Author Topic: What to use to secure delete a HDD? (Read 25443 times)

JoTo · « **on:** June 01, 2010, 07:57 AM »

Hi Codeys,

i need your help.

Situation:
I got a new pc and want to gift my old one (still functioning) to a poor soul (friend of mine that has a much worse one than my old). I just want to pass on the hardware (without OS and Software installed) as he owns all software himself.

As i also pass on my system harddisk (C:) and i FOR SURE WON'T pass on all my data, i'm in need to secure erase that HDD before giving it out of my hands.

I KNOW that there are a gazillion of good and free eraser apps out there, but there is a hoop i have to jump through.

Problem:
As i'm to dumb to use a screwdriver, i'd prefer to avoid like hell to open the old pc, remove the hdd, stick it to my new pc as a secondary drive, erase it with a normal windows gui app, remove it from my new pc and reinstall it on my old one again.

Question:
Is there any free and good eraser app out there that works from e.g. Windows Console (booting from the original windows cd into console - then change CD and fire up the erase all app? I don't mind if i get any nice gui or not, it has just to erase a 160GB SATA HDD.

Or does anybody know about a free bootable toolcollection diskimage that contains such an app?

Any other ideas i don't think for now? (Only suggestions that leave the HDD working please!

So "using a sledgehammer" is out! *LOL*)

Please enlighten me! TYIAVM!

Greetings
JoTo

lanux128 · « **Reply #1 on:** June 01, 2010, 08:01 AM »

the fastest way would be to use Darik's Boot and Nuke.

Darik's Boot and Nuke is a self-contained operating system that you boot onto, and then erases the hard drives so it can be properly disposed of. You can install the software to boot from a floppy disk, CD, or USB stick, depending on the computer's boot options. Wiping the disk before disposal ensures that no personal information ends up in the wrong hands, and to remain compliant to any applicable laws.

• http://dban.sourceforge.net/

P.S. congrats on your new PC..

ChalkTrauma · « **Reply #2 on:** June 01, 2010, 12:35 PM »

+1 for Darik's Boot and Nuke.

If you need the version for a bootable floppy get this:

http://sourceforge.n....7_i386.exe/download

It will create the floppy for you..

Otherwise use the latest and greatest to make a bootable CD.

Stoic Joker · « **Reply #3 on:** June 01, 2010, 12:41 PM »

+2 for DBAN

joby_toss · « **Reply #4 on:** June 01, 2010, 01:06 PM »

wr975 · « **Reply #5 on:** June 01, 2010, 01:09 PM »

+4 for DBAN

FWIW, a plain normal format (fill with blanks) is enough.

The myth that to delete data really securely from a hard disk you have to overwrite it many times, using different patterns, has persisted for decades, despite the fact that even firms specialising in data recovery, openly admit that if a hard disk is overwritten with zeros just once, all of its data is irretrievably lost

Source: http://www.h-online....ll-do-it-739699.html

Cyeb · « **Reply #6 on:** June 01, 2010, 01:23 PM »

+5 for DBAN (Darik's Boot and Nuke). Noticing a trend here?

jaden · « **Reply #7 on:** June 01, 2010, 03:22 PM »

And +6 for DBAN

f0dder · « **Reply #8 on:** June 01, 2010, 05:59 PM »

~~-1 for DBAN - all you need is a regular Windows format - be sure to do a full format (ie, not ticking the "quick format" checkbox).~~

EDIT: slap me around and call me an idiot - format is not enough

JoTo · « **Reply #9 on:** June 02, 2010, 02:26 AM »

THANKS to all of you!

Seems i missed a very popular application here. Shame on me

But that is why i call DC tenderly "My personal ThinkTank".

I don't have to protect military secrets on my hdd though. i just not want that my buddy, who's getting the pc, will see my pr0n collection in whole.

I got DBAN now and will erase my hdd soon with it.

@fodder: Beside that i don't have to extra get DBAN while format is built in, is there anything wrong with using it vs. format?

Greetings and thx. again
JoTo

ewemoa · « **Reply #10 on:** June 02, 2010, 02:35 AM »

JoTo,

Whether you believe it or not:

Number of overwrites needed

Data on floppy disks can sometimes be recovered by forensic analysis even after the disks have been overwritten once with zeros (or random zeros and ones). This is not the case with modern hard drives. The bits on modern drives are so small that deviation of tracks between writes cannot be discerned by any means[citation needed].

According to the 2006 NIST Special Publication 800-88 (p. 7): "Studies have shown that most of today’s media can be effectively cleared by one overwrite" and "for ATA disk drives manufactured after 2001 (over 15 GB) the terms clearing and purging have converged."[6]

According to the Center for Magnetic Recording Research, "Secure erase does a single on-track erasure of the data on the disk drive. The U.S. National Security Agency published an Information Assurance Approval of single pass overwrite, after technical testing at CMRR showed that multiple on-track overwrite passes gave no additional erasure."[7] "Secure erase" is a utility built into modern ATA hard drives that overwrites all data on a disk, including remapped (error) sectors.

Further analysis by Wright et al. seems to also indicate that one overwrite is all that is generally required.[8]

From:

https://secure.wikimedia.org/wikipedia/en/wiki/Data_erasure#Number_of_overwrites_needed

JoTo · « **Reply #11 on:** June 02, 2010, 02:55 AM »

Hi ewemoa (Acronym hidden for IRC channel use only <- Insider joke for regular irc channel members!)

Who am i not to believe!? Thank you for pointing that out.

BUT, what makes me REALLY suspicious is, that NSA agreed to it too. That stinks for me. I am sure they only claim that one shot overwrite is enough because they are able to recover easily and just want to keep their business as easy as possible, wrapping the public in the dream of safety.

For me, this NSA agreement, is a clear sign, that i have to come back to that i have to overwrite 35+ times my hdd data (and then still use my sledgehammer at it), as i trust the NSA (and many other LEAs) as far as i am capable throwing a 16 tons stone by hand.

The only thing is, IS the NSA interested in the data of MY hdd? I don't think so.

Greetins
Osama bin laden ... errrrr....JoTo of course!

Deozaan · « **Reply #12 on:** June 02, 2010, 03:41 AM »

-1 for DBAN - all you need is a regular Windows format - be sure to do a full format (ie, not ticking the "quick format" checkbox).
-f0dder (June 01, 2010, 05:59 PM)

But how do you use regular Windows format on the only HDD in a PC?

Format the partition from the Windows installer disc?

ewemoa · « **Reply #13 on:** June 02, 2010, 03:48 AM »

The only thing is, IS the NSA interested in the data of MY hdd? I don't think so.
-JoTo (June 02, 2010, 02:55 AM)

Not so fast -- how will they know until they take a look?

Do you think you are the only person to be using your PC for storage?

JoTo · « **Reply #14 on:** June 02, 2010, 04:11 AM »

@deozaan:

-1 for DBAN - all you need is a regular Windows format - be sure to do a full format (ie, not ticking the "quick format" checkbox).
-f0dder (June 01, 2010, 05:59 PM)

But how do you use regular Windows format on the only HDD in a PC?

Format the partition from the Windows installer disc?
-Deozaan (June 02, 2010, 03:41 AM)

Good point :/

@ewemoa:

The only thing is, IS the NSA interested in the data of MY hdd? I don't think so.
-JoTo (June 02, 2010, 02:55 AM)
Not so fast -- how will they know until they take a look?
Do you think you are the only person to be using your PC for storage?
-ewemoa (June 02, 2010, 03:48 AM)

WHAT? Others do it also? OMG! And i thought it was MY invention to do it.

Greetings
JoTo

f0dder · « **Reply #15 on:** June 02, 2010, 04:18 AM »

No, nothing wrong with using DBAN, except you'll be wasting time if you do a paranoid multi-pass shredding

. And yes, if it's the only harddrive in the system, you'll need to boot either DBAN, the windows installer disc, a linux installer, or whatever.

EDIT: I still believe multi-pass shredding is a waste of time, but a non-quick format is not enough.

JoTo · « **Reply #16 on:** June 02, 2010, 04:25 AM »

@fodder
Thanks for clarifying!

Greetings
JoTo

MerleOne · « **Reply #17 on:** June 02, 2010, 03:10 PM »

I strongly recomment "CopyWipe" from TerabyteUnlimited : download the free software, burn a bootable media (floppy, CD), reboot and follow the instructions. You may select the least secure module, it will be good enough.

JoTo · « **Reply #18 on:** June 03, 2010, 07:00 AM »

Thanks merle, i'll look at that one too!

Greetings
JoTo

40hz · « **Reply #19 on:** June 03, 2010, 11:23 AM »

Just use DBan's "quick" single-pass options for a good compromise between paranoia and time needed to wipe. If you need to be sure beyond that you'd probably be better off getting a sledgehammer, a book of matches, and a can of petrol.

A full disk zero overwrite is also sufficient according to most security and data recovery experts. Most drive utilities have a version of that if you don't want to run dban.

FWIW I use dban on my own and my client's machines.

JoTo · « **Reply #20 on:** June 04, 2010, 04:10 AM »

@40Hz:
As i said, i dont have to hide military secrets, just want to prohibit a simple undelete. So i follow your advise and use the single DBAN pass.

Thank you too.

Greetings JoTo

Curt · « **Reply #21 on:** June 06, 2010, 06:30 PM »

all you need is a regular Windows format - be sure to do a full format (ie, not ticking the "quick format" checkbox).
-f0dder (June 01, 2010, 05:59 PM)

Note: The Danish company PAD-DATASERVICE claims in their case summaries that they successfully have recovered ALL files from a re-formatted hard-drive. They don't say if it was a 'quick-format' - one will just have to assume and HOPE!

f0dder · « **Reply #22 on:** June 07, 2010, 06:44 AM »

all you need is a regular Windows format - be sure to do a full format (ie, not ticking the "quick format" checkbox).
-f0dder (June 01, 2010, 05:59 PM)
Note: The Danish company PAD-DATASERVICE claims in their case summaries that they successfully have recovered ALL files from a re-formatted hard-drive. They don't say if it was a 'quick-format' - one will just have to assume and HOPE!
-Curt (June 06, 2010, 06:30 PM)

With a recovery price of DKK 500, it's most definitely a quick-format, which is trivial to reconstruct.

EDIT:...and it turns out that a Windows non-quick (aka "full") format is actually just a quick format... followed by a non-write bad sector scan - so your data is not wiped with a non-quick format, meh.

40hz · « **Reply #23 on:** June 07, 2010, 09:05 AM »

With a recovery price of DKK 500
-f0dder (June 07, 2010, 06:44 AM)

Just out of curiosity, is DKK 500 very much money - or are we talking something like dinner out in Aarhus?

lanux128 · « **Reply #24 on:** June 07, 2010, 09:12 AM »

Just out of curiosity, is DKK 500 very much money - or are we talking something like a nice lunch in Aarhus?
-40hz (June 07, 2010, 09:05 AM)

about US$80, according to google. btw, aren't they supposed to be using the Euro?