A three dimensional sender anonymity metric
Neeraj Jaggi, Umesh Marappa Reddy, Rajiv Bagai · International Journal of Security and Networks · 2011
Measuring the degree of anonymity provided by various anonymous systems on the web, is a challenging task. We first illustrate using examples that existing measures in literature are not sufficient to fully characterise the anonymity provided by a system. We then propose a new isolation measure, based upon outliers in a distribution, and show that this measure is critical towards quantifying the overall anonymity level. We provide justification for three distinct aspects of anonymity, important from the perspectives of a user, a system designer, and an attacker, leading to a three-dimensional approach towards measuring sender anonymity. We outline various properties of the proposed three-dimensional metric and illustrate how the metric, along with adjustable weights, can be used to compare different anonymous systems. Finally, we apply the proposed metric to existing anonymous systems and discuss insights which should prove useful in the design of future anonymous systems.