Mod openpgp mod_openpgp is an Apache server module authored by Arturo 'Buanzo' Busleiman that implements access authorization to servers, virtual hosts, or directories when incoming requests' HTTP OpenPGP signatures are valid and known by the local keyring. It's the Apache server companion for the Enigform extension for Mozilla Firefox.Prior to version 0.2.2, mod_openpgp was known as mod_auth_openpgp.mod_openpgp participated in the OWASP Summer of Code 2008.