52 research outputs found
Pretty Good Democracy for More Expressive Voting Schemes
In this paper we revisit Pretty Good Democracy, a scheme for verifiable Internet voting from untrusted client machines. The original scheme was designed for first-past-the-post elections. Here, we show how Pretty Good Democracy can be extended to voting schemes in which the voter lists the candidates in their order of preference. Our scheme applies to elections using STV, IRV, Borda, or any other tallying scheme in which a vote is a list of candidates in preference order. We also describe an extension to cover Approval or Range voting
Pretty Understandable Democracy - A Secure and Understandable Internet Voting Scheme
Internet voting continues to raise interest. A large number of Internet voting schemes are available, both in use, as well as in research literature. While these schemes are all based on different security models, most of these models are not adequate for high-stake elections. Furthermore, it is not known how to evaluate the understandability of these schemes (although this is important to enable voters' trust in the election result). Therefore, we propose and justify an adequate security model and criteria to evaluate understandability. We also describe an Internet voting scheme, Pretty Understandable Democracy, show that it satisfies the adequate security model and that it is more understandable than Pretty Good Democracy, currently the only scheme that also satisfies the proposed security model
The New South Wales iVote System: Security Failures and Verification Flaws in a Live Online Election
In the world's largest-ever deployment of online voting, the iVote Internet
voting system was trusted for the return of 280,000 ballots in the 2015 state
election in New South Wales, Australia. During the election, we performed an
independent security analysis of parts of the live iVote system and uncovered
severe vulnerabilities that could be leveraged to manipulate votes, violate
ballot privacy, and subvert the verification mechanism. These vulnerabilities
do not seem to have been detected by the election authorities before we
disclosed them, despite a pre-election security review and despite the system
having run in a live state election for five days. One vulnerability, the
result of including analytics software from an insecure external server,
exposed some votes to complete compromise of privacy and integrity. At least
one parliamentary seat was decided by a margin much smaller than the number of
votes taken while the system was vulnerable. We also found protocol flaws,
including vote verification that was itself susceptible to manipulation. This
incident underscores the difficulty of conducting secure elections online and
carries lessons for voters, election officials, and the e-voting research
community
Cast-as-Intended Mechanism with Return Codes Based on PETs
We propose a method providing cast-as-intended verifiability for remote
electronic voting. The method is based on plaintext equivalence tests (PETs),
used to match the cast ballots against the pre-generated encrypted code tables.
Our solution provides an attractive balance of security and functional
properties. It is based on well-known cryptographic building blocks and relies
on standard cryptographic assumptions, which allows for relatively simple
security analysis. Our scheme is designed with a built-in fine-grained
distributed trust mechanism based on threshold decryption. It, finally, imposes
only very little additional computational burden on the voting platform, which
is especially important when voters use devices of restricted computational
power such as mobile phones. At the same time, the computational cost on the
server side is very reasonable and scales well with the increasing ballot size
Model Checkers Are Cool: How to Model Check Voting Protocols in Uppaal
The design and implementation of an e-voting system is a challenging task.
Formal analysis can be of great help here. In particular, it can lead to a
better understanding of how the voting system works, and what requirements on
the system are relevant. In this paper, we propose that the state-of-art model
checker Uppaal provides a good environment for modelling and preliminary
verification of voting protocols. To illustrate this, we present an Uppaal
model of Pr\^et \`a Voter, together with some natural extensions. We also show
how to verify a variant of receipt-freeness, despite the severe limitations of
the property specification language in the model checker
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
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