Measuring Vote Privacy, Revisited

Measuring Vote Privacy, Revisited. David Bernhard, Véronique Cortier, Olivier Pereira, and Bogdan Warinschi. In 19th ACM Conference on Computer and Communications Security (CCS'12), pp. 941–952, ACM, Raleigh, USA, October 2012.

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Abstract

We propose a new measure for privacy of votes. Our measure relies on computational conditional entropy, an extension of the traditional notion of entropy that incorporates both information-theoretic and computational aspects. As a result, we capture in a unified manner privacy breaches due to two orthogonal sources of insecurity: combinatorial aspects that have to do with the number of participants, the distribution of their votes and published election outcome as well as insecurity of the cryptography used in an implementation. Our privacy measure overcomes limitations of two previous approaches to defining vote privacy and we illustrate its applicability through several case studies. We offer a generic way of applying our measure to a large class of cryptographic protocols that includes the protocols implemented in Helios. We also describe a practical application of our metric on Scantegrity audit data from a real election.

BibTeX

@InProceedings{CCS2012-entropy,
  author = 	 {David Bernhard and V\'eronique Cortier and Olivier Pereira and Bogdan Warinschi},
  title = 	 {Measuring Vote Privacy, Revisited},
  booktitle = {19th ACM Conference on Computer and Communications Security (CCS'12)},
  year = 	 {2012},
  address = 	 {Raleigh, USA},
  month = 	 {October},
 pages = {941-952},
DOI = {10.1145/2382196.2382295},
  publisher = {ACM},
abstract =      {We propose a new measure for privacy of votes.
Our measure relies on computational conditional entropy, an extension of the traditional notion of entropy that incorporates both information-theoretic and computational aspects. As a result, we capture in a unified manner privacy breaches due to two orthogonal sources of insecurity: combinatorial aspects that have to do with the number of participants, the distribution of their votes and published election outcome as well as insecurity of the cryptography used in an implementation.
  Our privacy measure overcomes limitations of two previous approaches
  to defining vote privacy and we illustrate its applicability through
  several case studies.  We offer a generic way of applying our
  measure to a large class of cryptographic protocols that includes
  the protocols implemented in Helios. We also describe a practical
  application of our metric on Scantegrity audit data from a real
  election.},
}