The prosody XMPP server has a mod_onions module that can do federation between Tor .onion hidden services, to mitigate metadata analysis and add an additional layer of security.
If any of you Prosody server operators want to set it up, see the following URL for details: https://blog.thijsalkema.de/me/blog/blog/2013/06/11/xmpp-federation-over-tor-hidden-services/ If you do set it up, then we have some lua code you can use to add a map of the .onion hidden server addresses for a few popular services ( 9 at this time but there will surely be more soon - we hope you will add your service to the list ! ) https://github.com/nickcalyx/xmpp-onion-map best, Nick -- Nicholas Merrill Executive Director The Calyx Institute 287 Spring Street New York, NY 10013 Jabber: [email protected]
