Why Wipe Free Disk Space?

[xephyr69]

One good reason to wipe free space, or to wipe a hard drive period would be for the sale of it. If you have a used computer or just a used hard drive, wipe it clean so that none of the data that has been previously on that drive can be recovered. This protects your privacy by ensuring that the new owner does not get a hold of credit card info, phone numbers, addresses, or simply material that you would rather keep private. I used Darik's Boot and Nuke, a.k.a. DBAN. It is very easy to use and allows me to choose from several wipe methods, some of which are the standard for the Department of Defense.

[xephyr69]

http://www.pcworld.com/article/110338/a ... _data.html

[usdcs]

This thread began with a Spam message. But, I decided to allow xephyr69's remarks to remain. I thought that it would be beneficial to someone.

Regards,
Dan

[webfork]

http://www.pcworld.com/article/110338/a ... _data.html

One thing I really like about this link is that it answers the question "what wipe settings should I use?" :

"reading data that has been overwritten by even the simplest shredders requires expensive hardware, so unless you're worried about professional sleuths, such thorough overwriting probably isn't necessary."

[Hydaral]

Waking up the dead ones, eh webfork?

I would go further than professional sleuths and suggest that unless you are expecting some infinite-budget private corporation to try and decode your data (a shadowy government dept would never have the budget, technology or time), then a single pass is enough, up to three if you are especially paranoid.

http://www.nber.org/sys-admin/overwritt ... ttman.html

A quote from a linked PDF:

As a very rough approximation, if a 3 1/2" disk is to be imaged and the MFM (Magnetic Force Microscope) can scan and move to the next area in one minute (quite fast!). It would take about 60 weeks of 24 hour/day operation to scan one surface. If the disk surface holds 50GB of data, for example, the image files that would be generated from the MFM would be many times this amount - perhaps generating tens of terabytes of image information to analyze. For example, all of these individual images would need to be stitched together into a complete disk image and a software image processing algorithm would need to be used to l) servo on each track and 2) generate the read gate to indicate the beginning and ending of each sector. Finally a signal from the center of the track image would need to be generated as a readback signal, detected, decoded and assembled into useful files.

That is only one side of one platter and this is assuming that the software correctly guesses that the bit it was reading used to be either a one or a zero.

[carbonize]

I have been using eraser on a single pass pseudo-random to erase whatever i may have downloaded via torrent. Going to sto pdoing it as I doubt I am going to get busted and I don't think it does the hard drive a lot of good.

[webfork]

A much more indepth look at what's necessary in file wipe is on the Bleachbit page (http://www.portablefreeware.com/index.php?id=1561) by an alert user:

http://bleachbit.sourceforge.net/docume ... -wipe-disk

Good stuff.