Re: the cold-boot attack

Boyd Waters wrote:
> On Feb 21, 2008, at 12:17 PM, a co-worker wrote:
> 
>> Research at Princeton demonstrated that it is possible to recover
>> significant information from mounted FileVault, i.e. a stolen
>> sleeping laptop, using a cold reboot technique.
>>
>> from: <http://citp.princeton.edu/memory/>
> 
> 
> I really like the part about cooling the RAM to -50C with a can of
> compressed air. Keeps the bits from rotting.

Thanks! We thought it was a cute attack as well!

Cooling the RAM isn't strictly required. Some of our most fun proof of
concept attacks don't require anything more than a reboot.

> 
> No one has mentioned loop-aes, for Linux, which twiddles the bits of the
> key (in RAM) periodically (XOR with a known string of random bits,
> generated at boot-time) - so it moves the key around in memory, and
> flips the ones and zeroes back and forth. I think that would complicate
> the attack mentioned in the paper.
> 

We did run our attacks on loop-aes and we did find keying material. We
actually found a very large amount of keying material. We didn't bother
to implement a decryption utility with the keys found it memory, it
would be trivial to do so though.

Regards,
Jacob Appelbaum


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