed "true value". It is, of course, clear that there is no sharp distinction between these various modes of randomness. Whether we ascribe, e.g. the fluctuations observed in the results of a series of shots at a target mainly due to small variations in the initial state of the projectile, to the complicated nature of the ballistic laws, or to the action of small disturbing factors, is largey a matter of taste. The essential thing is that, in all cases where on eor more of these circumstances are present, an exact prediction of the results of individual experiments becomes impossible, and the irregular fluctuations characteristic of randomm experiments will appear. We shall now see that, in cases of this character, there appears amidst all irregularity of fluctuations a certain typical form of regularity that will serve as the basis of the mathematical theory of statistics." -- Richard Maine | Good judgment comes from experience; email: my first.last at org.domain | experience comes from bad judgment. org: nasa, domain: gov | -- Mark Twain
Post Follow-up to this messageLeslie Ballentine wrote: > There is an enormous amount of confusion about the meaning of the term > "random". Ask your friends for a definition, and consult a few books, and > you will discover a great variety of proposed meanings for the word. Indeed. A glimpse at Webster's New Universal was enlightening, mostly because it didn't include a statistical definition of the term. Consultation of my nearest statistics text then surprised me when I discovered that although it defined "random variable", "random number", "random process", and a few other related terms, it never defined "random" itself. Interesting. > I do > not have a pet definition to promote, but I would like to point out some > of the variety. > > 1. Random does not imply inteterministic. Indeed, dynamical chaos has > been aptly described (by the late Joe Ford) as "deterministic randomness". I find that one clever because it seems so oxymoronic (to me), yet as you say, it's very apt. > 2. Usually, in statistics and in Monte Carlo simulations, "random" means > that certain kinds of correlations are absent. Since there are an > infinite number of correlations that can be defined, there are infinitely > many degrees of statistical randomness. > The Geneva process is indeterministic, but that does not guarantee any > particular degree of statistical randomness. The fact that the value of each future output put bit is indeterministic does not guarantee absence of correlation, true. Nevertheless the underlying physical theory does not introduce such correlations, the equipment is designed to avoid introducing correlations as much as possible, and actual the self-correlation of the output has been examined and found to be quite small. I am not well enough versed in the theory or knowledgable enough about the experiment to determine whether the observed tiny self correlations were in fact within the range of the experiment's reasonable statistical error. Nevertheless, I certainly would assert that the reported degree of [non-]correlation should be at least as sufficient for statistical simulations as that of any pseudorandom number generation algorithm could be. > 3. In cryptography, "random" means "unpredictable". If you just ask me > for a number, my reply will be just as random (unpredictable) as a number > generated by the Geneva group. I'm not sure I agree. I would instead say that cryptographers use "random" numbers because they have the property of unpredictability. Also because you aren't available to most of them to satisfy their needs for unpredictable numbers. :-) > 4. A few decades ago, the Rand Corporation published a book of "random > digits". In those days, people seemed to think that "randomization" gave > an experimental design a kind of metaphysical virtue. That belief is > no longer so common. That definition of random goes more back to the question of correlation. The idea, as I understand it, is that if a sequence of digits is chosen from such a table (randomly, of course) all possible outcomes are equally likely. > 5. "Ranodmness" as "unpredicability" is often desirable. But now that > the Rand Corp. book and the Geneva sequence have been published, they are > no longer unpredictable. Whoah, we seem to have jumped the tracks here. In the first place, unpredictability relative to the Rand book is obtained through the method of selecting digits from it. It is therefore exactly as unpredictable as asking you for a sequence of digit indices can make it. (Thus highly unpredictable :-).) More importantly, however, what the Geneva group principally produced was a device, not a sequence -- a device that plugs into your computer's USB2 port and provides a 100 KHz stream of random bits. Because the device is based on a physical process that is fundamentally unpredictable, their publication of the technique does not make the output any more predictable. Neither does their commercial distribution of the device. > In conclusion, I doubt that the published Geneva "random" numbers have any > significant value. I disagree. As far as I can tell from the Geneva group's reports, Random numbers produced by their device have excellent properties of unpredictability, and they ought to be at least as useful for simulations, modulo the bit rate, as a PRNG can offer -- provided you don't ever need to repeat exactly the same simulation run. > I will certainly continue to use established random > number subroutines in my Monte Carlo simulations. I imagine most people will. Good PRNGs give satisfactory results in the vast majority of cases. A device like the one we're talking about is more useful where unpredictability must be absolutely guaranteed. John Bollinger jobollin@indiana.edu
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