Last Tuesday, millions of Americans stood in long lines to cast their votes. While they waited, sometimes for several hours, many used their smartphones to pass the time.
Some read articles about the election. Others updated their Twitter or Instagram feeds with pictures of the lines at the polls. And some took care of more private tasks, like sharing health information with their doctors, reading and editing confidential work documents, or paying bills and transferring money using banking applications.
Once in the voting booth, they slipped their phones into their pockets and purses and, in many cases, picked up a pen and a piece of paper to cast their ballot.
So at a time when we can see video shot by a robot on Mars, when there are cars that can drive themselves, and when we can deposit checks on our smartphones without going to a bank, why do most people still have to go to a polling place to vote?
That's because, security experts say, letting p eople vote through their phones or computers could have disastrous consequences.
“I think it's a terrible idea,†said Barbara Simons, a former I.B.M. researcher and co-author of the book “Broken Ballots: Will Your Vote Count?â€
Ms. Simons then ran through a list of calamitous events that could occur if we voted by Internet. Viruses could be used to take over voters' phones; rogue countries like Iran could commandeer computers and change results without our knowledge; government insiders could write software that decides who wins; denial-of-service attacks could take down the Internet on Election Day.
“It's a national security issue,†Ms. Simons said. “We really don't want our enemies to be able to determine our government for us - or even our friends for that matter.â€
Of course, many of those concerns make sense. None of us want some evil autocrat picking the next president.
But other countries allow citizens to vote via the Inter net, or are experimenting with the idea. In 2005, Estonia started testing an online voting system and has since registered more than a million voters who now cast their ballots online. Italy plans to test an online voting system this year.
Not the United States, the land of the free and the home of the smartphone.
Ronald L. Rivest, a computer scientist at the Massachusetts Institute of Technology, said that for now, the best technology out there is the one we've been using.
“Winston Churchill had a famous saying that democracy is the worst form of government, except for all those other forms that have been tried before,†Mr. Rivest said. “You can apply the same statement to paper ballots, which are the worst form of voting, but better than all the others that have been tried before.â€
Mr. Rivest, who is the R in the name of the RSA encryption system, which is used by government institutions and banks, said that if things went wrong on Election Day, chaos could ensue, because doubts about the results would rattle the foundations of our democracy.
“One of the main goals of the election is to produce credible evidence to the loser that he's really lost,†he said. “When you have complicated technology, you really do have to worry about election fraud.â€
So what's the solution? Ms. Simons and Mr. Rivest both seemed certain that the best alternative was to stick with a technology that's a couple of thousand years old. “Paper,†they both said, as if reading from the same script. “Paper ballots.â€
Voting by mail, which some cite as an option, lets people avoid the lines, but it is not so easy on the vote counters. In states where this is allowed, envelopes have to be opened and ballots sorted into precincts. Then the signature needs to be matched with that on the voter registration card. None of this is terribly efficient.
So in 10, 20 or 100 years, when our cars have been replaced wi th self-flying spaceships, robots take our children to school, and our smartphones are chips in our heads, will we still be using a pen and paper to choose our president? I sure hope not.
After Hurricane Sandy disabled power and transportation for many in New Jersey, the state announced that some people would be allowed to vote by e-mail. The entire operation was pulled together in three days. Although there were problems, the system worked for most.
Digital voting could drive more Americans to the polls. According to a report released by the Census Bureau this year, nearly 50 million Americans didn't vote in the 2008 election. Millions of people said this was because they were out of town, had transportation problems or were too busy to get to the polls. Internet voting could let millions more people take part.
There are, as the security experts point out, a litany of issues to confront before this happens, but it's not impossible.
Alexander Keyssar, a professor of history and social policy at Harvard and author of the book “The Right to Vote,†added one more issue to the list: voter coercion, in which your boss or someone else bullies you into picking a candidate, perhaps right in front of them. But Mr. Keyssar said people should eventually have the option to vote via the Web.
“I think it's something that the government should be looking to develop as a down-the-road option,†he said, adding that in Brazil, a government group called the Federal Election Tribunal has the task of developing all-digital voting technologies. “We could have a similar tribunal here,†he said.
In his acceptance speech, President Obama acknowledged the problems of those who had to wait in long lines to vote, saying, “By the way, we have to fix that.â€
There are more than twice as many mobile phones in the United States as there are people who voted during this last election. As one option to “fix that,†I'd vote for an app that allows me to cast my ballot from the privacy of my own home, rather than waiting in line to mark a piece of paper with a pen.
E-mail: bilton@nytimes.com
Louie Chin 
