[clug] Hard disk destruction

[Robert Edwards]

Brendan Jurd wrote:
> 2009/6/30 Sam Couter <sam at couter.id.au>:
>> How hot was your fire? You can tell from the colour of the glowing
>> disks:
>>
>> http://hearth.com/econtent/index.php/wiki/Temperature_when_metal_glows_red
> 
> I think we only got as far as the "red glow, visible in twilight" category.
> 
>> What's your threat model? Those platters are already out of the drive
>> in a non-clean environment so they're already rediculously expensive to
>> recover. Do you really have information that important?
> 
> Well if I really did have information that important, would I admit it
> and talk about it openly on a public mailing list? =)
> 
> The data we're talking about on these platters is the sort of thing
> that, if recovered, would be a Privacy Act problem.  No national
> secrets or plans for doomsday devices.
> 
> As you say, they are already well past the point where *cheap*
> recovery is possible.  The main purpose behind doing a full
> destruction is education/entertainment, with the side bonus being
> peace-of-mind in knowing that recovery is genuinely not possible.
> 
> Cheers,
> BJ

I think that you need to be careful with "genuinely not possible".
The only way you can assert that something is "not possible" is if you
are omniscient (ie. you know everything).

If you are talking about sensitive data, you need to think in terms
of risk management (and aversion). That is:
  a) how important is the data to you
  b) how valuable is it to someone else (and who are they)
  c) how much are you prepared to spend to protect it
  d) how much are they prepared to spend to get it

The person you are protecting the data from may well be someone in the
future who has access to all sorts of cool tech that we just don't know
about yet. They may look at our Scanning Electron Microscopes and our 
2048-bit public keys and just laugh at how primitive we are.

Melting the platters in a forge may be the best way to ensure data
destruction - but we don't know that either (yet). There may also be
all sorts of other traces of the data around (backup tapes etc.) that
also need to be destroyed.

Cheers,

Bob Edwards.