I think the key problem with electronic voting is the possibility of a "class break", as explained here by Bruce Schneier: https://www.schneier.com/blog/archive

I think the key problem with electronic voting is the possibility of a "class break", as explained here by Bruce Schneier: https://www.schneier.com/blog/archives/2017/01/class_breaks.html https://www.schneier.com/blog/archives/2017/01/class_breaks.... If there's a flaw in the system -- and there will be flaws, the only question is how soon they're found -- there's a risk that the whole thing can be compromised in one fell swoop. Whereas pen and paper voting, counted by hand, is slower and less accurate and has plenty of its own flaws, but there's no simple way to compromise the entire vote at once. You'd have to fool a whole bunch of different people in different ways, and/or recruit them into a huge conspiracy. Other countries use pen and paper and it works fine. Electronic voting machines should be banned.