Election Manipulation 100

Michelle Blom, Peter J. Stuckey, Vanessa J. Teague

Research output: Chapter in Book/Report/Conference proceedingConference PaperResearchpeer-review


The true election margin for an Instant Runoff Voting (IRV) election can be hard to compute, because a small modification early in the elimination sequence can alter the outcome and result in a candidate winning the last round by a large margin. It is often assumed that the true margin is the last-round margin, that is half the difference between the two candidates who remain when everyone else is eliminated, though it is well known that this need not be the case. Perceptions of confidence in the outcome, and even formal policies about recounts, often depend on the last-round margin. There is already some prior work on how to compute the true election margin efficiently for IRV, and hence how to find the minimal manipulation. In this work we show how to manipulate an election efficiently while also producing a large last-round margin. This would allow a successful manipulation to evade detection against naive methods of assessing the confidence of the election result. This serves as further evidence for accurate computations of the exact margin, or for rigorous Risk Limiting Audits which would detect a close or wrong election result (respectively) regardless of the last-round margin.

Original languageEnglish
Title of host publicationFinancial Cryptography and Data Security
Subtitle of host publicationFC 2019 International Workshops, VOTING and WTSC St. Kitts, St. Kitts and Nevis, February 18–22, 2019 Revised Selected Papers
EditorsAndrea Bracciali, Jeremy Clark, Federico Pintore, Peter B. Rønne, Massimiliano Sala
Place of PublicationCham Switzerland
Number of pages15
ISBN (Electronic)9783030437251
ISBN (Print)9783030437244
Publication statusPublished - 2019
EventWorkshop on Advances in Secure Electronic Voting 2019 - St. Kitts, St Kitts and Nevis
Duration: 22 Feb 201922 Feb 2019
Conference number: 4th

Publication series

NameLecture Notes in Computer Science
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349


ConferenceWorkshop on Advances in Secure Electronic Voting 2019
Abbreviated titleWTSC 2019
Country/TerritorySt Kitts and Nevis
CitySt. Kitts
Internet address

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