In one of those weird coincidences, someone asked a question to an email DL in MS this morning, about how to securely erase a hard disk (since, as every skoolboy kno, deleting files doesn't really remove them from the HDD, and even formatting a HDD still leaves residue that could be recovered).
A few suggestions came back:
- PDWipe from http://www.digitalintelligence.com/software/disoftware/pdwipe/
- Use the cipher utility in Windows 2003, as per http://support.microsoft.com/kb/814599
- Use a Degausser deviuce to physically wipe the disk - eg http://www.garner-products.com/PD-8700.htm
- Physically shred the hard disk into tiny bits
As it happened, Robin Harris from ZDNet blogged today about some freeware utilities to go over the disk and overwrite every track, even blocks marked as bad, using the "Secure Erase" function that's built into most ATA disks, but is not typically made accessible by the BIOS. It's a process that's not for the faint hearted, but still seems effective (and appears to be good enough for the US National Security Agency).
The best comment I saw in response to the internal mail was the final suggestion, though:
- Military method – a team with angle grinders destroy the platters + one person to witness that it was done.
I suppose the military really like to do things properly 🙂