Let's fix this problem once and for all, the RIGHT way...!
There are all sorts of people hawking stupid non-solutions to the election security/trustworthiness/auditability problem. One such nitwit is a radio talk show host, Brad Friedman, who is frustrating because he has such a loud microphone for his ignorance.
Some of the gripes are valid. Clearly election equipment must not be hackable, especially while it's deployed for an election. But when Brad mindlessly pushes "hand marked, hand counted paper ballots" as THE solution, he obviously hasn't thought very hard about the problem.
To begin with, there are a LOT of advantages to using smart, touch-screen voting machines, at least as the first stage of the election process. They prevent overvotes, warn of unintentional undervotes, and don't allow ambiguous marking of ballots.
Once a voter has finished their voting on the touch-screen machine, that machine should print an unambiguously marked, NOT MODIFIABLE, hard copy human-readable (and scannable) version of the voter's ballot. The voter should then verify that the definitive paper ballot as printed matches their choices. Then they walk over and slide their approved permanent ballot into a stage two, scanner/counter/lockbox machine.
When the polls close at the end of the night, the election judge and clerks will generate multiple copies of the printed results totals from both the first stage AND the second stage systems. These should be signed by the judge and each election clerk present. Here in Dallas County (Texas) we generate five sets of results tapes to give to the County... under my proposal, we would generate SEVEN sets of tapes, from EACH of the first-stage and second-stage systems. When the election judge drops off the results at the end of the evening, we would give the county the five tapes as we do now... AND hand one set of each stage's tapes to a representative of the Democratic Party, AND a representative of the Republican Party.
This allows the county, and BOTH parties, to independently compare the totals produced reflecting the ballots as printed, AND the totals counted by the ballots as deposited. Obviously, any discrepancies found would be investigated thoroughly. It would also allow all three parties to INDEPENDENTLY TALLY the votes, and this would catch (and thus prevent) any changing of the votes by someone in the county, or even at the state level.
Unlike "hand marked hand counted paper ballots", it would be IMPOSSIBLE for anybody to add extraneous marks to ballots after the ballot was cast... whether to create an overvote, or to fill in a voter-desired "no vote".
In addition, some statistically appropriate percentage of the definitive paper ballots would be selected for hand counting, just to verify that the first stage and second stage totals did in fact match the voter-verified printed definitive ballot they were casting.
While we're on the topic of voting integrity, note that generalized mailin ballots, AND online voting, MUST not be allowed... there is NO way to ensure that someone in a position of power over the voter isn't looking over their shoulder to make sure they're voting "the right way", perhaps selling their vote (drugs, sex, alcohol, money...).
Note that with my system, as long as the definitive ballots are printed and voter-verified, and with the verified random hand recounting and parallel tabulation by three parties... hacking of the machines (at the polls, or even at the county and state levels) becomes a non-issue. This is NOT true with ANY of the other election schemes I've seen proposed by others. And I haven't heard anybody I've told about my proposed system explain any remotely plausible way that it could be hacked.