If a ThreeBallot (as described in
http://theory.csail.mit.edu/~rivest/Rivest-TheThreeBallotVotingSystem.pdf)
voter wants a receipt to reveal nothing about how she voted, then she
should not choose uniformly among all the bubble-markings that encode
her choices. That produces a receipt on which a bubble for her chosen
candidate is twice as likely to be marked as a bubble for an unchosen
candidate.
Instead, she should mark or not mark each bubble on the ballot to
become the receipt according to a coin flip (A biased coin is OK.), then
mark the other two ballots to encode her choices.
My question is, does the term "Zero Knowledge" apply to such a
receipt? I've only seen "Zero Knowledge" applied to proofs. Is there
another term that would be better? "Zero Information"?
--Mike Amling
