Quote:
Originally Posted by BSDfan666
The last paragraph in robbak's post is a work of fiction, government agencies overwrite data multiple times because they're paranoid, absolute recovery is likely impossible.. determining the previous state of a single bit alone is theoretical, actually restoring enough of an original bit pattern would be improbable.
For example, the ksh shell on OpenBSD 4.3 is 324,992 bytes in length, 324,992*8 = 2,599,936 bits arranged in a unique pattern to form the executable.
I've yet to find any concrete evidence that recovery of data after being overwritten is possible..
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Thank you - again, it is a matter of repeating things I had heard, but you got me looking. I found this:
For the defence, I present
http://www.usenix.org/publications/l...ann/index.html
And for the prosecution,
http://www.nber.org/sys-admin/overwr...a-gutmann.html
Note that, with most text-based data, if you could get four bytes out of 5, you would have enough to recover the material. Bitwize, I'd back myself to read ascii with an average of one error bit in 16 any day.