Actually, very simple.

aptitude install seahorse seahorse-plugins
killall nautilus

Run seahorse and generate your PGP key and next time when you run nautilus, you’ll have a new option when pressed right click on file or folder – Encrypt…

in CLI write and execute two times command “edomtset“. when you press ?, you’ll get more commands.

more @ evilrouters.net

it actually works! all I had to do was to install vpn client called Shrew Soft VPN client and import Cisco vpn profile. if you have any problems, try enabling another network adapter in your Virtualbox host settings.