Voter-verified Paper Audit Trail

Voter-verified paper audit trail (VVPAT) or verified paper record (VPR) is a method of providing feedback to voters using a ballotless voting system. A VVPAT is intended as an independent verification system for voting machines designed to allow voters to verify that their vote was cast correctly, to detect possible election fraud or malfunction, and to provide a means to audit the stored electronic results.

The VVPAT offers some fundamental differences as a paper, rather than computer memory, recording medium when storing votes. A paper VVPAT is readable by the human eye and voters can directly interpret their vote. Computer memory requires a device and software which potentially is proprietary. Insecure voting machine records could potentially be changed quickly without detection by the voting machine itself. It would be more difficult for voting machines to corrupt records without human intervention. Corrupt or malfunctioning voting machines might store votes other than as intended by the voter unnoticed. A VVPAT allows voters the possibility to verify that their votes are cast as intended and can serve as an additional barrier to changing or destroying votes.

The VVPAT includes a direct recording electronic voting system (DRE), to assure voters that their votes have been recorded as intended. It is intended, and some argue necessary, as a means by which to detect fraud and equipment malfunction. Depending on election laws the paper audit trail may constitute a legal ballot and therefore provide a means by which a manual vote count can be conducted if a recount is necessary. The solution was first demonstrated (New York City, March 2001) and used (Sacramento,CA 2002) by AVANTE International Technology, Inc..

In non-document ballot voting systems – both mechanical voting machines and DRE voting machines – the voter does not have an option to review a tangible ballot to confirm the voting system accurately recorded his or her intent. In addition, an election official is unable to manually recount ballots in the event of a dispute. Because of this, critics claim there is an increased chance for electoral fraud or malfunction and security experts, such as Bruce Schneier, have demanded voter-verifiable paper audit trails. Non-document ballot voting systems allow only a recount of the "stored votes." These "stored votes" might not represent the correct voter intent if the machine has been corrupted or suffered malfunction.

A fundamental hurdle in the implementation of paper audit trails is the performance and authority of the audit. Paper audit systems increase the cost of electronic voting systems, can be difficult to implement, often require specialized external hardware, and can be difficult to use. In the United States, 27 states require a paper audit trail by statute or regulation for all direct recording electronic voting machines used in public elections. Another 18 states do not require them but use them either statewide or in local jurisdictions.