data shredder

[Rashkae]

NoOp wrote:
> On 12/21/2009 08:39 PM, Rashkae wrote:
>> NoOp wrote:
>>>
>>> o I recommended looking at shred and scrub.
>>> o Gilles recommended TrueCrypt (which isn't really an answer to the OP's
>>> question, and has nothing to do with the OP's question)
>>> o Amadee recomends dd - OK, but is this practical on a single file?
>>> o Kent write some nice rules about security
>>> o Ray does the same as Kent (who cares?) Security rules regarding
>>> passwords et al have been in place since I worked security & ciphony in
>>> the 1980's. Are they different now?
>>> o Karl of course throws security to the wind... Boggles the mind.
>>>
>>> So, other than my recommendations regarding shred & scrub and Gilles
>>> obtuse recommendation about TrueCrypt (which I use) but doesn't have
>>> diddly squat to do with shredding exisiting files etc.), do any of you
>>> thread drifting 'experts' have a recommendation for the OP?
>>>
>> I haven't looked at scrub, nor have I really been closely following yet
>> another long mis-informed chase into the paranoia rabbit hole.  However,
>> as seen by shred's own man page, you can't count on that program doing
>> what you want on modern filesystems.  
> 
> Did you miss:
> 
>>        Ext3  journaling  modes  can  be  changed  by adding the
>> data=something option to the mount  options  for  a  particular  file
>> system  in  the /etc/fstab file, as documented in the mount man page
>> (man mount).
> 
> So, I'll repeat:
> 
>>> So, other than my recommendations regarding shred & scrub and
>>> Gilles obtuse recommendation about TrueCrypt (which I use) but
>>> doesn't have diddly squat to do with shredding exisiting files
>>> etc.), do any of you thread drifting 'experts' have a
>>> recommendation for the OP?
> 
>> That's why we come to dd as the
>> only way to be sure you overwrite what you want.  (by filling the entire
>> free hard drive space in a new file, as root, then sync, then delete.)
> 
> Really? Cite - reference? If you think that dd will do the trick then I
> look forward to you providing details.
> 

I just did, but if you want exact commands:

sudo dd if=/dev/zero of=shred
sync && rm shred

or, the paranoid version:

sudo dd if=/dev/random of=shred
sync && rm shred

(repeat as many times as you think a shadow government can retrieve data
from previous imprints on your hd)

*note* since it might be possible that traces of the filename used might
be left behind, you may want to choose something more innocent sounding
than shred.  Name the output file whatever you like.