335 research outputs found
LIPIcs, Volume 251, ITCS 2023, Complete Volume
LIPIcs, Volume 251, ITCS 2023, Complete Volum
Power and truth in liquid democracy
This thesis studies a young voting method called liquid democracy, in which voters can freely choose to delegate their vote to other voters or directly use their own vote and accrual delegation votes. We mainly address two problems in liquid democracy. The first problem is that when voters decide whether to vote or delegate and to whom they delegate their votes, what level of voting power each voter has. The voting power of a voter denotes the probability that this voter can change the final voting result. We found that when voters care about their voting power, they do not delegate their votes easily. The second problem is whether it is beneficial for the quality of the voting result if voters are allowed to split their votes and delegate them to multiple delegatees, that is, the so-called weighted delegation. Our results show that in terms of the quality of the voting result, weighted delegation makes it possible to optimize the voting result quality, and it is never worse than the traditional single delegatee liquid democracy
Complexity of Conformant Election Manipulation
It is important to study how strategic agents can affect the outcome of an
election. There has been a long line of research in the computational study of
elections on the complexity of manipulative actions such as manipulation and
bribery. These problems model scenarios such as voters casting strategic votes
and agents campaigning for voters to change their votes to make a desired
candidate win. A common assumption is that the preferences of the voters follow
the structure of a domain restriction such as single peakedness, and so
manipulators only consider votes that also satisfy this restriction. We
introduce the model where the preferences of the voters define their own
restriction and strategic actions must ``conform'' by using only these votes.
In this model, the election after manipulation will retain common domain
restrictions. We explore the computational complexity of conformant
manipulative actions and we discuss how conformant manipulative actions relate
to other manipulative actions.Comment: A version of this paper will appear in the Proceedings of FCT 202
LIPIcs, Volume 261, ICALP 2023, Complete Volume
LIPIcs, Volume 261, ICALP 2023, Complete Volum
2014 GREAT Day Program
SUNY Geneseo’s Eighth Annual GREAT Day.https://knightscholar.geneseo.edu/program-2007/1008/thumbnail.jp
Ordering Transactions with Bounded Unfairness: Definitions, Complexity and Constructions
An important consideration in the context of distributed ledger protocols is fairness in terms of transaction ordering. Recent work [Crypto 2020] revealed a deep connection of (receiver) order fairness to social choice theory and related impossibility results arising from the Condorcet paradox. As a result of the impossibility, various relaxations of order fairness were investigated in prior works. Given that distributed ledger protocols, especially those processing smart contracts, must serialize the input transactions, a natural objective is to minimize the distance (in terms of injected number of transactions) between any pair of unfairly ordered transactions in the output ledger — a concept we call bounded unfairness. In state machine replication (SMR) parlance this asks for minimizing the number of unfair state updates occurring before the processing of any transaction. This unfairness minimization objective gives rise to a natural class of parametric order fairness definitions that has not been studied before. As we observe, previous realizable relaxations of order fairness do not yield good unfairness bounds.
Achieving optimal order fairness in the sense of bounded unfairness turns out to be connected to the graph theoretic properties of the underlying transaction dependency graph and specifically the bandwidth metric of strongly connected components in this graph. This gives rise to a specific instance of the definition that we call ``directed bandwidth order-fairness\u27\u27 which we show that it captures the best possible that any protocol can achieve in terms of bounding unfairness. We prove ordering transactions in this fashion is NP-hard and non-approximable for any constant ratio. Towards realizing the property, we put forth a new distributed ledger protocol called Taxis that achieves directed bandwidth order-fairness in the permissionless setting. We present two variants of our protocol, one that matches the property perfectly but (necessarily) lacks in performance and liveness, and a second variant that achieves liveness and better complexity while offering a slightly relaxed version of the directed bandwidth definition. Finally, we comment on applications of our work to social choice theory, a direction which we believe to be of independent interest
A comprehensive survey of V2X cybersecurity mechanisms and future research paths
Recent advancements in vehicle-to-everything (V2X) communication have notably improved existing transport systems by enabling increased connectivity and driving autonomy levels. The remarkable benefits of V2X connectivity come inadvertently with challenges which involve security vulnerabilities and breaches. Addressing security concerns is essential for seamless and safe operation of mission-critical V2X use cases. This paper surveys current literature on V2X security and provides a systematic and comprehensive review of the most relevant security enhancements to date. An in-depth classification of V2X attacks is first performed according to key security and privacy requirements. Our methodology resumes with a taxonomy of security mechanisms based on their proactive/reactive defensive approach, which helps identify strengths and limitations of state-of-the-art countermeasures for V2X attacks. In addition, this paper delves into the potential of emerging security approaches leveraging artificial intelligence tools to meet security objectives. Promising data-driven solutions tailored to tackle security, privacy and trust issues are thoroughly discussed along with new threat vectors introduced inevitably by these enablers. The lessons learned from the detailed review of existing works are also compiled and highlighted. We conclude this survey with a structured synthesis of open challenges and future research directions to foster contributions in this prominent field.This work is supported by the H2020-INSPIRE-5Gplus project (under Grant agreement No. 871808), the ”Ministerio de Asuntos Económicos y Transformacion Digital” and the European Union-NextGenerationEU in the frameworks of the ”Plan de Recuperación, Transformación y Resiliencia” and of the ”Mecanismo de Recuperación y Resiliencia” under references TSI-063000-2021-39/40/41, and the CHIST-ERA-17-BDSI-003 FIREMAN project funded by the Spanish National Foundation (Grant PCI2019-103780).Peer ReviewedPostprint (published version
Specialized IoT systems: Models, Structures, Algorithms, Hardware, Software Tools
Монография включает анализ проблем, модели, алгоритмы и программно-
аппаратные средства специализированных сетей интернета вещей.
Рассмотрены результаты проектирования и моделирования сети интернета вещей,
мониторинга качества продукции, анализа звуковой информации окружающей среды, а
также технология выявления заболеваний легких на базе нейронных сетей.
Монография предназначена для специалистов в области инфокоммуникаций,
может быть полезна студентам соответствующих специальностей, слушателям
факультетов повышения квалификации, магистрантам и аспирантам
On the Efficiency of An Election Game of Two or More Parties: How Bad Can It Be?
We extend our previous work on two-party election competition [Lin, Lu & Chen
2021] to the setting of three or more parties. An election campaign among two
or more parties is viewed as a game of two or more players. Each of them has
its own candidates as the pure strategies to play. People, as voters, comprise
supporters for each party, and a candidate brings utility for the the
supporters of each party. Each player nominates exactly one of its candidates
to compete against the other party's. A candidate is assumed to win the
election with higher odds if it brings more utility for all the people. The
payoff of each player is the expected utility its supporters get. The game is
egoistic if every candidate benefits her party's supporters more than any
candidate from the competing party does. In this work, we first argue that the
election game always has a pure Nash equilibrium when the winner is chosen by
the hardmax function, while there exist game instances in the three-party
election game such that no pure Nash equilibrium exists even the game is
egoistic. Next, we propose two sufficient conditions for the egoistic election
game to have a pure Nash equilibrium. Based on these conditions, we propose a
fixed-parameter tractable algorithm to compute a pure Nash equilibrium of the
egoistic election game. Finally, perhaps surprisingly, we show that the price
of anarchy of the egoistic election game is upper bounded by the number of
parties. Our findings suggest that the election becomes unpredictable when more
than two parties are involved and, moreover, the social welfare deteriorates
with the number of participating parties in terms of possibly increasing price
of anarchy. This work alternatively explains why the two-party system is
prevalent in democratic countries
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