Defending Against Sybil Attacks in Anonymizing Networks
An anonymity network enables users to access the Web while blocking any tracking or tracing of their identity on the Internet. Tor is open-source anonymity software free to public use. This type of online anonymity moves Internet traffic through a worldwide network of volunteer servers. Anonymity networks prevent traffic analysis and network surveillance or at least make it more difficult. Website administrators routinely rely on IP-address blocking for disabling access to misbehaving users, but blocking IP addresses is not practical if the abuser routes through an anonymizing network. As a result, administrators block all known exit nodes of anonymizing networks, denying anonymous access to misbehaving and behaving users alike.