In 2002, Brazil led the world's first informatized election. 117 million people voted for 19,000 candidates (including for presidency), and we knew the results of the presidential election in less than 4 hours. IT experts from many institutions, including international ones, participated in the elaboration and evaluation of the electronic ballot boxes. The elections were fraud-free as far as we know - and we know a lot.
Some observations:
* Brazil has a 11% illiteracy rate;
* Voting is compulsory from ages 18 to 65.
* Some areas of the country are very isolated. Think Amazon. In places without electricity, they used car batteries.
So how was it done? I can provide more links tomorrow. I can guarantee it keeps the privacy of the voters, it's very fast and simple.
From Wired and here an explanation of how the system works
Each candidate is assigned a number, and believe me you'll have those numbers badgered until you know them by heart. You can bring a memo with you. Radios and TV stations explain repeatedly how to do it, for the sake of the illiterate and technophobes.
Press number for President. You punch in 1, 5, in the number keyboard. The picture of your candidate appear. Then you press Confirm. Beep Beep Beep. It's over. You can opt to vote "blank" too.
When the elections are over, the machine prints the results. The data, also stored in a flash card, is collected and carried by officials until the local voting agency, and then sent via the internet to the federal agency. The system is very redundant, and every step is checked multiple times. 3% of all votes are chosen, randomically, to be checked against the printed ballots. Apparently, in the next elections, they will get rid of the printed votes, but that's still under debate. Sure, it's cheaper, but maybe less safe? Well, there WAS fraud when all the ballots were in paper, so...
Less than 1% of the machines were defective, and some were exchanged in time. In most cases, the heat provoked the malfunction. In those cases, paper ballots were used (and voters looked so disappointed).
The reasons ballots are not printed and given to the voter is that it was feared that some people (think isolated towns) could be coerced into exhiting their ballots to a third party. Also think of the possibility of votes being sold.
It's easy to say "no electronic system is safe", and that's true, but add enough safeguards and make it redundant, and you have trustworthy results. Candidates who were defeated made their mission in life to discredit the electronic ballots, to no avail.