Eraser Destroyed My USB Stick

Discussion in 'privacy technology' started by caspian, Jan 31, 2010.

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  1. caspian

    caspian Registered Member

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    I used Eraser to wipe the unused space on my USB stick and it's toast. I don't trust Eraser anymore. Another thing that I have noticed is when I erase a file on my Vista 64 bit computer, the shortcut remains on the desktop for a while. It says 0 bytes but you can still see it.

    Does anyone know how to wipe a USB stick safely? I use to use R-Wipe. But it no longer shows my USB stick in the menu. It shows my external hard drive but not a USB stick. I downloaded BC Wipe too and it didn't list the USB stick either.
     
  2. GrailVanGogh

    GrailVanGogh Registered Member

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    Personally I just format it a few of times then put new data on it.
     
  3. wtsinnc

    wtsinnc Registered Member

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    Hello caspian;

    Try Glary Utilities (Link)
    http://www.glaryutilities.com/gu.html

    I have used it to wipe the free space on USB flash drives as well as standard hard drives and it works as advertised.

    Following install, access the "privacy and security" tab, then select "file shredder", then "wipe free space".

    Be sure the box next to the drive you want to wipe is checked.
     
  4. traxx75

    traxx75 Registered Member

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    As far as I knew, properly erasing a USB flash drive using conventional HDD utilities is difficult due to the wear-levelling algorithm they implement. As far as I know, even if you do a full overwrite there is no guarantee you've actually overwritten every single bit of data. The program may think it's overwritten to every logical sector but in reality the algorithm probably hasn't touched every physical sector.

    The TrueCrypt documentation mentions this phenomenon, albeit for different reasons.

    Additionally, USB flash drives have finite read/write cycles so using erasing tools can significantly reduce their usable lifetime.
     
  5. ex_ployt_ed

    ex_ployt_ed Registered Member

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    So that would leave physical destruction as the only safe way to dispose of a flash drive with sensitive data?

    What would be a practical and safe way to physically destroy a flash drive?
     
  6. LockBox

    LockBox Registered Member

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    Single-file
    wiping is not advised due to wear-leveling. However, a full free-space wipe will destroy all the data.

    Lifetimes of flash drives have increased dramatically. It depends on the quality of NAND flash used in the drive. An MLC will have around 2-3 million write cycles, while the SLC (higher quality) flash will have write cycles in the 5-6 million range. A single free space wipe would wipe each cell one time. SLC cells give about 100,000 writes per lifetime in a drive utilizing wear-leveling.

    Things aren't quite as bleak as some may suggest. Though, the TrueCrypt warning is good because of the dangers of single-file wipes on NAND flash.
     
  7. HAN

    HAN Registered Member

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  8. ex_ployt_ed

    ex_ployt_ed Registered Member

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    Secure Erasure of FLASH Media (was Re: Eraser Destroyed My USB Stick)

    1.) How reliably? More so than for a SATA or IDE? Enough to withstand expert hardware-based recovery techniques?

    2.) Is there any way to do a full free-space wipe of a flash drive from within a Linux environment?

    Finally, a somewhat separate question:
    3.) Can DBAN or similar utilities be used to wipe a flash drive?

    Are these well-known and trusted programs?

    Doesn't it seem odd the way she seems to just have her own, 'homemade' license and not something like a GNU or CC one ?
     
  9. nikanthpromod

    nikanthpromod Registered Member

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  10. wat0114

    wat0114 Guest

    This did an awesome job for me on my old 500 MB stick :thumb: :)
     
  11. HAN

    HAN Registered Member

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    IMO, her apps are well known and reliable. Some (meaning me) feel a bit uncomfortable that TrueCrypt is anonymous. Ms Dean puts it all out there...
    http://en.wikipedia.org/wiki/FreeOTFE
     
  12. caspian

    caspian Registered Member

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  13. caspian

    caspian Registered Member

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  14. TheMozart

    TheMozart Former Poster

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    Eraser Destroyed Your USB Stick? Wow, Eraser works better than I thought.

    But seriously, how big is your USB stick? All you need to do is create a folder with random data the amount of your USB stick. And whenever you want to "wipe" your USB stick, just copy across all the files in your folder over to your USB stick, then delete. Then your original data that was there before is gone and forever removed.
     
  15. caspian

    caspian Registered Member

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    So if I create a TrueCrypt folder and copy it over it will wipe all of the private data? That sounds a lot safer. Thanks
     
  16. TheMozart

    TheMozart Former Poster

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    Think about it. If you copy data over existing data, the existing data is gone!

    You cannot have 2 separate pieces of data in the same place. That is not possible, for then your USB device would be "magical" and able to store different bits of data in the exact same place.

    So instead of wiping with Eraser, just copy different data over your USB device.
     
  17. Pleonasm

    Pleonasm Registered Member

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    In the case of a USB flash drive, the argument isn't necessarily correct. Surprised? The reason is that USB flash drives implement a wear-leveling mechanism, in which the same logical disk cluster address is dynamically mapped to different physical storage locations at each write operation. Thus, when you write to “the same” disk clusters on a USB flash drive, you may not actually be writing to the same physical disk clusters. The only way to truly destroy the contents of a file stored on a USB flash drive is to first delete the file and then wipe all of the free space.
     
  18. TheMozart

    TheMozart Former Poster

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    In all due respect I strongly disagree. If for example I have a 8GB USB stick, and I copy 8GB of new data unto that stick till it's full, then all the previous 8GB of data that was there before is gone. If not, that would mean that a 8GB USB stick is suddenly and magically dual layered which can store more than 8GB of different data.
     
  19. Pleonasm

    Pleonasm Registered Member

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    Yes, if you completely wipe all free space on the USB flash drive, then the contents of any deleted files on that drive is destroyed -- whether the wipe operation occurs through a manual file copy process (as you describe) or through the use of a wipe utility (e.g., R-Wipe&Clean). In contrast to a hard disk drive, overwriting the contents of a single file on the USB flash drive will not, however, necessarily destroy the information (as explained in Post #17).
     
  20. dantz

    dantz Registered Member

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    In this case prevention is far better than cure. If you encrypt all data when you add it to the flash drive then you won't have to worry about erasing inaccessible data fragments later. The same logic applies to hard drives and any data that may be trapped in bad sectors.
     
  21. caspian

    caspian Registered Member

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    So actually, if you have a TrueCrypt folder on your USB stick, you can copy a file directly into the folder and by doing this the contents of the file never touches the USB stick in it's unincrypted form. Is this correct?
     
  22. dantz

    dantz Registered Member

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    Yes, that's correct. However, we would call it a volume, not a folder, and you first need to mount it before you can copy any data in or out.
     
  23. TheMozart

    TheMozart Former Poster

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    Pleonasm, if I have an 8GB USB stick 100% filled with data, and I then overwrite with new and different 8GB of data... I challenge you to retrieve the original 8GB data that was there before being overwritten with the new and different 8GB of data. If you can do that, I will give you my house.
     
  24. LockBox

    LockBox Registered Member

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    If you go back and read what Pleonasm said, he agrees that filling the drive by manually copying files over to the drive would effectively destroy the contents.
     
  25. Pleonasm

    Pleonasm Registered Member

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    Yes, encryption is a very good alternative to worrying about wiping the remains of deleted files. However, it also worth noting that encryption can be potentially circumvented (especially if the user is employing a weak passphrase), whereas overwriting a file's contents appears to result in irreversible data destruction.

    Another option to consider is the use of a product such as Undelete by Diskeeper, which captures all deleted files in a “Recovery Bin” and (optionally) wipes them upon removal. (Again, the caution related to a USB flash drive using a wear-leveling mechanism applies.)
     
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