Re: Encrypted Filesystems

Tales Teixeira wrote:

>Dear sirs,
>
>I'm studying about encrypted filesystems and i found a few of then. I
>would like to know more about this in operation systems like Linux
>Debian, Slackware and others "flavors". I'm sorry if this question had
>been answer, but i didn't find.
>
>Sorry for my "Brazilian english"
>:-P
>
>Best Regards,
>Tales Teixeira.
>  
>
Encrypted filesystems in Linux are pretty much handled the same way in 
all distributions.  The loopback mechanism is used to associate a 
virtual filesystem with a real filesystem, but filtering it thru a crypo 
engine (or something else) first.  Usually, the crypto hooks in the 
Kernel must be activated and the algorithms you want to use selected 
before it all will work.

LoopAES (http://sourceforge.net/projects/loop-aes/) is a very nice 
package that implements the U.S. Advanced Encryption Standard as a 
filesystem or swap (virtual memory) encryptor.

Traditional Linux FS encryption uses losetup 
(http://linux.about.com/library/cmd/blcmdl8_losetup.htm) to set up the 
loop and specify the algorithm.  There are modifications (patches) to 
allow it to use more than just DES.  You will need the appropriate 
patches for the mount command as well.

With Linux kernel 2.6 the cryptographic functions are integrated.  You 
can read more about the cryptoloop subsystem from the HOWTO 
(http://www.ibiblio.org/pub/Linux/docs/HOWTO/Cryptoloop-HOWTO).

I hope this gets you started in the direction you wanted to go.

 Charles Hill