Privacy Analysis of Anonymous Communication Networks at the Example of Vuvuzela

In recent years, many anonymous communication networks have been proposed.
Since it is common for papers to introduce their own privacy goals and adversary models, comparing protocols can
be difficult.
To fix this problem, Kuhn et. al. proposed a framework that formalizes different privacy goals.
Protocols which have been analyzed using this framework can be directly compared to each other.
To provide more data for such a comparison, we present a formal analysis of the anonymous communication network Vuvuzela using this framework.
During the analysis, we identify significant weaknesses of Vuvuzela against replay and sender timing attacks.
We propose a variant of Vuvuzela called f -Vuvuzela which fixes the discovered weaknesses.
Finally, we reveal that these weaknesses are only partially fixed in Stadium and Karaoke, which are follow-up protocols to Vuvuzela.