Risk-Limiting Audits with Arlo

Democracy depends upon trust in the electoral process. In the United States, nearly every jurisdiction relies on machines to tally votes, so trusting the process means trusting the machines that scan and tally our paper ballots. Given the high stakes of our elections, and our adversaries’ demonstrated interest in them, what can we do to double-check the equipment producing the tallies?

The best safeguard we have against hacked or otherwise faulty voting systems is a Risk-Limiting Audit (RLA). Experts believe that RLAs are the most efficient way to gain certainty that the winner reported by the voting system is correct.

The RLA is efficient because of its insight that we do not need to manually recount every vote to gain certainty in the outcome of an election. Instead, the number of votes we need to manually count depends on the margin of victory in the contest we’re auditing. A typical state-wide RLA might require checking fewer than 1000 ballots to validate an entire state’s election results.

In 2017, Colorado became the first state to implement rigorous RLAs, auditing one race in each of 50 of its 64 counties. Colorado’s experience helped to create the requirements for software that is used to run RLAs today. VotingWorks is proud to lead the development of this software which has been renamed Arlo. Arlo is built on the pioneering work done by Colorado and its technical partner, Democracy Works.

Open-Source Software

The code for Arlo is open-source and freely available for anyone to use and host.

VotingWorks Hosting & Support

VotingWorks provides a hosted Software-as-a-Service version of Arlo to states and local jurisdictions that want it. VotingWorks’ hosted service runs in the cloud. Our cloud provider, AWS, conforms to security standards including SOC 1/SSAE 16/ISAE 3402, SOC 2, PCI DSS Level 1, ISO 27001, and FISMA. See https://aws.amazon.com/compliance/ for more details.

VotingWorks provides its hosted version of Arlo for the annual fees listed below, which includes support. There is a one time $5,000 set-up fee to get started.

The hosted version of Arlo is available to states for the fees listed below.

Registered Voters in StateAnnual Fee
Less than 2,000,000$17,500
2,000,000 - 7,000,000$30,000
7,000,000 - 10,000,000$45,000
10,000,000+Contact us

The hosted version of Arlo is also available to local jurisdictions for the fees listed below. (These fees do not apply if the state in which the local jurisdiction is located is already paying for the hosted version of Arlo.)

Registered Voters in Local JurisdictionAnnual Fee
Less than 250,000$5,000
250,000 - 500,000$10,000
500,000 - 1,000,000$15,000
1,000,000+Contact us

Want to Learn More?

Send us an email at rla-info@voting.works.

You can also find more resources and an RLA discussion board at RiskLimitingAudits.org.