Private peer-to-peer (P2P) systems are peer-to-peer (P2P) systems that allow only mutually trusted peers to participate.
This can be achieved by using a central server such as a Direct Connect hub to authenticate clients.
Alternatively, users can exchange passwords or cryptographic keys with friends to form a decentralized network.
Friend-to-friend systems only allow connections between users who know one another, but may also provide automatic anonymous forwarding.
Some software, such as WASTE, can be configured to create either group-based or F2F networks.