EasyPG is a GnuPG interface for Emacs.  It has two aspects: convenient
tools which allow to use GnuPG from Emacs (EasyPG Assistant), and a
fully functional interface library to GnuPG (EasyPG Library.)  It does
not cache passphrases, so gpg-agent (security/gnupg2) is recommended.

Note that EasyPG is built into emacs 23 and later.