Re: Wiping hard drives - Re: debian-user-digest Digest V2011 #1704
On 20/09/11 04:08, Lee Winter wrote:
> On Mon, Sep 19, 2011 at 12:57 PM, D G Teed <donald.teed@gmail.com> wrote:
>> On Mon, Sep 19, 2011 at 1:21 PM, Lee Winter <lee.j.i.winter@gmail.com>
>> wrote:
>>>
>>> On Mon, Sep 19, 2011 at 10:27 AM, Aaron Toponce <aaron.toponce@gmail.com>
>>> wrote:
>>>> On Sat, Sep 17, 2011 at 08:59:14AM +0200, Ralf Mardorf wrote:
>>>>> If you want to be safe, you need to overwrite the data several times,
>>>>
>>>> Have anything to back that up? If you're using drives that used the old
>>>> MFM
>>>> or RLL encoding schemes, and had massive space for bits per linear inch,
>>>> then sure, but on today's drives, with perpindicular encoding, and the
>>>> extremely dense bit capacity, going more than once is silly.
>>>
>>> I perform this service for commercial recyclers.
>>
>> Or in other words, it must be true because the service provided
>> depends on this being true.
Armchair logic ain't science...
>
> No. And I find your comment offeisive.
>
>> It remains an urban legend as long as there is no proof offered otherwise.
No - *that's* piss poor logic - the sort epoused by TV talk show hosts
and radio shock jocks.
I use Newtonian physics around the farm - does that disprove Quantum
physics?
Never confuse a neat sounding argument with evidence - it just makes you
sound like a pompous moron (which you're not). But that's the difference
between something untested that confirms beliefs, and a fact.
I thought the sophists were long dead... :-)
>> I'm not saying it is true or not, but just that there has never been
>> a demonstration�made public of getting data off drives after
>> a complete zeroing.
>
> That you know of. I suspect I read much more of this literature than you do.
Gutmman (et al)
>
>> �So it remains an unknown, and never demonstrated.
Unknow to D. G. Teed *may* simply mean "not shown on Discovery Channel"
- "never demonstrated"... to who?
The plural of anecdote is not evidence.
For non-military/investigative (sensitive) evidence - how do you think
data *has* (and is still) been recovered from fragments of shattered,
partially melted, hard drive platters from September 11? Yes - much of
the procedures are classified or considered proprietary secrets - but
some data reconstruction algorithims, and 3D magnetic field
visualization papers, have been published... could be that current
technology is based on them.
>
> You also failed to consider the asymmetry between the possible
> outcomes once the "truth" becomes known. If one-pass overwrite is
> sufficient, but one uses multiple passes, then one has lost a small
> increment of time. If one pass overwrite is not sufficient and you
> use only one pass, then you have a disaster on your hands.
The argument "it's not possible" is also based on the "idea" (if a deep
emotional investment is an idea) that data recovery implies complete
"information" recovery. eg. 1 TB of obscured data may contain 4K of
damaging information.
While data reconstruction is generally considered "tin foil hat" (so
was/is a spherical planet) by the "general public" - useful
reconstruction of voice and writing from <50% original material has been
possible since WW1.
>
> The way to resolve uncertainty is not to guess or flip a coin. It is
> to carefully evaluate the risk vs. cost tradeoff. People who perform
> that evaluation tend to be conservative about assessing unknown
> potential risks against known, fixed, and minor costs.
A lot of beliefs are dependant apon civilian technology (eg. years of
computing required to factorize large numbers) - and heavily dependant
apon "predicting" when new advances will become widely available.
History has shown both beliefs are not reliable.
It's worth considering how long data will remain on hard drives before
dismissing the idea that it can be recovered - and given many people's
inablity to distinguish the difference between data and information, let
alone an understanding of magnetic decay and head alignment, optical
circuit and quantum computing...
>
> Paranoia is whole 'nother story. I suspect you use the term for
> dramatic purposes rather than for the purpose of clarity. It devalues
> all of your comments.
Agreed - the lack of convincing evidence on-hand (sufficient to overcome
dogmatic belief) is *not* evidence to support a belief - it's the "risk
management" of morons.
>
> Lee Winter
> Nashua, New Hampshire
> United States of America (NDY)
>
>
Cheers
--
"Always question authority, and demand the truth."
— Bill Hicks
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