Election Verifiability in Electronic Voting Protocols

Abstract

We present a symbolic definition of election verifiability for electronic voting protocols in the context of the applied pi calculus. Our definition is given in terms of boolean tests which can be performed on the data produced by an election. The definition distinguishes three aspects of verifiability, which we call individual verifiability, universal verifiability, and eligibility verifiability. It also allows us to determine precisely which aspects of the system's hardware and software must be trusted for the purpose of election verifiability. In contrast with earlier work our definition is compatible with a large class of electronic voting schemes, including those based on blind signatures, homomorphic encryption and mixnets. We demonstrate the applicability of our formalism by analysing two protocols which have been deployed; namely Helios 2.0, which is based on homomorphic encryption, and Civitas, which uses mixnets. In addition we consider the FOO protocol which is based on blind signatures.

Vote-Independence: A Powerful Privacy Notion for Voting Protocols

“…This concerns privacy properties (privacy, receipt-freeness and coercionresistance) [7,8,16], election verifiability [14,21], or both [11][12][13]. We concentrate on privacy-type properties of voting protocols (i.e.…”

Deciding Epistemic and Strategic Properties of Cryptographic Protocols

“…Accountability and verifiability are properties relevant for protocols involving trusted parties, e.g., voting [KRS10], auctions [PRST08], contract signing [ASW98], identity-based encryption etc. In [KTV10a], a formal definition of accountability is given that is independent of the specific application.…”

Election Verifiability or Ballot Privacy: Do We Need to Choose?

“…Universally verifiable elections are realized by including in the voting process the production of an audit trail (which can be electronic, made of paper, or both) that makes it possible for voters to check that their vote was recorded properly and that the election outcome is consistent with all the votes submitted by legitimate voters (formal definitions appear in [28,26] for instance. )…”

“…This in part motivated the decision of the IACR to only display aliases instead of voter names on their election bulletin board: in case of broken encryption, the election bulletin board would then only reveal the content of encrypted votes but not their author (the voting server is still aware of the link between aliases and voters, though, and these aliases circulate in cleartext emails). Such a procedure however impairs eligibility verifiability, as it becomes infeasible for the voters to verify whether the ballots present on the bulletin board have been submitted by legitimate voters or are the result of ballot stuffing by the organizers [26,4].…”