[Cryptography] Magnetic media destruction question

[Peter Gutmann]

Darren Moffat <darren at nessieroo.com> writes:

>Specifically because some of those disks/tapes are unserviceable when they
>leave and you can’t perform software based overwriting at that point, only
>physical destruction.

That's what I do.  A friend of mine recently called me and rattled off some
extraordinarily resource-intensive process he uses for sanitising old drives
which would take hours per drive (some of it admittedly just being waiting for
overwrite passes to finish).

In my case I put a nail punch through the ASICs and flash on the controller
board (total time around a minute per drive), run a drill into the alu case
and give the top (often only) platter a few whacks with the nail punch (again,
a minute or so), then put the very-obviously-not-gonna-go-any-more drives
out with ordinary rubbish.

The threat model for the former is "ooh, a hard drive, I wonder what's on it?
Interesting, he missed a bit".  For the latter it's "that's gonna take
disassembly in a clean room and careful cleaning and (I have no idea what the
story is with current drives, it's not like you can mount the platters on a
spin stand and read them with a sampling scope any more)".

Peter.