From CryptoDox, The Online Encyclopedia on Cryptography and Information Security
ThreeBallot is a end-to-end auditable voting system invented by Ronald Rivest in 2006.
Until recently, it was believed to be impossible for a voting protocol to satisfy 2 seemingly contradictory requirements:
- a voter is able to prove to himself that his selection was included in the final vote total -- that a conspiracy of vote-counters haven't "flipped" or discarded his vote.
- a voter must not be able to prove to a vote-buyer that he really did vote the way the vote-buyer wanted.
What the voter does: simple 2-way race
- The voter is given 3 ballots, each one with a circle next to each candidate.
- The voter marks 2 of the ballots for the candidate he likes, and one of the ballots for the other candidate.
- The voter runs the 3 ballots through a "verifier" machine that makes sure there are exactly 2 marks for one candidate, and exactly 1 mark for the other candidate.
- The voter picks any 1 of the 3 ballots, and copies it with the copy machine. Only the voter should know which one of the 3 was copied.
- The voter puts all 3 ballots in the ballot box
- The voter leaves with 1 receipt (a copy of 1 of the 3 ballots).
What the paranoid voter does next
- (optional) The next day, the voter searches through all the ballots published on the internet for the one with the same serial number as the one on the receipts. If the published ballot matches the receipt, the voter knows that at least that vote was counted properly. If he can't find it, or the one published is different from the receipt, the voter complains to the appropriate authorities -- or takes the receipt to his favorite journalist to "blow the whistle" on voting fraud scandal.
how it works
No vote buying: ...
No conspiracy: ...
external links
