OneSwarm - Private P2P Data Sharing. Friend-to-friend. A friend-to-friend (or F2F) computer network is a type of peer-to-peer network in which users only make direct connections with people they know.
Passwords or digital signatures can be used for authentication. Unlike other kinds of private P2P, users in a friend-to-friend network cannot find out who else is participating beyond their own circle of friends, so F2F networks can grow in size without compromising their users' anonymity. RetroShare.