Re: Ruby/Forth challenge for WJ

From	anton@mips.complang.tuwien.ac.at (Anton Ertl)
Newsgroups	comp.lang.forth
Subject	Re: Ruby/Forth challenge for WJ
Date	2016-01-14 12:28 +0000
Organization	Institut fuer Computersprachen, Technische Universitaet Wien
Message-ID	<2016Jan14.132847@mips.complang.tuwien.ac.at> (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> <871t9luv44.fsf@nightsong.com>

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Paul Rubin <no.email@nospam.invalid> writes:
>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]

Actually it should be better with small-pixel cameras than with
big-pixel cameras.  E.g., if your pixel overflows when the well size
is 1.1M photons, so you target for 1M photons, and get on the order of
1000 photons noise (is there a constant factor that I would have to
factor in?); with a 12-bit A/D-converter the noise affects only the
lower 2 bits, with a 14-bit A/D converter the low 4 bits, but barely).

By contrast, if the pixel has a well size of, say, 5000 photons, and
we target 4096 photons, we get 64 photons of noise; with a 12-bit A/D
converter, that's close to 6 bits of noise.

So if you want lots of noise, a camera with lots of small pixels is
good; and for the precise reason why lots of mexapixels are not that
popular among photographers.

>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.

With real entropy, you should be safer against weaknesses in your PRNG
that may be found in the future.

- anton
-- 
M. Anton Ertl  http://www.complang.tuwien.ac.at/anton/home.html
comp.lang.forth FAQs: http://www.complang.tuwien.ac.at/forth/faq/toc.html
     New standard: http://www.forth200x.org/forth200x.html
   EuroForth 2015: http://www.rigwit.co.uk/EuroForth2015/

Thread

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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