[liberationtech] Linux distribution on encrypted USB?

[Moon Jones]

A portable distribution on an encrypted stick.

In the end, I think only an USB hard drive can offer that, because of 
the way memory locations are handled by flash media.

But is it feasable to have a two device solution? Media1 has the /boot 
but Media2 has the strong key. Media1 boots, prompts, than mounts 
Media2, takes the key, unmounts Media2 prompting and goes ahead with the 
boot without touching the other drives.

Are these doable? Are they already made?