There is a way to DoD wipe a single file (it just fills the normally occupied space with various patterns of 000s, then 111s, then alternating 0s and 1s) but I can't seem to recall which utility I could use<br><br><div class="gmail_quote">
On Sat, Jan 15, 2011 at 11:29 AM, Bear Giles <span dir="ltr"><<a href="mailto:bgiles@coyotesong.com">bgiles@coyotesong.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">


  
    
    
  
  <div bgcolor="#ffffff" text="#000000">
    Wouldn't that be a full-disk wipe?<br>
    <br>
    Idle side thought - is there a daemon that periodically scans a disk
    and overwrites the unallocated sectors?  I would be far more
    concerned about them than the hardware keeping a secret copy of
    deleted files.<br>
    <br>
    BTW years ago I read an article from somebody who managed to restore
    big chunks of a file by searching the raw device for key strings. 
    That would be a real pain with a 500 GB partition, vs. a 1 GB
    partition, but there's no reason it can't be done. <br><div><div></div><div class="h5">
    <br>
    On 1/15/2011 11:18 AM, Stephen Kraus wrote:
    <blockquote type="cite">There is a linux utility that does DoD level wipes as
      well, wipe works just fine but if you are really paranoid I can
      point you towards that<br>
      <br>
      <div class="gmail_quote">On Sat, Jan 15, 2011 at 7:15 AM, davide <span dir="ltr"><<a href="mailto:davide.del.vento@gmail.com" target="_blank">davide.del.vento@gmail.com</a>></span>
        wrote:<br>
        <blockquote class="gmail_quote" style="margin:0pt 0pt 0pt 0.8ex;border-left:1px solid rgb(204, 204, 204);padding-left:1ex">Since there was a discussion on this topic
          onlist not long ago, I thought you'd find this interesting.<br>
          <br>
          <div style="margin:0px 2px;padding-top:1px;background-color:rgb(195, 217, 255);font-size:1px ! important;line-height:0px ! important"> </div>
          <div style="margin:0px 1px;padding-top:1px;background-color:rgb(195, 217, 255);font-size:1px ! important;line-height:0px ! important"> </div>
          <div style="padding:4px;background-color:rgb(195, 217, 255)">
            <h3 style="margin:0px 3px;font-family:sans-serif">Sent
              to you by davide via Google Reader:</h3>
          </div>
          <div style="margin:0px 1px;padding-top:1px;background-color:rgb(195, 217, 255);font-size:1px ! important;line-height:0px ! important"> </div>
          <div style="margin:0px 2px;padding-top:1px;background-color:rgb(195, 217, 255);font-size:1px ! important;line-height:0px ! important"> </div>
          <div style="font-family:sans-serif;overflow:auto;width:100%;margin:0px 10px">
            <h2 style="margin:0.25em 0pt 0pt">
              <div><a href="http://www.boingboing.net/2011/01/14/paranoia-and-deletio.html" target="_blank">Paranoia and deletion: the wipe man
                  page</a></div>
            </h2>
            <div style="margin-bottom:0.5em">via <a href="http://dynamic.boingboing.net/cgi-bin/mt/mt-cp.cgi?__mode=view&id=1&blog_id=1" target="_blank">Recent Entries from Cory Doctorow</a> by
              Cory Doctorow on 1/14/11</div>
            <br>
            <img><br>
            Today I decided I wanted to really securely delete some
            files off my hard-drive; a quick search revealed that the
            GNU/Linux <tt>wipe</tt> command was just the thing. Before
            running it, I had a quick look at its <em>man</em> page and
            discovered something much more interesting than mere dry
            documentation: rather, the wipe manual is a paranoid
            masterpiece on the possible snitchware lurking inside your
            hard-drive and the special problems of being <em>really</em>
            sure you've deleted your data:
            <blockquote> I hereby speculate that harddisks can use the
              spare remapping area to secretly make copies of your data.
              Rising totalitarianism makes this almost a certitude. It
              is quite straightforward to implement some simple
              filtering schemes that would copy potentially interesting
              data. Better, a harddisk can probably detect that a given
              file is being wiped, and silently make a copy of it, while
              wiping the original as instructed.
              <p> Recovering such data is probably easily done with
                secret IDE/SCSI commands. My guess is that there are
                agreements between harddisk manufacturers and government
                agencies. Well-funded mafia hackers should then be able
                to find those secret commands too.
              </p>
              <p> Don't trust your harddisk. Encrypt all your data.
              </p>
              <p> Of course this shifts the trust to the computing
                system, the CPU, and so on. I guess there are also
                "traps" in the CPU and, in fact, in every sufficiently
                advanced mass-marketed chip. Wealthy nations can find
                those. Therefore these are mainly used for criminal
                investigation and "control of public dissent".
              </p>
              <p> People should better think of their computing devices
                as facilities lended by the DHS.
              </p>
            </blockquote>
            <a href="http://manpages.ubuntu.com/manpages/lucid/man1/wipe.1.html" target="_blank">wipe(1)</a>
            <p>
              (<i>Image: <a href="http://www.flickr.com/photos/jon_a_ross/1482849745/" target="_blank">Hard Drive 016</a>, a Creative Commons
                <a href="http://creativecommons.org/licenses/by/2.0/deed.en" target="_blank">Attribution (2.0)</a> image from
                jon_a_ross's photostream</i>)
            </p>
            <div>
              <em> </em>
              <ul>
                <li><a href="http://boingboing.net/2010/03/26/discarded-photocopie.html#previouspost" target="_blank">Discarded photocopier hard drives
                    stuffed full of corporate ...</a></li>
                <li><a href="http://boingboing.net/2008/03/28/device-remotely-dest.html#previouspost" target="_blank">Device remotely destroys hard drive
                    data - Boing Boing</a></li>
                <li><a href="http://gadgets.boingboing.net/2008/07/21/handcranked-fujitsu.html#previouspost" target="_blank">Hand-cranked Fujitsu ME-P3M hard
                    drive degausser - Boing Boing</a></li>
                <li><a href="http://gadgets.boingboing.net/2008/05/01/hard-drive-crushers.html#previouspost" target="_blank">Hard drive crushers... er.... crush
                    drives hard - Boing Boing</a></li>
                <li><a href="http://www.boingboing.net/2005/11/14/table-made-from-anci.html#previouspost" target="_blank">Table made from ancient, giant
                    hard-drive platter - Boing Boing</a></li>
              </ul>
            </div>
          </div>
          <br>
          <div style="margin:0px 2px;padding-top:1px;background-color:rgb(195, 217, 255);font-size:1px ! important;line-height:0px ! important"> </div>
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          <div style="padding:4px;background-color:rgb(195, 217, 255)">
            <h3 style="margin:0px 3px;font-family:sans-serif">Things
              you can do from here:</h3>
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                  Doctorow</a> using <b>Google Reader</b></li>
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        </blockquote>
      </div>
      <br>
      <pre><fieldset></fieldset>
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    </blockquote>
    <br>
  </div></div></div>

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