Not long after Halderman arrived at Michigan, he and his students had asked enough questions to be embroiled in his most public election hack yet. In the fall of 2010, Washington, D.C., officials had invited the public to participate in mock voting to test its upcoming internet-based election — the nation’s first. As Halderman has since joked, “It’s not every day you can hack an election without going to jail.”

In less than 48 hours, Halderman and his students had hacked the system and stolen votes. Election officials learned they’d been had only after hearing “Hail to the Victors” when the voting page was displayed. And the D.C. online voting plan was summarily scrapped.

Halderman video conferences with Dan Wallach, Rice University computer science professor, about an upcoming grant proposal for their voter election security work. The sharing of knowledge flows seamlessly between the two longtime collaborators. One of Wallach’s previous undergraduate researchers, Matt Bernhard, is now working with Halderman at the University of Michigan as a graduate student.

That same year, an Indian security researcher, essentially acting as an unprotected whistleblower, put one of his country’s electronic voting machines into the hands of Halderman and a Dutch colleague. These machines had become a source of national pride, a symbol of India’s modernity, and the government was resisting critics and keeping security inspections private. But the whistleblower knew better. Halderman and his collaborators readily exposed numerous vulnerabilities and made their findings public.

Halderman’s Indian colleague was later held and questioned by police about his complicity. When allowed a phone call, he contacted Halderman, who possessed both the presence of mind and the steely defiance to record the conversation and disclose its contents on Freedom to Tinker, a blog he had co-founded with Felten several years earlier.

Halderman’s faith in truth was vindicated. Public opinion, fully informed, turned against a government suppressing scientific inquiry, and the judge in the Indian researcher’s bail hearing not only set him free but hailed his patriotism.

But when Halderman returned to India several months later to lead an election security conference tutorial, his visa triggered a warning to deny him entry and return him to his point of origin. This time Halderman made a call. His insider-friends said they’d try to contact helpful authorities — and in the meantime Halderman should do whatever he could to delay being placed on the next plane back to the States.

“As a frequent traveler, there are things you learn to make the experience more efficient,” Halderman says. “I just did opposite.”

Halderman’s delaying tactics included claiming several times to have lost his passport; forgetting to remove liquids from his bag before passing them through the scanner; and, when asked whether anyone had given him anything while packing, Halderman answered, “Why yes, someone did — and come to think of it he may have been Pakistani, and I think it was ticking!”

Halderman laughs at the memory of officials ripping apart his bag only to be informed, once they had repacked it, of a secret compartment — and the process was repeated.

“At the end I was literally sitting on the floor as these two people were pulling me by the arms toward the plane,” Halderman says. “And at the last possible minute these immigration people appear out of nowhere and say we’ve just gotten a phone call from someone at the ministry: ‘You can stay the night; we’ll decide what to do with you in the morning.’”

In the morning, a political compromise was struck. Halderman was allowed entry to attend the conference, but he would not be permitted to give his talk concerning India’s vulnerable voting system.

The airport ordeal — which was reported in a local Indian newspaper and in the Ann Arbor News — may have been “a little scary” when it happened, Halderman allows, but he dismisses the notion that his resistance took courage.

“They had their job, and I had mine,” he says.

And living through it unscathed made him more aware of the impact his work could have. Despite initial resistance, Indian law now requires that a paper trail confirm electronic voting results.

“I think people are very easily scared,” Halderman says quietly. “Maybe more easily than they should be.”