[Trilug-ontopic] secure removal of files on a usb stick

[David Burton]

Truly, even with modern hard disk drives, I am sure that there's no way
that overwriting one time with zeros could be insufficient, not even if the
NSA and the Russian FSB (nee KGB) work together to try to recover your
overwritten data.

One possible problem with dd, however, is that it writes BIG chunks, and
when it gets to the end of the drive I think it might fail to overwrite the
last sectors, if the end of the requested write block doesn't align with
the end of the device. I could be wrong about that, though, and it might
vary from one system to another.

Dave


On Sat, Jul 26, 2014 at 11:50 PM, Alan Porter <porter at trilug.org> wrote:

>
> > Is there any benefit using /dev/random or /dev/urandom in this scenario?
>
> Not on a flash drive.
>
> Perhaps on a magnetic disk drive, since a forensics expert could look at
> the magnetic spots on the platter to distinguish a "1 covered up by a 0"
> from a "0 covered up by a 0".  This is where the multiple writes are
> useful.
>
> If you don't think someone is going to crack open the case and examine
> the platters, then "dd if=/dev/zero" should be good enough.
>
> Alan
>
>
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