[starman]

I have a bunch of hard drives I want to sell, but I want to make sure they're completely wiped before dumping them. I saw Wipe Drive come up a lot as an app to use to do it.

The problem is that I'm not going to get a boatload of money for them and Wipe Drive costs $40 which is about the amount I'll get for two of the drives.

Are there any free apps that are guaranteed to wipe my hard drives and guarantee that no information can be retrieved off them?

[Cold Warrior]

OS X's own Disk Utility works great. 7-pass wipe for security or a 35-pass wipe for the ultra paranoid.

[starman]

I saw that, but I think the difference between DU and other apps like WD is that WD wipes the drive with a random pattern where (IIRC) DU uses 0's which could still allow magnetic readers to read the difference of the data. Of course, I don't QUITE understand that, but from what I gather there's some kind of data still recoverable, even with a 35-pass wipe of 0's. Or, I may be wrong.

[starman]

Found this little nugget:

http://www.derkeiler.com/Newsgroups/.../msg00006.html

Almost makes me want to not even bother and just open the drives, sandpaper them, and cut my losses.

Drobos are $500. ouch.

[turtle777]

Originally Posted by starman 

Of course, I don't QUITE understand that, but from what I gather there's some kind of data still recoverable, even with a 35-pass wipe of 0's. Or, I may be wrong.

Theoretically, yes, perhaps possible, at very high cost.

Mind you, it hasn't even been proven, to my knowledge. Read this. Recovering of multiple wiped data (7 or 35 pass) is so far, just a speculative possibility.

Unless some knew with a high certainty that your data was worth a five or six figure sum, nobody would go into such great lengths trying to restore the data. It's NOT possible to recover the data just with software, it needs very expensive technical equipment (Magnetic Force Scanning Tunneling Microscopy (MFM or STM)) and lots of time.

-t

[starman]

I trust you know what you're talking about .

Ok, let's say you're right. Then what's with all these web sites saying that unless you do all this crap to wipe your data, that someone can buy your drive off eBay and get your personal info off it? Is it a load of crap?

I don't have info worth that much to anyone. Maybe these sites are making me paranoid.

[turtle777]

All I'm saying is a 7 pass wipe with Disk Utility should be good enough, unless your data is worth tens of thousands of dollars, and that there are people crazy enough to try to recover it.

Most won't bother, there's easier money to be made faster.

-t

[seanc]

To be honest, unless you label all of your drives with 'VERY SHOCKING SECRETS ABOUT <NAME>' on there, I doubt anyone would bother trying to recover data.

Heck, I've bought used machines which haven't even been erased AT ALL.

[starman]

Ok, 7-pass it is. Thanks.

[MacNNUK]

Is it really worth risking personal data for $20 a drive ?

Secure empty trash.

Disk Utility wipe, 7 pass, then physically destroy the drives.

[ghporter]

Originally Posted by MacNNUK 

Is it really worth risking personal data for $20 a drive ?

Secure empty trash.

Disk Utility wipe, 7 pass, then physically destroy the drives.

The 7-pass option with Disk Utility meets U.S. DoD standards for data erasure. That means in simple terms that your data is completely gone, as if it never existed, wiped from the face of the earth, <insert your own extreme term here>. It would take an extremely diligent, highly funded and very well equipped lab a very long time to get ANYTHING off of a drive that had been so erased. There would be, for all intents and purposes, NOTHING AT ALL LEFT. Your credit card numbers? HAH! Anyone worried about filching credit card numbers is more likely to see a drive like this as "completely blank" and move on.

Unless you're worried about the NSA being VERY interested in your p0rn collection, use the 7-pass option and you are COMPLETELY protected.

[pendragon]

Perhaps Permanent Eraser (donation ware) is for you. http://www.edenwaith.com/products/pe...aser/index.php

It uses the Gutmann Method: "overwrites your data thirty-five times, scrambles the original file name, and truncates the file size to nothing before Permanent Eraser finally unlinks it from the system. Once your data has been erased, it can no longer be read through traditional means."

Note: Permanent Eraser does not erase your HDs free space. You will still need Disk Utility for that.

That seems a bit of overkill (to me) and I don't know how it will work on an entire HD or how long it would take, but presuming it does work, you can sleep secure. Well, providing you subsequently immerse your drive in boiling aqua regia.

[turtle777]

Well, there are people that claim that Gutmann's claim that more than 7 passes is needed to achieve security is just an overhyped myth.

Read here: http://www.nber.org/sys-admin/overwr...a-guttman.html

To me, it seems it hasn't even been proven that 7 wipes can be recovered. It's all theory on Gutmann's part.

-t

[ghporter]

I wonder how many times Guttmann brushes his teeth. After fifteen or twenty minutes, he has to be wearing off the enamel.

Seriously, considering that Guttmann is concerned that someone may be able to use magnetic force microscopy to recover data unless you go through all of his steps (which, by the way can be done using Disk Utility), you have to ask "who would be that interested in Joe Sixpack's personal data?" The time, manpower and equipment costs to support that sort of recovery effort — which is not guaranteed to succeed — are so enormous that the average user's data (not classified data on some military computer) are too small pickings to bother with.

[B Gallagher]

I used Disk Utility to do a 7-pass on a 60GB HDD on my old PC. It took about 3 hours to complete, but I ran Data Rescue II on the drive once it had finished, and it couldn't restore any recognisable files. That was good enough for me.