We already have technology that, so far, is pretty much tamper proof that could easily be adapted for online voting. I would be highly skeptical/distrustful of any centralized voting system, but if there was a open ledger voting system that uses a blockchain, well I would be all for that as it would be extremely hard to tamper with, arguable harder to tamper with than with paper ballots.
And a receipt that shows my vote was counted as part of the final results.
Source: former poll judge, inspector.
To use the engineering aphorism, just because it can be done doesn't mean it is done. I'm curious about how physical security/verification works in that environment vs a hypothetical crypto solution.
Election and voting chicanery happens plenty in the USA. No need to look abroad. Merely lifting the floor here would be transformative.
The silver lining from the oversteer triggered by Gore v Bush 2000 is that HAVA did lead to greater federal involvement in our locally administered elections. eg Election Assistance Commission http://eac.gov is now fairly proactive.
re "vs a hypothetical crypto solution"
Estonia's online voting system hasn't faired well under scrutiny.
The thing about the crudeness of methods used to tamper with paper ballots is that it's also similarly trivial for a bunch of volunteers including members of all different parties involved in the election to spot, and in many cases trivial to reverse.
The old way, you need an entire army of idiots.
With paper ballots, it's not easy to tamper with the entire vote. You need a huge, widespread effort. Or your country is so fucked that your government ignores the vote and makes up some numbers. Everybody knows it's fraudulent, but nobody can do anything about it.
With electronic ballots, it's suddenly trivially easy for just a tiny handful rogue elements to stealthily forge every vote without anyone even realizing there was fraud.