Abstract
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.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Notes
- 1.
- 2.
A multiset allows for the inclusion of duplicate items.
References
Antonyan, T., et al.: State-wide elections, optical scan voting systems, and the pursuit of integrity. IEEE Trans. Inf. Forensics Secur. 4(4), 597–610 (2009)
Blom, M., Stuckey, P.J., Teague, V.J.: Ballot-polling risk limiting audits for IRV elections. In: Krimmer, R., et al. (eds.) E-Vote-ID 2018. LNCS, vol. 11143, pp. 17–34. Springer, Cham (2018). https://doi.org/10.1007/978-3-030-00419-4_2
Blom, M., Stuckey, P.J., Teague, V.J.: Computing the margin of victory in preferential parliamentary elections. In: Krimmer, R., et al. (eds.) E-Vote-ID 2018. LNCS, vol. 11143, pp. 1–16. Springer, Cham (2018). https://doi.org/10.1007/978-3-030-00419-4_1
Blom, M., Stuckey, P.J., Teague, V., Tidhar, R.: Efficient computation of exact IRV margins. In: European Conference on AI (ECAI), pp. 480–487 (2016)
Di Franco, A., Petro, A., Shear, E., Vladimirov, V.: Small vote manipulations can swing elections. Commun. ACM 47(10), 43–45 (2004)
Hall, J.L., et al.: Implementing risk-limiting post-election audits in California. In: Electronic Voting Technology Workshop/Workshop on Trustworthy Elections (EVT/WOTE 2009), Montreal, Canada, August 2009. USENIX (2009)
Lindeman, M., Stark, P.B., Yates, V.: BRAVO: ballot-polling risk-limiting audits to verify outcomes. In: Electronic Voting Technology Workshop/Workshop on Trustworthy Elections (EVT/WOTE 2011). USENIX (2011)
Magrino, T.R., Rivest, R.L., Shen, E., Wagner, D.A.: Computing the margin of victory in IRV elections. In: USENIX Accurate Electronic Voting Technology Workshop. USENIX Association, Berkeley (2011)
Richie, R.: Instant runoff voting: what Mexico (and others) could learn. Election Law J. 3, 501–512 (2004)
Sarwate, A.D., Checkoway, S., Shacham, H.: Risk-limiting audits and the margin of victory in nonplurality elections. Polit. Policy 3(3), 29–64 (2013)
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2020 International Financial Cryptography Association
About this paper
Cite this paper
Blom, M., Stuckey, P.J., Teague, V.J. (2020). Election Manipulation 100. In: Bracciali, A., Clark, J., Pintore, F., Rønne, P., Sala, M. (eds) Financial Cryptography and Data Security. FC 2019. Lecture Notes in Computer Science(), vol 11599. Springer, Cham. https://doi.org/10.1007/978-3-030-43725-1_15
Download citation
DOI: https://doi.org/10.1007/978-3-030-43725-1_15
Published:
Publisher Name: Springer, Cham
Print ISBN: 978-3-030-43724-4
Online ISBN: 978-3-030-43725-1
eBook Packages: Computer ScienceComputer Science (R0)