comments wanted on gbde

Dan Kaminsky dan at
Mon Mar 7 12:23:14 EST 2005

Re, GDBE--

    Some initial thoughts:

    I wouldn't be surprised if platters couldn't be analyzed for usage
levels / magnetic degradation (Peter?).  Even without a clean room, ATA
is pretty rich -- anyone remember the guy who graphically plotted the
spiral damage caused by a falled drive head w/ nothing but a massively
hacked ATA driver?  There's also likely to be useful information from
drive sectors duplicated by the drive firmware (there's extra space in
every drive; when particular sectors are judged "buggy" content from
them is migrated onto the spare space).

    I saw nothing establishing the integrity of sectors during
*decryption* in 7.5.  Random / polluted sectors will decrypt, though
into unpredictable noise (which tends to do bad things to file system
code).  Previous versions of sectors will also decrypt successfully --
the cleaning lady can take lessons from Mallory, as it were.  It's
useful to immediately grant though that their threat model is much more
aligned towards drives that will never be hot again.

    One wonders if there is a delivery service for Key-key's.


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