How To Make Self Destruct Electromagnet for HD

Discussion in 'Community Discussion' started by MacPil0T, Feb 5, 2009.

  1. MacPil0T macrumors member

    Joined:
    Apr 3, 2008
    #1
    I need some help with anyone that is knowledgeable in this area. I have a desktop machine that has about 4tb of data in it spanned across 4 HDs. The drives are in fairly close proximity to each other. I need help designing a home made electro magnet that is directional and large enough that when i flip a switch (or two) all four drives get erased. What i need to know specifically is how large to make the magnets to guarantee 100% data corruption. This is for a computer hardware class that I'm in and most of my classmates think it's not possible and only a thing of movies. Thanks for the help!
     
  2. Consultant macrumors G5

    Consultant

    Joined:
    Jun 27, 2007
    #2
    There is a mytbusters episode on erasing credit cards with magnets.

    You can probably apply similar principals to see what will erase a HD.
     
  3. Theophany macrumors 6502

    Theophany

    Joined:
    Nov 16, 2008
    Location:
    NW London.
    #3
    It would need to be totally overkill, frankly. Guaranteeing data loss is not an easy task. You can zero out disks and it's still possible to recover data if you have enough time. I remember a feature in a PC magazine some years ago where they took a standard, OEM disk and trashed it in water, fire, electricity and the pros were still able to recover some of the files from it.

    I'm not asserting this as any kind of professional, mind you, just saying that it might be a lot more difficult than you may have anticipated. Rugged things, are these hard disks. ;)
     
  4. ejb190 macrumors 65816

    ejb190

    #4
    My first question is why would you want to?

    That said, a couple of considerations. You will have to be very careful that the electromagnet does not have a residual charge when installed or it will cause damage before you want it to. The second part would be making sure there are multiple fail safes. Next, I would want to look into how much space is in the case, how big of a magnetic field would be needed, and how much voltage/amperage do you have to work with. Another line of questions involves what does it take to get to 100% data corruption and not 90%. With the range of the magnet and the mass of the cases, are you going to get 100% on drive 1, but only 50% on drive 4? I know there are some pretty sophisticated ways to recover data. What is the recovery rate with magnetically erased drives?


    From a security point of view, I would imagine physical destruction of the drives would be more secure then magnetically erasing them (thermite, anyone?). The next leap of logic occurs when you consider the development of RAM based hard drives. A magnet wouldn't have much effect on them, would it?

    Sorry, most of this is just me thinking out loud, so to speak. I would think this would take multiple magnets, maybe even one or more per drive.
     
  5. Sesshi macrumors G3

    Sesshi

    Joined:
    Jun 3, 2006
    Location:
    One Nation Under Gordon
    #5
    You'll need a hell of an (alternating) field to truly affect data in the first place - which is why effective bulk 'denial of data' methods are based around chewing HDD's up into tiny little pieces.
     
  6. mkrishnan Moderator emeritus

    mkrishnan

    Joined:
    Jan 9, 2004
    Location:
    Grand Rapids, MI, USA
  7. Unspeaked macrumors 68020

    Unspeaked

    Joined:
    Dec 29, 2003
    Location:
    West Coast
    #7
    I'm with mkrishnan on this one...
     
  8. Raid macrumors 68020

    Raid

    Joined:
    Feb 18, 2003
    Location:
    Toronto
    #8
    I was thinking launch it into orbit then nuke it, it's the only way to be sure! ;)

    While stuff like this does sound uber paranoid, I can't help be curious as to what works. Personally I'd like to see something like the home-made thermite Mel used in the movie "Conspiracy theory".
     
  9. Sesshi macrumors G3

    Sesshi

    Joined:
    Jun 3, 2006
    Location:
    One Nation Under Gordon
    #9
    What works is, as I've said, chewing them up into small pieces.
     
  10. Love macrumors 68000

    Love

    Joined:
    Jan 20, 2007
    Location:
    Just southeast of Northwestshire
    #10
    Wirelessly posted (Mozilla/5.0 (iPhone; U; CPU iPhone OS 2_2_1 like Mac OS X; en-us) AppleWebKit/525.18.1 (KHTML, like Gecko) Version/3.1.1 Mobile/5H11 Safari/525.20)

    I don't think it's possible to fully erase it with magnet.
     
  11. mkrishnan Moderator emeritus

    mkrishnan

    Joined:
    Jan 9, 2004
    Location:
    Grand Rapids, MI, USA
    #11
    There was an SVU this last season where the criminal had magnetic rings in their door jambs so supposedly their drives would be erased as soon as the forensic techs moved them out through the doorways. I iz a little skeptical that a magnet powerful enough to do that wouldn't jack something else up.... If you're going to do it, I would think that it would almost certainly have to be some sort of EMP device... I don't think you could rig anything with permanent magnets that wouldn't end up destroying a lot of your stuff inadvertently on a fairly regular basis.
     
  12. TuffLuffJimmy macrumors G3

    TuffLuffJimmy

    Joined:
    Apr 6, 2007
    Location:
    Portland, OR
    #12
    if you write to it with a magnet you can fully erase it with a magnet. It's a hard disk, nothing magical.
     
  13. kwood macrumors 6502a

    kwood

    Joined:
    Jun 26, 2006
    Location:
    In the Great White North.
    #13
    I'm thinking along the lines of an magnetic crane you would find in a junkyard. The magnet only magnetizes when it is introduced to electricity. In theory if you had a metal that became magnetized with electricity, as long as you provided it with enough power then it should do the job.

    Something like this, but obviously with a lot more then D Cell batteries. Maybe with a few car batteries and a larger gauge wire. If I had the time and resources I would love to try it. also I don't think the amount of storage on the hard drive matters. As long as you create a magnetic field larger enough (and powerful enough) to encompass both drives it should work.

    Schematic below.

    ***DISCLAIMER*** I am not an engineer or a physicist so I do not know for certain if this would work.
     

    Attached Files:

  14. Sesshi macrumors G3

    Sesshi

    Joined:
    Jun 3, 2006
    Location:
    One Nation Under Gordon
    #14
    A more surefire solution is to have a gravity assisted ejection system for the hard disks out of the server / DAS / SAN bays and an enveloping hopper in front of the servers (which can move out of the way for maintenance) which feeds to the aforementioned shredders, basically a highly optimised wood chipper in terms of general design which crunches the disks up in seconds - powered by UPS's inside the datacentre. With several such shredders in simultaneous operation you can achieve full deniability of entire datacentres in a matter of minutes with this setup, and it can be triggered remotely if neccessary. Other precautions would be required, such as the destruction of RAM - this can be achieved by conformal explosives or ignition of prepacked thermite inside the servers triggered after the HDD ejection process. You may also need to buy more time by rapidly flooding the datacentre with hydrogen cyanide or other such gases to impede ingress.
     
  15. iJohnHenry macrumors P6

    iJohnHenry

    Joined:
    Mar 22, 2008
    Location:
    On tenterhooks
    #15
    Getting past the metal case, grounded, IS magical.

    And why would you want to do such a thing, except for nefarious purposes??
     
  16. dvdhsu macrumors 6502a

    dvdhsu

    Joined:
    Mar 28, 2008
    Location:
    Palo Alto, CA
    #16
    I have to agree with you.
    That would be the surefire way.
    However, you can always do it the Live Free Die Hard way, where you just blow everything up.
    A little harder for the FBI to find anything.:D
    But I think the OP has porn on his 4 Terabyte HDs and is afraid somebody (mom or girlfriend) will catch him, so he has to have a way to erase it without it looking suspicious. :rolleyes:
     
  17. TuffLuffJimmy macrumors G3

    TuffLuffJimmy

    Joined:
    Apr 6, 2007
    Location:
    Portland, OR
    #17
    not really. Any metal can be magnetized, even nonmagnetic metals. All you'd have to do is magnetize the casing (a lot)

    You'd want to do this for security purposes mostly.
     
  18. Mr. Giver '94 macrumors 68000

    Mr. Giver '94

    Joined:
    Jun 2, 2008
    Location:
    London
    #18
    Actually I saw a program on Discovery that was about disposal of computer parts and they actually recommended drilling 3 holes into the HD to make sure none of the data would ever be possibly recoverable. They listed a name of a company that will do this but you could do it yourself. The show showed shipments of old computer parts being loaded off a cargo ship in India I believe and a bunch of the hard drives were just grabbed by random people. Not sure if this is relevant enough but it is interesting.
     
  19. iJohnHenry macrumors P6

    iJohnHenry

    Joined:
    Mar 22, 2008
    Location:
    On tenterhooks
    #19
    Yes, a lot. There is the problem.

    If you are not trying to kill a system, then just popping the "hood" on the drive(s) and waving a degaussing tool around a few times should do the trick. ;)

    Or, do as I did, just rip the disk out and trash it.
     
  20. Saladinos macrumors 68000

    Saladinos

    Joined:
    Feb 26, 2008
    #20
    It's really hard to do. I'm an Electronic Engineer, but I still don't know the kinds of fields you need.

    You could try get yourself a Neodynium magnet. Those things are so strong you can't go near one with a pacemaker. They can lift several kilos. Maybe a small child :)

    If you can't do it with a constant magnetic field, you'd need something massive. As in, the kinds of fields that are used to accelerate atoms in underground tunnels. Your best bet would be to rupture the casing or cover the "do not cover" hole.
     
  21. SuperCompu2 macrumors 6502a

    SuperCompu2

    Joined:
    Jul 23, 2006
    Location:
    MA
    #21
    A different approach worth thinking about (non magnetic but still instant) would be to place pressurized pneumatic pistons above each HD where, on command, they could be fired into the disks destroying the spindles and corrupting the data. Think of it kinda like a nail gun shooting straight down into the disk.

    Magnets would be cool, but there really is no way to focus that sort of magnetic power into a small area without threatening the surrounding components or having an immense amount of power stored nearby.
     
  22. MacPil0T thread starter macrumors member

    Joined:
    Apr 3, 2008
    #22
    thanks for all the input everyone. It's a very interesting discussion so far. At this point I'm leaning towards the thermite idea as it sounds like a more surefire method (no pun intended). I could then simply make sure than the entire server case is enclosed in something that cannot catch fire and it would be safe (assuming I knew what I was doing with thermite). At this point this is all theoretical. I could even setup a remote detonation and case opening trigger. For now let's just say that in this theoretical situation there is 4 HDs worth of information (porn, movies, financial data, use your imagination) that a person wanted destroyed ASAP if need be (once again, use your imagination). Along these lines, has anyone seen the movie Enemy of the State? Once again, great input everyone! Keep it coming!

    Update: I found this post on hack a day.
     
  23. QuarterSwede macrumors G3

    QuarterSwede

    Joined:
    Oct 1, 2005
    Location:
    Colorado Springs, CO
    #23
    Good luck with that.

    Source

    You simply couldn't contain the reaction. It would eat through the hard drive, then the case, then the floor and then set the place on fire.

    [Edit]
    After reading the hack-a-day link I have to say that is the most surefire way to protect any data from prying eyes. In fact, I'd really like to see someone try to read the data off those melted platters!
     
  24. Sun Baked macrumors G5

    Sun Baked

    Joined:
    May 19, 2002
    #24
    Thermite is likely the quickest and easiest to completely destroy the drives.

    Shaped charges might be able enough to cut the drives platters into small parts. But the can always scan in the data on the remaining parts. And likely they'd only need fragments of a data file to convict.

    Melting the drive is about all you can do to permanently destroy the data.

    ---

    If you have 15 minutes a sledgehammer, chisel, and a plasma torch would work.
     
  25. Luftwaffles macrumors regular

    Joined:
    Nov 25, 2008
    Location:
    Kansas City, MO
    #25
    Here's a cool idea:

    1. Place a small pyrotechnic charge inside each hard drive, one just big enough to fry the internal motor and do some decent damage to the spindle. Do NOT use Thermite as others have suggested - the tin-can lid on the drive won't contain that violent of a reaction, and even the cast-metal body of the drive probably wouldn't stand up to it.
    2. Wire the charge to a switch (with an activation key and big red button, of course. What if you accidentally bump the switch?)
    3. Put a glass case around the activation key and the big red button. Maybe a few caution stickers for good measure.
    4. ???
    5. Profit!

    Following the old adage that necessity is the mother of invention, what in God's name could the OP possibly be using this for? Something is rotten in the state of Denmark...
     

Share This Page