Mercuri method
The Mercuri method is another name for a Voter Verified Paper Audit Trail—a modification to DRE (electronic) voting machines that provides for a physical (paper) audit record that may be used to verify the electronic vote count. Because these machines record votes internally, in computer software, vote fraud may be difficult to detect. Reconciling the electronic vote count with the physical vote count in all, or a random sampling of, machines allows poll-workers to screen for vote fraud. The election benefits from the efficiency of the DRE machines, and the confidence instilled by a physical record.
The method works by displaying a (paper) vote record under glass or clear plastic after the voter indicates their vote(s). The voter is instructed to verify that the paper record correctly indicates their vote. They then finalize their vote by pressing a button or pulling a lever, and the paper record is stored. This is called a voter verified paper audit trail. At no point is there an opportunity for the voter to remove the paper record from the voting area, since to do so would allow for there to be a receipt which could be used to coerce the voter into voting for a candidate or to allow selling of votes.
The Mecuri method is named after Rebecca Mercuri who described it in her PhD Thesis at the University of Pennsylvania in 2000 further elaborated on the topic.[1]