Securely erasing data from hard drives and other media

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Flash
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Securely erasing data from hard drives and other media

#1 Post by Flash »

http://blogs.techrepublic.com.com/secur ... ag=nl.e040
[quote]...There is a persistent myth to the effect that to securely delete everything from a hard drive one must overwrite it thirty-five times with random data. This myth arises from a superficial read and misunderstanding of Peter Gutmann’s 1996 paper, Secure Deletion of Data from Magnetic and Solid-State Memory. The truth of the matter, as presented in his paper, is that 35 random overwrites serves only to apply the necessary means of securely deleting data for any of several different drive technologies. A specific data storage technology only requires some lesser technique applied to ensure secure deletion.

Perhaps more interesting is the fact that, for the most modern hard drive technologies, a single complete overwrite of a drive with zeros should be sufficient. Part of the reason for this is the fact that data density on a drive is much greater than it used to be. In layman’s terms, “the bits are smaller

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technosaurus
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#2 Post by technosaurus »

if you are doing this as a business - the time required to do the full wipe of machines to federal standards it is more cost effective to pull them all and melt them down.

randomize however many times you'd like with
dd if=/dev/urandom -of=/dev/sda
then zero out with
dd if=/dev/zero -of=/dev/sda
Check out my [url=https://github.com/technosaurus]github repositories[/url]. I may eventually get around to updating my [url=http://bashismal.blogspot.com]blogspot[/url].

Dragynn
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#3 Post by Dragynn »

I have used DBAN the last few years, works great but does take around 2 hours usually to do a 100 gig drive, I usually start it then go do something else for a while.

http://www.dban.org/

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rcrsn51
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#4 Post by rcrsn51 »

I find that bending over the pins of the IDE connector with a screwdriver works much faster than dban. :wink:

Dragynn
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#5 Post by Dragynn »

rcrsn51 wrote:I find that bending over the pins of the IDE connector with a screwdriver works much faster than dban. :wink:
:lol: :lol: I guess I should have included some context, i'm usually hoping to re-use the aforementioned drives :D

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Colonel Panic
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#6 Post by Colonel Panic »

DBAN's always been good enough for me. Use the "autonuke" option from the command prompt (I think you have to type F2 first), and a 20 GB drive will be thoroughly wiped in about 2 hours.

EBAN's essentially the same software, but runs over a network so you can wipe several computers at once (more cost-effective for a business which has to securely erase a lot of hard drives, as opposed to someone like me who only wipes my own).

The program you linked to looks like Windows-only.
Gigabyte M68MT-52P motherboard, AMD Athlon II X4 630, 5.8 GB of DDR3 RAM and a 250 GB Hitachi hard drive running Ubuntu 16.04.6, MX-19.2, Peppermint 10, PCLinuxOS 20.02, LXLE 18.04.3, Pardus 19.2, exGENT 200119, Bionic Pup 8.0 and Xenial CE 7.5 XL.

eternal-sunshine
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#7 Post by eternal-sunshine »

To all admins and moderators:

I posted today what I believed to be a perfectly reasonable and polite question to a post here in this thread and now see my post doesn't exist anymore nor the original post that I was responding to.

1. I would be surprised if the original post has been deleted by an admin/mod.
2. if my reply has been deleted as well then I consider that very heavy handed.
3. it would only be decent and respectful if whoever has deleted my message would have emailed me and told me why or said that in public.

I hope I am mistaken but if I am not then I fear this forum and its admin/mods have turned a very sad corner.

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AF Branden
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#8 Post by AF Branden »

Eternal, the poster you responded to was a spammer. He would have never answered your question.
[img]http://i56.tinypic.com/nwymax.png[/img]

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Flash
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#9 Post by Flash »

Eternal-sunshine, here are the system requirements to run the software the spam post you replied to was advertising:
System Requirements
Processor:Pentium Class
Operating System:Windows 7, Vista, Server 2003, XP, and 2000
That's why I removed the post and your reply to it. :)

eternal-sunshine
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#10 Post by eternal-sunshine »

Flash,
Thank you for replying and explaining why you deleted my post.
I still feel it would have been better if you had told me (PM etc).
Oh well. :)

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AF Branden
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#11 Post by AF Branden »

If you want to be 100% sure the data is unretrievable check out the guide below:

http://www.dominopower.com/issues/issue ... 0001737002
[img]http://i56.tinypic.com/nwymax.png[/img]

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Dave_G
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#12 Post by Dave_G »

Too complicated.
Below is the tool I use.
Works every time.

Dave.
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nooby
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#13 Post by nooby »

old HDD them say one need to low level write over with 0 something several times but them say that very modern Terra byte ones are so dense that one only need to write once?

Where is the line then. 250GB is maybe too old so one need to write several times? Does it take hours most likely? :)
I use Google Search on Puppy Forum
not an ideal solution though

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Dave_G
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#14 Post by Dave_G »

nooby said:
Does it take hours most likely?
Exactly, but with my system about 20 seconds. :lol:

Dave.

Sylvander
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#15 Post by Sylvander »

@Dave_G
I'm going to use your system on a faulty 750GB HDD [in a cheap/poor external enclosure] I have beside me here. :D

Bligh
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#16 Post by Bligh »

I like Daves tool above, but if you want to re-use the drive, it doesn't work well.
Cheers

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pemasu
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#17 Post by pemasu »

Dave_G method is good one. I used it when I removed hdd`s from about 30 comps before they went to some recycling site.

It didnt take long, before the metal disk inside was something else as circular, flat plate. The covers dont protect from sledgehammer. And the job was done in 15 minutes. I can recommend. The pins were smashed all together also.

And you dont recognize the hdd as hdd after hammering.... instantly.
Security by obscurity....great disguise.

PANZERKOPF
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#18 Post by PANZERKOPF »

Dave_G wrote:Too complicated.
Below is the tool I use.
Works every time.
Dave.
Big hammer is universal tool for solving any problem. :D
About erasing:
Modern HDDs have internal functions for erasing itself.
If we lock a HDD with user password then unlock it with master password,
all data will be sequentially erased. This is fastest way for erasing (in theory).
SUUM CUIQUE.

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Flash
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#19 Post by Flash »

But a sledgehammer also destroys those wonderfully strong magnets inside. :(

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pemasu
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#20 Post by pemasu »

That is true. I once got so strong one, that when I used it in our refrigerator door, it was impossible to get it off straight. Only way was to slide it to the edge or use the paper under it for swerving.

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