I don't care how much maths and encryption you use, you can't get out of the fact that things can be anonymous (no one can know how you voted) or verifiable (people can prove that you only voted once) but not both. - Switzerland usually gets around this by knowing where everyone lives and mailing them a piece of paper 'something you have' - South Africa gets around this by putting ink on your fingernail I've read qui…
The USA threads the needle by simply not having verifiable voting. And it turns out it works pretty well. Despite countless hours and lawsuits dedicated to finding people who voted more than once, only a handful of cases have actually turned up. It's not that there are no checks. You have to give your name, and they know if you've voted more than once at that station that day. To vote more than once you'd have to pre…
- Enter queue
- A front of queue, show ID of some sort (various accepted) to volunteer
- They scratch you from the list and hand you a paper scantron sheet
- Go to private booth, fill out scantron
- Go to exit, scan ballot (it scans and then drops into a locked box for manual tally later, if necessary)
The "easy" ways to vote fraudulently are also easily caught... fake ID documents, voting twice, etc.
For people who forget their ID or have address changes that haven't propagated through the voter roll, there is provisional voting - you do the same as above, but they keep the ballot in a separate pile and validate your eligibility to vote at a later time. IIRC, the voter gets a ticket # so they can check the voter portal later to see if the ballot was accepted.
As noted, the number of fraudulent votes are astonishingly small, given the amount of money spent on proving otherwise. The current GOP has spent 100s of millions or billions on proving wide-spread fraud and so far, all they've managed to prove a few voters, most of whom were actually GOP-leaning, have committed fraud (and most of them were caught day-of already).