Anonymity in the network

Privacy in networked communication extends beyond the protection of communicated data; it is equally critical to protect the identities of communicating parties. Anonymous communication systems protect the privacy of the users by hiding who is talking to whom and how packets are moving in the network. These systems, several of them deployed on the Internet, support applications with strong privacy requirements such as e-voting protocols, intelligence gathering for law enforcement, military communications, and such like. The importance of such systems is increasing and the largest deployed anonymity network, Tor has attracted an estimated half a million users. Most anonymity systems such as Tor are based on the concept of Chaum mixes; a mix is special proxy server that uses layered-encryption, random bit padding and batching to provide user anonymity to transmitted packets. Commonly deployed mix-networks, while they provide good protection against packet content/length based information retrieval, are vulnerable to timing analysis of packet. The primary reason for the vulnerability is the lack of optimized mix-network protocols under resource limitations of the network nodes in terms of memory and bandwidth, and QoS requirements such as delay and fairness. Guarding against unauthorized timing analysis incurs a penalty in network resources and QoS, and it is imperative to optimize the design of anonymity systems under constraints on resources and QoS requirements.


 * History


 * Traffic Analysis


 * Adversaries
 * Global Passive Adversaries
 * Malicious Nodes
 * Malicious External Nodes


 * What is the Anonymity?
 * Sender's Anonymity: None other than the sender can deduce the source of a packet.
 * Receiver's Anonymity: None other than the receiver can know the destination of a packet.
 * Sender-Receiver Anonymity: None can know the source and destination of a packet. <\ref>


 * Measures of Anonymity
 * Anonymity Set
 * Information theoretic approach


 * Anonymity in the Internet
 * Mixes
 * Onion Routing
 * Freedom
 * Morphix
 * Tor
 * Tarzan