Election security is not the problem. Common knowledge is.
I unequivocally believe that Electronic Voting of any type (even just electronic voting machines in booths) is a terrible idea in the United States. People should vote by marking paper ballots, which are then counted and recounted, by hand, in rooms with plenty of neutral and partisan observers.
This isn't because it is impossible to build a secure electronic (or internet) voting machine. But right now, 1) it is not possible for the average Joe to distinguish between a secure voting machine and an insecure voting machine. 2) there is no trusted civil service in the United States that would be trusted by 90%+ of the country if that civil service attested that a specific implementation was safe. It's not that we cannot build a secure evoting system. The real problem is that we cannot achieve common knowledge of the security of the system, regardless of its actual security properties.
Let me put this another way: if I was in charge of structuring a leader election process in some Amazonian tribe that did not understand addition and believed that closed boxes could be influenced by malignant spirits, I would not advocate for secret-ballot paper voting. It is a necessary condition of whatever voting system is set up that a very large super-majority of the electorate believe that the process is legitimate. I have a dream, that one day, every grandpa understands asymmetric cryptography and secure hash functions. When that day comes we can happily do away with the relatively tiny overhead of waiting a few extra hours and a few million dollars while volunteers count paper ballots.
Right now here's how it goes: Diebold makes a shoddy evoting machine that has, almost certainly, been hacked (a voting machine that drops every 30th vote for one political party in the right districts could easily be decisive, and probably would be interpreted as a Brady effect). Some ivory tower types decry Diebold's security, advocating for an "open source" secure implementation. What the hell is open source? It sounds very much like communism. Bold corporate leader (and stalwart Republican) Diebold CEO assures us that everything is fine. This becomes just another partisan battle. We are dangerously close to the entire legitimacy of the political process being thrown aside (mercifully, the Florida fiasco was hanging paper chads, imagine if it was Diebold electronic machines). All, for what? So that we avoid counting up some paper?
I am not arguing that any specific voting system should be used (although, of course, some things like STV become easier to implement if done computationally than counting-by-hand, so there are unfortunate side-effects). I am simply trying to assure the legitimacy of the system as a whole.
Perhaps some country where there exists an extremely high-trust bureaucracy could implement evoting (Switzerland? Finland? I have no idea). Just that bureaucracy's word would be sufficient for 90%+ of the population. But such a bureaucracy does not exist in the United States, so the process can only be as complex as grandpa can easily understand. Which means ballot boxes stuffed with paper ballots, counted by hand by multiple sets of neutral and partisan officials, observed by volunteers.