GnuPG is a Perl module that provides a limited programmatic interface to the
 GNU Privacy Guard program. It uses the coprocess hook system provided by gpg
 and communicates using shared memory. It attempts to map the interactive
 interface offered by the gpg command-line tool to a more programmatic API.
 .
 This module is compatible with the "classic" 1.4 version of gnupg only. It
 does not work with modern gnupg 2.1x currently.