When I tell you the following you can take as the genuine truth: There is NO POSSIBLE WAY UNDER THE SUN to "fix" voting machines to ensure their accuracy or their immunity from penetration from a party seeking personal gain. They are ALL, regardless of what "generation" they are, past, present or future, utterly unfixable in this context, whether or not they contain paper trails, and whether they're used merely to mark ballots or cast votes or are used to tabulate votes cast by other means (as with optical scanners). Every computer ever built is vulnerable to attack, and there is no possible way to render any computer genuinely invulnerable.
Every entity that has its hands on any kind of voting or vote counting device at any point in its construction, programming, or implementation, has a political aspect that will be served by one or another candidate in any given race, whether the entity is corporate or governmental in nature. Whether the mechanism or code is proprietary or open source, secret or public, sealed or unsealed, and regardless of any testing that might take place, at some points in the process there will be opportunities -- in fact, multiple opportunities -- to tamper with the mechanical, electronic or programming internals in a way as to alter the output from those devices in ways that are difficult or even impossible to detect, and that could change the apparent outcome of our elections.
It is because of my intimate familiarity with computers and computer security that I am so adamant in my opposition to computerized voting and vote counting. It is certainly not from any "dislike" of computers. I LOVE them and continue to make my living from my knowledge of them.
If we wish to rebuild confidence in our elections and any genuine integrity in our balloting processes, we must recognize that the stakes in our election outcomes are simply too high to introduce any potential for tampering at any point in the process -- any such vulnerability will CERTAINLY be exploited because of the truly enormous temptations that such high stakes represent. It is literally IMPOSSIBLE to provide any kind of integrity in ballot casting and vote counting unless the voter can actually SEE and fully understand for whom his or her ballot has ACTUALLY been cast, and those ballots are counted in the presence of bipartisan witnesses.
This goal can ONLY be achieved by PAPER ballots, manually marked and manually tabulated. NO OTHER SOLUTION IS OR CAN EVER BE ACCEPTABLE if the goal is to provide integrity in our balloting and in the counting of our votes. ANY device inserted between a voter and the tabulation of his or her vote introduces vulnerabilities to the system and diminishes confidence in the integrity of our elections.