Re: Encrypted Swap

From: Ryan Mack (rmack@mackman.net)
Date: Tue Aug 07 2001 - 01:45:33 EST


> Hmmm, let us suppose, that i copy your crypted partition per bit to my
> disk.
> After it I will disassemble your decrypt programm and will find a key....
>
> In any case, if anyone have crypted data, he MUST decrypt them.
> And for it he MUST have some key.
> If this is a software key, it MUST NOT be encrypted( it's obviously,
> becouse in other case, what will decrypt this key?) and anyone, who have
> PHYSICAL access to the machine, can get this key.
> Am I wrong?

I think the point you are missing is that encrypted swap only needs to be
accessible for one power cycle. Thus the computer can generate a key at
swapon using a cryptographically strong random number source. The key is
kept in RAM. When the computer powercycles again, the old key is lost
from RAM, and a new key is generated. The old key, and thus the old
encrypted contents of swap, are permenently lost.

-Ryan

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This archive was generated by hypermail 2b29 : Tue Aug 07 2001 - 21:00:43 EST