Results 1 to 7 of 7

Thread: Secure Erase

  1. #1
    Just burned his ISO
    Join Date
    Jan 2010
    Location
    Melbourne, Australia
    Posts
    22

    Default Secure Erase

    Hi

    I'm Interested in techniques to Sanitize Hard drives and looking at Secure Erase and Enhanced Secure Erase methods using ATA commands built into modern drives. With drives getting larger these techniques seem very efficient to sanitize entire hardisks

    have found the following utilities which work well

    HDDerase.exe from CMRR - Secure Erase

    and

    MHDD.exe from HDDGURU: MHDD

    although have had issues with getting it to work with USB connected drives.

    Was wondering if anyone knew of any alternative utilities, possibly running under linux ?

  2. #2
    Very good friend of the forum Gitsnik's Avatar
    Join Date
    Jan 2010
    Location
    The Crystal Wind
    Posts
    851

    Default

    Code:
    dd if=/dev/urandom bs=1k of=/dev/(device)
    Works pretty well for me. There is no point doing more than one pass these days, but I still do 15 for company financial drives, just in case.
    Still not underestimating the power...

    There is no such thing as bad information - There is truth in the data, so you sift it all, even the crap stuff.

  3. #3
    Super Moderator lupin's Avatar
    Join Date
    Jan 2010
    Posts
    2,943

    Default

    Theres DBAN (its a boot disk) plus shred and wipe (shred is for individual files but you may be able to use it on a device file).

    Personally I use dd. If you using /dev/zero as an input source is quicker than /dev/random or /dev/urandom if you are happy to overwrite using zeros instead of random data. In addition, if you determine the drive size first using fdisk -l, use /dev/zero as your input source, limit the amount read from the input using the count option, AND tee the output into both your drives device and md5sum, you can verify your overwrites.

    Example steps for wiping hard drive /dev/sda and verifying the overwrite:
    1. Find your drives total size by running "fdisk -l /dev/sda"
    2. Divide the total size of the disk by 512 "perl -e 'print <size>/512'"
    3. Run dd using the command below
    4. Verify the overwrite was succesful using "md5sum /dev/sda" and comparing the result to the output from the dd command


    Code:
    dd if=/dev/zero bs=512 count=<size/512> | tee /dev/sda | md5sum
    If the md5 values dont match, your drive is bad or some other overwrite failure occurred.

    If you want to see the progress of your wipe, you can also use a tool like pipebench, like so:

    Code:
    dd if=/dev/zero bs=512 count=<size/512> | pipebench| tee /dev/sda | md5sum
    Capitalisation is important. It's the difference between "Helping your brother Jack off a horse" and "Helping your brother jack off a horse".

    The Forum Rules, Forum FAQ and the BackTrack Wiki... learn them, love them, live them.

  4. #4
    My life is this forum thorin's Avatar
    Join Date
    Jan 2010
    Posts
    2,629

    Default

    We use DBAN often at work.

    Under Windows I usually keep anything important in a TrueCrypt file container and delete it directly (shift+delete) bypassing the recycle bin. A few times a month I run sdelete to wipe the freespace on my drive in case I've saved something to the wrong area or had any leakage.
    I'm a compulsive post editor, you might wanna wait until my post has been online for 5-10 mins before quoting it as it will likely change.

    I know I seem harsh in some of my replies. SORRY! But if you're doing something illegal or posting something that seems to be obvious BS I'm going to call you on it.

  5. #5
    My life is this forum Barry's Avatar
    Join Date
    Jan 2010
    Posts
    3,817

  6. #6
    Just burned his ISO
    Join Date
    Jan 2010
    Location
    Melbourne, Australia
    Posts
    22

    Default

    Thanks for your responses

    Always good to see what others do/use and has given me some alternatives to try - particularly like lots of fire

    Was specifically looking for "ATA Secure Erase" techniques as this has the advantages of being able to overwrite bad blocks as well as being a lot quicker than traditional methods. With Further searches have found the following Guide (Take note of the disclaimers at the start of the guide )

    ATA Secure Erase - ata Wiki

    haven't tried it as yet but will update once i have

    another perspective on ATA Secure Erase can be found
    Securely erase hard drives « ultraparanoid

  7. #7
    Junior Member
    Join Date
    Jul 2009
    Posts
    78

    Default paranoid erase

    Hello,

    I test it with a 1GB partition:

    root@bt:/media# mount /dev/hda1 /media/hda01/
    root@bt:/media#
    Code:
    dd if=/dev/urandom of=/media/hda01/foo.img bs=4M
    dd: writing `/media/hda01/foo.img': No space left on device
    245+0 records in
    244+0 records out
    1025818624 bytes (1.0 GB) copied, 274.237 s, 3.7 MB/s
    root@bt:/media#
    Code:
    shred -uvz -n 7 /media/hda01/foo.img
    shred: /media/hda01/foo.img: pass 1/8 (random)...
    shred: /media/hda01/foo.img: pass 1/8 (random)...17MiB/979MiB 1%
    shred: /media/hda01/foo.img: pass 1/8 (random)...34MiB/979MiB 3%
    shred: /media/hda01/foo.img: pass 1/8 (random)...50MiB/979MiB 5%
    shred: /media/hda01/foo.img: pass 1/8 (random)...67MiB/979MiB 6%
    shred: /media/hda01/foo.img: pass 1/8 (random)...84MiB/979MiB 8%
    shred: /media/hda01/foo.img: pass 1/8 (random)...100MiB/979MiB 10%
    shred: /media/hda01/foo.img: pass 1/8 (random)...116MiB/979MiB 11%
    --------------------------------------------

    complete shred procedure:
    1. create a non journaling filesystem and unplug the device (ext2)
    2. plug in the device

    root:~# : shred -uvz -n 7 /dev/sdX
    [COLOR="RoyalBlue"][SIZE="2"]Nought's had, all's spent, ... Where our desire is got without content
    [/COLOR][/SIZE]

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •