Security Basics: Re: Secure delete files

[Ansgar -59cobalt- Wiechers <bugtraq () planetcobalt net>]

On 2007-05-25 Adam Pal wrote:
> If you have such sensitive data that you need so much accuracy in
> deleting it, dont misunderstand me but all i can recommend you is to
> burn the data media, so that nothing remains.
> I say that because i`ve seen software which claimed to be
> military-safe in deleting data, by rewrite with about 20 sequences of
> 0 and 1 and i also read different comments about restoring data where
> it was claimed that you need about 200 or more sequences to be
> partialy safe.
That's superstition. I would like to see at least one case where
software has recovered data that was overwritten (even in a single pass
with zeroes).

Sure, when you wipe only files that may leave other options to recover
data from them (rolocated blocks on harddisk, temp files, swap, ...),
but that's a different story.

Regards
Ansgar Wiechers
-- 
"All vulnerabilities deserve a public fear period prior to patches
becoming available."
--Jason Coombs on Bugtraq