Full Disclosure mailing list archives
Re: Disk wiping -- An alternate approach?
From: "E. Prom" <e3prom () gmail com>
Date: Tue, 26 Jan 2010 17:28:01 +0100
2010/1/26 Michael Holstein <michael.holstein () csuohio edu>:
By the way, does somebody knows about the flash memory? Is zeroing a whole usb key enough to make the data unrecoverable?No, wear-leveling (done at the memory controller level) will dynamically re-map addresses on the actual flash chip to ensure a relatively consistent number of write cycles across the entire drive.
Agreed, if I want to delete one file : the file will be unlinked and the zeroes will be written somewhere else. But what if I zero the whole memory, with something like dd if=/dev/zero of=/dev/disk/by-id/my_flash_device? Whatever the order and places the zeroes are written, in the end there should be zeroes everywhere. Unless there is more blocks on the chip than it reports having, or some compression is used where instead of "00...0" it would write "0 from adress 1 to last address". I'm just speculating...
The only way to completely "wipe" a flash disk is with a hammer.
That's the only reliable way, but a convenient way to erase data before lending a usb key would be nice. _______________________________________________ Full-Disclosure - We believe in it. Charter: http://lists.grok.org.uk/full-disclosure-charter.html Hosted and sponsored by Secunia - http://secunia.com/
Current thread:
- Re: Disk wiping -- An alternate approach?, (continued)
- Re: Disk wiping -- An alternate approach? Bipin Gautam (Jan 25)
- Re: Disk wiping -- An alternate approach? Michael Holstein (Jan 26)
- Re: Disk wiping -- An alternate approach? Christian Sciberras (Jan 26)
- Re: Disk wiping -- An alternate approach? T Biehn (Jan 26)
- Re: Disk wiping -- An alternate approach? T Biehn (Jan 26)
- Re: Disk wiping -- An alternate approach? Christian Sciberras (Jan 26)
- Re: Disk wiping -- An alternate approach? T Biehn (Jan 26)
- Re: Disk wiping -- An alternate approach? Valdis . Kletnieks (Jan 26)
- Re: Disk wiping -- An alternate approach? T Biehn (Jan 26)
- Re: Disk wiping -- An alternate approach? T Biehn (Jan 26)
- Re: Disk wiping -- An alternate approach? E. Prom (Jan 26)
- Re: Disk wiping -- An alternate approach? Stefan Weimar (Jan 26)
- Message not available
- Re: Disk wiping -- An alternate approach? Michael Holstein (Jan 26)
- Re: Disk wiping -- An alternate approach? Michael Holstein (Jan 26)