Setting the correct key for epa in emacs 23

Emacs 23 has seen a new default sign/encrypt mechanism. I found zero documentation for it give or take but with the developers help the following shows how to use mml2015 using gnus-posting-styles:


(add-to-list `gnus-posting-styles `(".*"
(name "Richard Riley")
(from "Richard Riley ")
(eval(setq gnushush-user-agent-header (quote real)))
(signature-file "~/.emacs.d/.sigs/rgr.sig")
(eval (setq mml2015-signers '("b39a104a")))
(organization "aich tea tea pea dicky riley dot net")))