J. Alex Halderman writes: You may have read at NYMag that I’ve been in discussions with the Clinton campaign about whether it might wish to seek recounts in critical states. That article, which includes somebody else’s description of my views, incorrectly describes the reasons manually checking ballots is an essential security safeguard (and includes some incorrect numbers, to boot). Let me set the record straight about what I and other leading election security experts have actually been saying to the campaign and everyone else who’s willing to listen.

How might a foreign government hack America’s voting machines to change the outcome of a presidential election? Here’s one possible scenario. First, the attackers would probe election offices well in advance in order to find ways to break into their computers. Closer to the election, when it was clear from polling data which states would have close electoral margins, the attackers might spread malware into voting machines in some of these states, rigging the machines to shift a few percent of the vote to favor their desired candidate. This malware would likely be designed to remain inactive during pre-election tests, do its dirty business during the election, then erase itself when the polls close. A skilled attacker’s work might leave no visible signs  —  though the country might be surprised when results in several close states were off from pre-election polls.

Could anyone be brazen enough to try such an attack? A few years ago, I might have said that sounds like science fiction, but 2016 has seen unprecedented cyberattacks aimed at interfering with the election. This summer, attackers broke into the email system of the Democratic National Committee and, separately, into the email account of John Podesta, Hillary Clinton’s campaign chairman, and leaked private messages. Attackers infiltrated the voter registration systems of two states, Illinois and Arizona, and stole voter data. And there’s evidence that hackers attempted to breach election offices in several other states. [Continue reading…]