selection of GPG key in Gnus

[Hikaru Ichijyo <ichijyo@macross.sdf.jp>]

This is a Gnus question, but I've already asked in gnu.emacs.gnus.
Then, I noticed that no one has had a question answered in that group
for three months.  There are probably some people here who use Gnus.

I'd like to have selection of a default GPG key to use for signing and
encrypting to happen automatically depending on the group I'm in.  I'd
also like to be able to sign by default (using the correct key) in most
mail groups, and never sign/encrypt at all in newsgroups.

Basically, what I'd like is some sort of gnus-posting-styles mechanism
to control PGP behavior...or at the very least, something in the group's
customize menu.

The more I search online, the more I've gotten the impression Gnus can't
do anything like that.

I did find a message from over ten years ago that mentioned using
gnus-posting-styles to specify a X-PGP header for a group that selected
the right key.  That sounds great...but does that really work?  Is it
supposed to work, or would that qualify as a "dumb hack" (which may not
be reliable)?  Does Gnus actually invoke GPG in response to such
user-inserted SMTP headers?  I never saw any other source of information
on that.

Since Gnus aims to be a single message post/reply facility for regular
mail, mailing lists, Usenet newsgroups, Gmane style BBS's, etc...it
doesn't seem right that it would want you to have a one-size-fits-all
setting for your PGP behavior everywhere, does it?

-- 
He that would make his own liberty secure must guard even his enemy from
oppression; for if he violates this duty, he establishes a precedent
that will reach to himself.
					--Thomas Paine