Voting security advocates in the US are bracing for a repeat of problems in the upcoming general election that could rival Florida during the 2000 presidential race.
A number of voting security groups have focused on the electronic voting machines that have replaced paper ballots in many states.
Counties in 27 states, including presidential swing states such as Florida, Ohio and Pennsylvania, will use direct electronic recording machines (DREs), accounting for about 30% of US voters on 2 November.
Most local elections officials dismiss the controversy over electronic voting technology. But a flood of new voters, a mix of new voting technology and the US' scattershot system for running and managing elections could create confusion.
Voting security advocates have raised dozens of concerns about e-voting machines. Some of the back-end vote-counting tabulators can be easily hacked; some smartcards that provide access to the machines can be faked; and votes can be lost when machines crash.
In short, groups such as BlackBoxVoting.org and the Electronic Frontier Foundation (EFF) complain that DREs don't give voters any indication of what is going on inside the machine. Most DRE suppliers keep the inner workings of their machines proprietary, and critics complain that the DREs are in essence a "black box".
The EFF has focused on what it calls the lack of an audit capability in DREs. Most machines cannot print a so-called voter-verified paper trail, so when a politician demands a recount, most DREs will simply spit out the same set of disputed numbers again and again.
BlackBoxVoting.org and VerifiedVoting.org have lined up thousands of volunteers to check for problems with DREs on Election Day. At least one lawsuit still pending, filed by a Florida Democrat, seeks to stop his state from using DREs without adding a paper trail.
Supporters of DREs defend them as a much better alternative to the paper ballots that caused so much confusion in Florida in 2000. E-voting machines offer no less transparency than old paper balloting systems, argued Harris Miller, president of the Information Technology Association of America (ITAA), a trade association of technology suppliers.
To spur the adoption of updated voting technology and to address problems with paper ballots that sullied the 2000 presidential election, the US Congress passed the Help America Vote Act of 2002. The legislation provided $3.9bn (£2.1bn) for state and local governments to improve elections, including $325m to replace punch-card and lever voting machines.
Election officials say the DREs are a significant improvement over paper ballots. The common problem of over-voting - voting for more than one candidate per race - is impossible, and if a person under-votes - doesn't cast a vote in some races - the DRE also warns the voter.
Miller suggested that in the unlikely event a group of hackers found a way to change votes inside an e-voting machine, they wouldn't stop without changing the paper trail as well.
"Let's assume that someone was clever enough to fool the outside independent (machine) evaluators, clever enough to fool the state evaluators, clever enough to fool the local election officials and record votes for John Kerry that should've been for George Bush or vice versa," Miller said. "If they're clever enough to do that, they're clever enough to write the software to give you a false paper ballot, too."
While the issues raised by voting security experts could lower voters' confidence with the systems, the vast majority of elections workers interviewed by IDG News Service said they trust the machines to keep an accurate count of votes and not to break down.
Grant Gross writes for IDG News Service