Search for: All records

Ballot marking devices (BMDs) allow voters to select candidates on a computer kiosk, which prints a paper ballot that the voter can review before inserting it into a scanner to be tabulated. Unlike paperless voting machines, BMDs provide voters an opportunity to verify an auditable physical record of their choices, and a growing number of U.S. jurisdictions are adopting them for all voters. However, the security of BMDs depends on how reliably voters notice and correct any adversarially induced errors on their printed ballots. In order to measure voters' error detection abilities, we conducted a large study (N = 241) in a realistic polling place setting using real voting machines that we modified to introduce an error into each printout. Without intervention, only 40% of participants reviewed their printed ballots at all, and only 6.6% told a poll worker something was wrong. We also find that carefully designed interventions can improve verification performance. Verbally instructing voters to review the printouts and providing a written slate of candidates for whom to vote both significantly increased review and reporting rates-although the improvements may not be large enough to provide strong security in close elections, especially when BMDs are used by all voters. Based on these findings, we make several evidence-based recommendations to help better defend BMD-based elections. 

We report the first wide-scale measurement study of server-side geographic restriction, or geoblocking, a phenomenon in which server operators intentionally deny access to users from particular countries or regions. Many sites practice geoblocking due to legal requirements or other business reasons, but excessive blocking can needlessly deny valuable content and services to entire national populations. To help researchers and policymakers understand this phenomenon, we develop a semi-automated system to detect instances where whole websites were rendered inaccessible due to geoblocking. By focusing on detecting geoblocking capabilities offered by large CDNs and cloud providers, we can reliably distinguish the practice from dynamic anti-abuse mechanisms and network-based censorship. We apply our techniques to test for geoblocking across the Alexa Top 10K sites from thousands of vantage points in 177 countries. We then expand our measurement to a sample of CDN customers in the Alexa Top 1M. We find that geoblocking occurs across a broad set of countries and sites. We observe geoblocking in nearly all countries we study, with Iran, Syria, Sudan, Cuba, and Russia experiencing the highest rates. These countries experience particularly high rates of geoblocking for finance and banking sites, likely as a result of US economic sanctions. We also verify our measurements with data provided by Cloudflare, and find our observations to be accurate.