@Misc{RW06,
  replaced-by =  { Riv08b },                  
  author = 	 { Ronald L. Rivest and John P. Wack },
  title = 	 { On the notion of ``software independence'' in voting systems },
  date =         { 2006-07-28 },                  
  url =          { http://vote.nist.gov/SI-in-voting.pdf },                  
  howpublished = { Prepared for the TGDC, and posted by NIST at the given url. } },
  OPTyear = 	 { 2006 },
  OPTmonth = 	 { July 28, },
  OPTannote = 	 { A later (2008) version was published in the Philosophical Transactions
                   of the Royal Society A, but John Wack was unfortunately unable to 
                   participate as a co-author in the final journal version.
                 },
  abstract =     {
        This paper defines and explores the notion of ``software independence''
        in voting systems:  A voting system is \emph{software-independent}
        if an undetected change or error in its software cannot cause an undetectable 
        change or error in an election outcome. \par
        We propose that software independent voting systems should be preferred,
        and software-dependent voting systems should be avoided. VVPAT
        and some cryptographically-based voting systems are software-independent.
        Variations and implications of this definition are explored. \par
        This white paper is also for discussion by the Technical Guidelines Development
        Committee (TGDC) in its development of the Voluntary Voting
        System Guidelines (VVSG) of 2007.                  
                 },
}