Re: [tlug] How to wipe disk

["Stephen J. Turnbull" <turnbull.stephen.fw@example.com>]

dblomber@example.com writes:

 > For normal use that may be enough, but is not terribly secure by
 > itself.

How many dumpster divers in Tokyo have the special equipment required
to read-under a one-pass zeroed disk, I wonder?  (Note that in Chiba,
they just zero the filesystem superblock!  I wonder if they got the
copies? ;-)  I guess this isn't APT-level tech, it's something typical
commercial data recovery services can do?

 > I would use /dev/urandom

Why urandom?  Isn't the important thing to flip all bits multiple
times?  IIRC one of the common utilities claiming to perform secure
scrub writes 0x00, then 0xFF, then 0x99, then 0xAA.

 > if not sensative info

If the APT knows the info is sensitive, then XKCD #538 applies.

https://xkcd.com/538/

My wife worked for a doctor for a while, had to decommission a disk
with patient data on it.  We had a good time whacking the platter with
a hammer.

-- 
Associate Professor              Division of Policy and Planning Science
http://turnbull.sk.tsukuba.ac.jp/     Faculty of Systems and Information
Email: turnbull@example.com                   University of Tsukuba
Tel: 029-853-5175                 Tennodai 1-1-1, Tsukuba 305-8573 JAPAN