Use Paper Ballots
Most election experts agree that paper ballots are a solid defense against fraud. When coupled with an electronic system, paper provides not only a physical backup but also redundancy that can be cross-checked in a post-election audit.
Paper and electronic systems confer complementary security because they are susceptible to different attacks with different levels of consequence. Since paper must be physically altered, paper ballot fraud tends to be local and limited. Scaling up an attack on paper requires a large conspiracy.
Electronic election fraud can change a large number of votes, be accomplished by a small group of attackers, and sometimes be executed remotely. With current technologies and procedures it is almost impossible to detect.
By combining paper and electronic systems, threats can be reduced. According to election expert J. Alex Halderman, low technology plus high technology equals better security than either mode alone.