Knox - Knox offers easy disk image encryption and comes with a built-in backup service.
GPG Suite - Use GPG Suite to encrypt, decrypt, sign and verify files or messages.
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
GnuPG - GnuPG is a complete and free implementation of the OpenPGP standard as defined by RFC4880 (also known as PGP).
Kruptos - Lock and encrypt your photos, movies, files and folders using 256-bit file encryption.
CrococryptFile - Strong file encryption tool