[xori]

Because your vote also needs to be private to the point where a third-party can't verify that a vote belongs to you.

To prevent selling of votes, or forced votes via blackmail.

[florabuzzword]

Thanks. That’s the answer I was looking for. I guess there would be no way to verify privately.

[xori]

There's ways. A memorized "secret" that would be put on the ballot in addition to your vote could be used for you to verify a checksum.

The main issue is the hardware, and added complexity. But these are interesting problems that should be talked about.