"Hey Andrew, those harddrives that are left over there, can you arrange 
for somebody to come and take them away? I mean, we can't just leave 
them there. Even if they're been erased, you can still get the data off 
them if you want to."

Uh... like, WTF?

I mean, sure, if you take the drive apart and crawl over it with a 
microscope, you can recover data. But who the **** is going to bother? 
It's not like you could recover any particularly valuable data.

(Personally, I think my boss honestly believes that you can take an 
erased harddrive and just plug it in and type "undelete" and all the 
data will come back. It doesn't work like that...)

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

Post a reply to this message

"Invisible" <voi### [at] devnull> wrote in message
news:4863b9a3@news.povray.org...

> I mean, sure, if you take the drive apart and crawl over it with a
> microscope, you can recover data. But who the **** is going to bother?
> It's not like you could recover any particularly valuable data.

Um, actually...
http://www.pcworld.com/article/id,108831-page,1/article.html
http://www.guard-privacy-and-online-security.com/how-clean-off-the-hard-driv
e.html

Your boss is right. It may not be as easy as 'undelete' but the data's there
and it doesn't take a microscope to find it, and it could be worth a lot of
money.

Post a reply to this message

Gail Shaw wrote:

> Um, actually...
> http://www.pcworld.com/article/id,108831-page,1/article.html

A study found that some people selling drives hadn't even bothered to 
erase them at all. Pressing the "delete" button doesn't erase the file.

This isn't news.

> http://www.guard-privacy-and-online-security.com/how-clean-off-the-hard-driv
> e.html

This doesn't look terribly convincing to me.

> Your boss is right. It may not be as easy as 'undelete' but the data's there
> and it doesn't take a microscope to find it, and it could be worth a lot of
> money.

Right. Well I'll tell you what, you show me an actual technique that 
allows you to recover data from a harddrive after every individual block 
has been written with zeros, without the use of a microscope. ;-)

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

Post a reply to this message

Invisible wrote:
> (Personally, I think my boss honestly believes that you can take an 
> erased harddrive and just plug it in and type "undelete" and all the 
> data will come back. It doesn't work like that...)

Depends how erased it is, of course. Your boss might not know that you 
know how to erase a drive correctly. :)

-- 
Darren New / San Diego, CA, USA (PST)
  Helpful housekeeping hints:
   Check your feather pillows for holes
    before putting them in the washing machine.

Post a reply to this message

Gail Shaw wrote:
> Your boss is right. It may not be as easy as 'undelete' but the data's there
> and it doesn't take a microscope to find it, and it could be worth a lot of
> money.

It depends how you erased the drive. If you just formatted it, no, the 
data's all still there. If you actually overwrote it, it takes special 
electronics to retrieve it if you can at all.

If you're the DoD, and large numbers of people die when a foreign 
government spends several millions of dollars to recover the data from 
the disk, yes, 21 passes is probably good. That, or scrubbing the drive 
with a belt sander or wire brush and then soaking it in acid until it 
dissolves.

If shredding is good enough for your paper records (vs shred, 
incinerate, stir, then dissolve in acid) then the IFIPS standard is 
probably good enough for your hard drives.

If you're using Windows, simply running
   cipher /w:p:
will overwrite all the spaces on drive p: that don't hold files, first 
with zeros, then with ones, then with random patterns. You can do this 
while the machine is in use. Of course, if you format P: and then do it, 
it'll wipe pretty much everything except (potentially) old file names.

-- 
Darren New / San Diego, CA, USA (PST)
  Helpful housekeeping hints:
   Check your feather pillows for holes
    before putting them in the washing machine.

Post a reply to this message

"Gail Shaw" <initialsurname@sentech sa dot com> wrote:

> Um, actually...
> http://www.pcworld.com/article/id,108831-page,1/article.html
> http://www.guard-privacy-and-online-security.com/how-clean-off-the-hard-driv
> e.html
>
> Your boss is right. It may not be as easy as 'undelete' but the data's there
> and it doesn't take a microscope to find it, and it could be worth a lot of
> money.


This has always bothered me.  Something does not hang right.

Could one just copy a couple of version of a linux distro (0.6 to 4 GB) on top
of it?  Would THAT be enough to completely obfuscate what was originally on the
disk?   If not, then why hasn't anyone yet made a commercial use of the ability
of HDD's to remember everything that has ever been on them?

Post a reply to this message

"Invisible" <voi### [at] devnull> wrote in message
news:4863bd87@news.povray.org...

> Right. Well I'll tell you what, you show me an actual technique that
> allows you to recover data from a harddrive after every individual block
> has been written with zeros, without the use of a microscope. ;-)

Show me where in your original message you said anything about having done a
proper purge of the drive.

Post a reply to this message

"gregjohn" <pte### [at] yahoocom> wrote in message
news:web.4863c87ab122afc76cf3d0b10@news.povray.org...

> Could one just copy a couple of version of a linux distro (0.6 to 4 GB) on
top
> of it?  Would THAT be enough to completely obfuscate what was originally
on the
> disk?   If not, then why hasn't anyone yet made a commercial use of the
ability
> of HDD's to remember everything that has ever been on them?
>

Copying files over won't guarenteed overwrite ever single sector of the
drive

Post a reply to this message

Gail Shaw wrote:
> "Invisible" <voi### [at] devnull> wrote in message
> news:4863bd87@news.povray.org...
> 
>> Right. Well I'll tell you what, you show me an actual technique that
>> allows you to recover data from a harddrive after every individual block
>> has been written with zeros, without the use of a microscope. ;-)
> 
> Show me where in your original message you said anything about having done a
> proper purge of the drive.

I gave him more credit than to complain about it without having actually 
erased the drive. :-)

-- 
Darren New / San Diego, CA, USA (PST)
  Helpful housekeeping hints:
   Check your feather pillows for holes
    before putting them in the washing machine.

Post a reply to this message

Gail Shaw wrote:

> Show me where in your original message you said anything about having done a
> proper purge of the drive.

"Even if they've been erased, you can still get data off them."

Now, if I'd just done something like

   delete C:\*.*

then my boss would have a point. With the right tools, it wouldn't be 
too hard to get the files back.

What I actually did was

   dd if=/dev/zero of=/dev/sda

[Note that that's "sda", not "sda1", meaning the partition table and MBR 
are gone too.]

Using random data would be slightly more secure, but we have already 
reached the point where drive disassembly [and extremely expensive 
specialist equipment] is required. Given the sensitivity of the data 
involved... further effort seems overkill.

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

Post a reply to this message