> Technically it's possible for "residual magnetism" of the original data to > make it become visible again. And it has been done. I can't find the article, but there was an article about extreme data recovery on /. awhile ago. They were beta testing some computer voting systems, and the numbers didn't add up. They suspected the voting machine's audit trail would explain everything, but when they looked for the audit files they were nowhere to be found. What the (VERY highly paid) recovery expert determined is that Darik's boot and nuke had been run. Even after THIRTY FIVE passes, they were able to recover the data they needed. For a good technical read on data deletion and recovery, Peter Gutmann has a nice article: http://www.cs.auckland.ac.nz/~pgut001/pubs/secure_del.html (Unix Wipe is based on his theories, Darik's boot and nuke is Unix Wipe on a floppy) While his paper is all theory, this has been proven: THERE IS NO SECURE DATA DELETION! The more passes you use, the more costly (time and $$$) it becomes. There is no data that can't be recovered. The trick is to obscure it enough that the cost of recovery is so astronomical that no one would try it. If you can't risk it: melt it, grind it, crush it, just make sure it never sees the light of day again. I've put a lot of thought into this, as I assist in putting government PCs into public auctions. Peter Gutmann's paper hangs in my cubicle, and not a single hard disk leaves the building without extreme scrutiny. -Brian _______________________________________________ TCLUG Mailing List - Minneapolis/St. Paul, Minnesota http://www.mn-linux.org tclug-list at mn-linux.org https://mailman.real-time.com/mailman/listinfo/tclug-list