Probably not. You could make it anonymous - the unique combination of your vote, your key, and the election blockchain could produce a password unique to you.

Probably not. You could make it anonymous - the unique combination of your vote, your key, and the election blockchain could produce a password unique to you. This would allow you to verify that your vote was counted, but would not allow anyone else to do so - if they coerced you, you could run your key, the blockchain, and the opposite vote and produce a different password and your attacker would be none the wiser. But then if you find that your password has changed, how do you prove it? I don't think there's any way to prove election fraud without violating election confidentiality, even for paper ballots. How do you propose stopping election fraud with paper ballots? The current defense is merely "it is hard."