With the Scantegrity II voting system, voters mark op- tical scan paper ballots with pens, filling the oval for the candidates of their choice. These ballots are handled as traditional ballots, permitting all the usual automated and manual counting, accounting, and recounting. Ad- ditionally, the voting system provides a layer of integrity protection through its use of invisible-ink confirmation codes. When voters mark ballot ovals using a decoder pen, confirmation codes printed in invisible ink are re- vealed. Interested voters can note down these codes to check them later on the election website. The codes are generated randomly for each race and each ballot, and hence do not reveal the corresponding vote
