Third-party verifiable voting systems: addressing motivation and incentives in e-voting

Voter-verifiable voting systems place significant demands of both effort and knowledge onto ordinary voters who have only limited incentives to participate. We suggest the use of third-party verifiable voting systems, harnessing the very strong incentives for candidates and observers to verify that votes are correctly counted. A generic modification enabling this via the use of pre-filled ballots and secure depositing is outlined and we demonstrate this modification by applying it to two major voter-verifiable voting systems. Additionally, potential vulnerabilities of this approach are discussed

Scratch, Click & Vote: E2E voting over the Internet

We present Scratch, Click & Vote voting scheme, which is a modification of the Punchscan and ThreeBallot systems. The scheme is end-to-end veryfiable and allows for voting over the Internet. Security against malicious hardware and software used by a voter %TT is due to the fact that a voter\u27s computer does not get any knowledge about the voter\u27s choice. Moreover, it can change successfully a voter\u27s ballot only with a small probability. As a side result, we present a modification of the ThreeBallot that eliminates Strauss\u27-like attacks on this scheme

Private votes on untrusted platforms: models, attacks and provable scheme

International audienceModern e-voting systems deploy cryptographic protocols on a complex infrastructure involving different computing platforms and agents. It is crucial to have appropriate specification and evaluation methods to perform rigorous analysis of such systems, taking into account the corruption and computational capabilities of a potential attacker. In particular, the platform used for voting may be corrupted, e.g. infected by malware, and we need to ensure privacy and integrity of votes even in that case. We propose a new definition of vote privacy, formalized as a computational indistinguishability game, that allows to take into account such refined attacker models; we show that the definition captures both known and novel attacks against several voting schemes; and we propose a scheme that is provably secure in this setting. We moreover formalize and machine-check the proof in the EasyCrypt theorem prover

Electronic voting: Methods and protocols

The act of casting a ballot during an election cycle has been plagued by a number of problems, both intrinsic and extraneous. The old-fashioned paper ballot solves a number of problems, but creates its own. The clear 21st Century solution is the use of an automated electronic system for collection and tallying of votes, but the attitude of the general populace towards these systems has been overwhelmingly negative, supported in some cases by fraud and abuse. The purpose of this thesis is to do a broad survey of systems available on the market now (both in industry and academia) and then compare and contrast these systems to an “ideal” system, which we attempt to define. To do this we survey academic and commercial literature from many sources and selected the most popular, current, or interesting of the designs—then compare the relative strengths and weaknesses of these designs. What we discovered is that devices presented by industry are not only closed-box (which makes them inherently untrustworthy), but also largely inept in security and/or redundancy. Conversely, systems presented by academia are relatively strong in security and redundancy, but lack in ease-of-use or miss helpful features found on industry devices. To combat these perceived weaknesses, we present a prototype of one system which has not previously been implemented, described in Wang [1]. This system brings together many ideas from academia to solve a significant number of the issues plaguing electronic voting machines. We present this solution in its entirety as open-source software for review by the cryptographic and computer science community. In addition to an electronic voting implementation this solution includes a graphical user interface, a re-encryption mix network, and several decryption methods including threshold decryption. All of these items are described in-depth by this thesis. However, as we discuss in the conclusion, this solution falls short in some areas as well. We earmark these problem areas for future research and discuss alternate paths forward

Secure multi party computations for electronic voting

Στην παρούσα εργασία, μελετούμε το πρόβλημα της ηλεκτρονικής ψηφοφορίας. Θεωρούμε ότι είναι έκφανση μιας γενικής διαδικασίας αποφάσεων που μπορεί να υλοποιηθεί μέσω υπολογισμών πολλαπλών οντοτήτων, οι οποίοι πρέπει να ικανοποιούν πολλές και αντικρουόμενες απαιτήσεις ασφαλείας. Έτσι μελετούμε σχετικές προσεγγίσεις οι οποίες βασιζονται σε κρυπτογραφικές τεχνικές, όπως τα ομομορφικά κρυπτοσυστήματα, τα δίκτυα μίξης και οι τυφλές υπογραφές. Αναλύουμε πώς προσφέρουν ακεραιότητα και ιδιωτικότητα (μυστικότητα) στην διαδικασία και την σχέση τους με την αποδοτικότητα. Εξετάζουμε τα είδη λειτουργιών κοινωνικής επιλογής που μπορούν να υποστηρίξουν και παρέχουμε δύο υλοποιήσεις. Επιπλέον ασχολούμαστε με την αντιμετώπιση ισχυρότερων αντιπάλων μη παρέχοντας αποδείξεις ψήφου ή προσφέροντας δυνατότητες αντίστασης στον εξαναγκασμό. Με βάση την τελευταία έννοια προτείνουμε μια τροποποίηση σε ένα ευρέως χρησιμοποιούμενο πρωτόκολλο. Τέλος μελετούμε δύο γνωστές υλοποιήσεις συστημάτων ηλεκτρονικής ψηφοφοριας το Helios και το Pret a Voter .In this thesis, we study the problem of electronic voting as a general decision making process that can be implemented using multi party computations, fulfilling strict and often conflicting security requirements. To this end, we review relevant cryptographic techniques and their combinations to form voting protocols. More specifically, we analyze schemes based on homomorphic cryptosystems, mixnets with proofs of shuffles and blind signatures. We analyze how they achieve integrity and privacy in the voting process, while keeping efficiency. We examine the types of social choice functions that can be supported by each protocol. We provide two proof of concept implementations. Moreover, we review ways to thwart stronger adversaries by adding receipt freeness and coercion resistance to voting systems. We build on the latter concept to propose a modification to a well known protocol. Finally, we study two actual e-Voting implementations namely Helios and Pret a Voter

Matters of Coercion-Resistance in Cryptographic Voting Schemes

This work addresses coercion-resistance in cryptographic voting schemes. It focuses on three particularly challenging cases: write-in candidates, internet elections and delegated voting. Furthermore, this work presents a taxonomy for analyzing and comparing a huge variety of voting schemes, and presents practical experiences with the voting scheme Bingo Voting

Boardroom Voting: Verifiable Voting with Ballot Privacy Using Low-Tech Cryptography in a Single Room

A boardroom election is an election that takes place in a single room-the boardroom-in which all voters can see and hear each other. We present an initial exploration of boardroom elections with ballot privacy and voter verifiability that use only "low-tech cryptography" without using computers to mark or collect ballots. Specifically, we define the problem, introduce several building blocks, and propose a new protocol that combines these blocks in novel ways. Our new building blocks include "foldable ballots" that can be rotated to hide the alignment of ballot choices with voting marks, and "visual secrets" that are easy to remember and use but hard to describe. Although closely seated participants in a boardroom election have limited privacy, the protocol ensures that no one can determine how others voted. Moreover, each voter can verify that their ballot was correctly cast, collected, and counted, without being able to prove how they voted, providing assurance against undue influence. Low-tech cryptography is useful in situations where constituents do not trust computer technology, and it avoids the complex auditing requirements of end-to-end cryptographic voting systems such as Prêt-à-Voter. This paper's building blocks and protocol are meant to be a proof of concept that might be tested for usability and improved