International Association
for Cryptologic Research

This document details the cryptographic analysis of the sVote v2.2.1 system - an e-voting solution developed by Scytl for the Switzerland context. We prove the complete verifiability and privacy under the Swiss legislation's informally stated goals.

First, we derive the trust model for complete verifiability and voting secrecy from the Swiss Chancellery's requirements [1][2], supporting our interpretation by quotes from and references to relevant excerpts of the ordinance and the corresponding technical annex.

Then, based on the derived model, we prove that sVote with Control Components provides complete verifiability and guarantees voting secrecy and the non-disclosure of early provisional results. We demonstrate that sVote fulfills the requirements of the Swiss federal chancellery for completely verifiable E-voting systems. In other words, we show that an adversary cannot break the complete verifiability and voting secrecy properties of sVote without being detected by either the voter or auditors.

[1] Technical and administrative requirements for electronic vote casting v 2.0 https://www.bk.admin.ch/dam/bk/en/dokumente/pore/Annex_of_the_Federal_Chancellery_Ordinance_on_Electronic_Voting_V2.0_July_2018.pdf.download.pdf/Annex_of_the_Federal_Chancellery_Ordinance_on_Electronic_Voting_V2.0_July_2018.pdf [2] Federal Chancellery Ordinance on Electronic Voting https://www.fedlex.admin.ch/eli/cc/2013/859/en