Voting machines can be hacked; risk-limiting audits of paper ballots can detect incorrect outcomes, whether from hacked voting machines or programming inaccuracies; recounts of paper ballots can correct those outcomes; but some methods for producing paper ballots are more auditable and recountable than others.
A now-standard principle of computer-counted public elections is, use a voter-verified paper ballot, so that in case the voting machine cheats in counting the votes, the human doing an audit or recount can see the paper that the voter marked. Why would the voting machine cheat? Well, they’re computers, and any computer may have security vulnerabilities that permits an attacker to modify or replace its software. We must presume that any voting machine might, at any time, be under the complete control of an attacker, an election thief.
There are several ways that voter-verified paper ballots can be implemented:
- Voter marks an optical-scan ballot with a pen, deposits into optical-scan voting machine for counting (and for saving in sealed ballot box).
- Voter uses a ballot-marking device (BMD), a computer with touchscreen/audio/sip-and-puff interfaces, which prints an optical-scan ballot, deposits into optical-scan voting machine for counting (and saving).
- Voter uses a DRE+VVPAT voting machine, that is, a Direct-Recording Electronic “touchscreen” machine with a Voter-Verified Paper Audit Trail, which saves the VVPAT printouts in a ballot box.
- Voter uses an “all-in-one” voting machine: inserts blank paper into slot, voter uses touchscreen interface to mark ballot, machine ejects ballot from slot, voter inspects printed ballot, voter reinserts printed ballot into same slot, where it is scanned (or is it?) and deposited into ballot box.
There’s also 1a (hand-marked optical-scan ballots, dropped into a precinct ballot box to be centrally counted instead of counted immediately by a precinct-located scanner), 1b (hand-marked optical-scan ballots, sent by mail) and 2a (BMD-marked optical-scan ballots, centrally counted).
In this article I will put on my “adversarial thinking” hat, and try to design ways that the attacker might try to cheat (and get away with it). You might think that the voter-verified paper ballot will detect cheating, and therefore deter cheating or correct the result–but maybe that depends on which kind of technology is used!