Erasing USB key Drives

[DavidHB]

Is this correct?

In my understanding, entirely.

David

[Joel]

Seconded. To further elaborate, new information which I've gleaned indicate that even fully wiping the free space may be insufficient (see "over-provisioning" in SSDs)

[rbeede]

So any plans to enhance Eraser to handle these situations?

What are the best alternatives to

1. Wipe free space

2. Securely erase a single file while leaving others intact

[Joel]

As of now, there isn't a good defence against it. Both scenarios don't bode well for SSD users with over provisioning and block remapping -- the very design of it is meant to ensure that applications don't see the process. Thus, only the manufacturer can release applications to sanitise blocks.

Having said that, if your file is large, block remapping will cause the large file to be scrambled, so the file data may not be as recoverable as it seems. Nonetheless, SSDs have large block sizes (64KB) so if your sensitive data is within 64KB then probably you're out of luck.

[nesinsula]

Will it work to just format the whole USB stick? Or could someone still easily recover data from it?
On my MP3 player i have recovering software, will it work?

I would be grateful for your help

[DavidHB]

Will it work to just format the whole USB stick? Or could someone still easily recover data from it?

I'd welcome Joel's views, but I don't think you should apply what he said about SSDs directly to flash (USB) drives. The technology is similar, but there are significant differences; I don't think that USB drives typically have the over-provisioning found in SSDs, and they certainly have smaller block sizes. As far as I know, doing a free space erase on a USB stick will make all the deleted files on it non-recoverable, though it may not remove all the file names.

On my MP3 player i have recovering software, will it work?

Try it and see . Using a file recovery program is the best way for an ordinary user to test an erase.

David

[nesinsula]

OK, so i should use eraser to remove all the files and free space?
And it will not work to use the formatting (sorry i said "recovery" in the first post) software/firmware(?) on my MP3 player instead?

[DavidHB]

OK, so i should use eraser to remove all the files and free space?
And it will not work to use the formatting (sorry i said "recovery" in the first post) software/firmware(?) on my MP3 player instead?

If you are clearing the drive completely, I would format it first (if there is a 'quick format' option, that will be fine), then erase the free (that is, all the) space with Eraser. On a flash drive, erasing the files directly will not work.

David

[nesinsula]

Thanks for your answers. If i use eraser to erase all the free space on my MP3 player, is there a risk of removing the MP3 players software/firmware?

[DavidHB]

Thanks for your answers. If i use eraser to erase all the free space on my MP3 player, is there a risk of removing the MP3 players software/firmware?

In principle, no. But the point to bear in mind is that Windows has to see your MP3 player as a drive, and how it does so will be a function of the player's firmware.

Taking cameras and players I know as indicators, I would expect that formatting the player, or restoring it to factory condition would leave some sort of folder structure which would be visible when the player is mounted as a drive. If that's what you see in Windows, there shouldn't be a problem about erasing the free space. There may of course be space on the player that cannot be accessed as part of the drive, but, as you could never access that directly in any case, that should not be an issue.

David

[nesinsula]

Thank you, your response has been really helpful!

[nesinsula]

which erasure method in eraser should i use so i didn't use the flash-cells more than necessary?

[Altair1572]

Even 1 pass is hard work for a flash memory using wear levelling...

[Joel]

Yes -- but the way flash memory is designed probably means that one pass will render the data irrecoverable (one pass may also be too much for some people.) Modern magnetic drives should have the same behaviour, but because of historic differences (such as the commonly cited Gutmann paper) people still apply multiple passes on hard drives.

[JoeDoe5]

You can erase it by PHYSICALLY ADRESSING each byte on the device and writing data to each and every single byte on the device.