Before sending data over an anonymous connection, the first Onion Router adds a layer of encryption for each Onion Router in the route. As data moves through the anonymous connection, each Onion Router removes one layer of encryption, so it finally arrives as plaintext. This layering occurs in the reverse order for data moving back to the initiator. Data passed along the anonymous connection appears different at each Onion Router, so data cannot be tracked en route and compromised Onion Routers cannot cooperate. When the connection is broken, all information about the connection is cleared at each Onion Router.
Users can use Onion Routing in another, slightly more invasive way.
Currently we cannot redistribute the NRaD redirector because it contains commercial code for which we do not have distribution rights. We will be re-implementing the redirector in the next generation of the system without this restriction. Applications may choose whether to identify their users over an anonymous connection. However, the use of a switched public network should not automatically reveal who is talking to whom. This is the traffic analysis that Onion Routing complicates.