Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > comp.lang.forth > #44858
| From | Bernd Paysan <bernd.paysan@gmx.de> |
|---|---|
| Newsgroups | comp.lang.forth |
| Subject | Re: Ruby/Forth challenge for WJ |
| Date | 2016-01-14 05:01 +0100 |
| Organization | A noiseless patient Spider |
| Message-ID | <n776dv$kod$1@dont-email.me> (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> |
Paul Rubin wrote:
> 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.
Phyiscal entropie is usually biased; if you take the lowest bits out of a
digicam, the bits are suspects of DNL and INL problems of the ADC (usually
more than enough to be found by randomness test benches, but not enough to
actually be a problem for the image quality - e.g. if your LSB is 45% 0 and
55% 1 due to DNL, you wouldn't see it as artefact in the image).
> 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.
Indeed. The only problem with CSPRNGs in the past was NSA-induced backdoors
as with the (anyways awful) Dual_EC_DRBG, and possible easy backdooring of
the Intel RDRAND instruction by changing the writeable microcode into doing
AES(key=prefix|counter,data=entropy) instead of the secure
AES(key=entropy,data=prefix|counter). You can't distinguish the two outputs
from a randomness perspective, it's both equally good, but an attacker
knowing the backdoor prefix only needs a bit of guesswork to get at the
entropy.
--
Bernd Paysan
"If you want it done right, you have to do it yourself"
net2o ID: kQusJzA;7*?t=uy@X}1GWr!+0qqp_Cn176t4(dQ*
http://bernd-paysan.de/
Back to comp.lang.forth | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll 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
csiph-web