Knox - Knox offers easy disk image encryption and comes with a built-in backup service.
GnuPG - GnuPG is a complete and free implementation of the OpenPGP standard as defined by RFC4880 (also known as PGP).
Exocet - Exocet creates a Folder on your System.
Kleopatra - Kleopatra is a certificate manager and GUI for GnuPG.
Advanced File Security Basic - Download Advanced File Security Basic. Protect files by encrypting them with a strong password, a series of questions, or even an USB key you can carry around with this powerful security solution
PGP Tool - PGPTool allows you to encrypt and decrypt files. It's free and easy to use.