Everyone Counts uses "military-grade encryption" for its ballots, and can also provide a paper trail for clients who want it, Steele says. A "transparent code" policy allows any client to inspect the company's source code.

While Steele admits that online voting, like any system, is susceptible to attacks, she thinks the sheer number of devices in the wild would make it difficult for would-be hackers to hit their targets.

"They don't know which PCs or tablets or phones will be used for voting," Steele says. "Plus, people talk about paper being the Holy Grail of security, but that is so far from reality."

The biggest limitation of paper ballots was on display last week, when Hurricane Sandy decimated parts of the northeastern United States. The storm's destruction cut many voters off from their scheduled polling station.

On Saturday, New Jersey announced that displaced storm victims will qualify as "overseas voters," meaning they are eligible to vote via e-mail or fax.

"The storm was awful, but it could serve as a wider reminder that we need to reform the system," says Michelle Shafer, director of communications at Scytl USA.

Scytl's Spanish parent company has conducted online voting in over 30 countries worldwide. In the U.S., it's slowly gaining steam. The company has completed online "ballot delivery" -- digitally delivering a paper-ballot-like form that voters can fill out and submit -- in six U.S. states. Those digital ballots are typically used by military members and overseas residents. It has also run direct online voting for local elections in West Virginia, Florida and Alaska.

"I don't think we'll be voting online by [2016's general election], but my hope is that we'll continue to take slow and measured steps toward that eventuality," she adds.

While the United States takes it slow, countries like Canada and Norway continue to expand online voting.

Dean Smith, president and founder of Canada's leading online-voting firm, Intelivote, says the divide between his home country and the United States is vast. Popular Canadian labor unions have used online voting for years -- which means users have grown accustomed to the process -- and the country's ballots tend to be far less complex than those in the United States.

"In general, people here see the benefits of online voting and there's an acceptance," Smith says of Canada. "The U.S. would be a great coup, but there are so many academics who made their name by being naysayers. There's so much fighting about it. Right now, we don't need the additional problems."