[all / linux] password protect a file

[jeremy jozwik]

mornin list, ive got a crap memory. and i used to use a password
manager on my old blackberry that was, oddly enough, password
protected. so my question today is weather or not it is possible to
password protect a file on the openmoko so much so root cannot access
it without the correct password?

i know this would be tragic if i forgot the password but remembering
one is a lot easier then remembering 20.

at any rate is it do able or would i need to create a user login for the moko?