Re: random passwords

From	Jean-David Beyer <jeandavid8@verizon.net>
Newsgroups	alt.os.linux, comp.os.linux.misc, comp.security.misc
Subject	Re: random passwords
Date	2018-08-27 20:52 -0400
Organization	NewsGuy.com
Message-ID	<pm26cp02p8q@news2.newsguy.com> (permalink)
References	(11 earlier) <plonfi$v8i$1@dont-email.me> <plqdcm$hhd$1@gioia.aioe.org> <plrfp6$4bm$1@dont-email.me> <pm20hl$ldd$1@gioia.aioe.org> <pm24ar$fhm$1@dont-email.me>

Cross-posted to 3 groups.

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On 08/27/2018 08:17 PM, William Unruh wrote:
> On 2018-08-27, Computer Nerd Kev <not@telling.you.invalid> wrote:
>> In comp.os.linux.misc Paul <nospam@needed.invalid> wrote:
>>>
>>> https://spectrum.ieee.org/computing/hardware/behind-intels-new-randomnumber-generator
>>>
>>>     https://spectrum.ieee.org/image/MTkxMTQ4OQ
>>>
>>>     "Uncertain Circuits:
>>>
>>>        When transistor 1 and transistor 2 are switched on, a coupled pair of inverters
>>>        force Node A and Node B into the same state [left]. When the clock pulse rises
>>>        [yellow, right], these transistors are turned off. Initially the output of both
>>>        inverters falls into an indeterminate state, but random thermal noise within the
>>>        inverters soon jostles one node into the logical 1 state and the other goes
>>>        to logical 0.
>>>     "
>>>
>>> It's pretty conventional looking to me. No quantums were tortured on that one.
>>
>> Thanks for the link, that article was an interesting read. I'm not
>> sure about no quantums being tortured though, the root of the whole
>> thing is the "thermal noise", described later as "random atomic
>> vibrations". As I said before, I never managed to penetrate deeply
>> enough into this to understand it properly (and by now I've
>> forgotten everything that I did understand), but it certainly goes
>> further into physics than just electronic theory.
>>
>> The point is that _if_ you knew how to model the exact behaviour
>> that causes the "thermal noise", perhaps you could predict it
>> and thereby find that it isn't truly random. On the other hand,
>> the general assumption seems to be that it is intrinsically
>> random, and in practice I'm happy to believe that.
> 
> The problem is that the thermal noise comes about because of the
> interaction of the device with loads of other things in the vicinity.
> Unless you knew exactly what the state of those other things are (atoms
> for example) you do not know what their effect is on the thing you are
> trying to use (the reversed biased junction for example) And there are
> so so so many other things around that their effect become impossible to
> predict. 
> 
> Now, it may be there are "echos" for example. Something affects the device of
> interest, that device affects back that something which then comes back
> and affects the device again. That can produce long time correlations in
> the output of the device. Ie, most physical devices have such
> correlations, which, if you understand the device and its environment
> well, could give you some information about the random stream. Ie,
> biases need not just be "this device produces more ones than zeros" But
> "if it produces a one now it has a higher probability of producing a one
> 10 milliseconds later", even if the average probability of producin one
> of zero are equal.
> 
> 
>>
>>> The most fun kind is lava-rand. The usage of lava lamps
>>> (which are thermally driven by a heat source in the base),
>>> to generate random numbers. Cloudflare didn't invent this,
>>> and this is just an example.
> 
> Well, no. They tend to operate by heating and cooling. The blob is
> heated at the bottom, rises to the top where it cools and sinks back
> down. That process is probably in large part predictable. Ie, lava lamps
> are probably a terrible source of "random bits". 
> 
> 
>>>
>>> https://blog.cloudflare.com/lavarand-in-production-the-nitty-gritty-technical-details/
>>>
>>>    "In the lobby of our San Francisco office, we have a wall of lava lamps
>>>     (pictured above). A video feed of this wall is used to generate entropy
>>>     that is made available to our production fleet."
>>
>> It's the best excuse that I can think of for building a wall of
>> lava lamps. :)
> 
> As a source amongst many others it might be useful. As the only source
> it is probably terrible. 
> 
> 
>>

In the very old days, a common pseudo-random number generator was to
take a number (in binary), square it, and take a bunch on bits from the
middle as the random number. For the next random number, do it again to
the random number you just produced. Those numbers look pretty random,
and they pass some typical tests for randomness for a while but in  time
it tends to produce all zeros. Not very random.

Computer generated pseudo-random number generators these days are much
better than that, but of course they are not truely random: they
eventually repeat, but not that obviously as the original.

At one point, John von Neumann suggested using the original one, not
because it was so good, but because its failure mode was understood.

-- 
  .~.  Jean-David Beyer          Registered Linux User 85642.
  /V\  PGP-Key:166D840A 0C610C8B Registered Machine  1935521.
 /( )\ Shrewsbury, New Jersey    http://linuxcounter.net
 ^^-^^ 20:45:02 up 12 days, 13:03, 2 users, load average: 4.74, 4.65, 4.91

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random passwords Ivan Shmakov <ivan@siamics.net> - 2018-08-23 14:05 +0000
  Re: random passwords Robert Heller <heller@deepsoft.com> - 2018-08-23 09:47 -0500
    Re: random passwords Wouter Verhelst <w@uter.be> - 2018-08-24 10:16 +0200
      Re: random passwords The Natural Philosopher <tnp@invalid.invalid> - 2018-08-24 11:46 +0100
        Re: random passwords Jean-David Beyer <jeandavid8@verizon.net> - 2018-08-24 09:19 -0400
        Re: random passwords Daniel60 <daniel47@eternal-september.org> - 2018-08-25 21:57 +1000
          Re: random passwords The Natural Philosopher <tnp@invalid.invalid> - 2018-08-25 13:32 +0100
  Re: random passwords Richard Kettlewell <invalid@invalid.invalid> - 2018-08-23 15:50 +0100
    Re: random passwords Ivan Shmakov <ivan@siamics.net> - 2018-08-23 16:40 +0000
      Re: random passwords Rich <rich@example.invalid> - 2018-08-23 17:12 +0000
      Re: random passwords Richard Kettlewell <invalid@invalid.invalid> - 2018-08-23 18:49 +0100
        Re: random passwords Ivan Shmakov <ivan@siamics.net> - 2018-09-01 13:45 +0000
          Re: random passwords Rich <rich@example.invalid> - 2018-09-01 15:02 +0000
          Re: random passwords Allodoxaphobia <knock_yourself_out@example.net> - 2018-09-01 16:54 +0000
          Re: random passwords Richard Kettlewell <invalid@invalid.invalid> - 2018-09-04 07:37 +0100
  Re: random passwords Rich <rich@example.invalid> - 2018-08-23 15:12 +0000
    Re: random passwords Jean-David Beyer <jeandavid8@verizon.net> - 2018-08-23 12:49 -0400
      Re: random passwords Rich <rich@example.invalid> - 2018-08-23 17:18 +0000
        Re: random passwords William Unruh <unruh@invalid.ca> - 2018-08-23 17:27 +0000
          Re: random passwords Rich <rich@example.invalid> - 2018-08-23 17:44 +0000
    Re: random passwords Grant Taylor <gtaylor@tnetconsulting.net> - 2018-08-23 12:38 -0600
      Re: random passwords Grant Taylor <gtaylor@tnetconsulting.net> - 2018-08-23 12:47 -0600
        Re: random passwords William Unruh <unruh@invalid.ca> - 2018-08-24 02:20 +0000
        Re: random passwords Jasen Betts <jasen@xnet.co.nz> - 2018-08-24 05:10 +0000
      Re: random passwords The Natural Philosopher <tnp@invalid.invalid> - 2018-08-24 02:32 +0100
        Re: random passwords Rich <rich@example.invalid> - 2018-08-24 01:56 +0000
          Re: random passwords The Natural Philosopher <tnp@invalid.invalid> - 2018-08-24 11:37 +0100
        Re: random passwords Grant Taylor <gtaylor@tnetconsulting.net> - 2018-08-23 20:13 -0600
          Re: random passwords The Natural Philosopher <tnp@invalid.invalid> - 2018-08-24 11:42 +0100
            Re: random passwords Chris Elvidge <chris@mshome.net> - 2018-08-24 11:55 +0100
              Re: random passwords Paul <nospam@needed.invalid> - 2018-08-24 08:37 -0400
                Re: random passwords Chris Elvidge <chris@mshome.net> - 2018-08-24 13:51 +0100
                Re: random passwords Paul <nospam@needed.invalid> - 2018-08-24 12:41 -0400
            Re: random passwords not@telling.you.invalid (Computer Nerd Kev) - 2018-08-25 02:03 +0000
              Re: random passwords Java Jive <java@evij.com.invalid> - 2018-08-25 11:32 +0100
              Re: random passwords Paul <nospam@needed.invalid> - 2018-08-25 07:49 -0400
                Re: random passwords not@telling.you.invalid (Computer Nerd Kev) - 2018-08-27 23:12 +0000
                Re: random passwords not@telling.you.invalid (Computer Nerd Kev) - 2018-08-27 23:40 +0000
                Re: random passwords Paul <nospam@needed.invalid> - 2018-08-27 20:10 -0400
                Re: random passwords William Unruh <unruh@invalid.ca> - 2018-08-28 00:17 +0000
                Re: random passwords Jean-David Beyer <jeandavid8@verizon.net> - 2018-08-27 20:52 -0400
                Re: random passwords John Hasler <jhasler@newsguy.com> - 2018-08-27 22:31 -0500
                Re: random passwords The Natural Philosopher <tnp@invalid.invalid> - 2018-08-28 10:23 +0100
                Re: random passwords William Unruh <unruh@invalid.ca> - 2018-08-28 14:45 +0000
                Re: random passwords not@telling.you.invalid (Computer Nerd Kev) - 2018-08-28 23:00 +0000
                Re: random passwords William Unruh <unruh@invalid.ca> - 2018-08-29 01:22 +0000
                Re: random passwords not@telling.you.invalid (Computer Nerd Kev) - 2018-08-29 07:21 +0000
                Re: random passwords The Natural Philosopher <tnp@invalid.invalid> - 2018-08-29 11:37 +0100
                Re: random passwords William Unruh <unruh@invalid.ca> - 2018-08-29 12:25 +0000
                Re: random passwords The Natural Philosopher <tnp@invalid.invalid> - 2018-08-29 19:35 +0100
                Re: random passwords John Hasler <jhasler@newsguy.com> - 2018-08-29 17:46 -0500
                Re: random passwords The Natural Philosopher <tnp@invalid.invalid> - 2018-08-30 06:53 +0100
                Re: random passwords John Hasler <jhasler@newsguy.com> - 2018-08-30 07:48 -0500
                Re: random passwords The Natural Philosopher <tnp@invalid.invalid> - 2018-08-30 19:07 +0100
                Re: random passwords William Unruh <unruh@invalid.ca> - 2018-08-31 00:36 +0000
                Re: random passwords The Natural Philosopher <tnp@invalid.invalid> - 2018-08-31 03:10 +0100
                Re: random passwords Chris Elvidge <chris@mshome.net> - 2018-08-31 12:26 +0100
                Re: random passwords William Unruh <unruh@invalid.ca> - 2018-08-29 23:36 +0000
                Re: random passwords The Natural Philosopher <tnp@invalid.invalid> - 2018-08-29 11:35 +0100
                Re: random passwords not@telling.you.invalid (Computer Nerd Kev) - 2018-08-29 23:45 +0000
      Re: random passwords Ivan Shmakov <ivan@siamics.net> - 2018-08-24 18:07 +0000
        Re: random passwords William Unruh <unruh@invalid.ca> - 2018-08-24 20:27 +0000
    Re: random passwords Bud Frede <frede@mouse-potato.com> - 2018-09-03 07:23 -0400
  Re: random passwords Ivan Shmakov <ivan@siamics.net> - 2018-08-23 16:57 +0000
    Re: random passwords Rich <rich@example.invalid> - 2018-08-23 17:07 +0000
  Re: random passwords William Unruh <unruh@invalid.ca> - 2018-08-23 17:02 +0000
    Re: random passwords Ivan Shmakov <ivan@siamics.net> - 2018-08-23 17:25 +0000
      Re: random passwords William Unruh <unruh@invalid.ca> - 2018-08-23 17:32 +0000
      Re: random passwords Rich <rich@example.invalid> - 2018-08-23 17:46 +0000
        Re: random passwords Ivan Shmakov <ivan@siamics.net> - 2018-08-23 18:07 +0000
        Re: random passwords Grant Taylor <gtaylor@tnetconsulting.net> - 2018-08-23 12:51 -0600
    Re: random passwords Allodoxaphobia <knock_yourself_out@example.net> - 2018-08-24 02:35 +0000
  Re: random passwords John Hasler <jhasler@newsguy.com> - 2018-08-25 11:13 -0500
    Re: random passwords Rich <rich@example.invalid> - 2018-08-25 17:24 +0000
      Re: random passwords John Hasler <jhasler@newsguy.com> - 2018-08-25 13:17 -0500
        Re: random passwords Rich <rich@example.invalid> - 2018-08-25 20:27 +0000
          Re: random passwords Robert Heller <heller@deepsoft.com> - 2018-08-25 21:28 -0500
            Re: random passwords Jean-David Beyer <jeandavid8@verizon.net> - 2018-08-26 01:19 -0400
              Re: random passwords Rich <rich@example.invalid> - 2018-08-26 13:43 +0000
                Re: random passwords Ivan Shmakov <ivan@siamics.net> - 2018-08-26 14:15 +0000
                Re: random passwords Rich <rich@example.invalid> - 2018-08-26 15:18 +0000
                Re: random passwords Robert Heller <heller@deepsoft.com> - 2018-08-26 09:30 -0500
              Re: random passwords Michael Black <mblack@pubnix.net> - 2018-08-26 11:44 -0400
                Re: random passwords John Hasler <jhasler@newsguy.com> - 2018-08-26 16:40 -0500
                Re: random passwords Robert Heller <heller@deepsoft.com> - 2018-08-26 21:11 -0500
                Re: random passwords Allodoxaphobia <knock_yourself_out@example.net> - 2018-08-28 13:29 +0000
                Re: random passwords The Natural Philosopher <tnp@invalid.invalid> - 2018-08-28 14:32 +0100
                Re: random passwords The Natural Philosopher <tnp@invalid.invalid> - 2018-08-27 07:17 +0100
                Re: random passwords Melzzzzz <Melzzzzz@zzzzz.com> - 2018-08-27 06:21 +0000
                Re: random passwords The Natural Philosopher <tnp@invalid.invalid> - 2018-08-27 08:15 +0100
                Re: random passwords Roger Blake <rogblake@iname.invalid> - 2018-08-27 22:44 +0000
              Re: random passwords azigni <azigni@yahoo.com> - 2018-08-26 12:55 -0600
                Re: random passwords Robert Heller <heller@deepsoft.com> - 2018-08-26 16:09 -0500
                Re: random passwords Rich <rich@example.invalid> - 2018-08-26 21:32 +0000
                Re: random passwords Robert Heller <heller@deepsoft.com> - 2018-08-26 21:11 -0500
                Re: random passwords The Natural Philosopher <tnp@invalid.invalid> - 2018-08-27 07:19 +0100
            Re: random passwords Doug McIntyre <merlyn@dork.geeks.org> - 2018-08-26 00:41 -0500
              Re: random passwords Robert Heller <heller@deepsoft.com> - 2018-08-26 06:48 -0500

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