Re: Wiping hard drives - Re: debian-user-digest Digest V2011 #1704
On Tue, Sep 20, 2011 at 12:21 PM, D G Teed <donald.teed@gmail.com> wrote:
> On Mon, Sep 19, 2011 at 11:07 PM, Scott Ferguson
> <prettyfly.productions@gmail.com> wrote:
>> > On Mon, Sep 19, 2011 at 12:57 PM, D G Teed <donald.teed@gmail.com> wrote:
> I think it is healthy to have a dose of skepticism with these things.
You also need to apply that attitude to what you see in the mirror.
> It has been demonstrated that a zeroed drive cannot be
> recovered at the typical data recovery service business.
No it has not. There is no such thing as a "typical" data recovery
company. Each has strengths as weaknesses.
>
> There is also this outstanding challenge for someone to recover
> data from a zeroed drive:
>
> http://hostjury.com/blog/view/195/the-great-zero-challenge-remains-unaccepted
That challenge is a crok of crap.
> Kinda like the reward put up for psychics to prove themselves.
> The only caveat which could be getting in the way is to not
> disassemble.
1. So you think three days is enough time? Have you ever had to read
an entire drive one sector at a time? 80 GB is 160M 512-byte sectors.
Even on a 15K RPM drive, single-sector reads will take a long time at
one revolution per sector. 15K sectors per minute implies about 10K
minutes. Three days is less than half of that. Yet With induced
variations on the drive electronics one might need many such passes to
accomplish a decoding.
2. So you think the prohibition on writing to the drive is not an
obstacle? That eliminates a huge number of approaches based on
characterizing the write circuitry.
3. So you think the disclosure requirement is not an obstacle? There
is no word for that degree of naivete.
> This would get in the way of using a more
> powerful read head or other methods, but at the same time
> this does demonstrate if it is simply a personal drive you
> want to zero and sell on eBay, zeroing will cover the situation
> well enough.
No it will not. But two passes with a TRNG will certainly do so.
> The skeptics here await links illustrating data has been
> accurately recovered from zeroed drives.
Please hold your breathe until then.
Lee Winter
Nashua, New Hampshire
United States of America (NDY)
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