[fooyc]

The machine could give the same UUID to different voters:

- Voter 1 votes for Harker

- Voter 2 votes for Harker, gets the same UUID. The machine casts a vote for Dracula instead

It could also cast any number of fake/counter votes without the voter knowing.

[deegles]

You make the ID be a hash of a UUID and the voter’s name.

[amluto]

That allows proving who cast which vote. Instead, you could generate the ID when the vote is cast using a coin flip protocol.

Some effort would be needed to create an actual proof that the coin flip protocol doesn’t allow the voter to generate any sort of proof that they participated in the coin flips. I think the usual schemes do have this property (at least, they do if the parties don’t collide), but I haven’t seen this specifically proven.