Original URL: https://www.theregister.com/2007/07/30/black_hat_visa_refusal/

US denies entry to security researcher

Fear of a Black Hat

By John Leyden

Posted in Channel, 30th July 2007 11:02 GMT

A high profile security researcher has been refused entry to the US on the way to this year's Black Hat security conference over "visa irregularities".

Reverse engineer Thomas Dullien (better known by his nom de guerre Halvar Flake), and a long-time fixture of the Black Hat conferences, reports that he was denied entry to the US on a technicality.

Dullien has a contract with Black Hat Consulting to offer training at the show as an individual, not through the German start-up firm he founded. Because of this, customs officials refused to allow him permission to enter the country and sent him on the next plane back to Germany - following a four hour interview.

The white hat hacker has been offering training classes at Black Hat for six years without problem, always telling US immigration that he was coming to the US to present at a conference and hold a training class. This time around a routine customs search, which prompted questions about the training materials he carried, led to further questions that eventually led to his expulsion.

Dullien will need to obtain an H1-B visa if he wants to offer training at Black Hat USA in future. And, after being denied entry to the country under the scheme, he'll no longer be eligible for entry under the visa waiver programme the US extends to European citizens, even if he travels to the country on holiday. Ironically, as Dullien points out, most of the attendees at his training sessions are US government employees.

As a European citizen, Dullien (of course) faces no paperwork barriers in offering the same training service at Black Hat Europe. ®