@techreport{Smyth14-ballot-independence-for-election-schemes,
  author = {Ben Smyth and David Bernhard},
  title = {{Ballot secrecy and ballot independence:}}
        # {{ definitions and relations}},
  year = {2014},
  month = {October},
  number = {2013/235},
  institution = {Cryptology ePrint Archive},
  url = {https://publications.bensmyth.com/2014-ballot-independence-for-election-schemes/},
  url-pdf = {https://publications.bensmyth.com/files/Smyth14-ballot-independence.pdf},
  url-bib = {https://publications.bensmyth.com/files/Smyth14-ballot-independence-for-election-schemes.bib},
  url-yaml = {https://publications.bensmyth.com/files/Smyth14-ballot-independence-for-election-schemes.yml},
  url-md = {https://publications.bensmyth.com/files/Smyth14-ballot-independence.md},
  note = {Cryptology ePrint Archive version: https://eprint.iacr.org/2013/235},
  keywords = {ballot independence, ballot secrecy, elections, election schemes, electronic voting, e-voting, Helios, controlled malleability, malleability},
  abstract = {We study ballot independence for election schemes. First, we formally define ballot independence as a cryptographic game and prove that ballot secrecy implies ballot independence. Secondly, we introduce a notion of controlled malleability and prove that it is sufficient for ballot independence. We also prove that non-malleable ballots are sufficient for ballot independence. Thirdly, we prove that ballot independence is sufficient for ballot secrecy in a special case. Our results show that ballot independence is necessary in election schemes satisfying ballot secrecy. Furthermore, our sufficient conditions enable simpler proofs of ballot secrecy.}
}