According to Patrick Howell O’Neill (2019) at MIT Technology Review, there is a consensus among US cybersecurity and national security experts that paper ballots are necessary to ensure election security.

Even so, New York University’s Brennan Center for Justice shares in a new report (Cordova, Howard, & Norden, 2019) that a minimum of eight states — which amounts to at least 16 million American voters — will use paperless voting machines in the 2020 US elections. This means there are no paper ballots that can be used for vote audits.

References

Córdova, A., Howard, L., & Norden, L. (2019, August 13). Voting machine security: Where we stand six months before the New Hampshire primary. Retrieved from https://www.brennancenter.org/analysis/voting-machine-security-where-we-stand-six-months-new-hampshire-primary

O’Neill, P. H. (2019, August 13). 16 million Americans will vote on hackable paperless machines. Retrieved from https://www.technologyreview.com/s/614148/16-million-americans-will-vote-on-hackable-paperless-voting-machines/