sVote with control components voting protocol: computational proof of complete verifiability and privacy

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, 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.sVote with Control components is a cryptographic voting protocol that provides complete verifiability and guarantees voting secrecy and the non-disclosure of early provisional results. This report demonstrates that sVote fulfills the requirements of the Swiss federal chancellery for completely verifiable E-voting systems. We extract precise requirements from the ordinance and the corresponding technical annex and model the sVote cryptographic voting protocol based on its design documents. Based on this model, we show in a detailed security analysis that an adversary cannot break the complete verifiability and voting secrecy properties of sVote without being detected by either the voter or by auditorsThis work has received funding from the European Commission under the auspices of PROMETHEUS Project, Horizon 2020 Innovation Action (Grant Agreement No. 780701).Preprin

The Internet Based Electronic Voting Enabling Open and Fair Election

Voting is the pillar of modern democracies. However, examination of current voting systems (including E-voting techniques) shows a gap between casting secret ballots and tallying and verifying individual votes. This gap is caused by either disconnection between the vote-casting process and the vote-tallying process, or opaque transition (e.g. due to encryption) from vote- casting to vote-tallying and thus, damages voter assurance, i.e. failing to answer the question: “Will your vote count?” We proposed a groundbreaking E-voting protocol that fills this gap and provides a fully transparent election. In this new voting system, this transition is seamless, viewable, and verifiable. As a result, the above question can be answered assuredly: “Yes, my vote counts!” The new E-voting protocol is fundamentally different from all existing voting/E-voting protocols in terms of both concepts and the underlying mechanisms. It consists of three innovative Technical Designs: TD1: universal verifiable voting vector; TD2: forward and backward mutual lock voting; and TD3: in-process verification and enforcement. The new technique is the first fully transparent E-voting protocol which fills the aforementioned gap. The trust is split equally among all tallying authorities who are of conflict-of-interest and will technologically restrain from each other. As a result, the new technique enables open and fair elections, even for minor or weak political parties. It is able to mitigate errors and risk and detect fraud and attacks including collusion, with convincingly high probability 1 − 2−(m−log(m))n (n: #voters and m ≥ 2:#candidates). It removes many existing requirements such as trusted central tallying authorities, tailored hardware or software, and complex cryptographic primitives. In summary, the new e- voting technique delivers voter assurance and can transform the present voting booth based voting and election practice. Besides voting and elections, the new technique can also be adapted to other applications such as student class evaluation, rating and reputation systems

Public Evidence from Secret Ballots

Elections seem simple---aren't they just counting? But they have a unique, challenging combination of security and privacy requirements. The stakes are high; the context is adversarial; the electorate needs to be convinced that the results are correct; and the secrecy of the ballot must be ensured. And they have practical constraints: time is of the essence, and voting systems need to be affordable and maintainable, and usable by voters, election officials, and pollworkers. It is thus not surprising that voting is a rich research area spanning theory, applied cryptography, practical systems analysis, usable security, and statistics. Election integrity involves two key concepts: convincing evidence that outcomes are correct and privacy, which amounts to convincing assurance that there is no evidence about how any given person voted. These are obviously in tension. We examine how current systems walk this tightrope.Comment: To appear in E-Vote-Id '1

An Epistemic Approach to Coercion-Resistance for Electronic Voting Protocols

Coercion resistance is an important and one of the most intricate security requirements of electronic voting protocols. Several definitions of coercion resistance have been proposed in the literature, including definitions based on symbolic models. However, existing definitions in such models are rather restricted in their scope and quite complex. In this paper, we therefore propose a new definition of coercion resistance in a symbolic setting, based on an epistemic approach. Our definition is relatively simple and intuitive. It allows for a fine-grained formulation of coercion resistance and can be stated independently of a specific, symbolic protocol and adversary model. As a proof of concept, we apply our definition to three voting protocols. In particular, we carry out the first rigorous analysis of the recently proposed Civitas system. We precisely identify those conditions under which this system guarantees coercion resistance or fails to be coercion resistant. We also analyze protocols proposed by Lee et al. and Okamoto.Comment: An extended version of a paper from IEEE Symposium on Security and Privacy (S&P) 200