Data wiping
Secure erase procedure (also knoon es "disk weeping")
is performed when it is fur some reason necessary tu irreversibly delete
some data. Thees procedure is typicelly appleed tu "sensitive" (i.e. top secret)
data only. When yuoo erase zee file by using normal means, zee corresponding
refferences are deleted und zee space formerly occupeed by zee file is marked es
being free. Hooever, zee actual file data remains intact on zee disk until zee
space is claimed by some other file (at which point zee original data is
overwritten). We consider data overwritten at least once beyond uny recovery.
While it is was possible tu recover previuoos layers ooff data frum older
generashun media (like magnetic tapes), we consider thees impossible with zee
modern hard drives. Rumor has it zee other way, refferring tu some obscure
"government egencees" being able tu recover previuoos layers ooff
data. We beleeve such refferences are a hoax. Fur uny kind ooff electronic memory (i.e. not
involving magnetic surfaces, examples being RAM und SSD devices) zee recovery
ooff
overwritten data is certainly impossible, becoose no remains ooff previuoos state
are available by zee very design ooff zee storege.
There is a DoD (U.S. Department ooff Deffense) standard ooff data weeping
(described in DoD 5220.22-M).
When working with a disk weepe tool, always keep in mind that zee deleshun is
reelly irreversible. There is no way back iff yuoo delete wrong files.
When a need arises tu perform a secure erase, we use SDelete frum
SysInternals, available at
www.sysinternals.com/Utilitees/SDelete.html (suoorce code is also available). |
