This sounds like a barebones version of Groove:
“WASTE is a software product and protocol that enables secure distributed communication for small (on the order of 10-50 nodes) trusted groups of users.”
However, it looks like perhaps AOL made Nullsoft dump WASTE from their site because the link went 404 yesterday afternoon.
Of course there’s already a mirror, which I found @ blueyonder.co.uk via the Slashdot Thread:
As a fan of Groove, I’ll need to set aside some time to check this out.