The present invention is directed to a system and method for detecting security features on paper ballots. The security features allow a ballot tabulator to distinguish between an authentic ballot and a counterfeit ballot that does not include the required security feature. One or more security sensors in the ballot tabulator are operable to detect the security feature on the ballot, and provide an output indicating the presence or absence of the security feature. The ballot tabulator preferably generates a visual alert and/or audio alert if the security sensor does not detect the security feature on the paper ballot.