data shredder

[Amedee Van Gasse (ub)]

On Mon, December 21, 2009 10:04, Gilles Gravier wrote:

> The problem with these commands, is that you're not really helping...
> Forensics tools will read below one or more levels of re-write. You need
> to do this several times in a row... and, more importantly, you need to
> use special data patterns that will actually make reading shadows of
> former data harder if not impossible. There are standards for that. And
> they do not involve writing random data or zeros, but actual specific
> patterns.

Hi!

Can you name a few of those forensics softwares? + documentation about how
they actually work and what the conditions are to get usable results?
Preferably something recent, not some outdated standards published by the
USA government (I don't trust foreign governments on that subject, I don't
even trust my own government).

Or are you talking about disassembling a hard disk in a dustfree room and
reading the actual magnetic patterns with a scanning probe microscope to
get a palimpsest image of the disk?

If you're afraid of a casual hacker or even most law enforcement (I have
played a bit with the forensic tools cd of our Federal Computer Crime
Unit), overwriting it 10 times with random data will be more than enough.

It's only when you're afraid of *very* large organisations (intelligence
agencies, multinationals) that procedures with special RLL patterns are
worth the effort. But then again, if your data is really *that* important,
you should physically destroy the disk. Throw it in the blash furnace of a
steel mill.
But that's just my humble opinion...

Another argument, if you have 10 KB of sensitive data on a 500 GB drive,
the chances that it will be found are close to zero. The data density is
just too high. And then there is the case of perpendicular recording.


What about flash memory? To shred data on a NAND memory device you will
need something that is covered by patent WO/2009/009052.

-- 
Amedee Van Gasse