Groups > comp.os.linux.development.apps > #703

Re: shred or scrub

From	Rainer Weikusat <rweikusat@mobileactivedefense.com>
Newsgroups	comp.os.linux.development.system, comp.os.linux.development.apps
Subject	Re: shred or scrub
Date	2014-04-19 23:05 +0100
Message-ID	<87ppkd2cx5.fsf@sable.mobileactivedefense.com> (permalink)
References	<limvgj$tse$1@dont-email.me> <lio9r0$3jl$1@dont-email.me> <lisn3i$elq$1@dont-email.me>

Cross-posted to 2 groups.

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"Bill Cunningham" <nospam@nspam.invalid> writes:
> crankypuss wrote:
>
>> There exist pseudo-devices 'zero', 'random', and 'urandom':
>> http://en.wikipedia.org/wiki/Device_file#Pseudo-devices
>
>     What's the difference in urandom and random devices?

The kernel is supposed to collect 'bits with unpredictable values' from
'suitable sources' and the random-device will only return such bits,
blocking a reader in case the already collected ones have all been
handed out. /dev/urandom is a hash-based PRNG which generates bits as
required by performing a set of calculations on the existing
'unpredictable value bit pool'. In theory, someone who knows what the
PRNG returned in the past could be able to predict what it will return
in future. In practice no "method for doing so" has been published and
this is considered to be 'a very difficult problem which might be
impossible to solve'.

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Thread

shred or scrub "Bill Cunningham" <nospam@nspam.invalid> - 2014-04-16 18:17 -0400
  Re: shred or scrub crankypuss <crankypuss@nomail.invalid> - 2014-04-17 04:19 -0600
    Re: shred or scrub "Bill Cunningham" <nospam@nspam.invalid> - 2014-04-18 22:30 -0400
      Re: shred or scrub Jasen Betts <jasen@xnet.co.nz> - 2014-04-19 07:42 +0000
        Re: shred or scrub Richard Kettlewell <rjk@greenend.org.uk> - 2014-04-19 10:04 +0100
      Re: shred or scrub crankypuss <crankypuss@nomail.invalid> - 2014-04-19 02:15 -0600
      Re: shred or scrub Rainer Weikusat <rweikusat@mobileactivedefense.com> - 2014-04-19 23:05 +0100
        Re: shred or scrub crankypuss <crankypuss@nomail.invalid> - 2014-04-20 02:47 -0600
          Re: shred or scrub John Hasler <jhasler@newsguy.com> - 2014-04-20 07:56 -0500
            Re: shred or scrub crankypuss <crankypuss@nomail.invalid> - 2014-04-21 03:51 -0600
              Re: shred or scrub Jasen Betts <jasen@xnet.co.nz> - 2014-04-21 11:50 +0000
                Re: shred or scrub crankypuss <crankypuss@nomail.invalid> - 2014-04-21 06:14 -0600
            Re: shred or scrub "Bill Cunningham" <nospam@nspam.invalid> - 2014-04-21 18:44 -0400
          Re: shred or scrub Rainer Weikusat <rweikusat@mobileactivedefense.com> - 2014-04-21 13:24 +0100
            Re: shred or scrub crankypuss <crankypuss@nomail.invalid> - 2014-04-22 04:10 -0600
              Re: shred or scrub Rainer Weikusat <rweikusat@mobileactivedefense.com> - 2014-04-22 14:39 +0100
  Re: shred or scrub David Brown <david.brown@hesbynett.no> - 2014-04-17 16:41 +0200
  Re: UNIX(*)/ Linux history & system design Rainer Weikusat <rweikusat@mobileactivedefense.com> - 2014-05-07 22:01 +0100
    Re: UNIX(*)/ Linux history & system design crankypuss <crankypuss@nomail.invalid> - 2014-05-08 03:37 -0600
      Re: UNIX(*)/ Linux history & system design Rainer Weikusat <rweikusat@mobileactivedefense.com> - 2014-05-08 14:02 +0100
        Re: UNIX(*)/ Linux history & system design Rainer Weikusat <rweikusat@mobileactivedefense.com> - 2014-05-08 15:43 +0100
        Re: UNIX(*)/ Linux history & system design crankypuss <crankypuss@nomail.invalid> - 2014-05-09 02:56 -0600
          Re: UNIX(*)/ Linux history & system design Rainer Weikusat <rweikusat@mobileactivedefense.com> - 2014-05-09 17:57 +0100

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