To protect your data in a directory is easy with Ubuntu 8.10.
Step 1 :
sudo apt-get update
sudo apt-get install ecryptfs-utils
Step 2 :
Step 3 :
For the first question that asking for login passphrase, please enter your login password.
Step 4 :
For the second question that asking for mount passphrase, please let the system generate one for you and copy the passphrase to a safe place.
Step 5 :
Log out and Log in again. Save your sensitive data in the ~/Private directory.
Step 6 (Optional) :
If you want to encrypt the data of Firefox or Evolution, for example. Make sure that the application whose data you want to protect (e.g. Firefox or Evolution) is not running
ps -ef | grep evolution
Move the application’s data directory (e.g. ~/.mozilla or ~/.evolution) into your ~/Private directory
mv ~/.evolution ~/Private
Establish a symbolic link from the old location to new location
ln -s ~/Private/.evolution ~/.evolution
If you put all of .ssh in ~/Private, you won’t be able to ssh into the system using public key authentication. In this case, you might want to only put your private key in ~/Private, and leave the rest in the clear.