Cold Reboot Attacks on Disk Encryption [LWN.net]

Cold Reboot Attacks on Disk Encryption

Posted Feb 21, 2008 18:44 UTC (Thu) by freemars (subscriber, #4235)
Parent article: Cold Reboot Attacks on Disk Encryption

A possible work around -- an expensive one -- could be to store part of the key in a CPU
register (perhaps one of those 128-bit SSE registers).  Not only would this require kernel
completely rewritten to leave that register alone, it would probably slow the operating system
by something like 1/(#_of_registers_in_this_CPU).  Having to guess the final 128 bits of the
key would at least annoy brute-force attackers.

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Cold Reboot Attacks on Disk Encryption

Posted Feb 21, 2008 19:21 UTC (Thu) by ncm (subscriber, #165) [Link]

Or, alternatively, in some other device: perhaps the graphics chip.  On any given system
there's some bit of complicated hardware that is not used.  On many systems the 3D features
are never used (e.g. Nvidia chip w/ nv driver).   Others have firewire, or an MMC slot.  For
security, it could be an advantage that the key is stored at different addresses on different
machines, particularly if random values are stored in the others, and the actual location used
on any given boot is chosen from among them at random.