Protect your data: Secure deletion

When you delete a file it is not really gone. Even if you empty the recycle bin, the file can be recovered until it has been overwritten by another file. Deleting a file merely marks that file as no longer being needed/visable. The same is true if you just format a hard drive. I don’t see the point in that but it’s a fact of life. So how can you actually delete your files?

To actually delete files you need to use a file wiping, or shredding, program. There are many programs available; a lot of them are free. All file shredding programs use one or more of the following wiping standards:

Canadian RCMP TSSIT OPS-II
American DoD 5220-22.M
Gutmann
PRNG Stream (ps

The difference in the wipes is mainly how the wipe is performed. The processes vary in the way they overwrite the sectors where a file was stored. All of the overwrite the sector multiple times with either all 1’s and 0’s or random characters before writing all 0’s.

Wiping a hard drive
The easiest way to completely clean a drive is by using Darik’s Boot and Nuke, aka DBAN. Simply boot from a floppy disk or CD, choose what type of wipe should be performed and walk away. DBAN will overwrite everything. Nothing will be able to be retrieved from the drive once the wipe process is complete.

Wiping individual files
The two programs I recommend are Simple File Shredder and Eraser.

	Simple File Shredder	Eraser
Cost	Free	Free
Open Source	No	Yes GNU General Public License
Wiping methods available	Canadian RCMP TSSIT OPS-II American DoD 5220-22.M Gutmann PRNG Stream	Canadian RCMP TSSIT OPS-II American DoD 5220-22.M Gutmann PRNG Stream
Operating System supported	Windows NT/2000/XP/2003	Windows 9x/NT/2000/XP/2003

Both of those programs are easy to use. They also integrate into the right-click context menu so you can securely delete a file or directory (folder) by right-clicking on it and choosing either Erase or Simple File Shredder (depending on which program you choose). You can also use them to wipe an entire secondary drive instead of using DBAN.

Screenshots

Simple File Shredder: