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Groups > comp.os.linux.misc > #90506
| From | "Carlos E.R." <robin_listas@es.invalid> |
|---|---|
| Newsgroups | comp.os.linux.misc |
| Subject | Re: Overwriting with random data |
| Date | 2026-08-25 11:36 +0200 |
| Organization | Tebibyte_Retro_Gaming |
| Message-ID | <4a40mmx4l5.ln2@Telcontar.valinor> (permalink) |
| References | (12 earlier) <116h5be$2nco1$1@dont-email.me> <vefulmxca.ln2@Telcontar.valinor> <wwvfr03z3ye.fsf@LkoBDZeT.terraraq.uk> <71mulmxumi.ln2@Telcontar.valinor> <4R-dndpP7cWGpBD3nZ2dnZfqn_adnZ2d@giganews.com> |
On 2026-08-25 08:39, c186282 wrote: > On 8/24/26 16:26, Carlos E.R. wrote: >> On 2026-08-24 21:57, Richard Kettlewell wrote: >>> "Carlos E.R." <robin_listas@es.invalid> writes: >>>> Using true random data is slow, specially if the disk or partition is >>>> very big. Depends on how fast can the machine create new random data >>>> (see man random and urandom). So I do tricks to do it faster. >>> >>> With very few exceptions nobody uses true random[1] data directly. >>> /dev/random is a DRBG seeded from the random sources the kernel finds; >>> shred sees its internal RNG with 32 bytes from the kernel (strace >>> it...); I don’t know where you’re getting random data from but the >>> chances that it’s direct from a TRNG are negligible. >> >> Normally >> >> dd if=/dev/urandom of=$BIGRANDOM count=1024 bs=1M >> >> or in pascal >> >> var >> randomsource : file of byte; >> x: Integer; >> begin >> try >> assign(randomsource, '/dev/urandom'); >> reset(randomsource); >> for x:= 1 to shuflecount do >> read(randomsource, BigData[Index, x]); >> finally >> close(randomsource); >> end; >> end; > > MIGHT not be as "random" as you hope. This has > LONG been a problem. Sure. Right now I have the doubt if I should have used /dev/random instead (I never remember which is which). But it is not that important. > > Rather than rely on some canned function, DO add > some shit from very transient machine-related vars > as well. Video vars, CPU temps, that kind of shit. > STILL not really truly "random" - but a lot closer. > > If you want TRUE "random", I suspect some kind of > little quantum device will be needed. it is true random in the sense that the kernel provides it as random. That is enough. The kernel provides two sources: one that waits if there is not enough random data, and the other that doesn't wait and provides what it can. I call the former "true random". More true random I consider unobtainium and go without. > >>> >>> [1] in the sense described by >>> e.g. https://link.springer.com/content/ >>> pdf/10.1007/978-3-540-85053-3_10.pdf >>> > -- Cheers, Carlos. ES🇪🇸, EU🇪🇺;
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/dev/tcp Eli the Bearded <*@eli.users.panix.com> - 2026-08-19 21:20 +0000
Re: /dev/tcp Richard Kettlewell <invalid@invalid.invalid> - 2026-08-19 23:53 +0100
Re: /dev/tcp Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-08-19 23:42 +0000
Re: /dev/tcp Eli the Bearded <*@eli.users.panix.com> - 2026-08-20 00:59 +0000
Re: /dev/tcp Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-08-20 03:59 +0000
Re: /dev/tcp Nuno Silva <nunojsilva@invalid.invalid> - 2026-08-20 10:10 +0100
Re: /dev/tcp Eli the Bearded <*@eli.users.panix.com> - 2026-08-20 18:15 +0000
Re: /dev/tcp Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-08-20 23:30 +0000
Re: /dev/tcp Nuno Silva <nunojsilva@invalid.invalid> - 2026-08-21 01:18 +0100
Re: /dev/tcp Marc Haber <mh+usenetspam2616@zugschl.us> - 2026-08-21 09:52 +0200
Re: /dev/tcp Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-08-21 08:12 +0000
Re: /dev/tcp Marc Haber <mh+usenetspam2616@zugschl.us> - 2026-08-21 11:16 +0200
Re: /dev/tcp Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-08-21 22:57 +0000
Re: /dev/tcp Marc Haber <mh+usenetspam2616@zugschl.us> - 2026-08-22 06:17 +0200
Re: /dev/tcp c186282 <c186282@nnada.net> - 2026-08-21 21:50 -0400
Re: /dev/tcp Anssi Saari <anssi.saari@usenet.mail.kapsi.fi> - 2026-08-24 17:42 +0300
Re: /dev/tcp Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-08-24 23:53 +0000
Re: /dev/tcp c186282 <c186282@nnada.net> - 2026-08-25 02:27 -0400
Re: /dev/tcp vallor <vallor@vallor.earth> - 2026-08-23 00:56 +0000
Re: /dev/tcp Rich <rich@example.invalid> - 2026-08-23 04:01 +0000
Re: /dev/tcp c186282 <c186282@nnada.net> - 2026-08-23 03:37 -0400
Re: /dev/tcp "Carlos E.R." <robin_listas@es.invalid> - 2026-08-23 13:50 +0200
Re: /dev/tcp vallor <vallor@vallor.earth> - 2026-08-23 22:28 +0000
Re: /dev/tcp "Carlos E.R." <robin_listas@es.invalid> - 2026-08-24 09:35 +0200
Overwriting with random data (was: Re: /dev/tcp) Nuno Silva <nunojsilva@invalid.invalid> - 2026-08-24 11:10 +0100
Re: Overwriting with random data "Carlos E.R." <robin_listas@es.invalid> - 2026-08-24 20:34 +0200
Re: Overwriting with random data Richard Kettlewell <invalid@invalid.invalid> - 2026-08-24 20:57 +0100
Re: Overwriting with random data "Carlos E.R." <robin_listas@es.invalid> - 2026-08-24 22:26 +0200
Re: Overwriting with random data c186282 <c186282@nnada.net> - 2026-08-25 02:39 -0400
Re: Overwriting with random data Richard Kettlewell <invalid@invalid.invalid> - 2026-08-25 08:45 +0100
Re: Overwriting with random data c186282 <c186282@nnada.net> - 2026-08-25 21:39 -0400
Re: Overwriting with random data "Carlos E.R." <robin_listas@es.invalid> - 2026-08-25 11:36 +0200
Re: Overwriting with random data Richard Kettlewell <invalid@invalid.invalid> - 2026-08-25 15:19 +0100
Re: Overwriting with random data c186282 <c186282@nnada.net> - 2026-08-26 03:33 -0400
Re: Overwriting with random data The Natural Philosopher <tnp@invalid.invalid> - 2026-08-26 09:18 +0100
Re: Overwriting with random data The Natural Philosopher <tnp@invalid.invalid> - 2026-08-25 12:12 +0100
Re: Overwriting with random data c186282 <c186282@nnada.net> - 2026-08-26 00:09 -0400
Re: Overwriting with random data The Natural Philosopher <tnp@invalid.invalid> - 2026-08-26 08:52 +0100
Re: /dev/tcp c186282 <c186282@nnada.net> - 2026-08-25 00:37 -0400
Re: /dev/tcp c186282 <c186282@nnada.net> - 2026-08-24 00:31 -0400
Re: /dev/tcp "Carlos E.R." <robin_listas@es.invalid> - 2026-08-24 09:45 +0200
Re: /dev/tcp The Natural Philosopher <tnp@invalid.invalid> - 2026-08-23 12:52 +0100
Re: /dev/tcp The Natural Philosopher <tnp@invalid.invalid> - 2026-08-23 12:50 +0100
Re: /dev/tcp Rich <rich@example.invalid> - 2026-08-20 13:50 +0000
Re: /dev/tcp c186282 <c186282@nnada.net> - 2026-08-20 13:02 -0400
Re: /dev/tcp Rich <rich@example.invalid> - 2026-08-20 18:26 +0000
Re: /dev/tcp The Natural Philosopher <tnp@invalid.invalid> - 2026-08-21 13:54 +0100
Re: /dev/tcp c186282 <c186282@nnada.net> - 2026-08-21 22:57 -0400
Re: /dev/tcp "Carlos E.R." <robin_listas@es.invalid> - 2026-08-22 21:47 +0200
The hammer is best (Was: /dev/tcp) gazelle@shell.xmission.com (Kenny McCormack) - 2026-08-22 23:50 +0000
Re: The hammer is best (Was: /dev/tcp) c186282 <c186282@nnada.net> - 2026-08-23 04:28 -0400
Re: The hammer is best Richard Kettlewell <invalid@invalid.invalid> - 2026-08-23 10:14 +0100
Re: The hammer is best "Carlos E.R." <robin_listas@es.invalid> - 2026-08-23 13:55 +0200
Re: The hammer is best The Natural Philosopher <tnp@invalid.invalid> - 2026-08-23 13:16 +0100
Re: The hammer is best Marc Haber <mh+usenetspam2616@zugschl.us> - 2026-08-23 21:20 +0200
Re: The hammer is best c186282 <c186282@nnada.net> - 2026-08-24 02:18 -0400
Re: The hammer is best The Natural Philosopher <tnp@invalid.invalid> - 2026-08-24 11:26 +0100
Re: The hammer is best c186282 <c186282@nnada.net> - 2026-08-25 02:06 -0400
Re: The hammer is best The Natural Philosopher <tnp@invalid.invalid> - 2026-08-25 12:18 +0100
Re: The hammer is best c186282 <c186282@nnada.net> - 2026-08-26 00:51 -0400
Re: The hammer is best Joed Oakes <lost@noway.home.invalid> - 2026-08-23 19:42 -0400
Re: The hammer is best Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-08-23 23:56 +0000
Re: The hammer is best c186282 <c186282@nnada.net> - 2026-08-24 02:25 -0400
Re: The hammer is best rbowman <bowman@montana.com> - 2026-08-24 01:14 +0000
Re: The hammer is best "Carlos E.R." <robin_listas@es.invalid> - 2026-08-24 09:50 +0200
Re: The hammer is best c186282 <c186282@nnada.net> - 2026-08-25 00:56 -0400
Re: The hammer is best c186282 <c186282@nnada.net> - 2026-08-24 00:53 -0400
Re: The hammer is best rbowman <bowman@montana.com> - 2026-08-24 06:42 +0000
Re: The hammer is best c186282 <c186282@nnada.net> - 2026-08-24 23:34 -0400
Re: The hammer is best rbowman <bowman@montana.com> - 2026-08-25 04:08 +0000
Re: The hammer is best "Carlos E.R." <robin_listas@es.invalid> - 2026-08-25 11:29 +0200
Re: The hammer is best rbowman <bowman@montana.com> - 2026-08-25 18:52 +0000
Re: The hammer is best c186282 <c186282@nnada.net> - 2026-08-26 04:19 -0400
Re: The hammer is best The Natural Philosopher <tnp@invalid.invalid> - 2026-08-26 09:29 +0100
Re: The hammer is best c186282 <c186282@nnada.net> - 2026-08-25 22:18 -0400
Re: The hammer is best The Natural Philosopher <tnp@invalid.invalid> - 2026-08-24 11:28 +0100
Re: The hammer is best c186282 <c186282@nnada.net> - 2026-08-25 02:07 -0400
Re: The hammer is best rbowman <bowman@montana.com> - 2026-08-25 06:39 +0000
Re: The hammer is best The Natural Philosopher <tnp@invalid.invalid> - 2026-08-25 12:23 +0100
Re: The hammer is best Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2026-08-25 18:26 +0000
Re: The hammer is best The Natural Philosopher <tnp@invalid.invalid> - 2026-08-25 20:05 +0100
Re: The hammer is best "Carlos E.R." <robin_listas@es.invalid> - 2026-08-25 21:43 +0200
Re: The hammer is best The Natural Philosopher <tnp@invalid.invalid> - 2026-08-26 08:35 +0100
Re: The hammer is best Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2026-08-25 20:21 +0000
Re: The hammer is best "Carlos E.R." <robin_listas@es.invalid> - 2026-08-25 23:14 +0200
Re: The hammer is best rbowman <bowman@montana.com> - 2026-08-25 19:08 +0000
Re: The hammer is best c186282 <c186282@nnada.net> - 2026-08-26 04:38 -0400
Re: The hammer is best The Natural Philosopher <tnp@invalid.invalid> - 2026-08-26 10:22 +0100
Re: The hammer is best c186282 <c186282@nnada.net> - 2026-08-26 01:49 -0400
Re: The hammer is best The Natural Philosopher <tnp@invalid.invalid> - 2026-08-25 12:20 +0100
Re: The hammer is best c186282 <c186282@nnada.net> - 2026-08-26 01:23 -0400
Re: The hammer is best c186282 <c186282@nnada.net> - 2026-08-23 22:16 -0400
Re: /dev/tcp Geoff Clare <geoff@clare.See-My-Signature.invalid> - 2026-08-21 13:41 +0100
Re: /dev/tcp Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-08-21 22:58 +0000
Re: /dev/tcp c186282 <c186282@nnada.net> - 2026-08-21 22:28 -0400
ksh (was: /dev/tcp) Geoff Clare <geoff@clare.See-My-Signature.invalid> - 2026-08-24 13:56 +0100
Bash vs. ksh - Does it matter? And the 'vi' mode thing... (Was: ksh (was: /dev/tcp)) gazelle@shell.xmission.com (Kenny McCormack) - 2026-08-24 14:57 +0000
Re: ksh (was: /dev/tcp) Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-08-24 21:08 +0000
Re: ksh (was: /dev/tcp) gazelle@shell.xmission.com (Kenny McCormack) - 2026-08-24 21:28 +0000
Re: ksh (was: /dev/tcp) rbowman <bowman@montana.com> - 2026-08-25 01:11 +0000
Re: ksh (was: /dev/tcp) Geoff Clare <geoff@clare.See-My-Signature.invalid> - 2026-08-25 13:25 +0100
Re: ksh (was: /dev/tcp) Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-08-25 21:58 +0000
Re: ksh (was: /dev/tcp) Geoff Clare <geoff@clare.See-My-Signature.invalid> - 2026-08-26 13:34 +0100
Re: ksh c186282 <c186282@nnada.net> - 2026-08-25 02:25 -0400
Re: ksh rbowman <bowman@montana.com> - 2026-08-25 06:52 +0000
Re: ksh The Natural Philosopher <tnp@invalid.invalid> - 2026-08-25 12:27 +0100
Re: ksh Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2026-08-25 18:26 +0000
Re: ksh Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-08-25 22:03 +0000
Re: ksh c186282 <c186282@nnada.net> - 2026-08-26 04:04 -0400
Re: ksh c186282 <c186282@nnada.net> - 2026-08-26 02:35 -0400
Re: ksh Marco Moock <mm@dorfdsl.de> - 2026-08-25 09:56 +0200
Re: ksh "Carlos E.R." <robin_listas@es.invalid> - 2026-08-25 11:24 +0200
Re: ksh Marc Haber <mh+usenetspam2616@zugschl.us> - 2026-08-25 20:36 +0200
Re: ksh rbowman <bowman@montana.com> - 2026-08-26 04:23 +0000
Re: ksh "Carlos E.R." <robin_listas@es.invalid> - 2026-08-26 10:04 +0200
Re: ksh Nuno Silva <nunojsilva@invalid.invalid> - 2026-08-26 10:03 +0100
Re: ksh c186282 <c186282@nnada.net> - 2026-08-25 21:50 -0400
Re: ksh The Natural Philosopher <tnp@invalid.invalid> - 2026-08-25 12:27 +0100
Re: ksh c186282 <c186282@nnada.net> - 2026-08-26 02:43 -0400
Re: ksh Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-08-25 22:01 +0000
Re: ksh "Carlos E.R." <robin_listas@es.invalid> - 2026-08-26 01:32 +0200
Re: ksh c186282 <c186282@nnada.net> - 2026-08-25 21:46 -0400
Re: ksh rbowman <bowman@montana.com> - 2026-08-26 04:25 +0000
Re: /dev/tcp Eli the Bearded <*@eli.users.panix.com> - 2026-08-20 18:22 +0000
Re: /dev/tcp The Natural Philosopher <tnp@invalid.invalid> - 2026-08-21 13:57 +0100
Re: /dev/tcp Lars Poulsen <lars@beagle-ears.com> - 2026-08-23 06:37 -0700
Re: /dev/tcp Richard Kettlewell <invalid@invalid.invalid> - 2026-08-23 14:49 +0100
Re: /dev/tcp The Natural Philosopher <tnp@invalid.invalid> - 2026-08-23 16:13 +0100
Re: /dev/tcp Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-08-23 22:31 +0000
Re: /dev/tcp Richard Kettlewell <invalid@invalid.invalid> - 2026-08-24 19:08 +0100
csiph-web