What is "punchscan"

Punchscan is an optical scan vote counting system invented by cryptographer David Chaum. Punchscan is designed to offer integrity, privacy, and transparency. The system is voter-verifiable, provides an end-to-end (E2E) audit mechanism, and issues a ballot receipt to each voter. The system won grand prize at the 2007 University Voting Systems Competition.

The computer software which Punchscan incorporates is open source; the source code was released on 2 November 2006 under a revised BSD licence. However, Punchscan is software independent; it draws its security from cryptographic functions instead of relying on software security like DRE voting machines. For this reason, Punchscan can be run on closed source operating systems, like Microsoft Windows, and still maintain unconditional integrity.

The Punchscan team, with additional contributors, has since developed Scantegrity.