Tarzan is a peer-to-peer anonymous IP network layer. Many P2P systems try to implement anonymity at the application layer, instead of at a lower-level network layer. A robust free infrastructure which can anonymize any Internet traffic would benefit a wide array of existing protocols and current p2p systems, since the anonymous connection could seamlessly replace the current connection. Main designs goals of Tarzan, ordered by priority: 7 Application independence: Tarzan should provide the abstraction of an IP tunnel and perform transparently to user applications. 7 Anonymity against malicious nodes: Tarzan should ensure that colluding nodes cannot link a participating host as the sender (or recipient) of any message. 7 Fault-tolerance and availability: Tarzan should resist an adversary's attempts to overload the system or to block system entry or exit points. Tarzan should minimize the damage any one adversary can cause by running a few compromised machines. 7 Performance: Tarzan should maximize the performance of tunnel transmission, subject to our anonymity requirements. 7 Anonymity against a global eavesdropper: An adversary observing the entire network should be unable to determine which Tarzan relay initiates a particular message. http://www.pdos.lcs.mit.edu/tarzan/