Master Thesis

An empirical study of privacy-preserving blockchains with the transaction graph

The two most prominent blockchains, Bitcoin and Ethereum, offer very little privacy for their users. Any transaction reveals sender, recipient and exchanged amount. Privacy-preserving blockchains such as Monero, Zcash, Mimblewimble or Dash, alleviate this issue by hiding this information. Although most of these chains use well-established cryptographic methods, their implementations have been the subject of multiple attacks and vulnerabilities over the past, mostly due to empirical studies (e.g., Monero [1,2,3,4,5]).

In this project, we propose a novel approach to empirically study the privacy guarantees of such blockchains. The transaction graph has been recently used to model different privacy-preserving systems, but it was never used to study empirical properties. This work addresses that specifically. It consists in building the transaction graph from an existing blockchain and performing an empirical analysis, using the underlying properties of the graph.

Requirements: Interest in privacy-preserving blockchains, knowledge of at least one programming language, ease with data extraction and manipulation, and willingness to explore a graph-based data structure.

References

[1] Malte Möser, Kyle Soska, Ethan Heilman, Kevin Lee, Henry Heffan, Shashvat Srivastava, Kyle Hogan, Jason Hennessey, Andrew Miller, Arvind Narayanan, and Nicolas Christin. 2018. An Empirical Analysis of Traceability in the Monero Blockchain. Proc. Priv. Enhancing Technol. 2018, 3 (2018), 143–163. DOI:https://doi.org/10.1515/popets-2018-0025

[2] Dimaz Ankaa Wijaya, Joseph K. Liu, Ron Steinfeld, Dongxi Liu, and Tsz Hon Yuen. 2018. Anonymity Reduction Attacks to Monero. In Information Security and Cryptology - 14th International Conference, Inscrypt 2018, Fuzhou, China, December 14-17, 2018, Revised Selected Papers (Lecture Notes in Computer Science), Springer, 86–100. DOI:https://doi.org/10.1007/978-3-030-14234-6_5

[3] Abraham Hinteregger and Bernhard Haslhofer. 2019. Short Paper: An Empirical Analysis of Monero Cross-chain Traceability. In Financial Cryptography and Data Security - 23rd International Conference, FC 2019, Frigate Bay, St. Kitts and Nevis, February 18-22, 2019, Revised Selected Papers (Lecture Notes in Computer Science), Springer, 150–157. DOI:https://doi.org/10.1007/978-3-030-32101-7_10

[4] Zuoxia Yu, Man Ho Au, Jiangshan Yu, Rupeng Yang, Qiuliang Xu, and Wang Fat Lau. 2019. New Empirical Traceability Analysis of CryptoNote-Style Blockchains. In Financial Cryptography and Data Security - 23rd International Conference, FC 2019, Frigate Bay, St. Kitts and Nevis, February 18-22, 2019, Revised Selected Papers (Lecture Notes in Computer Science), Springer, 133–149. DOI:https://doi.org/10.1007/978-3-030-32101-7_9

[5] Christoph Egger, Russell W. F. Lai, Viktoria Ronge, Ivy K. Y. Woo, and Hoover H. F. Yin. 2022. On Defeating Graph Analysis of Anonymous Transactions. Proc. Priv. Enhancing Technol. 2022, 3 (2022), 538–557. DOI:https://doi.org/10.56553/popets-2022-0085

Contact François-Xavier Wicht for more information.

Nature of the project: Theory 50%, Systems 50%.