Based on our findings, we propose a new game-based definition of privacy which we call BPRIV. We also identify a new property which we call {\em strong consistency}, needed to express that tallying does not leak sensitive information. We validate our security notions by showing that BPRIV, strong consistency (and an additional simple property called strong correctness) for a voting scheme imply its security in a simulation-based sense. This result also yields a proof technique for proving entropy-based notions of privacy which offer the strongest security guarantees but are hard to prove directly: first prove your scheme BPRIV, strongly consistent (and correct),then study the entropy-based privacy of the result function of the election, which is a much easier task.
Category / Keywords: cryptographic protocols / electronic voting, ballot privacy Original Publication (with major differences): IEEE S&P 2015 Date: received 18 Mar 2015, last revised 19 Mar 2015 Contact author: david galindo at scytl com Available format(s): PDF | BibTeX Citation Version: 20150319:100626 (All versions of this report) Short URL: ia.cr/2015/255 Discussion forum: Show discussion | Start new discussion