Security expert and TerraSwarm PI Alex Halderman claims paper ballot best technology for casting votes.

According to Reveal, University of Michigan computer science professor Alex Halderman and a team of activists, urged Hillary Clinton to challenge election results in three key swing states. The team which included Professor Halderman and civil rights lawyer John Bonifaz said they'd discovered evidence that votes were manipulated in Michigan, Wisconsin and Pennsylvnia. Further, the team successfully hacked Washington's pilot internet voting system in less than 24 hours. The team's actions followed hacker intrusions that breached the Democratic National Committee and the email account of one of Hillary Clinton's top staffers as reported in Wired on 11/23/2016.

In a post in Medium, Halderman states that though this year’s deviations from pre-election polls were not likely the results of a cyberattack, he says

I believe the most likely explanation is that the polls were systematically wrong, rather than that the election was hacked. But I don’t believe that either one of these seemingly unlikely explanations is overwhelmingly more likely than the other. The only way to know whether a cyberattack changed the result is to closely examine the available physical evidence — paper ballots and voting equipment in critical states like Wisconsin, Michigan, and Pennsylvania.

Halderman reaffirmed his position that the US electronic voting infrastructure is vulnerable and added that the the only surefire way to guarantee an election’s integrity is a paper audit.