MultiBallot: Verifiable and privacy-preserving E-Collecting in the Swiss setting

TL;DR

This paper introduces MultiBallot, a secure protocol for verifiable and privacy-preserving electronic signature collection in Switzerland, ensuring privacy without anonymous channels and supporting legally binding political processes.

Contribution

It proposes a novel protocol tailored for Switzerland's e-collecting needs, combining privacy and verifiability under realistic trust assumptions.

Findings

Achieves privacy without anonymous channels by leveraging parallel collections.

Ensures verifiability and security in the Swiss e-collecting setting.

Addresses legal and practical requirements for electronic signature collection.

Abstract

As part of the political process, citizens may participate in signature collections to influence policy changes. In Switzerland, this even results in legally binding acts, similar to an election system. In this work, we first derive a realistic setting for e-collecting in Switzerland, based on the setting established for e-voting. Then, we propose a secure protocol in this setting, achieving both privacy and verifiability under realistic trust assumptions. Notably, participation privacy is guaranteed without assuming an anonymous channel, by considering the fact that at any given point in time, many collections are active in parallel.