Automatic Margin Computation for Risk-Limiting Audits

Reviewed Paper In Proceedings

Author(s):Bernhard Beckert, Michael Kirsten, Vladimir Klebanov, and Carsten Schürmann
In:First International Joint Conference on Electronic Voting – formerly known as EVOTE and VoteID (E-Vote-ID 2016)
Publisher:Springer
Series:LNCS
Volume:10141
Year:2017
Pages:18-35
PDF:
DOI:10.1007/978-3-319-52240-1_2

Abstract

A risk-limiting audit is a statistical method to create confidence in the correctness of an election result by checking samples of paper ballots. In order to perform an audit, one usually needs to know what the election margin is, i.e., the number of votes that would need to be changed in order to change the election outcome.
In this paper, we present a fully automatic method for computing election margins. It is based on the program analysis technique of bounded model checking to analyse the implementation of the election function. The method can be applied to arbitrary election functions without understanding the actual computation of the election result or without even intuitively knowing how the election function works.
We have implemented our method based on the model checker CBMC; and we present a case study demonstrating that it can be applied to real-world elections.

BibTeX

@InProceedings{BeckertKirstenEA2017,
  author     = {Bernhard Beckert and Michael Kirsten and
                Vladimir Klebanov and Carsten Sch{\"u}rmann},
  title	     = {Automatic Margin Computation for Risk-Limiting Audits},
  booktitle  = {First International Joint Conference on Electronic Voting 
                 – formerly known as EVOTE and VoteID (E-Vote-ID 2016)},
  editor     = {Robert Krimmer and
                Melanie Volkamer and
                Jordi Barrat and
                Josh Benaloh and
                Nicole J. Goodman and
                Peter Y. A. Ryan and
                Vanessa Teague},
  publisher  = {Springer},
  series     = {LNCS},
  pages      = {18--35},
  volume     = {10141},
  month	     = jan,
  year       = {2017},
  doi        = {10.1007/978-3-319-52240-1_2},
  abstract   = {A risk-limiting audit is a statistical method to create confidence
                in the correctness of an election result by checking samples of
                paper ballots. In order to perform an audit, one usually needs to know
                what the election margin is, i.e., the number of votes that would need
                to be changed in order to change the election outcome.
                \newline

                In this paper, we present a fully automatic method for computing
                election margins. It is based on the program analysis technique of
                bounded model checking to analyse the implementation of the election
                function. The method can be applied to arbitrary election functions
                without understanding the actual computation of the election result or
                without even intuitively knowing how the election function works.
                \newline

                We have implemented our method based on the model checker CBMC; and
                we present a case study demonstrating that it can be applied to
                real-world elections.},
  venue      = {Lochau / Bregenz, Austria},
  eventdate  = {2017-10-18/2017-10-21}
}