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Re: Ruby/Forth challenge for WJ

From Paul Rubin <no.email@nospam.invalid>
Newsgroups comp.lang.forth
Subject Re: Ruby/Forth challenge for WJ
Date 2016-01-13 11:39 -0800
Organization A noiseless patient Spider
Message-ID <871t9luv44.fsf@nightsong.com> (permalink)
References <35f4686c-f2c4-4ed8-9c46-2238645b9b97@googlegroups.com> <569528f5$0$23800$e4fe514c@news.xs4all.nl> <2016Jan13.164504@mips.complang.tuwien.ac.at> <n765pi$5e1$1@dont-email.me>

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rickman <gnuarm@gmail.com> writes:
>> With a 20 Megapixel camera, if you only assume 4 bits of randomness
>> per pixel, you can get 10MB of randomness per shot... You need to
>> post-condition the data so that, e.g., dead pixels or dust on the
>> sensor don't compromise your random number generator.
> Has anyone tried this?  I can see huge issues relating to variations
> among the pixels which would need to be averaged out some way.

That digicam performance is limited by shot noise is well known, though
I'm skeptical of getting 4 bits of physical randomness per pixel,
especially with small-sensor consumer digicams where only few thousand
photons are enough to saturate a pixel.[1] Yes of course you have to
massage the output: there's a bunch of mathematical theory ("randomness
extraction") about how to do it with guaranteed minimal loss of
information, but in practice most people just run the data through a
cryptographic hash function.

In practice again, if you can get a few hundred bits of physical
entropy, that's enough to seed a CSPRNG and get unlimited output that
doesn't seem feasible to distinguish from actual random bits.

[1] http://clarkvision.com/articles/does.pixel.size.matter/

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Ruby/Forth challenge for WJ Chris Curl <ccurl609@gmail.com> - 2016-01-12 07:47 -0800
  Re: Ruby/Forth challenge for WJ Albert van der Horst <albert@spenarnc.xs4all.nl> - 2016-01-12 16:25 +0000
    Re: Ruby/Forth challenge for WJ Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-01-12 10:45 -0600
    Re: Ruby/Forth challenge for WJ Chris Curl <ccurl609@gmail.com> - 2016-01-12 08:46 -0800
      Re: Ruby/Forth challenge for WJ rickman <gnuarm@gmail.com> - 2016-01-12 11:57 -0500
        Re: Ruby/Forth challenge for WJ Chris Curl <ccurl609@gmail.com> - 2016-01-12 09:22 -0800
          Re: Ruby/Forth challenge for WJ hughaguilar96@gmail.com - 2016-01-12 21:04 -0800
            Re: Ruby/Forth challenge for WJ Ron Aaron <rambamist@gmail.com> - 2016-01-13 07:59 +0200
      Re: Ruby/Forth challenge for WJ Albert van der Horst <albert@spenarnc.xs4all.nl> - 2016-01-12 19:42 +0000
        Re: Ruby/Forth challenge for WJ Paul Rubin <no.email@nospam.invalid> - 2016-01-12 12:53 -0800
    Re: Ruby/Forth challenge for WJ anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-01-13 15:45 +0000
      Re: Ruby/Forth challenge for WJ rickman <gnuarm@gmail.com> - 2016-01-13 13:44 -0500
        Re: Ruby/Forth challenge for WJ Paul Rubin <no.email@nospam.invalid> - 2016-01-13 11:39 -0800
          Re: Ruby/Forth challenge for WJ Bernd Paysan <bernd.paysan@gmx.de> - 2016-01-14 05:01 +0100
          Re: Ruby/Forth challenge for WJ anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-01-14 12:28 +0000
  Re: Ruby/Forth challenge for WJ Chris Curl <ccurl609@gmail.com> - 2016-01-12 09:50 -0800
  Re: Ruby/Forth challenge for WJ Pablo Hugo Reda <pabloreda@gmail.com> - 2016-01-12 11:50 -0800
  Re: Ruby/Forth challenge for WJ Chris Curl <ccurl609@gmail.com> - 2016-01-12 12:30 -0800
  Re: Ruby/Forth challenge for WJ Chris Curl <ccurl609@gmail.com> - 2016-01-12 12:43 -0800
    Re: Ruby/Forth challenge for WJ stephen@mpeforth.com (Stephen Pelc) - 2016-01-12 21:01 +0000
    Re: Ruby/Forth challenge for WJ peter.m.falth@gmail.com - 2016-01-12 15:00 -0800
      Re: Ruby/Forth challenge for WJ Paul Rubin <no.email@nospam.invalid> - 2016-01-12 16:13 -0800
        Re: Ruby/Forth challenge for WJ mhx@iae.nl - 2016-01-12 16:22 -0800
        Re: Ruby/Forth challenge for WJ Paul Rubin <no.email@nospam.invalid> - 2016-01-12 16:24 -0800
          Re: Ruby/Forth challenge for WJ mhx@iae.nl - 2016-01-12 17:46 -0800
            Re: Ruby/Forth challenge for WJ Paul Rubin <no.email@nospam.invalid> - 2016-01-12 18:39 -0800
              Re: Ruby/Forth challenge for WJ mhx@iae.nl - 2016-01-13 13:05 -0800
                Re: Ruby/Forth challenge for WJ Bernd Paysan <bernd.paysan@gmx.de> - 2016-01-14 04:33 +0100
                Re: Ruby/Forth challenge for WJ m.a.m.hendrix@tue.nl - 2016-01-14 03:27 -0800
                Re: Ruby/Forth challenge for WJ peter.m.falth@gmail.com - 2016-01-14 04:42 -0800
                Re: Ruby/Forth challenge for WJ anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-01-14 13:03 +0000
                Re: Ruby/Forth challenge for WJ Paul Rubin <no.email@nospam.invalid> - 2016-01-13 21:17 -0800
                Re: Ruby/Forth challenge for WJ hughaguilar96@gmail.com - 2016-01-13 21:44 -0800
                Re: Ruby/Forth challenge for WJ anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-01-14 10:57 +0000
                Re: Ruby/Forth challenge for WJ mhx@iae.nl - 2016-01-14 12:20 -0800
                Re: Ruby/Forth challenge for WJ mhx@iae.nl - 2016-01-14 13:57 -0800
                Re: Ruby/Forth challenge for WJ Paul Rubin <no.email@nospam.invalid> - 2016-01-14 14:22 -0800
                Re: Ruby/Forth challenge for WJ mhx@iae.nl - 2016-01-14 16:14 -0800
                Re: Ruby/Forth challenge for WJ Melzzzzz <mel@zzzzz.com> - 2016-01-15 03:05 +0100
                Re: Ruby/Forth challenge for WJ Waldek Hebisch <hebisch@antispam.uni.wroc.pl> - 2016-01-15 00:41 +0000
                Re: Ruby/Forth challenge for WJ anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-01-15 16:22 +0000
                Re: Ruby/Forth challenge for WJ mhx@iae.nl (Marcel Hendrix) - 2016-01-16 11:44 +0200
                Re: Ruby/Forth challenge for WJ mhx@iae.nl - 2016-01-16 04:49 -0800
                Re: Ruby/Forth challenge for WJ Albert van der Horst <albert@spenarnc.xs4all.nl> - 2016-01-16 15:05 +0000
                Re: Ruby/Forth challenge for WJ m.a.m.hendrix@tue.nl - 2016-01-18 03:26 -0800
                Re: Ruby/Forth challenge for WJ anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-01-18 12:48 +0000
                Re: Ruby/Forth challenge for WJ Bernd Paysan <bernd.paysan@gmx.de> - 2016-01-19 22:26 +0100
                Re: Ruby/Forth challenge for WJ mhx@iae.nl - 2016-01-20 03:05 -0800
                Re: Ruby/Forth challenge for WJ Bernd Paysan <bernd.paysan@gmx.de> - 2016-01-20 21:00 +0100
                Re: Ruby/Forth challenge for WJ mhx@iae.nl - 2016-01-20 15:57 -0800
                Re: Ruby/Forth challenge for WJ Bernd Paysan <bernd.paysan@gmx.de> - 2016-01-21 23:02 +0100
                Re: Ruby/Forth challenge for WJ Albert van der Horst <albert@spenarnc.xs4all.nl> - 2016-01-22 01:25 +0000
                Re: Ruby/Forth challenge for WJ hughaguilar96@gmail.com - 2016-01-21 18:05 -0800
                Re: Ruby/Forth challenge for WJ mhx@iae.nl - 2016-01-21 22:03 -0800
                Re: Ruby/Forth challenge for WJ anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-01-20 13:40 +0000
                Re: Ruby/Forth challenge for WJ m.a.m.hendrix@tue.nl - 2016-01-18 03:55 -0800
                Re: Ruby/Forth challenge for WJ Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-01-23 15:13 -0600
                Re: Ruby/Forth challenge for WJ mhx@iae.nl - 2016-01-24 00:55 -0800
                Re: Ruby/Forth challenge for WJ Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-01-25 04:48 -0600
                Re: Ruby/Forth challenge for WJ Albert van der Horst <albert@spenarnc.xs4all.nl> - 2016-01-25 12:39 +0000
                Re: Ruby/Forth challenge for WJ Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-01-25 08:05 -0600
                Re: Ruby/Forth challenge for WJ Albert van der Horst <albert@spenarnc.xs4all.nl> - 2016-01-25 16:40 +0000
                Re: Ruby/Forth challenge for WJ Mark Wills <markwills1970@gmail.com> - 2016-01-25 04:44 -0800
                Re: Ruby/Forth challenge for WJ stephen@mpeforth.com (Stephen Pelc) - 2016-01-25 14:01 +0000
                Re: Ruby/Forth challenge for WJ Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-01-25 08:08 -0600
                Re: Ruby/Forth challenge for WJ Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-01-25 11:56 -0600
                Re: Ruby/Forth challenge for WJ "Elizabeth D. Rather" <erather@forth.com> - 2016-01-25 11:12 -1000
                Re: Ruby/Forth challenge for WJ Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-01-26 03:33 -0600
                Re: Ruby/Forth challenge for WJ stephen@mpeforth.com (Stephen Pelc) - 2016-01-26 11:09 +0000
                Re: Ruby/Forth challenge for WJ stephen@mpeforth.com (Stephen Pelc) - 2016-01-26 11:06 +0000
                Re: Ruby/Forth challenge for WJ Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-01-26 07:45 -0600
                Re: Ruby/Forth challenge for WJ anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-01-26 16:46 +0000
                Re: Ruby/Forth challenge for WJ Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-01-26 11:16 -0600
                Object-oriented Forth (was: Ruby/Forth challenge for WJ) anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-01-27 14:13 +0000
                Re: Object-oriented Forth Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-01-27 10:33 -0600
                Re: Object-oriented Forth hughaguilar96@gmail.com - 2016-01-27 08:45 -0800
                Re: Object-oriented Forth Chris Curl <ccurl609@gmail.com> - 2016-01-27 09:14 -0800
                Re: Object-oriented Forth hughaguilar96@gmail.com - 2016-01-29 21:57 -0800
                Re: Object-oriented Forth Albert van der Horst <albert@spenarnc.xs4all.nl> - 2016-01-30 10:58 +0000
                Re: Object-oriented Forth Chris Curl <ccurl609@gmail.com> - 2016-01-30 09:38 -0800
                Re: Object-oriented Forth Coos Haak <chforth@hccnet.nl> - 2016-01-30 20:39 +0100
                Re: Ruby/Forth challenge for WJ Bernd Paysan <bernd.paysan@gmx.de> - 2016-01-26 15:56 +0100
                Re: Ruby/Forth challenge for WJ stephen@mpeforth.com (Stephen Pelc) - 2016-01-26 20:46 +0000
                Re: Ruby/Forth challenge for WJ Bernd Paysan <bernd.paysan@gmx.de> - 2016-01-25 22:27 +0100
                Re: Ruby/Forth challenge for WJ Roelf Toxopeus <rt4all@notthis.hetnet.nl> - 2016-01-28 14:20 +0100
                Re: Ruby/Forth challenge for WJ Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-01-28 08:06 -0600
                Re: Ruby/Forth challenge for WJ Bernd Paysan <bernd.paysan@gmx.de> - 2016-01-28 16:14 +0100
                Re: Ruby/Forth challenge for WJ Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-01-28 10:32 -0600
                Re: Ruby/Forth challenge for WJ anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-01-28 17:26 +0000
                Re: Ruby/Forth challenge for WJ Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-01-28 12:13 -0600
                Re: Ruby/Forth challenge for WJ Albert van der Horst <albert@spenarnc.xs4all.nl> - 2016-01-29 11:07 +0000
                Re: Ruby/Forth challenge for WJ Bernd Paysan <bernd.paysan@gmx.de> - 2016-01-29 21:18 +0100
                Re: Ruby/Forth challenge for WJ Tessa Bonting <tessa.bonting@gmail.com> - 2016-01-16 06:24 -0800
          Re: Ruby/Forth challenge for WJ Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-01-13 05:21 -0500
            Re: Ruby/Forth challenge for WJ Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-01-13 05:36 -0500
            Re: Ruby/Forth challenge for WJ Paul Rubin <no.email@nospam.invalid> - 2016-01-13 10:33 -0800
              Re: Ruby/Forth challenge for WJ Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-01-14 01:37 -0500
  Re: Ruby/Forth challenge for WJ Chris Curl <ccurl609@gmail.com> - 2016-01-12 13:45 -0800
  Re: Ruby/Forth challenge for WJ Chris Curl <ccurl609@gmail.com> - 2016-01-12 13:55 -0800
    Re: Ruby/Forth challenge for WJ Paul Rubin <no.email@nospam.invalid> - 2016-01-12 14:34 -0800
    Re: Ruby/Forth challenge for WJ rickman <gnuarm@gmail.com> - 2016-01-12 19:00 -0500
      Re: Ruby/Forth challenge for WJ Chris Curl <ccurl609@gmail.com> - 2016-01-12 16:49 -0800
        Re: Ruby/Forth challenge for WJ rickman <gnuarm@gmail.com> - 2016-01-12 22:18 -0500
  Re: Ruby/Forth challenge for WJ hughaguilar96@gmail.com - 2016-01-12 14:31 -0800
    Re: Ruby/Forth challenge for WJ Chris Curl <ccurl609@gmail.com> - 2016-01-12 16:05 -0800
  Re: Ruby/Forth challenge for WJ "WJ" <w_a_x_man@yahoo.com> - 2016-01-13 07:58 +0000
    Re: Ruby/Forth challenge for WJ Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-01-13 05:17 -0500
      Re: Ruby/Forth challenge for WJ Paul Rubin <no.email@nospam.invalid> - 2016-01-13 12:36 -0800
        Re: Ruby/Forth challenge for WJ Chris Curl <ccurl609@gmail.com> - 2016-01-13 12:53 -0800
        Re: Ruby/Forth challenge for WJ Andrew Haley <andrew29@littlepinkcloud.invalid> - 2016-01-14 06:50 -0600
    Re: Ruby/Forth challenge for WJ Julian Fondren <julian.fondren@gmail.com> - 2016-01-13 05:36 -0800
    Re: Ruby/Forth challenge for WJ lehs <skydda.barnen@gmail.com> - 2016-01-13 11:59 -0800
    Re: Ruby/Forth challenge for WJ Chris Curl <ccurl609@gmail.com> - 2016-01-21 21:08 -0800
    Re: Ruby/Forth challenge for WJ "WJ" <w_a_x_man@yahoo.com> - 2016-02-09 13:36 +0000
    Re: Ruby/Forth challenge for WJ "WJ" <w_a_x_man@yahoo.com> - 2016-02-09 13:48 +0000
      Re: Ruby/Forth challenge for WJ hughaguilar96@gmail.com - 2016-02-09 12:02 -0800
    Re: Ruby/Forth challenge for WJ "WJ" <w_a_x_man@yahoo.com> - 2016-02-09 13:58 +0000
    Re: Ruby/Forth challenge for WJ "WJ" <w_a_x_man@yahoo.com> - 2016-02-09 14:30 +0000
    Re: Ruby/Forth challenge for WJ "WJ" <w_a_x_man@yahoo.com> - 2016-02-14 15:35 +0000
      Re: Ruby/Forth challenge for WJ franck.bensusan@gmail.com - 2016-02-14 08:50 -0800
        Re: Ruby/Forth challenge for WJ Julian Fondren <julian.fondren@gmail.com> - 2016-02-14 20:09 -0800
          Re: Ruby/Forth challenge for WJ hughaguilar96@gmail.com - 2016-02-15 08:52 -0800
    Re: Ruby/Forth challenge for WJ "WJ" <w_a_x_man@yahoo.com> - 2016-02-14 21:31 +0000
  Re: Ruby/Forth challenge for WJ "WJ" <w_a_x_man@yahoo.com> - 2016-01-14 22:49 +0000
    Re: Ruby/Forth challenge for WJ Paul Rubin <no.email@nospam.invalid> - 2016-01-14 15:31 -0800
      Re: Ruby/Forth challenge for WJ Melzzzzz <mel@zzzzz.com> - 2016-01-15 06:55 +0100
  Re: Ruby/Forth challenge for WJ djc <ciesinger@gmx.net> - 2016-02-11 07:39 -0800

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