[GRLUG] Data wiping / recovery / paranoia

[Tim Schmidt]

On 9/15/06, Justin Denick <justin.denick at gmail.com> wrote:
> I think the name of the prog Jorge is thinking of is called "shred" You can
> even psecify how many time the data will be over written.
>
> But in the name of security, wouldn't Flah drives be the most secure an
> easiest to sanitize. With the size of theses drives now they can hold a
> pretty serious amount of Data.

Flash drives are worse...  the wear-leveling logic in any modern flash
drive transparently changes the effective location of bits any time it
wants.  So, for instance, if you were to de-solder the actual flash
chip and read the information from it in raw form, there would likely
be lots more available than on a typical hard drive.  Even after using
something like shred (unless of course you're shredding the entire
drive - and not just the partition or file).

That said...  modern hard drives do the same thing.  It's impossible
to make a multi-trillion bit basket without quite a few errors...  so
all drives have reserve sections of bits that they can remap into bad
areas of the disk.  They come that way from the factory, and most can
do it on the fly as well.  The reserve area isn't very large in
relation to the total size of the drive, but it's just one more layer
of indirection that makes 100% assurance that your data is sanitized a
very hard thing to guarantee.

--tim