Bruno Wolff wrote: > Given 1, this seems like a foolish policy. Just eat the cost as part of > securing your data. It might be cheaper than having you keep an eye of > multiple write passes covering several days. "I have no comment at this time." :-) > There was some old documentation that claimed reading the remmants from > previous writes were recoverable, though I don't remember seeing costs > estimates that low. I would have expected a lot of human time needed to > help deal with the incomplete recovery. I suppose the cost of such equipment is much cheaper now than in the olden days of 15 years ago. Also, given my comment below, a sensitive read head (rather than an MF or AF Microscope) may be all that's needed in the case of a "zero write-over". > If one can recover a significant amount of data after writing zeros, one > is going to be able to do it after writing a single pass of random data > as well. I don't think this is correct, based on my reading. The situation is a little bit like trying to decrypt a file after adding an unknown constant numerical value to the data, vs. adding a "one-time pad" of random numbers. That's because writing zeros does not completely zero out the local magnetic orientations so the variations can still be detected. A random pattern makes the problem much harder. Multilple passes (which is what /usr/bin/shred does) makes it even harder. Dean -- fedora-list mailing list fedora-list@xxxxxxxxxx To unsubscribe: https://www.redhat.com/mailman/listinfo/fedora-list Guidelines: http://fedoraproject.org/wiki/Communicate/MailingListGuidelines
