Electronic voting machines are becoming an increasingly popular alternative to paper ballots. With this increase in use we must analyze how well these machines adhere to voting requirements, including those relating to security, privacy, and anonymity. This paper includes analysis of the security and auditing mechanisms of the open-source electronic voting system Scantegrity. We focus on Scantegrity, not to single it out as a vulnerable system, but because it is a popular system that has actually been used in practice. It may contain design flaws and vulnerabilities that might exist in other systems of similar designs, current or future. Therefore, it is our hope that the vulnerabilities that we bring to light will be considered by current and future designers of electronic voting systems, and that the solutions that we propose will also be considered as possible remediations.