  Zcash is a privacy-preserving cryptocurrency that provides anonymous monetary
transactions. While Zcash's anonymity is part of a rigorous scientific
discussion, information on the underlying peer-to-peer network are missing. In
this paper, we provide the first long-term measurement study of the Zcash
network to capture key metrics such as the network size and node distribution
as well as deeper insights on the centralization of the network. Furthermore,
we present an inference method based on a timing analysis of block arrivals
that we use to determine interconnections of nodes. We evaluate and verify our
method through simulations and real-world experiments, yielding a precision of
50 % with a recall of 82 % in the real-world scenario. By adjusting the
parameters, the topology inference model is adaptable to the conditions found
in other cryptocurrencies and therefore also contributes to the broader
discussion of topology hiding in general.
