Boldizsár Bencsáth took a bite from his sandwich and stared at his computer screen. The software he was trying to install on his machine was taking forever to load, and he still had a dozen things to do before the Fall 2011 semester began at the Budapest University of Technology and Economics, where he taught computer science. Despite the long to-do list, however, he was feeling happy and relaxed. It was the first day of September and was one of those perfect, late-summer afternoons when the warm air and clear skies made you forget that cold autumn weather was lurking around the corner.

Bencsáth, known to his friends as Boldi, was sitting at his desk in the university's Laboratory of Cryptography and System Security, a.k.a. CrySyS Lab, when the telephone interrupted his lunch. It was Jóska Bartos, CEO of a company for which the lab sometimes did consulting work ("Jóska Bartos" is a pseudonym).

"Boldi, do you have time to do something for us?" Bartos asked.