[lswainemoore]

What if when you vote you were given one real sha, which shows who you actually voted for, and then one fake sha, which would show the opposite? As long as only you (and the vote aggregator) knew which one was which, you could produce "proof" to any vote buyer.

[comex]

But the fake SHA would have to not be counted, yet the purpose of the SHA is to prove that your vote was counted. There are variations on the scheme, but fundamentally, in a system where the voting machine gives you a real and fake token, which have to be indistinguishable after the fact, what's preventing it from swapping them?