[wellylug] Darik's Boot and Nuke ("DBAN") HDD eraser

[Daniel Pittman]

Atom Smasher <atom at smasher.org> writes:
> On Wed, 2 Jun 2010, Daniel Pittman wrote:
>
>>> if you fill a modern drive with zeros there is NO WAY to recover any data
>>> previously stored on the drive... unless the drive is taken apart and
>>> subject to VERY expensive, time consuming and unreliable data recovery
>>> techniques.
>>
>> Well, it isn't that expensive: remapped bad sectors, and stray writes
>> outside the track, can be recovered for as little as a few tens of thousands
>> of dollars.  (...and prices may have dropped since I last looked.)
> =================
>
> recovering bad sectors, it makes no difference if the rest of the drive (good
> sectors) is filled with zeros or random bits. the *ONLY* way to overwrite bad
> sectors with modern commodity hardware is with the ATA secure erase function.
>
>
>>> so unless you've pissed off the CIA, zeros are fine. this assumes that
>>> you're using a drive that was made within the last 10-20 years...
>>
>> *nod* As I note, a single pass overwrite with zero is enough for the .au
>> government, so anything more than that is going to be above and beyond.
> ==============
>
> the US standards are... let me say "more thorough". but only because they're
> outdated. in the 70s it almost made sense to retire a sensitive disk by
> writing a dozen special passes to it, then burning it and scattering the
> ashes throughout several secure sites.

I should have mentioned here, like elsewhere, that is for X-IN-CONFIDENCE,
which is not a very secure option.  The standards do ramp up when you head
into serious verification levels. :)

> now it's useless, aside from the therapeutic value. but those procedures are
> still followed by a lot of govts and corps that could otherwise give the
> disks a new home... meanwhile plenty of disks from ATM machines,
> photocopiers and even computers are still easy to find second hand with the
> sensitive data FULLY INTACT.

That always entertains me.
        Daniel

Almost as much as I am entertained by people who feel that, say, opening a
hard disk is not sufficient assurance for their data ... because, frankly,
pretty much no one is /that/ interesting.  I sure ain't. :)
-- 
✣ Daniel Pittman            ✉ daniel at rimspace.net            ☎ +61 401 155 707
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