Ron Rivest has posted a fascinating paper called The ThreeBallot Voting System. This paper describes a paper-based, low-tech, three-part voting system. Each voter actually marks three identical ballots. To vote FOR a candidate in a race, they mark exactly 2 of the 3 ballots. To vote AGAINST a candidate in a race, they mark exactly 1 of the 3 ballots. The ballots are checked by a stateless checking device. The voter then gets a copy of any one of the three ballots but deposits all three originals in the ballot box. Each individual ballot has a unique number on it and at the end of the election all of the ballots (including how they were cast) are posted online. The voter can then verify that their vote was included. Assuming there are n voters, tallying works by simply adding all 3n cast ballots. The actual number of voters a candidate receives is the number of cast ballots minus the number of voters. This is a very interesting result and the paper goes into all the necessary details of election integrity, voter coercion, vote selling, recounts, and audits.
(via Risks-Forum Digest Volume 24 : Issue 44)