CONTROL THE TRADEOFF BETWEEN PERFORMANCE AND ANONYMITY THROUGH END-TO-END TUNABLE PATH SELECTION

Tor (originally short for The Onion Router) is a system intended to enable online anonymity. The modern day anonymity networks hide user identities with the help of relayed anonymity routers. However, the lack of effective trust model disables users to monitor malicious or vulnerable routers, thus making them susceptible to such router based attacks. The Tor network uses self-reported bandwidth values from all routers for building optimal tunnels “performance vs. anonymity”. Since tunnels are allocated in proportion to this bandwidth, this allows a malicious router operator to attract tunnels for compromise. This gauge being insensitive to load does not adequately respond to changing conditions and results in unreliable performance, eventually driving users away. Tor, a circuit-based low-latency anonymous communication service, is a protocol that is both ore secure and performs better, both in terms of observed performance and in terms of achievable anonymity and provides anonymous connections that are strongly resistant to both eavesdropping and traffic analysis. This paper proposes improvements to the existing Tor router bandwidth evaluation and router selection algorithms. Additionally, by allowing the user to select their preferred balance of performance and anonymity, these improvements increases the usability, and therefore the potential user base and security of the Tor network. It is proposed to increase the fidelity of the packet-level simulation in the Tor network by including such effects as variable file sizes, variable intervals between requests, and TCP slow-start behavior. This paper also proposes to examine the other aspects (such as latency, apart from bandwidth) of the tradeoff between performance and anonymity in anonymous networks of varying types and an opportunistic bandwidth measurement, tunable performance extensions are examined in the Tor network.