[Robert DeLong]

which can be checked by the voter

Only problem there is that ballots are supposed to be private and only shared at the discretion of the voter, which your suggestion would void completely.

[Lazamataz]

Only problem there is that ballots are supposed to be private and only shared at the discretion of the voter, which your suggestion would void completely.

It can be done, and remain private, via simple blockchain technology.

Blockchain is what powers BitCoin.