A German security researcher headed for Las Vegas and the annual Black Hat conference said he was refused entry by U.S. immigration officials, apparently over paperwork issues.
Thomas Dullien, CEO of Sabre Security and a longtime presenter at the training sessions held at Black Hat, said on his blog Sunday that he was refused entry after a four-and-a-half-hour interview on arrival in the U.S. He was put on the first available flight back to Germany.
According to Dullien, a reverse-engineering specialist who is better known in security circles as "Halvar Flake," customs agents found printed materials for the class in his luggage, prompting immigration officials to question him about the training, his association with Black Hat and why the session could not be taught by a U.S. citizen.
"After four hours, it became clear that a decision had been reached that I was to be denied entry to the U.S., on the ground that since I am a private person conducting the trainings for Blackhat, I was essentially a Blackhat employee and would require an H1B visa to perform two days of trainings in the U.S.," Dullien wrote in his blog.
Dullien's sold-out session, which cost attendees between US$2,000 and $2,400, has been canceled, said Ping Look, who manages Black Hat's training classes.
Previously, Dullien said, he had always been admitted under a visa waiver -- available to citizens of 27 countries, including Germany, who come to the U.S. for 90 days or less on business or tourism. But because his arrangement was between him and Black Hat rather than between his company and Black Hat, a work visa was technically required.
According to the U.S. Department of State's Web site, one of the criteria used to judge when a visa cannot be waived is when the applicant "wants to work ... in the United States."
Ironically, Dullien claimed that the majority of those who have attended his Black Hat sessions in the past have been U.S. government workers, including employees from the departments of Defense and Homeland Security.
In an update later Sunday, Dullien blamed the entry denial on differences between German and American work classifications. "I hope that I can clear up this misunderstanding tomorrow morning, but right now, I am not terribly optimistic," he said.
In an e-mail, Black Hat's Look said that Dullien wasn't the only person connected with the conference who got the once-over. "We have had many speakers and trainers tell us that anyone flying through Detroit has been given a lot of scrutiny," said Look. He also noted that Black Hat officials had spoken with the immigration officer who interviewed Dullien.
"We have referred him to a good immigration lawyer," Look said.