On 20/09/11 00:27, Aaron Toponce wrote: > On Sat, Sep 17, 2011 at 08:59:14AM +0200, Ralf Mardorf wrote: >> If you want to be safe, you need to overwrite the data several >> times, > > Have anything to back that up?
Try eating your own dog food - the citation in the wikipedia link (made no more official by the circuitous url shortening) contradict your own statements. > If you're using drives that used the > old MFM or RLL encoding schemes, and had massive space for bits per > linear inch, then sure, but on today's drives, with perpindicular > encoding, and the extremely dense bit capacity, going more than once > is silly. Magnetic fields decay - regardless of track layout. I don't know where Ralf got the laser idea from - I'm only familiar with side-scanning electron microscope techniques. Used to recover unmelted segments or S11 platters - and also to recover data from disks deliberately overwritten many times in a futile effort to erase evidence. > >> 'shred' does delete data several times. We hardly are able to >> recover data that one time really was deleted at home, but CSI is >> able to do this > > [citation needed] > <snipped> > > You may want to read this, as well as the references the article > links to: > > http://goo.gl/5QG4U I'd suggest you actually *read* the material you reference. Those conclusions are backed up in more detail for the referenced articles... Note especially (the ones I'm familiar with):- http://www.oregon.gov/DAS/OP/docs/policy/state/107-009-005_Exhibit_B.pdf?ga=t http://www.dsd.gov.au/publications/Information_Security_Manual_2010.pdf Let me summarize it for you - multiple, random. overwrites is considered a minimum requirement for data security *onsite* *before* being taken (by secure) methods for high-temperature destruction. Some sites have a special device that fires a bullet through hard drives scheduled for destruction - somehow that has led people to ignore the "scheduled for destruction" bit and focus on the bullet. Damaging (by bullet, degausser, or *multiple* overwrites) is an onsite measure take prior to shipping to a smelter (in case the shipper loses a drive/tape). The same procedures apply to tapes - 1 minute of wipes across the noisy 3M degausser before being put in the locked bins to be shipped for high temperature destruction. Not out of uninformed paranoia - but because data can be recovered and information can be reconstructed. Are the same procedures necessary for home users/SMEs? No. Does that make false statements true? No. > > Claiming that you can recover data after a single pass of zeros on > today's spinning platters is urban legend. Many companies make their living from that "urban legend". The magnetic fields decay over time (anytime) - so recovery is always possible provided the time, equipment, and expertise is available. It would be more accurate to say - it's very unlikely anyone has the equipment, skills, and motivation to recover data from a drive that has multiple layers of data overwritten - than to make patently, and demonstrabley absurd statements like you have. > I guess There's the problem. > if you like wasting your time, go for it. I've got better things to > do than do several passes on a 2TB SATA disk, running at 30MBps, and > I can sleep at night knowing that no one will get access to the > data. > <snipped> The vast majority of the time your single wipe will be enough to protect your data - though it's probably quicker, and simpler to break off the point of a pin in the breather hole and/or damage the power connectors. There's probably no need to shred old DVDs and CDs either. Cheers -- "Always question authority, and demand the truth." — Bill Hicks -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/4e77e498.8060...@gmail.com
