There are many reasons to encrypt files — even on a system that is well maintained and comparatively secure. The files may highly sensitive, contain personal information that you don’t want to share with anyone, or be backed up to some variety of online storage where you’d prefer it be extra secure.
Fortunately, commands for reliably encrypting files on Linux systems are easy to come by and quite versatile. One of the most popular is gpg.
gpg vs pgp and OpenPGP
Used both to encrypt files in place and prepare them to be sent securely over the Internet, gpg is related to, but not the same as, pgp and OpenPGP. While gpg is based on the OpenPGP standards established by the IETF, it is — unlike pgp — open source. Here’s the rundown: