I'm just curios, if i have a HDD (a working one ie. not defected), can I physically erase all the data without leaving the possibility to be recovered? ie. to completely format the hdd.
By physically i mean not to connect it to any kind of electric device, just using a screwdriver (or some other tools if needed).
We use Darik's Boot And Nuke to wipe all of our drives before they leave for reuse elsewhere.
Even the fastest wipe option should be more than sufficient imho.
Disks are precision devices - the moment you take your (special, anti tampering )screwdriver and open anything that is near the data, say, the top plate, you'll get dust and other lovely things, or throw something out of alignment, and next thing you know, drive heads are ploughing lovely furrows all over that polished data surface.
The moment you try physical destruction, it is permanant, and irrecoverable
Very powerful magnets can be used to erase modern HDD's. Not flash Drives and not the kind of magnets you can go buy for few backs at wal-mart (although floppies can be destroyed with cheap-o magnets).
That being said, even a hard drive that has been physically damaged as by fire still has the possibility of having data recovered. Just depends on who you are hiding from and how much funding they have..if it's the FBI, well good luck.
I vaguely recall being told during a seminar at infosec that it's possible to recover data from a drive that has been overwritten up to 8 times, so to securely erase it you need to write 8 passes of random data to it. The time invested in doing that is usually more than the value of the disk though so they are usually shredded.
You cannot format the hard drive using physical means - you can use something like a degausser to erase everything from it, but then it will not be usable, as you will have removed metadata on track positions etc.
