Science News has a story this morning that focuses on the problems of voting technologies, but outlines some of the new approaches, including the “scratch and vote” approach of Adida and Rivest, Chaum’s “Punchscan”, and other new cryptographic approaches to the voting process. The story has a user-friendly presentation of these new methods:
Scratch & Vote and some new cryptographic approaches like it use a perforated ballot with voting boxes on one half and candidates’ names—printed in varying order from ballot to ballot—on the other. After marking a ballot, each voter detaches and shreds the portion with the printed candidate names. The voter then feeds the marked portion, which includes an encrypted version of the names and their order, through an optical scanner to record the vote in the election system. That portion, which the voter keeps as a paper receipt, doesn’t reveal the voter’s choices but does provide an indelible record of the voter’s ballot.
A major issue for cryptographic schemes is that the encrypted information must truly represent the order of selections on a given ballot, Adida notes. That’s where the scratch part of his and Rivest’s scheme comes in. Each ballot has a scratch foil like that of a lottery ticket, which voters can scrape away to verify that the codes are correct.
After voting, citizens can also look on the election district’s Web site and confirm that their ballots were scanned. Moreover, because all the encrypted votes are posted on the Web with no violation of their secrecy, outsiders have a way to independently perform tallies on the encrypted data, Adida explains.
Because the cryptographic systems are so transparent, they “achieve a class of verification that’s really far superior to current systems,” he says.
Another new cryptographic scheme, called Punchscan, uses scannable ballots with two separable layers that are marked by voters with ink daubers like those used in bingo games. Unlike Scratch & Vote, a Punchscan election would allow voters to keep either layer of the ballot while destroying the other. But neither half on its own includes enough information to reveal a voter’s choices.