Voters in the recent Iowa caucuses and Tuesday's New Hampshire primary will rely on paper ballots as they have for generations. In the very next primary on January 21, South Carolinians will vote with backlit touch-screen computers.

In an age of electronic banking and online college degrees, why hasn't the rest of the nation gone the way of the Palmetto State? The reason is simple and resonates with the contentious debate that has yet to be resolved after at least 15 years of wrangling over the issue of electronic voting. No one has yet figured out a straightforward method of ensuring that one of the most revered democratic institutions—in this case, electing a U.S. president—can be double-checked for fraud, particularly when paperless e-voting systems are used.

Electronic balloting has yet to reconcile two conflicting needs in the polling place: Any election must proceed under a cloak of anonymity. But if a recount is required, election officials must go back and reproduce a verifiable audit trail. No account number ties the transaction to an individual, as it does when he transfers cash from bank checking to savings. What tangible proof then is there that all 5,734 votes cast really registered at the elementary school on Main Street? "If you have a machine collecting and recording votes with an electronic ballot box there's no way to go back after the fact and see if the machine made a mistake, whether through malice or simple software error," says Stanford University computer science professor David Dill and founder of Verified Voting Foundation, a nonpartisan election watchdog.

Electronic voting has its share snafus to prove the case of the doubters. In 2006 voters in Florida's 13th Congressional District election learned firsthand that there is little recourse when e-voting election results are in dispute. That year Democratic nominee Christine Jennings, who lost the election by 369 votes to Republican Vern Buchanan, claimed that 18,000 ballots went uncounted in the district. Without a paper trail to follow, the matter was left to the courts and Buchanan held onto the seat.

"They couldn't audit the election because there was no way to evaluate the machine's accuracy," Dill says. "It's like you have a worker who's doing your accounts who is very smart but not very trustworthy. If you have some independent way of checking the numbers he started with against the numbers he finished with then you don't have to trust him. You can double-check his work and catch any major errors. That's what we need for voting machines."

How do you cast your ballot?
Voters can cast their ballot in a variety of ways, depending on the method adopted by their election district. This includes paper ballots; punch cards; two types of touch-screen electronic voting systems (one that prints out a receipt verifying your vote and one that does not); optical scanners used to digitize paper ballots; or some combination of these.

New Hampshire, like nearly two thirds of the country, has a paper ballot system that voters mark and turn in to election officials who count the ballots either by electrical scanners or by hand. With the optical-scan approach, if the ballot is not filled out properly or is unreadable, the scanner will not accept it but the voter can fix it before leaving the polling place, Dill says.

South Carolina is one of the more than 15 states that thought they were forward-looking when they decided to rely primarily on touch-screen e-voting systems. The systems, however, do not provide any verification receipt for voters to review and which election officials can consult later if ballot accuracy is questioned and a recount is demanded.

The accuracy of the paperless Election Systems & Software (ES&S) iVotronic direct recording electronic (DRE) touch-screen machines used throughout South Carolina has come under scrutiny in recent years. Researchers from the University of South Carolina, Columbia, along with Clemson University and the League of Women Voters of South Carolina last year analyzed the results of the state's November 2010 elections. Audit trail files produced by ES&S system software indicated to the researchers that "votes were not counted, that procedures that should have been checked automatically were not checked, and that vote data to support the certified counts has not been collected or stored," according to their report (pdf).

Given that South Carolina spent more than $30 million to implement e-voting systems, it is unlikely they will replace them, particularly with low-tech paper ballots and optical scanners. Still, the stakes are high, with national implications. Since 1980, every winner of the South Carolina Republican presidential primary has gone on to win the party nomination.

Internet voting
Online e-voting seems a logical step at a time when home buyers can take virtual tours of real estate thousands of kilometers away and students can receive college degrees without ever setting foot in a classroom. Some voting districts allow military personal and overseas voters to print mail-in ballots from Web sites.

Not unexpectedly, some groups are even calling for the right to take voting directly to "the cloud" in the hope of accommodating absentee voters and attracting those not inclined to make the trip to their local polls. Americans Elect, a Washington, D.C.-based nonprofit has registered as a political party in Alaska, Arizona and 13 other states with a platform that advocates Internet-based voting. Americans Elect does not yet have a candidate for the 2012 presidential election, but the group is using an Internet-based nominating process to solicit one. Given that primary season has begun, it's more likely that this movement will prove mostly symbolic in 2012.

Internet and electronic voting share all of the same problems, with the added threat to the former of votes being flipped to the other candidate or erased by a hacker based anywhere in the world, Dill says.

Efforts to test prospects for Internet voting have failed miserably thus far, asserts Jeremy Epstein, a senior computer scientist at SRI International who has researched voting technology, citing in particular the Internet-based system that the Washington, D.C., Board of Elections and Ethics tried to set up in 2010. That system was undone when a group of security testers were able to hack into the site and make the University of Michigan fight song play each time someone cast a vote.