Author: Andrew Appel
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Finding a randomly numbered ballot
In my previous posts, I’ve been discussing ballot-level comparison audits, a form of risk-limiting audit. Ballots are imprinted with serial numbers (after they leave the voter’s hands); during the audit, a person must find a particular numbered ballot in a batch of a thousand (more or less). If the ballot papers are numbered consecutively, that’s…
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Why we can’t do random selection the other way round in PCOS RLAs
In my last article, I posed this puzzle for the reader. We want to do ballot-level comparison audits, a form of RLA (risk-limiting audit) on a precinct-count optical-scan (PCOS) voting system. This requires a serial number printed on every ballot, linked with an entry in the cast-vote-record (CVR) file. The standard method is to pick…
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Ballot-level comparison audits: precinct-count
Special bonus: This article contains two puzzles for the reader, marked in green. Try to solve them yourself before reading the solutions in a future post! In my last post I described a particularly efficient kind of risk-limiting audit (RLA) of election results: ballot-level comparison audits, which rely on a unique serial number on every…
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Ballot-level comparison audits: central-count
All voting machines these days are computers, and any voting machine that is a computer can be hacked to cheat. The widely accepted solution is to use voting machines to count paper ballots, and do Risk-Limiting Audits: random-sample inspections of those paper ballots to ensure (with a guaranteed level of assurance) that the election outcome…
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How to do a Risk-Limiting Audit
In the U.S. we use voting machines to count the votes. Most of the time they’re very accurate indeed, but they can make big mistakes if there’s a bug in the software, or if a hacker installs fraudulent vote-counting software, or if there’s a misconfigured ballot-definition file, or if the scanner is miscalibrated. Therefore we…
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ImageCast Evolution voting machine: Mitigations, misleadings, and misunderstandings
Two months ago I wrote that the New York State Board of Elections was going to request a reexamination of the Dominion ImageCast Evolution voting machine, in light of a design flaw that I had previously described. The Dominion ICE is an optical-scan voting machine. Most voters are expected to feed in a hand-marked optical…
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BMDs are not meaningfully auditable
The 2019 article described here was later revised and published in a peer-reviewed journal as, Ballot-Marking Devices Cannot Assure the Will of the Voters, by Andrew W. Appel, Richard A. DeMillo, and Philip B. Stark. Election Law Journal, vol. 19 no. 3, pp. 432-450, September 2020. (Non-paywall version, differs in formatting and pagination). This paper has just…
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Voting machines I recommend
I’ve written several articles critical of specific voting machines, and you might wonder, are there any voting machines I like? For in-person voting (whether on election day or in early vote centers), I recommend Precinct-Count Optical Scan (PCOS) voting machines, with a ballot-marking device (BMD) available for those voters unable to mark a ballot by…
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Reexamination of an all-in-one voting machine
The co-chair of the New York State Board of Elections has formally requested that the Election Operations Unit of the State Board re-examine the State’s certification of the Dominion ImageCast Evolution voting machine. The Dominion ImageCast Evolution (also called Dominion ICE) is an “all-in-one” voting machine that combines in the same paper path an optical scanner…
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Pilots of risk-limiting election audits in California and Virginia
In order to run trustworthy elections using hackable computers (including hackable voting machines), “elections should be conducted with human-readable paper ballots. … States should mandate risk-limiting audits prior to the certification of election results.” What is a risk-limiting audit, and how do you perform one? An RLA is a human inspection of a random sample of…