"System-wide security solutions such as SELinux, AppArmor,
Bastille and grsecurity can, in most cases, make your Linux desktop
more than reasonably secure. But there are still cases where file
or directory encryption is necessary. Here are some tools that can
help you when you need to move files outside of your home computer,
carry personal data around with you on a pendrive, or send email
messages containing sensitive information.
"Most of these tools are command-line only, but they are so
simple that even the most CLI-challenged newbie should be able to
use them with little effort. All are highly portable, small in
size, and have few or no library dependencies..."