Map-Z: Exposing the Zcash Network in Times of Transition

Abstract

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.

Blockchain Layer Zero: Characterizing the Bitcoin Network through Measurements, Models, and Simulations

“…Interestingly, the measured rates of peers located in the CN region are lowest with a mean peak rate of only around 106 Mbit/s. This observation is particularly notable, as the regional distribution of blockchain networks have been discussed in literature for quite a while [18,20] and these measurement results are in line with prior research that suggests that the so-called "Great Firewall" of China may pose a significant bandwidth bottleneck, which the authors link to detrimental miner behavior, such as creating empty blocks [19].…”

“…While early entries were mainly concerned with the network topology and block propagation behavior [3,31], more recent contributions measured the latency, bandwidth [29,32], and mining power distributions [18,33,34], as well as the node churn [29,35] exhibited by the Bitcoin network. Moreover, the peerto-peer networks of Ethereum [17,32,36], Zcash [20], and Monero [37] have been explored in literature. However, most entries do not entail recent measurement results that consider the current state of blockchain network provisioning.…”

“…The separate cluster for China is justified on the basis of earlier research that highlights its special role for blockchain networks[18,19,20].…”

Privacy and Cryptocurrencies—A Systematic Literature Review

“…However, the use of the shielded pool is minimal (1.3% of transactions in September 2019 10 ) with users impeding anonymity through their leaking behaviour (deanonymization of 69.1% of the shielded transactions) [58]. Another issue faced in Zcash is that large fractions of the network can be deanonymized; [59] shows that transactions can be linked to IP-addresses with 50% precision and 82% recall. To address this issue, Kappos et al [60] propose the use of Mixnets for anonymous broadcasting.…”

Counting Down Thunder

“…As the estimators of course presuppose the knowledge of the underlying channel graph to be able to return the candidate endpoint of maximum likelihood, they are bound to fail in these circumstances. Therefore, applying methods from the research area of topology inference [31,32] in order to detect hidden channels would be an interesting avenue for future research.…”