linux-kernel - Re: urandom is too slow

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20121030213850.7b987ddf@pyramind.ukuu.org.uk>
Date:	Tue, 30 Oct 2012 21:38:50 +0000
From:	Alan Cox <alan@...rguk.ukuu.org.uk>
To:	"Theodore Ts'o" <tytso@....edu>
Cc:	Lasse Kärkkäinen <ljkarkk2@...hut.fi>,
	linux-kernel@...r.kernel.org
Subject: Re: urandom is too slow

> If you just want to wipe a disk, you shouldn't be using /dev/urandom for that
> purpose.

If you want to wipe a disk issue a security erase command via hdparm.
There is no guarantee that simply writing crap all over it will re-use
the same sectors of physical media, and for a flash drive it causes
massive wear and takes forever while a security erase is normally near
immediate.

Alan
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/