Contributed by: /usr/share/bong Submitted: 03-15-2003
Introduction:
You can delete files on a Windows-based machine by clicking the file, then click the delete button on your keyboard. Yes, this works. Or you could click a file in Windows Explorer and right-click, then go to Delete, then clear our your Recycle Bin. This all works, but there’s a problem. The way Windows deletes files is pretty strange.
YOUR FILES ARE NOT PERMANENTLY DELETED. Windows deletes files by removing the first three letters from a filename. Let’s say porn.jpg was on your computer and you ?deleted? it. This file would still reside on your hard drive, renamed as ?_.jpg?. Windows is waiting for you to over-write that file later on, which SHOULD delete the file, but doesn’t.
There are many file wiping utilities out on the market these days, but I know of one that works. Believe me, I know this one works. A nameless state police department once had to examine one of my hard drives on one of my machines by court order years ago, and thanks to this piece of software, I never did any jail time.
Downloading BCWipe:
The program’s name is BCWipe for Windows 95/98/ME/NT/2000/XP v.3.04 and we’re going to install it on a Windows 95 machine. We picked this type of machine because it’s the oldest machine we have and most people will probably have Win95/98/ME and not the newer NT/2000/XP.
If you go to http://www.jetico.com/, there is a program called BestCrypt which encrypts files/folders as an encrypted file, then BestCrypt mounts that file as a hard drive, so all your encrypted stuff would show up as the E:\ drive, or whatever directory you specify.
BCWipe can be downloaded from: http://www.jetico.com/bcwipe3.exe
(note: BCWipe supports Linux, SunOS, Solaris, IRIX, Digital Unix, *BSD)
Installing:
Double-click bcwipe3.exe and follow the instructions. You must agree to a licensing agreement. This piece of software is a demo. If you like this program, you should buy it. It will save your life one day when you seriously need it.
Wiping:
Go to Start - Programs - BC Wipe 3.0 - BCWipe Task Manager
We then go to Tasks - Create new Task - Wipe free space.
WHY DO WE WIPE FREE SPACE?
Sure, we could delete individual files, but when you know the cops are coming, it’s better to wipe your free space because the free space contains all the webpages you went to, all the e-mails you thought you deleted, etc. ALSO MAKE SURE TO DELETE IRC/AIM/MSN/YAHOO/ICQ CHAT LOGS OR DON’T LOG AT ALL. Believe me, they will come back to haunt you.
First: we must decide what drives we want to get wiped. BCwipe estimates to wipe my C: drive in 59 minutes with the DoD 7 pass wiping scheme – not too bad with a 350Mhz machine with 128mb of ram.
Second: we must decide when we want to wipe. You could setup a daily wipe at 12:00am when you sleep to wipe all your sensitive stuff out if you’re a paranoid person. For this instance, we are going to wipe once.
Third: wipe options. We must decide what scheme we want to do.
The U.S. DoD 5200.28-STD wiping standard wipes your hard drive 7 times, while the Peter Guttman scheme does it 35 times. Compare 59 minutes for the DoD to 4 hours of Peter Guttman. Security is essential – I’m doing the Peter Guttman scheme.
Keep every box checked unless you know what you are doing. In the Wiping Scheme Editor, the Peter Guttman scheme looks far more superior. In the first 4 passes, random bytes are written to the free space on the hard drive, and in the last 4 passes, this is done also. This is very good for us and very bad for the guys who want to read our hard drive.
Note: the Peter Gutmann scheme would work excellent if you wiped your hard drive that way let’s say weekly, then you DoD wiped your hard drive daily. 4 hours? That’s not too long. You could get it started, then go see a movie, go shopping, etc. You can leave your computer for more than 4 hours, you know.
7 passes on the DoD scheme means that the DoD thinks that 7 passes is enough to destroy sensitive data, but in this world of electronic uncertainty, 35 passes works for me. Also, do not log your wipe. This is something that has the potential of being used against you.
I clicked back on the Schedule tab and clicked the big button that says Start Now! BCWipe wipes your slack files, your free space, and your deleted
directory entries.
NOTE: you might see this screen and believe it won’t take very long. If you look up at the very top, it says Pass 1 (total 35) – don’t forget about it takes a very long time to wipe your hard drive 35 times. 35 times might seem like over-kill, but over-kill will probably save you one day.
Tip: install a 2gb hard drive for all your sensitive stuff. How long would it take to wipe a 2gb hard drive with the fast computers we have today? No time at all.