Voter Verified Audit Trail
Put simply, we need a Voter Verified Audit Trail because voters can't see what happens inside voting machines. The machine might display one vote to the voter and record something else internally.
For a demonstration, go to this website.
What exactly is a Voter Verified Audit Trail?
A voter verified audit trail (VVAT) is paper ballots that have been verified by individual voters. The all-paper system that's been used here since before the beginning of the State had a VVAT - the paper ballots filled in by voters. If a recount was called, counters went back to those paper ballots. There are many electronic voting systems which do provide VVAT, including systems which print ballots and systems which scan ballots. Unfortunately, the Nedap/Powervote system purchased for use in Ireland doesn't currently provide a VVAT, but it would be simple to modify it so that it did.
We propose that a printer be added to each voting machine. The voter would see their ballot paper printed and see it go into a ballot box. They would be safe in the knowledge that their vote had been recorded correctly on paper. VVAT would not completely prevent the electronic results being altered by mistakes or tampering (though it would significantly discourage tampering), but it would mean any alterations could be detected and corrected.
Is VVAT easy to implement?
Yes, VVAT is very easy to implement. As mentioned above, there are many products out there that do provide VVAT. Take a look at Fergal Daly and John Lambe's pages describing how VVAT might work in Ireland.