The NSA disagree and have conducted laboratory tests. I work for NYC as a unix admin (Solaris). We use the sun format purge to erase disks (that can be written to; drives that won't spin up or can't be written are another problem). I guarantee that a sufficiently strong degausser will erase your data...along with the timing tracks and possibly burning out micromotors and ball bearings. Its a question of how many oersteds you need for the drive so that the magnetic field penetrates the housing (take out the platters and you have another situation entirely). I don't have the site bookmarked at home but NIST or NSA have a site which reviews the degaussing equipment and other data erasure techniques. On Wed, 20 Jul 2005, Jared Johnson wrote: > All, > > Do you all agree with Peter Gutman's conclusion on his theory that data can > never really be erased, as noted in his quote below: > > "Data overwritten once or twice may be recovered by subtracting what is > expected to be read from a storage location from what is actually read. Data > which is overwritten an arbitrarily large number of times can still be > recovered provided that the new data isn't written to the same location as > the original data (for magnetic media), or that the recovery attempt is > carried out fairly soon after the new data was written (for RAM). For this > reason it is effectively impossible to sanitise storage locations by simple > overwriting them, no matter how many overwrite passes are made or what data > patterns are written. However by using the relatively simple methods > presented in this paper the task of an attacker can be made significantly > more difficult, if not prohibitively expensive." > > It seems that the perhaps the only real way to rid your Hard Drives of data > is to burn them. > > I'd love to hear some thoughts on this from security and data experts out > there. > > > >
