A privacy attack on the Swiss Post e-voting system

Véronique Cortier (1) , Alexandre Debant (1) , Pierrick Gaudry (2)

1 PESTO - Proof techniques for security protocols
2 CARAMBA - Cryptology, arithmetic : algebraic methods for better algorithms

The SwissPost e-voting system is currently proposed under the scrutiny of the community, before being deployed in 2022 for political elections in several Swiss Cantons. We explain how real world constraints led to shortcomings that allowed a privacy attack to be mounted. More precisely, dishonest authorities can learn the vote of several voters of their choice, without being detected, even when the requested threshold of honest authorities act as prescribed.

Domaines: Cryptographie et sécurité [cs.CR]

Véronique Cortier, Alexandre Debant, Pierrick Gaudry. A privacy attack on the Swiss Post e-voting system. RWC 2022 - Real World Crypto Symposium, IACR, Apr 2022, Amsterdam (NETHERLANDS), Netherlands. ⟨hal-03446801⟩