Surtr: Transparent Verification with Simple yet Strong Coercion Mitigation

Rosario Giustolisi; Maryam Sheikhi Garjan; Peter Browne Rønne

Paper 2025/1675

Surtr: Transparent Verification with Simple yet Strong Coercion Mitigation

Rosario Giustolisi, IT University of Copenhagen

Maryam Sheikhi Garjan, University of Hamburg

Peter Browne Rønne, University of Luxembourg

Abstract

Transparent verification allows voters to directly identify their vote in cleartext in the final tally result. Both Selene and Hyperion offer this simple and intuitive verification method, and at the same time allow for coercion to be mitigated under the assumption that tally servers can privately notify voters of the keying material needed for verification. Subsequently, a voter can generate fake keying material to deceive a coercer. In this paper, we propose Surtr, a new scheme that enables transparent verification without requiring a private notification channel. This approach strengthens coercion mitigation, since a coercer can monitor the notification channel, and simplifies the process by eliminating the need for voters to generate fake keying material for the coercer.

Metadata

Available format(s): PDF
Category: Cryptographic protocols
Publication info: Published elsewhere. E-Vote-ID 2025
Keywords: End-to-end verifiability Vote privacy Coercion resistance
Contact author(s): rosg @ itu dk
maryam sheikhi garjan @ uni-hamburg de
peter roenne @ uni lu
History: 2025-09-18: approved; 2025-09-16: received; See all versions
Short URL: https://ia.cr/2025/1675
License: CC BY

BibTeX

@misc{cryptoeprint:2025/1675,
      author = {Rosario Giustolisi and Maryam Sheikhi Garjan and Peter Browne Rønne},
      title = {Surtr: Transparent Verification with Simple yet Strong Coercion Mitigation},
      howpublished = {Cryptology {ePrint} Archive, Paper 2025/1675},
      year = {2025},
      url = {https://eprint.iacr.org/2025/1675}
}