> allowing voters to check their votes were recorded properly violate anonymity requirements
Why can't voters be provided with a random vote ID, which they can write down and later check against a list?
If you're concerned about people buying votes directly by buying IDs, just make the set of possible IDs small enough (ie, the same size as the number of registered voters) to confound buyers into being uncertain whether their provider might have just thought up a random ID and written it.
How is giving them a unique ID any different than the current situation? They can just as easily take a video of themselves voting as proof for these purposes.
Why can't voters be provided with a random vote ID, which they can write down and later check against a list?
If you're concerned about people buying votes directly by buying IDs, just make the set of possible IDs small enough (ie, the same size as the number of registered voters) to confound buyers into being uncertain whether their provider might have just thought up a random ID and written it.