1,633 research outputs found
A Proof of Entropy Minimization for Outputs in Deletion Channels via Hidden Word Statistics
From the output produced by a memoryless deletion channel from a uniformly
random input of known length , one obtains a posterior distribution on the
channel input. The difference between the Shannon entropy of this distribution
and that of the uniform prior measures the amount of information about the
channel input which is conveyed by the output of length , and it is natural
to ask for which outputs this is extremized. This question was posed in a
previous work, where it was conjectured on the basis of experimental data that
the entropy of the posterior is minimized and maximized by the constant strings
and and the alternating strings
and respectively. In the present
work we confirm the minimization conjecture in the asymptotic limit using
results from hidden word statistics. We show how the analytic-combinatorial
methods of Flajolet, Szpankowski and Vall\'ee for dealing with the hidden
pattern matching problem can be applied to resolve the case of fixed output
length and , by obtaining estimates for the entropy in
terms of the moments of the posterior distribution and establishing its
minimization via a measure of autocorrelation.Comment: 11 pages, 2 figure
Verification of the Socio-Technical Aspects of Voting: The Case of the Polish Postal Vote 2020
Voting procedures are designed and implemented by people, for people, and
with significant human involvement. Thus, one should take into account the
human factors in order to comprehensively analyze properties of an election and
detect threats. In particular, it is essential to assess how actions and
strategies of the involved agents (voters, municipal office employees, mail
clerks) can influence the outcome of other agents' actions as well as the
overall outcome of the election. In this paper, we present our first attempt to
capture those aspects in a formal multi-agent model of the Polish presidential
election 2020. The election marked the first time when postal vote was
universally available in Poland. Unfortunately, the voting scheme was prepared
under time pressure and political pressure, and without the involvement of
experts. This might have opened up possibilities for various kinds of ballot
fraud, in-house coercion, etc. We propose a preliminary scalable model of the
procedure in the form of a Multi-Agent Graph, and formalize selected integrity
and security properties by formulas of agent logics. Then, we transform the
models and formulas so that they can be input to the state-of-art model checker
Uppaal. The first series of experiments demonstrates that verification scales
rather badly due to the state-space explosion. However, we show that a recently
developed technique of user-friendly model reduction by variable abstraction
allows us to verify more complex scenarios
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
A Survey of Requirements for COVID-19 Mitigation Strategies. Part I: Newspaper Clips
The COVID-19 pandemic has influenced virtually all aspects of our lives.
Across the world, countries have applied various mitigation strategies for the
epidemic, based on social, political, and technological instruments. We
postulate that one should {identify the relevant requirements} before
committing to a particular mitigation strategy. One way to achieve it is
through an overview of what is considered relevant by the general public, and
referred to in the media. To this end, we have collected a number of news clips
that mention the possible goals and requirements for a mitigation strategy. The
snippets are sorted thematically into several categories, such as
health-related goals, social and political impact, civil rights, ethical
requirements, and so on.
In a forthcoming companion paper, we will present a digest of the
requirements, derived from the news clips, and a preliminary take on their
formal specification
07311 Abstracts Collection -- Frontiers of Electronic Voting
From July the 29th to August the 3th, 2007, the Dagstuhl Seminar
07311 ``Frontiers of Electronic Voting\u27\u27 was held in the International Conference and Research Center (IBFI), Schloss Dagstuhl.
During the seminar, several participants presented their current
research, and ongoing work and open problems were discussed. Abstracts of
the presentations given during the seminar as well as abstracts of
seminar results and ideas are put together in this paper. The first section
describes the seminar topics and goals in general.
Links to extended abstracts or full papers are provided, if available
09311 Abstracts Collection -- Classical and Quantum Information Assurance Foundations and Practice
From 26 July 2009 to 31 July 2009, the Dagstuhl Seminar 09311 ``Classical and Quantum Information Assurance Foundations and Practice\u27\u27 was held
in Schloss Dagstuhl~--~Leibniz Center for Informatics. The workshop was intended to explore the latest developments and discuss the open issues in the theory and practice of classical and quantum information assurance. A further goal of the workshop was to bring together practitioners from both the classical and the quantum information assurance communities. To date, with a few exceptions, these two communities seem to have existed largely separately and in a state of mutual ignorance. It is clear however that there is great potential for synergy and cross-fertilization between and this we sought to stimulate and facilitate
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