You can encrypt and decrypt files with gpg

To encrypt a file

gpg -c file.to.encrypt

To decrypt a file

gpg file.to.encrypt.gpg

But gpg will not do entire directories. For entire directories you have several options, ecryptfs is popular.

# Install if ecryptfs-utils if needed

sudo apt-get install ecryptfs-utils



# Make an encrypted directory

ecryptfs-setup-private

That will make a directory "Private". Any data you put into the directory Private will automatically be encrypted when you log out and decrypted when you log in.

If you want a different behavior or a different directory ...

mkdir ~/secret

chmod 700 ~/secret



sudo mount -t ecryptfs ~your_user/secret ~your_user/secret

Put your data into ~/secrte

To encrypt

sudo umount ~your_user/secret

To Decrypt

sudo mount ./secret ./secret -o key=passphrase,ecryptfs_cipher=aes,ecryptfs_key_bytes=16,ecryptfs_passthrough=no,ecryptfs_enable_filename_crypto=yes

Hint: make an alias for that second command.

See http://bodhizazen.com/Tutorials/Ecryptfs or man ecryptfs for additional details.