funsec mailing list archives
Re: "Hard drive destruction 'crucial'" (BBC)
From: "nick hatch" <nicholas.hatch () gmail com>
Date: Sat, 10 Jan 2009 14:50:02 -0800
On Sat, Jan 10, 2009 at 7:37 AM, der Mouse <mouse () rodents-montreal org>wrote:
How long does it take to extract gigabytes of data by using an atomic force microscope to image each bit's recording area? I don't know how fast they are, but whatever fraction of a second it takes to extract a byte, reading a gigabyte of disk will take an equal fraction of a gigasecond, which I shall let you work out for yourselves.
Hmmm. Wikipedia says that the nominal maximum size of an AFM scan is 150 micrometers^2 . From my experience with AFM, that sounds about right. Quick math puts the minimum number of scans for one side of a platter at 315,000 -- and that's an absolute minimum based on surface area. I don't know the data density or track structure for modern magnetic media, but I don't think you'd even be able to see the bits at this resolution. I found an image [1] of a "test platter" (not sure what that means) which is only a few micrometers in size. Increase the above estimate by many orders of magnitude. The bigger problem here is tracking. Anyone who has done microscopy of any sort knows how difficult it can be to get adjacent images. At the very least, you're talking high-precision piezo movements. AFM is fun if you're doing bulk surface analysis ("ahh! that's a clear image, let's stop now"), and can be amazingly frustrating for defect analysis ("where the hell did that spot go?"). I'm willing to say that nobody (spooks or otherwise) reads data off a HD using AFM. It's just not the right tool. If you're worried about it: hit the case with a hammer hard enough to bend/shatter the platter. A bent platter would be a nightmare for ANY microscopy technique, even for a theoretical custom spook machine. -Nick [1] http://www.rhk-tech.com/results/UHV-MFM-image-of-Hard-Drive-Test-Platter_5.php
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Current thread:
- Re: "Hard drive destruction 'crucial'" (BBC), (continued)
- Re: "Hard drive destruction 'crucial'" (BBC) Paul M. Moriarty (Jan 08)
- Re: "Hard drive destruction 'crucial'" (BBC) Nipper, Johnny R. (Jan 08)
- Re: "Hard drive destruction 'crucial'" (BBC) Andri Möll (Jan 08)
- Re: "Hard drive destruction 'crucial'" (BBC) Jeff Rosowski (Jan 08)
- Re: "Hard drive destruction 'crucial'" (BBC) Nipper, Johnny R. (Jan 08)
- Re: "Hard drive destruction 'crucial'" (BBC) Dragos Ruiu (Jan 08)
- Re: "Hard drive destruction 'crucial'" (BBC) Tomas L. Byrnes (Jan 09)
- Re: "Hard drive destruction 'crucial'" (BBC) Valdis . Kletnieks (Jan 09)
- Re: "Hard drive destruction 'crucial'" (BBC) Andri Möll (Jan 10)
- Re: "Hard drive destruction 'crucial'" (BBC) der Mouse (Jan 10)
- Re: "Hard drive destruction 'crucial'" (BBC) nick hatch (Jan 10)
- Re: "Hard drive destruction 'crucial'" (BBC) Valdis . Kletnieks (Jan 10)
- Re: "Hard drive destruction 'crucial'" (BBC) Paul M. Moriarty (Jan 08)
- Re: "Hard drive destruction 'crucial'" (BBC) Valdis . Kletnieks (Jan 10)
- Re: "Hard drive destruction 'crucial'" (BBC) der Mouse (Jan 11)