Vote Selling, Voter Anonymity, and Forensic Logging of Electronic Voting Machines

Much recent work has focused on the process of auditing the results of elections. Little work has focused on auditing the e-voting systems currently in use. The facilities for doing the former include the voter-verified paper audit trail; unfortunately, that VVPAT is not particularly helpful in tracking down the source of errors within e-voting systems. This paper discusses the need for a detailed forensic audit trail (FAT) to enable auditors to analyze the actions of e-voting systems, in order to demonstrate either the absence of problems or to find the causes of problems. We also discuss methods to prevent the use of the FAT as a covert channel for violating the necessary properties of secrecy of the ballot, so voters cannot sell their votes, and anonymity of the ballot, so a third party cannot associate a particular ballot with the voter who cast it.