etch installer and dm-crypt

[sigi <dugongs@gmx.de>]

Hi, 

during my next debian etch-install I want to give the facility to 
encrypt my hdd a try.

Now I read in the installation-howto, that it's recommended to set up 
one partition for every encrypted mount-point, like /var /tmp and /home.

This section of the howto
-----------------------
If you created encrypted volumes during the installation and assigned 
them mount points, you will be asked to enter the passphrase for each of 
these volumes during the boot. The actual procedure differs slightly 
between dm-crypt and loop-AES.
-----------------------
made me a little unhappy with this pocedure. If I understand this right, 
I would have to type a passphrase 4 times during the system boot:
3 times to access encrypted partitions and 1 time to login... this 
sounds a lot not userfriendly. 

Is there a way to set all this up, and to type the passphrase once for 
all the encrypted volumes? 
Or to make the system bootable with a key on a usb-stick inserted in 
it's slot during the boot? 

I didn't find very useful hints on the web. And if there is no 
practical solution, I think I'd better leave it all unencrypted... 

Any possibilities known here by anyone?

Regards,
sigi.