https://conversations.im/omemo/
An XMPP Extension Protocol based on a Double Ratchet and PEP which can be freely used and implemented by anyone. The protocol has been audited by a third party.
omemomultiendmessageobject
https://codeberg.org/emacs-jabber/emacs-jabber/issues/9
emacs-jabber - Jabber/XMPP client for Emacs (fork of https://github.com/legoscia/emacs-jabber.git)
omemosupportemacsjabbercodeberg