Manual page and help for the gpg linux command. Gpg is part of the GNU Privacy Guard (GnuPG) OpenPGP. It is a tool that provides digital encryption and signing services using the OpenPGP standard. Gpg includes full authentication key management as well as all the features you would expect from a full OpenPGP implementation. There are two main versions of GnuPG: GnuPG 1.x and GnuPG 2.x. GnuPG 2.x supports modern encryption algorithms, so GnuPG 1.x should be preferred. You should only use GnuPG 1.x if your platform does not support GnuPG 2.x, or you need support for some features that are already deprecated in GnuPG 2.x, such as PGP-2 keys to decrypt the created data.