gpg can do symmetric encryption: http://www.gnupg.org/documentation/manuals/gnupg/Operational-GPG-Commands.html#Operational-GPG-Commands http://www.gnupg.org/d

gpg can do symmetric encryption: http://www.gnupg.org/documentation/manuals/gnupg/Operational-GPG-Commands.html#Operational-GPG-Commands http://www.gnupg.org/documentation/manuals/gnupg/Operational... There are a few algorithms to choose from.