Tornado Vote: Anonymous Blockchain-Based Voting

Robert Muth; Florian Tschorsch

Paper 2023/1112

Tornado Vote: Anonymous Blockchain-Based Voting

Robert Muth, Technical University of Berlin

Florian Tschorsch, Technical University of Berlin

Abstract

Decentralized apps (DApps) often hold significant cryptocurrency assets. In order to manage these assets and coordinate joint investments, shareholders leverage the underlying smart contract functionality to realize a transparent, verifiable, and secure decision-making process. That is, DApps implement proposal-based voting. Permissionless blockchains, however, lead to a conflict between transparency and anonymity; potentially preventing free decision-making if individual votes and intermediate results become public. In this paper, we therefore present Tornado Vote, a voting DApp for anonymous, fair, and practical voting on the Ethereum blockchain. We propose to use a cryptocurrency mixer such as Tornado Cash to reconcile transparency and anonymity. To this end, we adapt Tornado Cash and develop a voting protocol that implements a fair voting process. While Tornado Vote can technically process 10k votes on Ethereum in approximately two hours, this is not feasible under realistic conditions: Third-party transactions on the Ethereum Mainnet reduce the possible throughput, and transaction fees make it infeasible to use all available block capacities. We therefore present various Gas cost models that yield lower bounds and economic estimations with respect to the required number of blocks and voting costs to assess and adjust Tornado Vote's feasibility trade-off.

Metadata

Available format(s): PDF
Category: Applications
Publication info: Published elsewhere. Minor revision. 2023 IEEE International Conference on Blockchain and Cryptocurrency (ICBC)
DOI: 10.1109/ICBC56567.2023.10174889
Keywords: anonymous voting decentralized applications smart contracts
Contact author(s): muth @ tu-berlin de
florian tschorsch @ tu-berlin de
History: 2023-07-19: revised; 2023-07-17: received; See all versions
Short URL: https://ia.cr/2023/1112
License: CC BY

BibTeX

@misc{cryptoeprint:2023/1112,
      author = {Robert Muth and Florian Tschorsch},
      title = {Tornado Vote: Anonymous Blockchain-Based Voting},
      howpublished = {Cryptology {ePrint} Archive, Paper 2023/1112},
      year = {2023},
      doi = {10.1109/ICBC56567.2023.10174889},
      url = {https://eprint.iacr.org/2023/1112}
}