Somehow Brazil makes it work, there are many many layers of redundancy so that any tampering would not affect the result, or be obvious.
That's awesome for Brazil. They discovered a perfect flawless man made system. I completely believe it is entirely tamper proof. It's much easier to change whole datasets than to edit enough paper ballots to make a difference in a vote where many millions of people have submitted paper votes. Ctrl+a, del.... Goodbye data. Not that it's possible to do in the Brazilian system. But it certainly is possible in many databases...