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Securely wiping hard disks

Discussion in 'Computer Security' started by nugget, Aug 23, 2004.

  1. nugget
    Honorary Member

    nugget Junior toady

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    I remember someone somewhere mentioning that for removing data from a hard disk permanently they use a magnet. I would like to know how big the magnet should be and for how long I would need to leave it on the disk.

    As a side thought, does anybody know what happens when you put a magnet next to a working hard disk? I can guess what the effect would be but does anyone have first hand experience?
     
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  2. tripwire45
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    tripwire45 Zettabyte Poster

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    If you absolutely, positively want to wipe out your data on a hard drive so that it can never be recovered again by anyone, get a 5 pound hammer (in this case, I mean it's weight and not how much it costs) and beat the HDD until the platters are in little, tiny pieces.

    Other than that, I use a program called killdisk to wipe out the data from a hard drive. There's almost no method that's absolute but the more drastic measures you take, it takes more processing power and memory on someone else's part to recover your data. I've heard that at least some data can be recovered from pieces of broken drive platters. :eek:
     
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  3. AJ

    AJ Administrator Administrator

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    My boss insists that all HDD are disposed of in such a state that they are un-usable. I have a particular tool for this job called a big hammer.

    There are applications for this but they will use Windows. A quick goggle threw this up. It looks like freeware, not used it but if anyone can shed some light onto it then please post. If you are talking about wiping a disk to dipose of then would not an fdisk do the job?


    <AJ now hiding from the thunder of replies saying I'm wrong>
     
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  4. Jakamoko
    Honorary Member

    Jakamoko On the move again ...

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    As far as I understand, fdisk only clears the flag for the first sector of each cluster where data is stored. At this point, the data is still recoverable.

    <Gav awaits thunderous opposition alongside AJ>

    I have an app called Evidence Eliminator, which claims to fully wipe a HDD, but I have heard reports contradicting this.

    I'm sure I heard of a (very) expensive prog that the FBI use called Encase, that pretty much does the job in hand (as well as pulling data from broken bits of platter, but I agree that the 5lb hammer is the best option.
    Do we think our Swiss Aussie friend is feeling a tad guilty here ? [​IMG]
     
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  5. Phoenix
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    Phoenix 53656e696f7220 4d6f64

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    hmm
    hammers dont work
    neither do standard magnets


    you should have a look at the US DoDs standards for wiping rigid magnetic storage

    • 10 write overs with a psuedo random 1,0 generating disk wiper
    • de gaussing with an NSA/CSS approved degausser, were talking enough power here to break the motors in the disks with a magnetic field!!
    • melting the platters down into molton slag
    • burying in concrete

    to be honest, wiping over the data few times with random bits is going to be fine for the average user, your talking about getting to the point where it will cost enough money to recover it that it will sway nosey people, but obviously not government espionage :)

    the only true way to be safe is to never let unencrypted data touch the hard disk, in BSD i use GEOM to encrypt the disk platters, before any 'data' is placed on them, that means the data is encrypted at creation, before its placed on the platters, nice system which i've just started to deploy
     
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  6. Fergal1982

    Fergal1982 Petabyte Poster

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    i have a program from micro2000 called Eraserdisk which apparently wipes the hard drive of everything. it actually overwrites the data, several times making it untraceable to anyone except those who go to extraordinary lengths to revive it (i believe the sort of cost is thousands if not hundreds of thousands, government level really), although i only know this because there was a guy who does this for a living who was interviewed by FHM a while back.

    Hope That Helps

    Fergal
     
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  7. nugget
    Honorary Member

    nugget Junior toady

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    Thanks for the replies and information guys.

    Jak, my attitude has gone from the Aussie "she'll be right mate:funfun" to the Swiss "they are my secrets:noway" point of view.
     
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  8. ant2005uk

    ant2005uk Byte Poster

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    When I sold my old pc I used a program called Eastec Disk sanitizer to securely erase my hd. Apparantly it erases data beyond military standards and uses a 7 pass disk sanitizing method. On my system it took just over 5 hours. Hope this helps.
     
  9. vaceituno

    vaceituno New Member

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  10. nugget
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    nugget Junior toady

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    Thanks for that. It looks really cool and I'll check it out. :thumbleft

    Oh, and the price is right too.:D
     
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  11. tripwire45
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    tripwire45 Zettabyte Poster

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    Remember, always use your vast powers for good and never for evil. :biggrin
     
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  12. Sandy

    Sandy Ex-Member

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    Hi All

    I have a pal who works for the British military they use a big hammer on all their HDs!

    If you have Ghost (and I ALWAYS recommend it) then you can do a full DOD data clear down on your HD.
     

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